Tall Buildings

PREFACE.

Organisers.

Organising Committee.

Technical Committee.

Supporting Organisations.

With the Chinese government always attaching great attention to the development of higher education, higher education in China has made great progresses, especially after the adoption of opening-up policy and reform at the end of 1970s. At present, facing the increasingly severe challenges of resources, energy and environment and the reality of economic development in China, the Chinese government has put forward the strategy of accelerating the industrialization process and adopting new approaches with Chinese characteristics for this purpose. At the same time, with the strategic objective of improving the overall competitiveness and building up an innovative country, higher education bears the task of producing a large number of talents with high quality. Therefore, higher education in China bears important and historic responsibilities.

The importance of sustainability is highlighted and the environmental, economic and social aspects of tall buildings are discussed. Sustainable construction of tall buildings in different aspects are delineated, including the building environmental assessment methods, the structures and services of tall buildings as well as energy efficiency and renewable energy to achieve sustainability.

No abstract received.

A summary of the development of the world and the thermo-dynamics are of industrialisation is given to justify the need to reduce the use of carbon fuel in our society. The passive design of buildings to provide light, thermal capacity, and ventilation, so as to provide good control of the internal environment without mechanical and electrical systems is described. The influence of the height of the building on the passive principles is outlined.

Hong Kong's realm of tall buildings makes the place not only magnificent to look at but also exciting to be in. As the authority for enforcing building laws, the Buildings Department has provided the appropriate framework and facilities to secure and promote the construction of tall buildings that are not only safe and healthy but also environmentally friendly and sustainable.

This paper reviews the changing conceptualizations and prospects of high-rise living in contemporary cities. The argument is not for or against high-rise. Rather effort is to situate the modern high-rise in perspective at a moment where many cities around the world are re-discovering and building ever increasingly taller housing for their population in the wake of globalization and technological advancement. Using data largely from Singapore where 90% of the population resides in high-rise, this paper explores the issue of high-rise and everyday life. Intention is to raise residents' perception and acceptability issues not just from the Asian perspective, but also to explore the wider urban representations and performance pathways in the endeavour towards better quality of life with this housing style.

Building management has become a highly sophisticated profession in the last decade, and the management of mega towers is particularly challenging for building managers. Completed in July 2003, the 88-storey Two International Finance Centre (Two IFC) is currently Hong Kong's tallest building with the most up-to-date technological provisions, making it an unprecedented challenge faced by the building manager, the MTR Corporation. The Corporation also faces stringent customer expectation as tenants of Two IFC are all prominent players in the global financial market. By blending five-star hotel services and security standard into property management, the MTR Corporation has been able to meet all the challenges, and is also dedicated to exceeding customers' expectation at all times.

Space value, habitat value and people value are the essences that make up city value. Tall buildings and high density living, to certain degree, compromise lifestyle, life quality and social cohesion. Yet tall buildings, in contrast to spread out habitation, release land for public space and greening. From a compensatory aspect, public space and public facilities should be zoned and designed to remedy the constraints in urban high-density living. In another words, high density could be humanized by the humanness of public common space and facilities that welcome the newborn, that celebrate the newly wed, that energize the newly retired, that honor the newly departed. Romanticism and humanism could add value to a city of tall buildings. Climate responsive, environmentally informed, hazard alert and resource efficient, building designers, builders, managers and occupiers have a role to play in enhancing city sustainability.

In modern cities, tall buildings are now looked upon in terms of their sustainability. Efficient use of energy in buildings, either in daily operation or as embodied energy in materials, is an important consideration of sustainability. While energy efficient devices are increasingly used in building services systems, an integrated approach should be adopted to achieve an overall reduction in energy consumption. With Hong Kong importing all its materials and fuels from abroad, energy efficiency could bring about benefits to the local economy and help to ease the environmental burden on the producer countries. There should also be greater efforts in exploring alternative renewable energy sources and in promoting energy efficiency.

The revised provisions of Technical Specification for Concrete Structures of Tall Building (JGJ3-2002) are briefly introduced in the paper. The main contents include the actions, the structure regularities and the principal requirements for structural analysis and design of high-rise buildings. Some requirements for complicated structures are stressed.

A design project of a concrete frame-corewall tall building is presented in this paper. Due to the required inner balconies with 3-story-height at the two opposite corners on some floors, the corresponded edge beams cannot be connected to the two corner columns which are in a diagonal line. The layout affects the lateral stiffness of the structure. The behavior of the structure is compared with the ordinary frame-corewall structure which has continuous exterior frame beams; and in another way, comparison of behaviors of similar structures, in which inner balconies are with different-story-heights, is carried out. It is concluded that the lacking of some corner beams of the introduced structure has little influence on its overall behavior. The influence is only about 3~4%, and the seismic behavior of the structure is quite well. The related section of the Technical Specification for Concrete Structures of Tall Building of China is also discussed in this paper.

This paper puts forward the design model of beam-wall semi-rigid joint in super high-rise hybrid structure. Five groups of joint models are tested to analyze the mechanics performance of beam-wall joint under low cyclic reverse loading. Test results manifest that this semi-rigid joint has greater bearing capacity and better seismic behavior, thus it can make up the deficiency of hinge joint's seismic behavior. Based on the tests, this paper adopts ANSYS program to do nonlinear finite element analysis of test models, in which quite a lot of nonlinear traits are put into considerations, such as the crack and crush of concrete, the shear force transferring function when the concrete crevice open and close, bonding and slippage between the joint's anchoring connector and concrete, etc. The results of calculation and analysis fit the test quite well.

Outrigger braced core wall structure often forms the major lateral load-resisting system to provide the required moment resistance and lateral stiffness for high-rise buildings and skyscrapers. Due to practical considerations, outrigger braces are usually made of structural steel and cast into the reinforced concrete core walls for the buildings in Hong Kong. The correct structural analysis and design of the connections are vitally important to enable it to carry huge amount of internal forces. This paper aims to enhance practicing engineers to understand the general structural behaviour of outrigger braced core wall system. Strut-and-tie method is applied to analyze the whole lateral structural system. The complete load transfer mechanism between the outrigger brace and the core wall is displayed. Many practical concerns in design including the structural behaviours of different configurations of outriggers, the effect of openings through the core wall adjacent to the outrigger brace, the arrangement of shear studs on outrigger brace and the shear link arrangement in core wall are briefly discussed. Some common deficiencies in numerical modelling of this system are pointed out and a set of recommendations related to finite element modelling is given for reference.

It is very important to calculate the shearing stiffness of column in frames. But at present, it is seldom concerned with the effects induced by external forces. Therefore, the results of calculation may contain some errors to a certain extent, sometimes being larger. In this paper, taking an example into consideration, the current D-value method will be applied to explain it.

Columns under various magnitudes of load are not uncommon in tall buildings. Resulting from differential loads, uneven shortening of two adjacent columns will induce moment, shear and crack in the connecting slab or beam. The magnitude of this induced moment, shear and crack will increase with time due to the effects of creep and shrinkage. As the creep strain depends on the magnitude of the load, the higher is the load applied to the column, the more is the shortening. In this paper, a systematic time dependent analysis method will be introduced to investigate this problem. This method, which is developed on the concept of age adjusted effective modulus approach, accounts for not only the material nonlinearities but also the geometric nonlinearities of the structural members. Time step analysis is implemented in the analysis in order to simulate the loading situation of typical constructions. Numerical results are analyzed and compared to previously published results by other researchers.

Energy dissipation-seismic reduction design is a new way in structure earthquake resistant; it has been placed in China's code for seismic design of buildings (GB 50011-2001). But it is introduced briefly in this code and cannot be used facilely, as well lacked practical project referenced to. So this paper cited one tall building with irregular floors (its outside braces worked with velocity-depended nonlinear dampers) to discuss its energy dissipation-seismic reduction design, and compared it to the result of its model shaking table test. This design process and experience could be referred to by the similar projects.

Based on a practical project, a three-dimension FEM model is established to analyze the dynamic characteristics and seismic response of the Six-tower Connected Structure. The effects on the structure behavior due to the long span connections stiffness and two kinds of connecting method between the corridors and the towers are studied in this paper. The paper establishes a foundation for further researches.

Recently, a large number of mid-highrise buildings appeared in large cities in China, and they are very popular among the constructions for residents and commerce. Steel braced frame is one of the widely used structural forms in mid-highrise building. In the paper, one nine-storey braced frame in Langfang is investigated as an example by the finite element software ANSYS. Three-dimensional model is proposed in which the seismic response is analyzed including modal analysis, response spectrum analysis, elastic/elastoplastic time-history analysis. Futhermore, the lateral deformation of the structure and the distribution of the braces are computed, and the study can be served as the references of similar structure design.

Research work into the structural system schemes of displacement control are summarized and the corresponding research aimed to establish some available methods of displacement control of high rise buildings in high seismic intensity area based on analytical results from a practical project has been done. It is revealed that the structural displacement can be controlled by improving both vertical and horizontal structural element stiffness. The conclusion from this research can be used as a reference for relative engineering design.

This paper points out that the main design principles of an asymmetrical building subject to horizontal earthquake are to take into consideration of (1) the torsional angle of the floor (rigid diaphragm) not to induce torsion exceeding the allowable, (2) the inter-story displacement at utmost end frame or shear wall should be less than that required by design code, (3) stresses in plane of the slab shall be controlled within acceptable extent under different intensity earthquakes. Current seismic design code only utilizes the torsional displacement ratio to control the floor torsion. This seems not reasonable enough since its definition is the multiple of the floor torsional angle and the distance of floor mass center till the utmost end frame or shear wall. The International Mayor Building of Shenzhen City is 26 storied high, the tower is L-Shaped in plan and with a transfer beam-slab system at 9^th floor. The earthquake action will induce evident torsion to the structure. This paper introduces the seismic design considerations of the building.

The reinforced concrete core wall-steel frame hybrid structure is a non-proportional damping system. In practical structural designs, equivalent damping ratio is used and specified in the Technical Specification for Concrete Structures of Tall Building JGJ3-2002 of China. In this paper, a reinforced concrete core wall-steel frame hybrid structure under frequently-occur earthquake is calculated by using time history method in elastic range, with the non-proportional damping model and the equivalent damping model, respectively. It is found that there are great differences between the displacement and inner force responses by the two damping models. Some suggestions for using equivalent damping ratio of the structures is put forward.

This study mainly focuses on the development and application of variable friction damper as a joint control device to enhance the seismic resistance of a main building with podium structure. Shaking table tests using small scale building structures and damper were performed to provide a realistic demonstration and evaluation of effectiveness of the proposed control scenario. The real-time adjustment of the small scale variable friction damper was mechanically realized by using a piezoelectric actuator. A local feedback controller was proposed and implemented in the coupled building system. The improved performance over the uncontrolled cases, including uncoupled and rigid coupled configuration, was verified by considering four simulated historical earthquakes. The test results showed that prompt regulation of friction force by the piezoelectric actuator can be achieved, and the desired control performance and robustness can be guaranteed. The proposed local feedback controller also demonstrated an increased seismic resistance to the coupled system.

The development of the seismic analysis procedures has proven that the displacement-based seismic design method will be gradually incorporated in the seismic design codes in near future. Recently, push-over analysis, as the kernel of the displacement-based design method, has been required in the Chinese code for seismic design of buildings (GB 50011-2001) for analysis of the structures with plan or vertical irregularities. Following a brief review on the history of seismic analysis procedures in China, the seismic design method of a tall buildings with out-of-plane offset, diaphragm discontinuity and in-plane discontinuity in vertical lateral-force-resisting elements is given in this paper to illustrate the application of push-over analysis. The results of push-over analysis show that the structure yielded earlier at the edge of long narrow cut and large deformations would consequently occur as the pushing force increased. The long slit is a weak place to resist the seismic ground motion and has great effects to structural capability of damage restriction and collapse prevention after the corner elements around it yielded. It could be concluded that the push-over analysis should be used for seismic design of the structures with irregularities. It will help structural engineers in identifying hidden weak points in a structure when conducting the seismic design.

Considering the phenomenon of stiffness degradation of components in RC frame structure under load, the structure is simplified as model of rods system, Damage model of component of structure is build and damage index of component is proposed. At last the damage index is applied to estimate the damage behavior of two spans and three stories RC structure.

The method for figuring the optimal shear wall quantity for frame-shear wall tall buildings with variable lateral rigidity along the height in earthquake zone is presented in this paper by means of dispersal-serial interaction method. It is the first time to put forward the method for figuring the optimal amount of shear wall in frame-shear wall structure by classifying the vertical members. The definition of Inter-Story Drift is made clear and definite by the author. A 20-storey framed-shear wall tall building is numerically examined and the results show that the method is accurate enough for use in the preliminary stage of design.

In this paper, coupled vibration characteristics and dynamic response of asymmetrical tall buildings under seismic loads are analysed. Based on the basic theory of structure control, the principle and method of computation are given for asymmetrical tall buildings with LTTMD control system, and computer program is compiled.

According to the characteristic of shear wall structure, its performance level is divided into three levels, which are serviceability, life-safety, and collapse prevention. The three levels are qualified with storey drift ratio. Applying the inverted triangular distribution of lateral force to the cantilever wall with identical section, the displaced shape is regarded as the initial lateral displacement mode of shear wall structure. For the serviceability and collapse prevention performance levels, it is assumed that the curvature at the bottom cross section of the first storey of the shear wall structure reaches yield curvature and ultimate curvature, respectively. Then, the target displacement mode of the two performance levels can be obtained. Based on the target displacement mode of shear wall structure in the serviceability performance level, the effective parameter, the base shear V_b and horizontal earthquake force F_i at each floor of the building can be determined, and then the structural members can be designed to satisfy strength demand and details of seismic design. Finally, the designed structure is analyzed with nonlinear static analysis procedure and is adjusted by the pushover analysis result until it is satisfied.

Based on the investigation of earthquake damages on building structures, through the studies of several projects elastic-plastic static and dynamic analyses and table vibration tests, referring to IBC2003&ATC40, for the most popular cast-in-situ RC building structures, this paper presents the update aseismic design philosophy to achieve this target-no damage while mild earthquake, little damage while moderate earthquake, no collapse while severe earthquake. The update philosophy is consisted of these new concepts: moderate or severe earthquake action for vertical members (columns and walls), mild earthquake action for horizontal members (secondary beams and spandrel beams) and the control standards for minimum ductility. Several projects practices revealed that, these new concepts and methods are coordinated to GB 50011-2001&JGJ3-2002 well and easy to operate. Especially for complicated tall building structures, they are able to provide the realizable platform to do further elastic-plastic static and dynamic analyses and evaluations.

Future performance-based seismic design, directly addressing the inelastic deformation induced in buildings by earthquake ground motions, should be based on probabilistic approaches. In recent years, reliability-based structural optimization has gained much research attention due to its advantages of accounting for the various sources of the uncertainties and approximation in design process. However, there is yet no effective method for reliability-based design optimization of concrete buildings subject to seismic performance criteria. This paper therefore presents an effective reliability-based design optimization approach for reinforced concrete buildings subjected to earthquake loading in which the structural performance is assessed at the system level by push-over analysis. Such developed approach, which integrates structural reliability theories with optimization technique, can provide a good balance between the structural reliability and the steel reinforcement cost under specified performance requirements.

An optimization technique by incorporating the performance-based seismic design of concrete building structures in the form of multiobjective optimization has been developed to meet the emerging trend of performance-based design approach. Specifically, the life-cycle cost of a reinforced concrete (RC) building frame is minimized subject to multiple levels of seismic performance design criteria. Explicit formulation of design constraints involving inelastic drift response performance caused by pushover loading is expressed with the consideration of the occurrence of RC plasticity and the formation of plastic hinges. Due to the fact that the initial construction cost and the expected damage loss are conflicting by nature, the life cycle cost of a building structure can be posed as a multiobjective optimization problem and solved by the ε–constraint method to produce a Pareto optimal set, from which the best compromise solution can be selected. The methodology for each Pareto optimal solution is fundamentally based on the Optimality Criteria (OC) approach.

Based on experimental investigation, the interface bond-slip model of CFRT was put forward, and the hysteretic model of in-filled concrete and steel considering Bauschinger Effect was also built. With fiber section model, the analytical model for CFRT columns was constructed. Analysis program for CFRT columns considering interface slip was accomplished. Full range analysis of the CFRT columns was conducted. The simulation results were compared with test records at the levels of load-displacement and load-strain. To investigate the mechanism of bond-slip interface, simulated stress-strain of fibers was also presented. The effect of the interface bond strength on the hysteretic behavior of CFRT columns was evaluated. At the end, design suggestions were presented for structural application of CFRT columns in high-rise buildings.

In this paper, a 1/15 scale model of concrete filled square steel tubular frame structure with dampers is tested on shaking table to study the dynamic characteristics and seismic response, especially the effect of dampers on seismic behavior of the structure. Test results show that the structure has no obvious weak story, the torsion of the whole structure is small, and the dampers play important role in energy dissipation, but the lateral stiffness of structure is not enough, because the Elasto-Plastic inter-story drift is not meet the code requirement(1/80) for energy dissipation structures. So according to the test results, the structure design is improved to meet the code requirement.

It has been a practical construction scheme to make column beam joints poured with the same strength concrete as beams. Three groups spacial column beam joints, which included 2 interior joints, 2 exterior joints, and 2 corner joints, which only joint concrete strength different in each group, are tested under cyclic loading. The failure pattern, bearing capacity, dissipative capacity and the displacement ductility parameter were investigated. The test results shown that, on the one hand, it is fesible to pour the joint with the same strength concrete as beams, on the other hand, it is necessary to check the axial compression and shear capacity of such joints. Finally, the further investigations on this field are prospected.

The height of 101-story Shanghai World Financial Center Tower is 492m above ground making it possible the tallest building in the world when completed. Three parallel structural systems including mega-frame structure, the reinforced concrete and braced steel services core and the outrigger trusses, are combined to resist lateral loads. The building could be classified as a vertically irregular structure due to a number of stiffened and transfer stories in the building. According to Chinese Code – Technical specifications for concrete structures of tall building (JGJ3-2002), the height of the building clearly exceeds the stipulated maximum height of 190m for a composite frame/reinforced concrete core building. The aspect ratio of height to width also exceeds the stipulated limit of 7 for seismic fortification intensity 7. A 1/50 scaled model is made and tested on shaking table under a series of two-dimensional base excitations with gradually increasing acceleration amplitudes. This paper presents the dynamic characteristics, the seismic responses and the failure mechanism of the building. The test results demonstrate that the structural system is the optimum solution to withstand earthquakes. The inter-story drift and the overall behavior meet the requirements of Chinese Code. Furthermore, weak positions under seldom-occurred earthquakes of seismic fortification intensity 8 are pointed out based on the visible damages, and corresponding suggestions are proposed for the engineering design purposes.

Reversed cyclic-load tests on full-scale RC exterior beam-column joints, which are fabricated to simulate those in as-built reinforced concrete framed buildings designed to BS 8110, are carried out. Emphasis of the study is placed on the effects of the types of beam bar anchorage on the seismic behaviour and shear strength of reinforced concrete exterior joints subjected to simulated earthquake load. The behaviour is investigated with different types of anchorage in beam reinforcement. It has been shown from the experiment that all the specimens have low ductility capacity and poor energy dissipation ability. The test results are compared with two preseismic design codes (BS 8110 and EC 2). It is shown that the types of reinforcement anchorage in beams have significant effects on the shear capacity and hysteretic behaviour of exterior beam-column joints. Present codes of practice do not accurately predict the shear strength of the non-seismically detailed joints. It is indicated that ignoring the design of beam-column joints may lead to potential damage of reinforced concrete framed buildings in an unexpected low to moderate earthquake.

Shimao Riviera Garden is the largest scale super-high riverscape deluxe residential building in China, located in Pudong, Shanghai and comprised seven 49-to-55-storey high deluxe apartments with 169m high, 2.0m thick bottom slab of box foundation and bored piles of φ 850mm driven into silty sand to a depth of 58m. In one apartment the settlement, loads on pile group and stress in bottom slab of box foundation are analyzed using the theory of superstructure-foundation interaction. The analytical results have been shown that the theory presented in this paper is comparatively accurate and feasible in practice.

The diameter of the south anchor pit of Yangluo Yangtze river bridge is about 70m and the depth of it is 45m. During the process of construction, the internal force of the support for this pit must be controlled strictly. Informational construction technology such as numerical method and observation system is used to control excavation process. Based on the appropriate material constitutive equation, failure criterion and model of cracking, a nonlinear FEM model of retaining structure is presented. The stress of diaphragm wall is presented by back analysis based on in-situ displacement of retaining structure. The result fit the in-situ data well and provide theoretical basis for the safety evaluation of the retaining structure.

Based on the experience of Jimao Building of 88-storey in Shanghai, this paper attempts to predict the behavior of piled raft foundation for Shanghai World Financial Center of 101-storey, such as the bearing capacity of pile and its increase with time, load-sharing between piles and raft, thickness of raft, settlement and theory of design of piled raft foundation. Finally, some comments on these two buildings have been made for examining the theory of super-long pile foundation design for super-tall building in Shanghai.

This paper describes the process of design of a piled raft foundation for a high rise residential building on the Gold Coast in Queensland, Australia. The design process comprised an initial stage of geotechnical site characterization using the results of a series of investigation boreholes to prepare a subsurface model and derive geotechnical parameters for raft and pile design from empirical correlations. Following this a preliminary analysis was undertaken using a combination of elastic theory and allowances for non linear behaviour of the piled raft system to assess the viability of such a foundation system and any potential advantages of a piled raft over conventional fully piled foundation systems. Finally, a detailed analysis was undertaken using the GARP8 computer program. These detailed analyses were used to design a more efficient piled raft system and to provide design actions for structural design of the foundation system for a variety of load combinations.

It is the first time in China to carry out such a field experimental study to provide the information on the frame-shear wall structure/super-long pile/thick raft interaction in soft soils. Chang-feng Market is of 60-storey, 238m high, with 4.5m~6.25m thick raft and bored piles of Ф850mm drilled into silty sand layer with medium and coarse sands (i.e. 9-2 soil layer in Shanghai) to a depth of 72.5m. This building is composed of a 60-storey building and a 10-storey podium. Both have 4-storey basement. The depth of embedment is 18.95m. In order to obtain the more information on interaction, after completion of excavation engineering, on July 11, 2004 the following transducers for different purposes were installed in foundation with construction stage, respectively. 19 rebar stress gauges and 19 strain gauges on the top of piles and 36 earth pressure cells beneath the foundation base were installed to measure the pile load and foundation. contact pressure. 28 rebar stress gauges were attached to the top and bottom reinforcing steel at 7 locations in the raft to measure the steel stresses. 5 piezometers were installed about 0.5~1.0m below the base of excavation to observe the lift and dissipation of excess pore water pressure and the effect of buoyancy on the bottom. To get the special information for checking the real load on the mega columns and corresponding contribution of every storey stiffness to foundation, 5 rebar stress gauges and 5 strain gauges were attached 5 typical columns. Meanwhile, for the same purpose, to record the settlements of the building with respect to time, 21 permanent reference points were established on columns and walls. Based on the change of settlement type it will provide an important evidence to analyze the contribution of every storey stiffness to foundation. Now the building is still under construction. However, some valuable data have obtained. For example, load-sharing between pile and raft is an objective fact even for super-long pile foundation. The main structure will be completed in the coming September. It is expected that the field experimental and analytical results will be satisfied.

Combined with the respective advantages in S-R(Sway-Rocking) impedance concept and finite-element method, a simplified 3D structural dynamic FEM considering composite pile-group-soil effects is presented. The structural members including piles are modeled by space beam or shell elements, and raft-base is divided into thick-shell elements with its spring-dashpot boundary coefficient obtained by impedance backcalculated. The mass-spring elements for soil between piles are set to simulate vertical, horizontal pile-group effects by strata-equivalent approach. The soil beside composite body is separated into near-field and far-field parts. The former is modeled by nonlinear spring-dashpot elements based on Winkler's hypothesis, while the latter is modeled by a series of linear mass-spring-dashpots. With the effects of boundary track forces and energy radiation, the presented model enables researchers to conduct the time-domain nonlinear analysis in a relatively simple manner which avoids sophisticated boundary method and solid-element mesh bringing with tremendous computational cost. The seismic effect on dynamic interaction of pile-soil-complicated structures would be efficiently annotated from two structural engineering and geotechnical engineering aspects and the numerical calculation effort would be drastically decreased too. The complete procedure is mainly performed using the parametric design language assembled in the Finite Element Code Ansys. With the dynamic analysis of foundation and superstructure for a pile-supported 15-storey building, the influence of the participant effect on structural dynamic response will be depicted by various dynamic parameters of pile-soil-raft foundation in detail. Not only do the results have an agreement with some conclusions drawn by the general interaction theory, but also certain of phenomena which would be disagree with that by general analysis is involved. Even with the finite-element meshes for 68 piles, the time-history analysis procedure for PGSS (Pile-Group-Soil-Superstructure) system and the qualitative evaluation with various SSI parameters can be also fulfilled efficiently and rapidly by presented means. These results may be of help to the designers to quickly assess the significance of interaction effect for the high-rise buildings resting on any type or layout of pile-group foundation.

In a pile group subjected to lateral or moment loading, the soil movements are primarily along the loading direction. In a torsionally load pile group, however, the primary soil movements are rotational. The movements of soils in the pile group can be in arbitrary directions. As a result, the soil response in a torsionally loaded pile group is different from that in a laterally loaded pile group. In this paper, three-dimensional finite-difference analyses of a torsionally loaded single pile, a torsionally loaded pile group, a laterally loaded single pile and a laterally loaded pile group are conducted to study soil responses and group interactions in torsionally loaded pile groups. The large-diameter bored piles studied are 2 m in diameter and 13.2 m in length. The pile groups are 2×2 groups with a three-diameter spacing. The soil response is represented by horizontal stresses in front of the piles and p-y curves derived from calculated bending moments along the piles. The p-y curves of the piles in the torsionally loaded pile group are lower than those of the laterally loaded single pile and the leading pile in the laterally loaded pile group. In addition, the ultimate subgrade reaction is mobilized at a much smaller local displacement (say, 20 mm) compared with the laterally loaded single pile (> 60 mm). The horizontal normal stresses caused by lateral loading and the horizontal shear stresses caused by torsion interact and reduce the lateral pile resistance in the torsionally loaded pile group.

The control of ground movements is one of the most critical restraints in modern shoring design, especially when the excavation is carried out in vicinity of buildings, utilities and tunnels. In this study, several lateral supporting systems are investigated, with an effort to identify the key factors contributing to ground movements. It is shown that the ground movement is sensitive to the excavation depth and ground conditions, yet seems to be relatively less sensitive to the wall and strut stiffness. It is also noted that the location of the first layer of strut can be critical to the wall deflection, and an optimum strut arrangement can be achieved to minimize the wall deflection and subsequently the ground movement.

To evaluate the response of pile groups under lateral loading, a widely accepted approach is to use the curve of soil resistance, p versus local pile deflection, y (p-y curve) together with p-multiplier. The limiting force per unit length p_u (limit of p) is often attained within a depth normally up to 8d (d = pile diameter), and the response of laterally loaded piles is generally controlled by the mobilized p_u. Thus, determination of this p_u is critical to a satisfactory prediction of the pile response. Various expressions have been developed previously for the p_u. However, based on 70 field tests on single piles and 20 tests on pile groups, an extensive study conducted recently by the author and his team indicates that only three parameters are sufficient to describe the limiting force profile (LFP), while the parameters themselves may be modified to account for other factors. This paper addresses the effect of pile-head conditions, and group interaction on the LFP by comparing measured with predicted response of a few typical pile tests.

In the soft soil ground area, the underground continual walls (or underground concrete diaphragm slurry walls) together with the temporarily horizontal-shoring systems are found effective in deep excavation for high-rise buildings. The temporary shoring will be demolished at the consequent stage when the structures of the underground basement are formed, and in most cases, the underground continual walls remain underground, enclosed with the walls of basement inside. The creative idea of "2 in 1" technology refers to the integration of underground continual walls and the external walls of basement in deep foundation design. The technology has been proved to be effective in control of deformation and settlement of soils during the construction of foundation, and having very light influences on the environmental surroundings. The shoring system could be used as permanent structural skeletons for the basement structures if it is well designed, and the underground continual walls also act as the external walls of basement for buildings, so that construction cost can be reduced. In the paper, the art and key procedures of the technology are assessed and the application of the technology in Phase 2 Project of Shanghai City Hotel is summarized.

Based on the finite element analysis program ANSYS, the soil-foundation-supporting pile-superstructure dynamic interaction system was analyzed in this report. It was found out that the existing of supporting piles affects the aseismic behavior of high-rise building. Commonly used equivalent linearity model is chosen as constitutive relation of soil. Viscous boundary of soil is implemented in ANSYS program. The parameter study includes the length and rigidity of the supporting piles, the various rigidity of superstructure and the foundation type.

While piled raft foundations are widely adopted in the construction of tall or multistory buildings, an accurate estimation and control of load capacity possessed by supporting soil become essential for the safety of buildings and construction cost reduction, especially in the case on soft soil subgrades. This paper presents an effective analytical model to estimate load capacity possessed by supporting soil for piled raft foundations. In this approach the bending plate is approximately assumed to have linear elastic properties and is modeled by the generalized conforming finite element method while the supporting soil subgrade is modeled by the finite layer method(FLM). Each pile is represented by a single element, and its nonlinear stiffness is evaluated through a load vs. pile head displacement curve obtained from static loading tests, resulting in the governing system of equations for plate-pile-soil interaction problems. The FLM is not only capable of representing the layered subgrade behavior, but it is also of low computation cost. Several real piled raft foundations on the soft soil subgrade have been analysed. The numerical results indicate that, in general, for tall buildings, the load capacities possessed by supporting soil are about 8~15% of the whole one; and that for multistory buildings, where the piles are often used to prevent excessive settlements, are often more than 25%. It can be seen from the numerical results that the load capacity possessed by supporting soil is more affected by stiffness of piles, and increases with the settling of the building, its full utilization in design would evidently reduce the cost of a piled raft foundation construction.

Large-diameter bored piles are commonly used in groups to support high-rise buildings or bridges. In addition to vertical, lateral, and moment loads, these piles have to resist torsional loadings from the superstructure by eccentricity of lateral loads. Compared with studies on responses of pile groups subjected to vertical, lateral and moment loadings, only limited study on response of torsionally loaded pile groups has been reported. In this paper, three-dimensional analyses are conducted to investigate the torsional response of a single pile and a 2×2 large-diameter bored pile group. The piles are 2 m in diameter, 13.2 m in length, and 6 m in spacing. For the relatively rigid piles studied, the relative twisting angle between the pile head and the pile toe is small for the torsionally loaded single pile and the individual piles in the pile group. However, the movements of the single pile and the pile group under torsion are quite different. The single pile only shows a pure torsional response while the group piles not only twist but also deflect in the direction of torsional movements. The applied torque is resisted by the torsional resistance and the lateral resistance of the group piles. The torsional resistance provided by the individual piles is mobilized at relatively small movements but the lateral resistance is mobilized continuously with the pile group rotation. At large deformations, the applied torque increment is mostly taken by the lateral resistance. The torsional resistance of individual piles is approximately 30% of the total resistance at a twist angle of 1.0 degree.

Top-down construction method is a rapidly developing construction technology which used in the deep foundation of high-rise Buildings. As the diaphragm wall or the row of piles can act as both the basement wall and the embosom, and the strutbracings are the floor slabs underground. So the joint nodes of pile and column, column and slab, slab and diaphragm are difficult to deal with. In this article, some practical and effective joint nodes are introduced through some project practice.

Model test and in-situ monitoring results show that in common structure form, large-area thick raft foundation can diffuse the load of tall building but in the limited way. By the interaction of supper structure, thick raft and soil, the effect of the tall building on its podium is limited to the area around the main tower, where an effective range of interaction is produced with the tall building focused. Design for the thick raft foundation under multiple tall or low buildings shall take the characteristic into full account.

The behavior of a free-head pile under lateral soil movement and vertical load was investigated using a newly developed experimental apparatus. Typical test results are presented to demonstrate the similarity and difference in the response of the pile subjected to triangular and rectangular soil movement profiles. It was found that the response such as distribution of bending moment, and pile displacement, etc. is significantly affected by the soil movement profiles.

A new experimental apparatus has been developed, which allows lateral soil movements and vertical load to be applied simultaneously on a pile. A number of tests have been undertaken, which offer consistent results. In this paper, a brief description of the apparatus was presented. Results from two model tests were reported, which were conducted on two instrumented pile groups embedded in sand subjected to uniform lateral soil movement. Preliminary analysis indicated that the increase in bending moment, shear force, soil reaction and the change of pile deflection mode due to axial load on the pile groups.

According to the latest studies of quality control of rushed stone pile, this paper first fixed on the functional aim and measuring parameter of the apparatus. And then on the base of the research of sensors distributed widely, analogue and digital signal processing and data storage, the circuits are designed and a kind of embedded computer with very much storage and a sort of operating system used as the heart of the apparatus to increase the capacity of storing data and to be seasoned with atrocious environment. The apparatus also posed a kind of UATR serial communication port and a kind of device driver program was designed in order to fit to the different kinds of distributed monitoring system. With characteristic of the smallest code size and real time operating, the system software of the apparatus introduced many of the modern technologies usually used in the current operating system development and software architecture and other software develop methods. Except for this, the mechanical apartment used to install the sensors was also designed through mechanical module technology and might be installed on all kinds of cranes without modification of the structure. The result of testing the apparatus in the construction of Da Yang mountain harbor proved it to be easy operating and poses high reliability and satisfy the designing objective.

Rapid development of high-rise and underground buildings makes exact demands on retaining structures for deep foundation pit. As a retaining structure, reinforced soil-cement mixture has more advantages compared with Soil Mixing Wall. But both experimental study and designing theory for it are far behind practice. By model testing, distribution and variety of stress in soil-cement mixture and in shaped steel during loading process are studied in this paper. Strong restraint of shaped steel on cracks is found by analysis of crack development, which can increase the cracking load and the rigidity of specimen obviously. By the data analyzing, effects of factors to structural behaviors are discussed, and some suggestions are made towards designing. By analyzing the experimental data, carrying capacity expression is derived theoretically.

In this paper, the ultimate bearing capacity of single pile is used for the pile, and the loads acted on the composite pile foundations are distinctly shared by the piles and the soil under the cap. Based on the theory of composite pile foundations, the concept of plastically bearing pile is established. The methods of settlement calculation, the design principals of application and some problems of nonlinear design of composite pile foundations interaction are presented. These methods and concept have been used for the design of a 9-story library and a 30-story high-rise. The success of the field experimental studies has fully verified the feasibility and advance of the research and it has a broad prospect in practical application.

The advent of computers in conjunction with a boom in the construction industry following the Great Depression and World War II facilitated the development of new structural systems and forms. It is now possible to analyse and investigate different structural systems and concepts with the aid of the computer, which has never been possible before. This is in fact, a primary reason why conventional rigid-frame systems have been the prevalent structural systems for tall buildings until then. Fazlur Khan developed and refined the revolutionary tubular building concept, and the buildings reached to an unimaginable height with unimaginable amount of material. Here the building skeleton comprises closely T aced perimeter columns that provide much greater lateral resistance than is obtained with conventional systems because of the three-dimensional response of the building to lateral loads. This paper gives a brief explanation of tubular systems with a number of case studies from Turkey and abroad. In this context, the historical development of tubular systems is given firstly. Then, the tube concept is identified from the structural point of view as well as architectural point of view, and types of tubular systems – such as framed tubes, trussed tubes, and bundled tubes – are considered. While giving information about various kinds of tubular systems, a number of tall buildings are also presented.

An extensive literature review has been carried out on the differential shortening measurement and behaviour of columns and cores in tall buildings. This covers various assessment methods for determining different types of shortening including: time dependent and seasonal reversible influences, instrumentation techniques required to acquire field data, and correction measures undertaken to overcome differential shortening in actual structures. Also presented is a comparison of predicted and measured axial shortening of a particular column in an 80-storey building currently under construction in Australia.

CCTV new headquarters building is a 234m tall building in the form of a three-dimensional continuous cranked loop formed by a 9-storey podium structure joining two 50-storey high leaning towers which are linked at the top via a 13-storey cantilevered "overhang" structure at 36 storeys above the ground. This innovative and iconic shape of the building is exploited to provide the primary structural support system, as well as achieving the architectural vision of high-rise occupancy with occupant interface maintained within short distances in a continual loop. The building's primary support, in high-seismic intensity Beijing, is achieved by its external skin of leaning columns, horizontal beams and triangulated bracings forming a network of diagrids in an extremely strong closed braced tube structure. This external diagrid structure is also expressed boldly in the building's façade. It reinforces the transparency between structure and architecture, a central philosophy to the building's design. The internal structure is supported by vertical columns and steel cores which diminish in size progressing up the building height, in tune with the shape of the leaning towers. The columns emerge and terminate up the height of the building, again influenced by the angled towers. Transfer trusses are located at various levels to collect these column loads into the cores and external structure.

Three Pacific Place is recognized as a successful urban redevelopment project in Wanchai District of Hong Kong. The development has taken over a decade from inception to completion. The development comprises a 38-storey Grade A+ office tower on top of three levels of podium and three levels of basement. During construction, the site was divided into four parcels due to phased land acquisition. This imposed significant challenges to the construction and the engineering design.

The 280m high twin tower is the key component of the prominent development, "Gate To The East", Suzhou China. With the theme of being a "Gate to the East", two towers, which are of same height but have different number of storeys, will stand 60m apart at ground level and link together at top 8 floors. The underground light rail transit system will pass right through the "gate" formed by the twin tower. Each tower mainly comprises a reinforced concrete core and composite perimeter columns, linked together by belt trusses and outriggers system at three different mechanical and refuge floors, The continuous change in tower profile from bottom to top necessitates the extensive transfer structures in the middle and high zone of the tower for supporting the additional columns. Among those transfer structures, the long span linking structure located at level of approximately 240m above ground for supporting the top 8 floors between two towers provided the greatest engineering challenge of the project to structural engineers, primarily resulting from that the top linking structure would be subjected to a variety of structural responses arising from gravitational load, wind load, seismic load as well as differential shortening of the towers. Extensive studies have been carried out to evaluate the structural behaviour of the twin tower structure, prior to arriving at the final design of the twin tower structure. This paper will outline how the structural design resolved these engineering challenges, with the focus on those driven by the top linking structure, and meanwhile addressed the architectural, functional as well as economic considerations.

The Mega Tower, China World Trade Centre Phase 3, Beijing China is 330m high and composed of a five-star hotel, grade-A office levels and multi-purpose spaces. The height of the building and the high seismic design intensity in Beijing poses a great challenge to the structural engineers, especially considering various stringent requirements by Chinese codes. Various structural types, utilising different materials, have been explored until the final design was accomplished, which comprises a composite braced frame core and a composite perimeter frame, linked by two outrigger systems at relevant E&M floors. The tapered elevation of the tower building necessitates three transfer belt trusses that allow the reduction in number of perimeter columns in middle and high zone of the tower. The use of 8 storeys high V-shaped columns with transfer belt truss admit of the grand entrances with wide spacing of columns at ground floor for the five-star hotel and grade-A office, and meanwhile provide a smooth structural transition to the perimeter moment frame above. Composite elements of various types are extensively used and positioned carefully to satisfy the combined requirements for stiffness, ductility, redundancy, and cost-effectiveness. The composite steel plate wall (C-SPW) is implemented in the structure, possibly the first time in China, to increase the shear capacity and stiffness and improve the ductile behaviour at specific zone. Accurate finite-element analysis and advanced non-linear elasto-plastic time history analysis have been carried out to evaluate the structural behaviour and ensure the building safety under different seismic levels.

The leaning tower of Pisa in Italy, although not intentionally designed, had been a well-known landscape all around the world. Several modern high-rise leaning buildings including Puerta de Europa (Gateway of Europe) in Madrid - the first modern leaning buildings, Barcelona Communication Tower and CCTV New Headquarters have been worked out by contemporary architects and engineers. During the construction of a high-rise leaning building structures, both the P-∆ effect and geometric nonlinearity must be considered because the continually added gravity loads cause additional bending moment to the structure. The construction of a leaning building structure is a challenging task involving in the determination of pre-set displacement amount as well as implementation of construction schemes. Key issues about construction tracing and simulating analysis of leaning structures are outlined and studied; some helpful conclusions which have been used in CCTV New Headquarters project are presented.

Frame-bracing structure system is adopted in the high-rise steel structure of Zhongguancun Financial Center Tower. The objective of this paper is to give a brief introduction of the structural arrangement, lateral force-resisting system, local composite structure, kinky outer columns, floor horizontal trusses, excellent-property steel material Q345GJ for columns, and foundation design of the building.

The Sun Hung Kai Properties Group is the developer/co-developer of the three captioned landmark tall buildings in Hong Kong, and Ove Arup & Partners Hong Kong Ltd. is the structural consultant. With a height of 368 metres and 78 storeys, the Central Plaza became the tallest reinforced concrete building in the world upon its completion in December 1992. The 88 storeys Two International Finance Centre was completed in 2004. It stands 420 metres and is now the 5th tallest in the world. The upcoming International Commerce Centre, which will be of 118 storeys and 484 metres in height, could be the tallest building in the world when it is completed (given that there are many tall buildings now under design and/or construction). In properties developments, financial, marketing and business goals are key considerations of the developers. This paper reviews how experienced and innovative structural and civil engineering, apart from providing sound solutions to technical matters, can collaborate to achieve the developer's such goals in tall building developments.

The behavior of Chongqing International Exhibition and Convention Mansion under wind is systematically studied. The Mansion is a steel structure tall building, its height is 303m, and the first frequency of which is 0.1234Hz. To obtain the wind load and wind-induced responses and assess the living comfort and safety of the building, wind-tunnel model test is done in the turbulent boundary layer, which simulates the natural wind on the site of the Mansion. The distribution of wind pressure on every surface of the Mansion is measured by the static model. the static wind load is calculated. The wind-induced responses, including the displacements, acceleration and angular velocity responses, are measured by the aero-elasticity model. The dynamic wind load is also acquired. The effect of surrounding buildings and structures was discussed. It is shown, that the building's structural stiffness and dynamic properties, which is vibration period and damping, strongly affect the wind-induced responses of the building, and the surrounding buildings influence the distribution of wind pressure and wind load seriously. no galloping will occur under the design velocity, the acceleration and angular velocity on the top of the building is smaller than the allowance and the living comfort of the building meets the need of China national code.

Under the Building Codes of Hong Kong Special Administration Region, the provision of refuge floors has been an indispensable element in their high-rise building design since 1996. A refuge floor is a designed temporary safe place to improve high-rise evacuation during fires. It is a fire-protected semi-permeable feature in buildings taller than 25 storeys. Direct cross natural ventilation by natural wind is an important design criterion of a refuge floor. It helps to prevent any smoke entering the refuge floor from logging and impairing the safe conditions of the floor. This paper reports a study of the wind flow patterns around a high-rise building with a refuge floor at wind incident angle perpendicular to the building. The study is based on CFD simulations which are qualified by wind tunnel data. The results revealed a smoke hazard potential if smoke is dispersed from the rear face of the building at a level closely below the refuge floor. Smoke may be logged inside the refuge floor area behind the internal blockage.

Aimed at the wind-induced vibration of the long span steel spatial corridor, based on FEM and data obtained from the wind tunnel test, an analysis of time domain is used to calculate the wind-induced vibration factor of along wind displacement of the corridor for Hangzhou citizen. Furthermore, the changing law of wind-induced vibration factor of the displacement of long span steel spatial corridor is also obtained. Characteristics of the dynamic wind-load factor are drawn.

Accelerometer is a common sensor used to monitor displacement response of tall buildings under gust winds. Owing to the incapability of measuring static or quasi-static displacement response with accelerometers, Global Positioning System (GPS) has become an emerging sensor for measuring and monitoring both static and dynamic (termed total) displacement responses of tall buildings. However, the accuracy of total displacement measurement with GPS is affected by multipath signals. The current GPS is also incapable of accurately measuring high frequency displacement response. This study explores the possibility of integrating GPS signals with accelerometer signals to enhance the measurement accuracy of total displacement response of tall buildings. An interactive data processing procedure using both empirical mode decomposition (EMD) and adaptive filtering techniques is developed. In order to assess the effectiveness of the interactive processing method, a series of field measurement tests is performed on a site using a motion simulation table to generate various types of wind-induced dynamic displacement motions of a tall building in the pre-defined static position. In these tests, the GPS antenna and an accelerometer are installed on the same motion simulation table. The GPS and accelerometer data are processed with the interactive data processing method and are compared with the simulated motion. The test results show that the developed method can significantly enhance the measurement accuracy of total displacement response.

Water leakage is a common problem during wind and rain for high-rise buildings. This problem arises due mainly to inadequate knowledge on the phenomenon of wind-driven rain acting on building faces. The design and testing criteria for water tightness are not well defined. This paper sets out a framework for the calculation of the effects of wind-driven rain on buildings using wind and rain information and based on computational fluid dynamics method. The dependency of the effects on the local climatic conditions is examined. Wind-driven rain characteristics are calculated for buildings situated in different geographic regions, e.g. Hong Kong, Singapore and Sydney, and are compared. The effects of building height and build geometry are investigated.

As taller- and longer-span power transmission towers (PTT) are recently being constructed in China, they tend to be more sensitive to wind action, and it is more important to accurately estimate their response to wind forces. For this purpose, a new method, called as probability density evolution method (PDEM), which had been proved to be of high accuracy and efficiency, is firstly described, Secondly, wind stochastic field is studied from a new viewpoint of stochastic Fourier spectrum (SFS). The basic random parameters of the wind stochastic field, that is, the roughness length z₀ and the mean wind velocity at 10m height U₁₀, as well as their probability density functions (PDF), are obtained. It provides opportunities to apply the PDEM in this problem here. The wind-induced dynamic response for a PTT was studied. The time process of mean and standard deviation of the top displacement response were obtained, and the instantaneous PDF of it was shown by means of two-dimensional and three-dimensional pictures. All of them verify that the PDEM is feasible and efficient in the dynamic response analysis of wind-excited PTT.

The full-scale tests on wind-induced response of Di Wang Tower during several typhoons were conducted during the past few years. The amplitude-dependent nonlinear damping ratios for this tall building were obtained from these full scale tests. Meanwhile a Monte Carlo simulation procedure was adopted in this study to generate the time series data of local fluctuating along-wind force acting on this building. The wind-induced response of this building was numerically analyzed in time domain based on the generated local fluctuating wind force and the established finite element model. The effect of nonlinear damping on the wind-induced response was evaluated under different load cases. Finally the effect of time constant on the wind-induced response was analyzed by comparing the time domain analysis results with those from conventional spectral analysis method. Some conclusions resulted from this study may be helpful to the wind resistant design of tall building structures.

In this paper, according to the relative provisions of several important load codes/specifications in the world, estimation of the speed-up ratios of wind speed or wind pressure profile considering topographical effect has been discussed based on a practical important tall building being built on an island, and the effect of topography on the gust factor of wind speed has also been analyzed according to the related provisions of the new load code in Japan. Then, with an escarpment model and a ridge model, topographical effects on the estimated wind load for designing the main structural system and the maintenance components of this practical project were analyzed, respectively. Based on these investigations, the difference of the estimated values of the speed-up ratios due to topographical effect among these codes/specifications, including china load code, is presented, and the tendency in current revision of the corresponding provisions is discussed. The results can offer a convincible reference to wind load analysis in wind-resistant design for the practical tall building, as well as of other similar projects in the future.

In this paper, the settlement of the vertical members supported by the secondary transfer beam is analyzed, and overturning resisting rigidity at the supporting point is studied for earthquake and the wind load. A comparison with those results obtained in primary beam case is made. It is reasonable to use secondary transfer beam to support the vertical member with the smaller lateral rigidity, if there is difficulty to use primary beam. Two secondary transfer beams can be used in crossing form rather than the single, to increase the settlement resisting rigidity and entirety.

A transfer plate is a very thick and large solid concrete slab, which is placed between shear wall and column supports, with a heavy self weight and large amount of reinforcement. Transfer plates give architect and structural engineer a great flexibility in modifying the upper commercial and residential tower blocks and the supporting system underneath the transfer plate in the design process. The tower blocks, the transfer plate and the supporting system, which are meshed separately, have to be put together to form a finite element model for structural analysis. However, the merging of the load bearing walls and columns will be more challenging if tower blocks of arbitrary shapes and orientations are allowed to load on the transfer plate. In order to cope with the most general situation of arbitrary number, position, size and orientation of load bearing members on a transfer plate, the idea of coupling element is proposed. By means of a penalty integral, the coupling element ensures that load bearing members are in full contact with the transfer plate. As the integral can be evaluated based on a Gaussian point scheme, the node for node matching over the interface of two solid elements is not required. This effectively allows solid hexahedral meshes to be connected without mesh modification over the contact surface. Examples of transfer plate structure will be given to demonstrate the effectiveness of the coupling elements compared with results where no coupling element has been used.

Some factors influencing the crack control of overlong jointless transfer structures had been synthetically analyzed including the layout of a building, the structural system and the transfer forms of the high-rise building. The comparative research on the transfer form for the overlong jointless structures was carried out through a practical engineering project. With the aim of the finite element method for numerical calculation, the mechanical properties of the globe structure and the transfer beam was analyzed. Some fortification measures for overlong jointless transfer structure were put forward lastly. The result obtained from this research may serve as a reference for the similar project design.

Shrinkage of a concrete structure as the concrete dries after hardening could lead to substantial shortening movement and, if the movement is restrained, serious cracking of the concrete structure. This is a common problem in Hong Kong. If a large podium is structurally connected to two or more core walls supporting tower blocks above the podium, the comparatively stiff core walls will prevent the shortening of concrete structures and shrinkage stresses will develop. In many cases, the shrinkage cracks formed have been causing aesthetic, water leakage and durability problems. To minimise the effect of shrinkage, it is a common practice to adopt stage construction by providing late-cast strips to be cast later. In this case, various structural members may have different ages, and hence different strengths and tendencies to shrink. The effects of stage construction on the long-term response of reinforced concrete podiums are investigated by the finite element method using the step-by-step time integration and based on the conventional creep coefficients, time-dependent concrete moduli and shrinkage strains. Investigation into various problems of a typical podium arrangement is also carried out. Factors affecting the effectiveness of late-cast strips including the optimum time lag between the first-cast area and late-cast strips, and the locations and number of late-cast strips are evaluated. The tensile stress criteria of concrete are used to predict possible cracking of concrete. Results show that stage construction is an effective measure to reduce the risk of shrinkage cracking. The maximum shrinkage stresses are reduced because a significant part of shrinkage movements have taken place relatively freely before various parts are stitched together. The above cases are analysed by using the shrinkage models suggested by the MC-90 Code, the ACI-209 Code, BS5400 and the Hong Kong Code, which are based on different material parameters. An approximate shrinkage model for concrete with shrinkage reducing agent is also proposed. To investigate the effectiveness of shrinkage reducing agent, the shrinkage behaviour of a typical podium is analysed. Finally, some design recommendations including the arrangement of late-cast strips and the possible methods to mitigate the adverse effects of shrinkage of concrete are made.

The research and development of post-processing system is the bottle neck of the CAD of steel structures. In this paper, the post-processing system for high-rising steel building based on 3D solid model is introduced. In this system, the complex spatial relationship between bars and detailed constitution of joints of steel structure is shown accurately in 3D solid model. Based on the 3D solid model, the drawing is created automatically in this system by using the geometrical and structural information of the solid model, namely the blue-print drawings, the designing drawings, and the manufacture drawings. Presently, this system has used in projects successfully.

This paper investigates the potential of using genetic algorithms (GA) in optimization of reinforced concrete (RC) structures. The optimum cost design of three RC structures, a beam, a low-rise frame, and a high-rise single core wall building, using GAs with variable operators are presented. The results show that GAs help to efficiently locate a near optimal solution offering lower overall cost designs compared to traditional design methods.

This work is concerned with technical development of the optimum RC structural design. Based on the algorithm developed, BUILDS-C which is for the RC structural design program and one of subsystems in i-BUILDS (an intelligent BUILding Design System) has been developed. This optimum design algorithm, the structural behavior of beams and columns is implemented in the design sections of members satisfying code requirements are stored in the database and are manipulated by one major variable, i.e. the section identification number(N) linked with all other design variables. In design procedures, a continuous preliminary solution is obtained first, on the basis of regression curve equations, and then an effective direct search for the discrete optimum section is carried out. In advance, automatic design of walls, slabs and SRC columns for given design condition is followed.

An application of multi-level optimization technique for structural design of tall buildings is presented. The strategy of optimization analysis is conducted by considering the structural behavior of a building at three levels, namely, element-by-element, sub-structural and global levels. In addition to the live and dead loads, both the wind and earthquake loading are considered in accordance with the Chinese design codes. From these, constraint requirements are formulated by including member's strengths, local and global buckling, maximum and inter-story drift limits. The building types treated include steel frames, concrete frames, shear walls, and hybrid structures (concrete and steel). In the paper, mathematical formulations of the optimization problem with constraint conditions are given. Two demonstration examples, i.e. a steel braced-frame and hybrid structure, are included to illustrate the utility of the methodology presented.

The behaviors of reinforced concrete frame under different lateral loading patterns are investigated by using nonlinear finite element method in this paper. A constitutive model of reinforced concrete based on continuum damage mechanics is proposed. The Non-local Damage Model is employed as the constitutive equation specialized to continuum damage, and to prevent spurious strain and damage localization. The Smeared Crack Model is adopted to offer automatic generation of cracks and complete generality in crack orientation, without the need of redefining the finite element topology. Traditional bond-link element is modified to save the time in calculation by condensing out the degrees of freedom associated with the reinforcing steel. The reinforced concrete frame was modeled, calculated, presented using the program Virtual Digital Laboratory v1.0 (VDL v1.0) that is developed by the authors. From the numerical calculation results, the pushover method is used, and the results of analysis well accorded with the conclusion of correlative literature.

In this paper the development of a CAD system for detailing designing of frame is introduced and presented. Using this system, user can shape new joint type and calculate the new type. This paper studies the joint location and constraint solution. The result of joint detail design is shown with 3D solid.

AT present, engineers create a structural model for a tall building based on paper drawings of an architectural CAD model and it is usually difficult to engage in design collaboration between the architects and structural engineers. The future trend in design technology is to promote the use of object-oriented CAD model in which a building is represented by 3D objects such as beams, columns, walls, floor slabs, windows, doors, stairs, etc. These objects can contain not only the geometric information, but also physical behavior and design data associated with them. As a result, one may construct a unified common design platform so that information can be shared across different disciplines in Architecture Engineering and Construction (AEC) industry. With this objective in mind, we have initiated a development program for direct data integration between the architectural and structure disciplines as the first step in building design.

TBSA (Tall Building Structure Analysis) is a three-dimension analysis program for tall buildings. Version 6.0 is a new version based on new Building Codes of China. In version 6.0 there are many new features added to enhance the usability and quality. This paper illustrates some of the new features and discusses some points that should pay attention to when we analyze tall building structures with the program.

The design efficiency of tall buildings depends largely on the advancement of technologies, specifically Computer Aided Design (CAD) technologies. To days, CAD tools have become a routine practice for architectural and engineering designs and significantly improved quality and productivity in the building design. Nevertheless, a fragmentation characteristic of these CAD tools barriers the further improvement of productivity of the design in building industry. To address the fragmentation problem, an integrated CAD framework for the design of building structure is proposed in this paper, which is based on a process model and building product model. The proposed framework benefits the development of integrated CAD systems and potentially promotes design automation in building industry.

Inelastic static pushover analysis is a powerful tool for the study of seismic evaluation of structures. It has been proved by overseas practical projects to be accurate and simplified. It can save both financial cost and computing time. But, there is few software packages programmed towards the analysis of pushover test. In this paper, a series of studies are carried out on the theory of reinforced concrete frame pushover test, and the whole process of pushover static test including concrete frame virtual model building, load applying, sensor installation and final numeric analysis is implemented with object-oriented method. Overall programming idea and implementation method of concrete frame pushover test are also presented in the paper.

Transfer storey itself is studied more than supporting system in constructing it. This paper bases on an actual project to study scaffold supporting system of thick reinforced concrete slab, which transfers loads of superstructure to the lower frame. Through measuring the stresses in the slabs and forces of supporting bars on the spot, the characteristic curve of regularity of developing of concrete strength and unloading of steel pipe supporting are acquired. Analyzing model is set up in the light of finite element method. During analyzing with FEM, contribution of concrete-filled tube to the stiffness of supporting system is included, while Young's modulus and strength of concrete evolving with various ages are considered. Contrasting the results with FEM with data from measuring, the same conclusions are arrived at. Based on this, Scaffold supporting system of top floor of basement is optimized and some constructive suggestions for the actual project are provided.

Self-climbing scaffold attached to structure is widely used in high-rise building construction. It is significant for wind resistance and construction safety to learn of the dynamical property of self-climbing scaffold attached to structure. In this paper, the finite element model of scaffold is founded and the dynamical property under several constructing conditions is calculated. The results indicate the dynamical loads under self-climbing state should be considered in the design of self-climbing scaffold in high-rise building. At last, some advice is brought forward: that we can choose only a scaffold as the calculate object and the exaltation state maybe the most disadvantage loads state.

Excavator is a kind of multifunctional build-construction machine, which is widely used. Its working condition is bad and its working state is complicated. Hydraulic system is its kernel parts, which plays a very important role to the capability of an excavator. On the basis of analysis excavator's usual working state, we made a detailed analysis about some particular working states and hydraulic systems, after that, we make a comprehensive conclusion about the design requirements of an excavator. According to the analysis of the design requirements for the hydraulic system, this thesis integrates loading sensing and electric control and any other technologies, designs a new kind hydraulic system of excavator, promotes the function of energy-saving and manipulative characteristics more.

Information construction technology is a developing trend of construction machine. As a typical earthwork machine, bulldozer usually works with high loads and shift frequently in complex situations and bad surrounding. The existing machines are mostly equipped with manual shift transmissions, which are inefficient and need driver's hard work. The intelligent control of bulldozer's transmission has many advantages: ①It will release the drivers from hard work, make the drive easy and comfortable; ②The transmission will match with engines better during running, which will improve the dynamic performance and efficiency of the machines and reduce the discharge for saving energy and protecting environment; ③The intelligent control system will decrease the crash of the shift and prolong the life of the transmission; ④It will become the foundation of information construction. In this paper, some improvements are made on the basis of the traditional hydraulic control system and a fully new electronic control system for bulldozer's transmission is developed. On this base, the hardware of the control system is build up. According to the requirement of bulldozer's work situation, a suitable shift strategy is scheduled. After a series of simulation studies and tests, the system is verified and modified. The result shows that the control system of the transmission is effective.

Construction of high rise buildings is no longer a local industry due to improved methods of transportation and information exchange which means the Global Village is becoming a reality. Moreover, the design and construction functions for very large hi-rise buildings tend to draw from the best practices and technology available on a worldwide basis because of the scale of the investment and the stakes involved. Witness the recent decisions to proceed with two of the tallest buildings in the world – one in Makkah, Saudi Arabia, and the other in Dubai, United Arab Emirates. In attempting to produce a quality product which meets capital cost and time expectations as well as life cycle expectations, amongst a number of challenges that need to be addressed, two very important ones are (i) how do firms gather and manage knowledge pertaining to new concepts in design and technological developments in terms of materials, physical systems, information systems, management systems, and construction methods in a way that makes it readily accessible to designers and constructors alike; and, (ii) what factors must be considered (e.g. logistics, codes, cultural norms, etc.) when assessing the suitability of these concepts and technologies for a given building and geographical context? This paper explores these questions by using a case study pertaining to the methods of design and construction of washrooms in the Middle East, an area of the world where the frontier of hi-rise buildings in terms of size and quality of systems is constantly being pushed. Current solutions adopted for building these elements constitute a significant part of the total cost of high rise building construction and have a direct impact on the speed of delivery. In this paper, we describe the rationale behind current practice, and how solutions used elsewhere can be adapted to meet local needs and sensitivities. We then generalize our discussion to describe elements of a framework currently being developed as part of a research program that allows design and construction technologies to be classified and represented in a way that facilitates their speedy assessment as to technical feasibility, environmental feasibility (including social norms), and impact on time, cost, and quality performance. Traditionally, high-rise building wet areas (e.g. washrooms and toilets) are made of blocks, plastering and in-situ finishes and enjoy social acceptance in the Middle East. Such acceptance has created a cultural barrier that inhibits the use of wet areas which are made of moisture resistant dry-wall partitions and in-situ finishing works which are easier and faster to install with minimal cleaning after work completion. The challenges of the traditional method include wet activities with low productivity rate, longer construction and curing times, large crew sizes, and logistical challenges in terms of materials handling and storage. The question becomes: what other technologies exist that can provide the sense of permanence and quality offered by existing partition systems, while addressing the objectives of cost, speed of delivery and quality. One potential alternative is the use of a concrete Pods system (a system introduced to the construction industry at a construction exhibition in Europe) which consists of a fully prefabricated bathroom including all internal finishing, electro-mechanical systems and accessories. The Pod's design in terms of area, finishing works and electro-mechanical systems can be changed as necessary to meet the project requirements. Pods can be manufactured using fibreglass, steel and normal concrete mix or lightweight concrete. Although fibreglass and steel Pods are easier and faster to install than concrete Pods, they have yet to gain social acceptance. As compared to wet areas built of block, plaster and in-situ finishes, concrete Pods offer the following advantages: moisture resistance, a fire rating of more than 2 hours, sound proofing up to 50 dB, a factory made product with minimum tolerance and high-quality finishes, a short site installation process which leads to faster project completion, comparable construction cost with the traditional method, efficient use of raw materials in production with no site waste, and easy logistical terms. A case study is used to illustrate the use of a framework that facilitates the representation of design and construction technologies, their interaction with other physical systems and construction processes, and their performance in terms of a number of metrics and constraint conditions.

The post-peak flexural behaviour of reinforced normal- and high-strength concrete beams has been investigated using complete moment-curvature analysis taking into account the effect of strain reversal in the tension steel. The results reveal that the major factors influencing the flexural ductility of reinforced concrete beams are the concrete grade, compression and tension steels ratios, and compression and tension steels yield strengths. Generally, flexural ductility increases with increase of compression steel and its yield strength, but decreases with increase of tension steel and its yield strength. However, the effect of concrete grade on flexural ductility is more complicated. To quantify how these parameters affect the flexural ductility, the authors have proposed a parameter λ as a measure of the degree of a beam section being under- or over-reinforced. Based on λ, an equation for direct evaluation of flexural ductility is established. Furthermore, the authors have studied the interrelation between the flexural strength and ductility that could be concurrently achieved and presented the interrelation in the form of charts for design applications.

Even in a structure that is loaded monotonically, some parts of it may experience curvature reversal, not to mention the much more complex loading history imposed by earthquakes. Therefore to get a reliable estimate of the safety of a structure under earthquake loading, it is worthwhile to carry out full-range analysis under cyclic loading. In this paper, the complete nonlinear behaviour of reinforced concrete beams made of normal- and high-strength concrete under cyclic loading is studied using a numerical method that employs the actual stress-strain curves of the constitutive materials and takes into account the stress-path dependence of the concrete and steel reinforcement. The loading history considered includes loading, and repetitive cycles of unloading and reloading. In particular, loading past the peak strength into the post-peak stage is investigated. It is found that the complete moment-curvature relationship, which is path-dependent, is similar to the material stress-strain relationship with stress-path dependence. Degradation of section stiffness is observed as the cyclic loading extends to large curvatures, especially at the post-peak stage. Upon reloading, it may not follow the original unloading path, but the difference between the two paths is not significant for the cases studied. Different aspects of behaviour between under- and over-reinforced sections have been observed which include, for example, the characteristics of moment-curvature envelope curve and the variation of neutral axis depth.

Coupling beam is an important member that has great influences on the behavior of coupled shear-wall structures under lateral loads. In conjunction with the society and economic development, more and more old reinforced concrete structures need to be strengthened, retrofitted, refurbished or rehabilitated to satisfy the modern requirements. This research aims to study the use of steel plates to strengthen deep RC coupling beams with dynamic set anchors. The numerical model developed for the nonlinear finite element analysis (NLFEA) is validated by the previous experimental results. Parametric study is then conducted to investigate the effects of varying thicknesses of steel plates and bolt group arrangements on the load-rotation behaviors of the strengthened beams. A set of design recommendations has been developed for strengthening deep RC coupling beams by attachment with steel plates using dynamic set anchors.

It is shown in experimental study that the coupled shear walls with stiffening coupling beams is superior to the common coupled shear walls in aseismic performance. But the available method of determining the optimum locations and number of stiffening coupling beams is not presented currently. In this paper, several hypotheses based on uniformly coupled shear walls are made. The restraining effect of weak coupling beams is incorporated to walls whose rigidity is expressed with equivalent rigidity. Thus, the coupled shear walls is simplified to a coupled shear walls which only includes stiffening coupling beams. The restraining moment applied to walls is acquired through the equation of deformation compatibility at the location of stiffening coupling beam. The top drift of structure is got with unit-load method. The optimum locations are obtained by maximizing the drift reduction caused by the stiffening coupling beams, while the needed number n of stiffening coupled beams is worked out according to the top drift of structure meeting the serviceability limit state.

The Hong Kong Housing Authority (HA) pioneered the precast concrete construction in high-rise residential buildings in the early '90s by successful introduction of planar precast elements, i.e. precast façades, semi-precast floor slabs and precast staircases, which altogether amount to some 18% of the total concrete volume of a building. Seeing the immense potential of precasting in building construction to enhance quality and sustainability, the HA has been dedicated to bringing greater benefits to the public through more precasting. To increase the percentage of precasting, to precast structural walls (given that a standard housing block is a wall-slab structure) and to leap from planar to volumetric precast construction has thus become the prime and foremost task. The HA has recently made a breakthrough in this area and developed an Enhanced Precast and Prefabrication System (EPPS) for the construction of standard high-rise housing blocks. The EPPS contains a lot of innovative initiatives in prefabrication and precast construction that include the key precast structural walls and volumetric precast construction as well. With the EPPS, the precast concrete volume will substantially increase to 70% of the total concrete volume of a building. Evolution of the EPPS has satisfactorily progressed stage by stage – from design development, a site mock-up to the present stage that the precast buildings are under construction.

The experimental investigation and simulation computation for steel shear walls with slits under the low cyclic horizontal loading are presented. The experimental data show that the stability is the most important influence factor concerned with the load-bearing capacity of the steel shear walls without stiffening ribs. The simulation computation for the test shows that the thin steel shear walls with slits and stiffening ribs can increase the ductility of the structure and consume large amount of the earthquake energy through the plastic deformation produced.

A test program was conducted to study the effects of transverse welds on the strength of aluminum columns. A total of 42 fixed-ended column tests were conducted, which included 23 columns with both ends welded to aluminum end plates using Tungsten Inert Gas method, and 19 columns without welding of end plates. The column lengths were either 300 or 1000 mm. Local and overall initial geometric imperfections of the columns were measured. The material of the column specimens were 6063-T5 and 6061-T6 heat-treated aluminum alloys. Non-welded and welded material properties were obtained from various coupon tests. The observed failure modes of the columns include local bucking, overall bucking, interaction of local and overall bucking, and material yielding in the heat-affected zone. The test strengths are compared with the design strengths predicted by the American, Australian/New Zealand and European specifications for aluminum structures. It is shown that the design strengths predicted by the three specifications are conservative for the non-welded columns. The welded column design strengths predicted by the three specifications are generally more conservative than the non-welded column predictions.

The paper describes a test program on cold-formed high strength stainless steel compression members. The duplex stainless steel having the yield stress and tensile strength up to 750 and 850 MPa, respectively was investigated. The material properties of the test specimens were obtained from tensile coupon and stub column tests. The test specimens were cold-rolled into square and rectangular hollow sections. The specimens were compressed between fixed ends at different column lengths. The initial overall geometric imperfections of the column specimens were measured. The strength and behaviour of cold-formed high strength stainless steel columns were investigated. The test strengths were compared with the design strengths predicted using the American, Australian/New Zealand and European specifications for cold-formed stainless steel structures. Generally, it is shown that the design strengths predicted by the three specifications using the material properties obtained from tensile coupon and stub column tests are conservative for the cold-formed high strength stainless steel columns. In addition, reliability analysis was performed to evaluate the current design rules.

As a promising lateral force resisting system, Steel Plate Shear Walls (SPSW) have been widely used in new buildings as well as in retrofit of existing buildings since the early 1970s . It has demonstrated many advantages such as large elastic stiffness, stable hysteretic behavior and good energy dissipation capacity. But in case of severe earthquakes, steel plate shear walls may loss part of their stiffness and energy dissipation ability after buckling of the infill steel plate. A new kind of steel plate shear wall system, namely Buckling-Restrained Steel Plate shear Walls (BR-SPW), is put forward in this paper. This system is composed of the infill steel panel and the reinforced concrete slabs (RC slabs) on both sides. The RC slabs can restrain the buckling of the steel panel in out-of-plane so that the steel panel can reach full sectional yield stress without buckling. Meanwhile, the connection of the steel panel and reinforced concrete slabs can be deliberately designed to ensure their freely relative slide on the contact layer in case of strong ground motions. In this way, the concrete slabs can be protected from being crashed and the steel panel is prevented from buckling. Numerical studies presented reveal a good static behavior of BR-SPWs and some useful conclusions are presented.

It is a common problem in earthquake resistant design that lateral-torsion vibration is coupled in tall buildings. Especially, when the building appears obviously irregular, the seismic response would be magnified because of its highly coupled. It is an advanced study in seismic design that irregular tall buildings worked with energy-dissipation devices. This paper discusses the steel frame-brace system with energy-dissipation braces (velocity-depended viscoelastic dampers), and analyze its non-scaled structure damper ratio and the seismic response. Based on the optimal energy-dissipation principle and a recently finished shaking table test of a 21-story steel frame-brace structure, it discusses the optimized location of braces with added viscoelastic dampers. It finds that the structure with the optimized location of energy-dissipation braces changes the distributing of structure damping factor, gains higher damping level, and has acceptable seismic performances, while improves its economy. This paper may provide reference for the application and development of this technology.

In general, public tall building is a kind of hardware facilities for each citizen's use. The constricting quality of each public tall building construction program during the working process will have highly relative influence with construction management. Construction job-sites have too many workers and lots of stuff that become complexity. Such situation causing construction management has full with challenge. Meanwhile, once the performance of construction management doesn't work well, it not only makes worse quality but also threatens citizen's life. So how to transfer the high technology of wireless transmission into tall buildings construction job-sites to improving and promoting construction management will be an useful research. This paper will introduce relative techniques of wireless transmission, discuss how to apply the wireless transmission technique as a management tool for each tall building inspection engineer. Also will demonstrate and test the performance with practice application.

People often take building age as a proxy for building performance, and thus equate old buildings with decrepit buildings. In Hong Kong, a number of public policies also use building age as a criterion to screen off eligible applications for subsidies. The belief in the conveyance of information on building performance by building age rests on the traditional wisdom that building fabrics and building services will wear and tear and ultimately become obsolete over time. However, if building maintenance and management is in place, it is uncertain how much information building age can still convey. There has seldom been any empirical test in this regard, due to the lack of an objective method to quantify building performance. This paper aims to fill this gap by examining the relationship between building age and its performance in respect of health and safety based on results from a standardized assessment of the health and safety conditions of 134 residential buildings in Hong Kong. Our preliminary results confirmed that there was a significant negative relationship between building age and its health and safety conditions. However, the 20-year cutoff adopted in most public policies was not supported by the empirical results. In addition, we analytically show that the use of building age as a decision tool for resource allocation may lead to inefficiency, and accordingly propose three solutions.

In Taiwan, the population is unceasing growth and the useable area is continuously decreasing. These situations are causing construction projects of tall building getting more and more. In each year, there are lots of fire disasters happened in tall buildings. Such tragedy always caused serious properties damage and many citizens' life lost. The characteristics of tall buildings are main factors to cause that serious damage, including too high to rescue, too complex in use, too many flammable materials, and etc. For example, in 2001, the fire disaster of the building of Eastern Science Park in Taiwan, burn for 42 hours and properties lost about US$ 300 million dollars. Therefore, it is really important issue in disaster prevention research. This paper will illustrate this specific practice fire disaster case of tall building to derive the prevention key factors of fire disaster in tall buildings, also will explain the collection of questionnaires from 200 firefighters, and then analyze the appropriate prevention policy of fire disaster of tall buildings.

Tile finishes have been extensively used in the decoration of the external walls of various buildings in Hong Kong. Debonding of such external finishes not only affects the appearance of buildings but also endangers the pedestrians. The aim of this paper is to discuss the failure mechanism and reasons of failure of external wall finishes that is a combination of concrete surfaces, rendering and tile finishes. Standard sizing wall panel is obtained and strain gauges are attached on each interface to measure the mechanical strain (i.e. the ratio: elongation/original length). While applying onto the wall panel, strain and stress distribution can be measured.

The fireproofing compartmentation measure for all the openings of a stage in the theater is one of the most important part in the fire design of the stage, and the metallic fire curtain that we usually adopt will make the collocation of the craftwork of the stage and the design of the architecture more complicated. So if we can use the drencher system replacing the fire curtain is to resolve this problem. Otherwise, the sprinkler system for the auditorium is another difficult problem in the fire design of the stage. In this article several system have been presented, we will recommend you the one in reason and more economical.

The construction industry is project-based, and design and construction transactions within projects are generally separated. Effectively balancing the diverse interests of multiple stakeholders (e.g. clients, consultants, constructors) along with efficiently managing multiple risks across various project interfaces is a challenging task. Rework often arises from the unnecessary efforts of redoing/rectifying incorrectly implemented processes or activities. In poorly managed construction projects, rework can significantly impact the time, cost and quality performance. Thus, from a business sustainability perspective of constructors, the control of rework is a great concern. A pilot study on the effective management of rework in construction projects was recently launched to address this concern. The research methods of this study exercise include (a) focused interviewing and questionnaire surveying of various experts and experienced persons in the Hong Kong construction industry and (b) conducting some case studies. The main focus areas of this study are (i) to identify the common root causes of significant rework items and (ii) to develop suitable structured frameworks for effective rework control and management. This paper presents (a) an interim summary of relevant findings from this study that relate to rework management in building construction projects; and (b) a proposed framework for monitoring rework in tall building works.

A cost comparison study of plasterboard drywall partitions vs. traditional masonry/concrete partitions in High-rise Residential Buildings in Shanghai is summarized. The study was purposed at demonstrating the cost advantages by using plasterboard drywall partitions over the traditional masonry/concrete partition system in high-rise residential buildings in Shanghai region. With the drywall plasterboard partitions substituted for the masonry/concrete partition system, it is found that the main structural construction cost can be reduced by 10% for the typical building studied. Besides, there is a massive reduction of laboring, and the construction period for the building is expected be reduced by 40 days approximately. An extra usable floor area of 360 m² is also expected for the building redesigned. The study reveals the positive cost advantages of high-rise residential building constructions with plasterboard partitions over those with masonry/concrete partitions. Although the cost comparison was based on a real-life high-rise residential building in Shanghai, the results can be applied to any regions where the material and labor rates are similar to those in Shanghai.

This paper introduces the calculation method of reinforced concrete hollow girderless floor. With this method, the quantity of the reinforced bar and concrete needed in reinforced concrete hollow girderless floor is computed. And unit material quantity of reinforced concrete hollow girderless floor is compared with that of waffle floor, flat slab and ribbed floor, unbonded prestressed concrete floor with the same span and loads. On this basis, unit square costs of floors are calculated according to market price of materials and economical efficiency comparison is conducted for floors. Then the performance of the hollow floor is presented, compared with that of other floors. Through comparison and analysis, it is concluded that service performance and economical efficiency of hollow girderless floor are better.

The construction industry is often criticized for its sluggishness, if not inertia, in deriving early benefits from various innovative developments in enabling technologies. Recently, various applications of wireless technologies (e.g. Bluetooth) as well as radio frequency identification (RFID) and barcode tags are being increasingly used e.g. in automated inventory control, procurement tracking and supply chain management. This paper is based on a pilot study that aimed to map such advanced technologies enabling automation in construction industry. This research exercise is mainly based on an extensive literature review from various sources. A summary of basic information regarding an array of such enabling technologies is presented in this paper. Furthermore, a proposed framework for automation in tall building works, e.g. facilities maintenance and asset management using RFID applications is presented in this paper.

Nikken Design has built three high-rise office buildings in Pudong of Shanghai, that is the bank of China Mansion in Pudong, Shanghai Information Mansion and the City Bank Mansion in Shanghai. By studying these three buildings, this paper tries to examine the change of the tendency of the value for high office building in Shanghai these years, and then give the criterion to evaluate the high office building.

The concrete filled square steel tube structures (CFST) become more and more popular nowadays. In this paper the design and research for a tall building of this kind was introduced. On the basis of calculating and adjusting of mass and stiffness for many times, braced-frame system was adopted to reduce the torsion effect brought by architectural irregularities of plan and elevation. The modal analysis, response spectrum analysis and time history analysis was carried out by several software. The period, displacement and story shearing force etc. were obtained and compared with each other. Relative design methods and research conclusions could be referenced to similar projects.

The application of concrete-filled steel tube (CFST for short) structure in high rise buildings becomes more and more extensive, and in the whole structure the design of joints takes a great part. In the article, several types of common joints are briefly discussed. Static experiment of compression and bending on joints with outer ring connections generally used in CFST structures has been undertaken. Through the experiment, the load-deformation curves and the stress distribution are both raised. Finite element method is also adopted to verify the feasibility of experiment, and the analysis indicates that the results of both methods agree well. According to the characteristic of compression bending test on joint and on the base of the experimental results, their value may emerge in the design of projects.

Concrete-filled steel tubes have been commonly used in the construction of tall buildings. Stainless steel tubes can be used to provide high corrosion resistance, ease of maintenance and construction as well as aesthetic appearance. This paper presents an experimental investigation of concrete-filled high strength stainless steel tube columns. A series of tests was performed to investigate the effects of the shape of stainless steel tube, plate thickness and concrete strength on the behaviour and strength of concrete-filled cold-formed high strength stainless steel tube columns. The high strength stainless steel tubes were cold-rolled into square and rectangular hollow sections. The concrete-filled high strength stainless steel tube specimens were subjected to uniform axial compression. The column strengths, load-axial strain relationships and failure modes of the columns were presented. The test strengths were compared with the design strengths calculated using the American specifications and Australian/New Zealand standards that consider the effect of local buckling using effective width concept in the calculation of the stainless steel tube column strengths. Based on the test results, design recommendations were proposed for concrete-filled high strength stainless steel tube columns.

The tall apartment building of Fortune Center phase□sited in Beijing is 193.4m height which structure system is mixed frame-corewall structure. In this paper, some analysis methods used to solve the problems presented because of the composite structure beyond the code-specification are introduced. The design criteria and analysis results in this paper can be referenced in the design of similar structures.

Different structural materials possess different characteristics. In order to maximize the respective benefits of different materials, they are often used in combination. The result of this combination is the composite or hybrid systems, which has come to have the specific meaning of steel and concrete components connected together. In this manner, they behave as a single structural unit. In current practice, composite construction is one of the most efficient construction types for multi-story buildings. It can be applied to both lateral and gravity load resistance system. Since buildings of the future will involve a variety of forms, and will be flexible for multiple use spaces, composite construction will enable the designers for their desire to design contemporary tall buildings. This paper is intended to give general information of composite structures employed in multi-story buildings by giving descriptions of a number of buildings related to architectural applications of steel and composite building systems.

This paper describes emphatically several construction technologies used in the third phase construction of Chongqing Jufucheng Building, which include the steel structured support technology for form-work suspension of building transition floor, the large-diameter HRB400 reinforced bar connection technology, the application technology of high-strength and high-performance fiber concrete, the single-side form-work support technology in "converse operation" process of concrete wall in basement as well as the technology of "resistance" and "release" for the construction of large-area building floor.

A collapse of a piled industrial building in Shanghai, China is reported herein. Based on a field test of pile foundation adjacent to surcharge loads in the same area with soft clay soils, causes of the collapse were investigated. The field test indicated that (1) pile foundation would experience considerable deflection due to lateral soil movement generated by surcharge loads nearby; (2) differential settlement between the front and rear piles would be initiated by the negative friction due to soil settlement. The negative friction could also give rise to reduction of net pile capacity. As studied elsewhere, secondary stresses generated in the superstructure by the lateral displacement and differential settlement of pile foundation, and the loss of the pile capacity would be the main causes for the collapse. Thus, the response of pile foundation subjected to soil movement should be involved in design of piled industrial buildings.

Prestressed technology is more and more applied to floor of super tall building because of its one's own characteristic. This paper takes a super tall building in shanghai as an example to discuss the application of prestressed technology to floor system of super tall building. Comparison among three prestressed floor designs is shown. Earthquake resistant performance in the entire structure and secondary interior force under restraint of tube structure are analyzed.

In recent decades, composite steel-concrete beams have been more and more used in tall buildings. The mechanical connectors are commonly used to transfer longitudinal shear forces across the interface of the steel beam and concrete slab in composite beam design. The empirical equation for the shear strength of stud connectors, which was presented by Ollgaard et al in 1971, has been incorporated in codes of various countries. In this paper, based on experimental data of 95 push-out specimens and 11 composite beams with partial shear connection from home and abroad, the effects of concrete strength on the shear resistance of stud connectors and moment resistance of composite beams are analyzed and investigated. It was found that the shear strength calculated according to Ollgaard's empirical equation is lower than that of test results when the concrete strength is lower, while higher when the concrete strength is higher. And the same conclusions are got in composite beams with partial shear connection. A modified formula for the shear resistance of stud connectors is presented by means of regression analysis of the test data. From comparing calculated values with the results of push-out specimens and composite beams with partial shear connection, it is observed that the error of equation proposed by Ollgaard can be eliminated when used the modified formula proposed this paper. And the calculated value is in good agreement with the experimental results.

According to different structure systems, the lateral displacement modes of tall buildings are classified. The difference of storey drift of frame and shear wall, which are two different structure systems, is analyzed in this paper. Then, the potential problem that the storey drift angles, which are calculated by the storey lateral displacement difference, is regarded as the deformation control parameter of shear wall structure is presented. Based on the characteristic of shear wall structure, the floor displacement is divided into destructive floor displacement and nondestructive floor displacement. Similarly, the storey drift is divided into nominal storey drift ∆u_i and destructive storey drift . Nondestructive floor displacement is produced by rigidity rotation of the floor, and the proportion of innocuous floor displacement is accumulated gradually from the base to roof for shear wall structure. In this paper, applying the inverted triangular distribution of lateral force to the cantilever wall with identical section, the displaced shape is regarded as the approximate lateral displacement curve. The relationships among nominal storey drift ∆u_i, destructive storey drift , interstorey rotational drift angle and bending curvature of section ϕ(ξ) is derived, and practical formulas to calculate the destructive storey drift is presented. Finally, by the sample analyzing, the relationship of nominal storey drift, destructive storey drift, inter-storey rotational drift angle and bending curvature of section is explained. Moreover, the practical formulas to calculate the destructive storey drift are confirmed, and the validity and feasibility of the method is verified.

The development of many of the underground services has a direct impact on the planning of sustainable buildings development and environmental concerns. In promoting a more sustainable approach to the planning of our city (e.g. the West Kowloon complex and the large Kai Tak development), there is a strong desire to adopt a better practice in the design of the location of the principal utility services. This short paper addresses the major problems we face regarding the underground infrastructure: social and economic disruption caused by performing engineering works. In the second part, the author discusses how we engineers can solve the problems with the use of unusual services subways and the employment of some trenchless construction for more greener underground services. It is hoped that the discussions made will provide a forum for all construction stakeholders to explore the suggestions for the needs of a greener city.

With the development of science and technology, peoples' living style is getting farther away from what used to be in nature, and city development is a good illustration of this change. As an artificial system, city has a way of development of its own, which is quite different to the natural system. This inconsonance brings about much disarrangement, such as pollutions, heat island, overburden of resource and waste, etc. From the view of evolvement and balance of ecosystem, this paper discusses the relationship between city construction and environment protection. Pluralistic industry based on multi-dependence is suggested to construct a sub-circulation in city, and a sustainable development pattern could thus be achieved. By partly converting scraps into building materials, cities could reduce its negative influences on environment. In the circulation, particular attention is given to tall buildings, for which there is a rising market demand. Some suggestions on tall building construction were proposed.

The compact urban form implies intensification, high density, mixed land uses, efficient public transport and dimensions that encourage walking and it is argued to have both negative and positive implications on urban living space and thereby quality of life and sustainability. Perceptions on lack of open space, urban greenery, poor environmental quality, crowding, lack of privacy, noise are some negative implications while urban variety, vitality, robustness, accessibility, permeability, social interaction, safety, efficiency and reduced travel time to services are some positive implications. The problems presented in the compact city debate can be sumarised as; claims about sustainability of the compact city; the feasibility, or the social acceptability of the compact city and the requirement of tools or measures that ensure successful implementation of the compact city [1]. Claims on social acceptability of a compact city is related to issues such as congestion, lack of privacy, poor environmental quality, constrained living spaces, high rise living, lack of open space and urban greenery. It is argued that individual proximity to a concentration of people increases social interaction [2] but some argue that crowding leads to weaker ties [3]. But the response towards such implications and arguments are based on human perceptions, preferences, adaptability and tolerance which differ across each cultural and urban context. This paper focuses on implications and arguments on compactness in relation to open space within two selected mixed use residential developments in Hong Kong. Critical implications of compactness are analysed in a pilot survey conducted among a total of 120 respondents in 3 open spaces located within the selected developments. Questionnaire interview is conducted to gather user's response to the following; perceptions on lack of open space, importance of open space, social interaction in open space, aesthetic and environmental quality of open space, crowding, time spent in open space, travel time to open space and the use of alternatives or substitutes to open space. Conclusions are drawn from survey findings in order to facilitate hypothesis for future research where regression analysis will be used for further investigating the implications of a compact mixed use urban context on the perceptions and use of open space with reference to compact residential mixed use developments in Hong Kong.

Suburban sprawl has been criticized by many to produce many costly and unfortunate impacts – environmental, economic, and social. Planners in communities are increasing turning to neighborhood environment as potential solutions to reduce automobile dependence. New Urbanism suggests that the right design would encourage walking, thereby foster a greater sense of community. Calthorpe (1993) argues that "Pedestrian are the catalyst which makes the essential qualities of communities meaningful". New Urbanism proposes neighborhood design elements consists of: compact, walkable neighborhoods; a diverse mix of activities and housing options; an interconnected street network. These claims about urban form and pedestrian choices have initiated a lot of empirical studies to investigate the difference of residents' pedestrian behavior in traditional vs. conventional suburban development. Most of these studies have supported these claims by founding less auto use and more walking trips in traditional neighborhoods (for instance, McNally and Ryan, 1993; Ewing et al. 1994; etc). These studies have found some sort of association between mixed-use attributes (compact, mixed-uses, and pedestrian oriented environment) and more pedestrian choices. The main objective of this paper is to clarify what aspects of neighborhood environment influence what aspects of pedestrian behavior through systematic evaluation. First, a model for urban form characteristics about pedestrian trips is proposed. Second, the results of a study of two neighborhoods in Guangzhou are presented. The characteristics of neighborhood form are analyzed by a variety of techniques and described, and the factors influencing choice about pedestrian trips are explored through an analysis of the results of a neighborhood travel survey. These analyses support the proposed model and suggest that certain different aspects of urban form can play an important role in different aspects of pedestrian behavior.

The collection and irrigation of rainwater, including waterproof and infiltration, is the key point of the large area vegetation of building. As the combination of waterscape with biology can create a harmonious create sustainable ecosystem environment.

This paper is a socio-cultural analysis of high-rise living buildings in contemporary Chinese cities. The considerable construction of high-rises has dramatically transferred Chinese cityscape, and has provoked a critical question of how to understand the Western influence in Chinese architecture and urban pattern. From the viewpoint of urban culture and spatial arrangement, this paper examines the way in which Chinese people inhabit in the modern city. This investigation is based on a case study of a high-rise residential development in Shenzhen Central District. By looking at the image making and spatial organisation in city construction, residential development and household space, this study reveals the re-interpretation and transformation of the Western importations in terms of Chinese fantasy of the 'modern', and an ambivalent relationship between the individuals and the city which is accommodated and constructed by a series of mediating spaces.

High-rise high-density building developments are one of the most spectacular features in Hong Kong's urban areas. Buildings are built as tall as possible, subject to statutory and contractual controls, in order to maximize development profits. Developing tall apartment buildings has at least two implications in the occupancy stage: 1) the availability of more shared facilities and 2) overcrowding. This paper aims to study the economic impacts of building density and the disposition of building services on property prices. It also sheds light on the important question of how floor levels are priced by property buyers in high-rise buildings. Our sample came from the transaction records of a unique estate-type development in Hong Kong. It comprises buildings which, except for their heights (ranging from 11 to 26 floors), are highly homogeneous. This means that other factors affecting property prices, such as location and views, can be effectively held constant. Based on hedonic pricing analysis, we found that taller (and thus denser) buildings were sold at a discount compared to shorter buildings, ceteris paribus. These results suggested that while developers build taller buildings for better returns, they should be reminded that it also comes with a decrease in sales for units on lower levels.

This study examines the relationship between air quality and property prices at a microscopic level to eliminate district level noise. A densely populated area dominated by high-rise developments was chosen for a case study. The street level air quality of the chosen area was estimated by computational fluid dynamics software using a three-dimensional Reynolds stress turbulence model. Property transaction prices in the same areas were then collected to construct a hedonic price model, which includes simulated air quality as an explanatory variable. Our findings indicated that air quality was reflected in property prices. This suggested that the property market was more efficient than any studies have implied so far, since there was no publicly available information on street level air quality. Further research and field measurements may be conducted to validate the findings.

The urban environment modifies microclimate in numerous ways. In general, urban climates are warmer and less windy than that in rural areas. A review of literature shows that the modification to urban climates is highly variable, and depends on particulars such as topography, regional wind speeds, urban morphology, time of year, and other physical factors. Measurement work around buildings, scale models, and simulation work have been used to try and identify the processes that govern the microclimatic changes. Alteration to temperature, as exemplified by Urban Heat Island Effect (UHI), is a particularly important aspect of microclimatic changes, as this has a direct impact on domestic fuel use: in a sub-tropical climatic region like Hong Kong, warmer temperatures increase air conditioning use substantially, particular during the hot humid summer months. The Urban Heat Island also affects the human comfort levels which can influence human behaviour. Literature reveals a considerable body of research work describing the conditions in cities and how they are different from their more rural surroundings. Most studies are directed at understanding urban climatology, rather than on the impact UHI on urban areas and the lives of urbanites. In order to mitigate the possible adverse effects of UHI, the impact of UHI needs to be investigated. This paper is a study into the extent of UHI in three high-rise high-density residential developments in Hong Kong. The differences in UHI between these developments are then explained in terms of urban design factors.

Previous studies on the SARS outbreak in Hong Kong in 2003 that sought to determine the causes of SARS transmission assumed that the living environments of SARS patients were critical. This article tests the null hypothesis that the SARS incidents in a local housing estate were random, and hence unrelated to the built environment. This test was executed by: (a) using the chi-square method to evaluate eight empirical hypotheses about the relationship among the built environment variables of floor level, block location, and flat location; and (b) employing the Gini Coefficient and Lorenz Curve to measure SARS information aggregated by residential unit for analysis of inequalities and concentration of dates of SARS incidence. The results show the disparity of SARS incidence distribution is significantly large, i.e. the probability that the SARS incidents in the sample area occurred randomly was insignificantly low. Using the same data set that has been used to establish Yu's theory (2003), the results were not inconsistent with the theory that SARS was possibly transmitted by contaminated domestic moisture carried by air currents, so the limitations of the analysis will be discussed.

Ground coupled heat pumps (GCHPs) are a promising new technology that has been used in recent years in Chinese market. The most important component of the GCHP systems compared to conventional air conditioning systems is the ground heat exchanger (GHE). This paper mainly presents the entire simulation model of heat transfer of GHEs in GCHPs. The explicit analytical solution of the finite line source in semi-finite medium is derived for convenient calculation of the thermal resistance outside the borehole for long time steps. The resistance inside the borehole is also better expressed accounting for the thermal interference between the two legs of the U-tube. The techniques of spatial superimposition for multiple boreholes and sequential temporal superimposition for arbitrary heating/cooling loads of the systems are also presented in this paper. The validation of the models by experiments in the actual project of GCHP system in China is carried out. The results of these tests have shown that the measured data on site agree quite well with predicted data according to the model. The simulation model is suitable for engineering applications.

Energy efficiency and indoor air quality have been the focuses for green and sustainable building design project. Whilst energy-efficient air conditioning, water heating and lighting systems are subjects of interest in the commercial and industrial sectors, households also have a growing quest for a safe, healthy and quality living. The preference for a combustion free indoor environment is therefore emerging. This paper discusses the latest technologies in electrical cooking, water heating, clothes drying and indoor air quality (IAQ), and the benefits they bring to consumers.

The Hong Kong climate is sub-tropical with hot and humid weather from May to September and temperate climate for the remaining 7 months period. A mechanical ventilation and air conditioning (MVAC) system is usually operated to get rid of the high peak cooling loads. The support of the MVAC system by means of natural ventilation are in the summer period limited due to the very high humidity. There is nevertheless a possibility for supporting the mechanical ventilation system by using the buoyancy effect in a 'solar chimney' to extract exhaust air. A 'solar chimney' is a chimney integrated in the façade with Photovoltaic (PV)-arrays on the outside for electricity production. High-rise buildings of 35 stories and above are common in all building sectors in Hong Kong, providing adequate pressure differences, ensuring the efficacy of solar chimneys. In this report different dimensions of a solar chimney and its implications for extracting air from an office building were investigated. It could be demonstrated that the geometry of solar chimneys with a fixed airflow are more efficient when designed with maximum width and depth. From the examined sizes it could be shown that a width of 1.5m and a depth of 1.5m are the most appropriate geometries for a solar chimney with a fixed airflow rate of 481/s.

The feature of building devices control system can be described as multi-point, exact demands of synchronization and real-time control, dynamic connections among the control points and so on. Aim at it, this paper presents a complex control system based on Ethernet and CAN (Control Area Network). Hardware and software of the field-controllers, area-controllers and control center are designed in the paper. In CAN Field-bus, field-controllers are in charge of receiving instructions from the host computer, showing real-time control effect, obtaining fault information of lighting devices and sending it to the host computer. Area-controllers realize the conversion between the data transmission protocol of Ethernet and that of CAN Field-bus. Meanwhile, it makes the data transmission between host computer and field-controllers transparent. The host computer will calculate the matrixes in control instructions, send them to the field-controllers, change the control strategy according to the fault information from field-controllers and send the alarm signal out as well. The whole system is designed as a modularization configuration, flexible, easy to be integrated and extended. Alarm function is introduced into the control system, in which the alarm message is transmitted by GSM wireless network. It can also receive remote wireless control instructions. The project has been applied into a 29-story building's lighting scene project successfully.

This paper describes a distinctive case design of the electric system design for the provincial mobile telecommunications hub building, which located at Ji Nan City of Shan Dong Province, has a two-storey basement and twenty-one storeys reaching a height of 86 meter and covering a total building area of 46000 square meters. For such a high building with its complete architectural functions it is necessary to have a rational electric design for various power systems as well as advanced electric facilities. This paper, while omitting the power design for the routine systems, gives an elaborate description of the electrical design for the building.

No abstract received.

Two International Finance Centre (2IFC) is the tallest building in Hong Kong and the 6^th tallest building in the world today. With its outstanding height of about 420 meter, which is almost the same level as The Peak in Hong Kong, 2IFC might have been the only tall building of this height to be set up right next to the waterfront in the world today. This paper has looked at the sustainability of the software and hardware of 2IFC more from the users and management point of view.

During the past 25 years, cities throughout Asia have expanded more rapidly than ever before. Tokyo is no exception. The urbanization tide that began in the latter half of the 1960s made Tokyo one of the world's largest cities; nevertheless, the era of industrialization is now over, and we have shifted to a post-industrial society based on knowledge and information. Now, with the change of times, urban planning in Tokyo also needs to evolve out of its priorities of the industrial era. It is true that, compared to the West, Asia has lagged behind in terms of investment into cities. By employing new technologies and concepts, however, Asian cities undoubtedly have the ability to become leading cities of the 21^st century. The future direction calls for multi-functional, compact cities where workplaces, residences and leisure are within close proximity. In order to realize this, the present urban structure, which is horizontally dense and vertically sparse now needs to be remodeled in order to build multi-functional cities which can achieve high density and favorable environment simultaneously. By taking Roppongi Hills (opened: spring 2003) as an example, let us look at a new lifestyle for the 21^st Century that makes this compact city concept a reality. If a newly attractive urban lifestyle for the 21^st century is established in Asia, the world will look to Asia for a new urban model.

Air quality is a major concern for quality of life in high-rise high-density urban environments like Hong Kong. The physical fabric of this environment is suspected to have contributed to poor dispersion of air pollution caused primarily by emissions from automobiles. This paper reports an ongoing research that investigates the relationship between street level air pollutant concentration and the morphology of hyper dense residential environments in Hong Kong. The research postulates that urban morphological attributes, such as locality factor, development intensity and built-form configuration affect the concentration or dispersion of air pollutant within an urban locality. A method has been developed to model the relationship between morphological attributes, microclimatic conditions and air pollution phenomena in real situations. Preliminary findings from empirical studies provide evidence supporting theoretical assumptions and validating the method. Conclusions and new hypotheses arising from the study shall be used to guide extensive empirical survey and further development of theory and research methodology.

The skyline of central district area has been re-drawn by the completion of an 88-storey skyscraper called Two IFC which stands at 420m off the ground and the tallest building in Hong Kong. Two IFC is a grade A office building with a total gross floor area (GFA) of more than 180,000m² and an estimated working population of 15,000 person. The tower is divided into 7 lift zones with twin sky lobbies and 4 mechanical floors to service each individual zones of the building in the most economical and energy saving manner. Two IFC tower is also the icon building of the integrated development which comprises of the Airport rail link extension on the northern concourse, a mega retail mall of 70,000 m2 linking to the 1000 rooms Four Seasons Hotel complex, totalling over 4,500,000 sq. ft. development area. The sustainable M&E services design features in Two IFC includes (i) achieving building thermal comfort and energy efficiency through detailed OTTV study and external façade treatment; (ii) pre-fabrication and pre-commissioned technology employed for AHU, PAU and others ready for "plug-and-play" installation; (iii) energy comfort and controls through advance BMS DDC control running on TCP/IT fast speed ethernet; (iv) hydraulic treatment in M&E system design in super highrise building; (v) continuous energy monitoring/auditing for energy saving opportunities.

The world first most comprehensive quantitative assessment method to audit intelligent buildings was published and released on 18 January 2005. It is known as the Intelligent Building Index (IBI) Manual version 3.0. The technical tool consists of 10 important constituting index modules (M) in any intelligent buildings namely Green, Space, Comforts, Working Efficiency, Culture, High-tech Image, Safety & Structure, Management Practice & Security, Cost Effectiveness, and Health & Sanitation. Under the index modules, there are 378 constituting elements (x). The manual employs the concept of "Relative Importance" of each element (x) contributing to the corresponding module (M). The relative importance is reflected by the weighting (w) of the elements using the Cobb-Douglas function in calculation. Similarly, the manual can be applied to audit various types of buildings but with different weight per module. Again, the concept of relative importance or weight (Y) is used for each modules contributing to the overall IBI index (I). In November 2004, the IBI manual v3.0 was used for the intelligent building audit for the 88-storey office building "Two International Finance Centre", the tallest building in Hong Kong. The overall score is 95% which is the highest score so far audited by the IBI manual. The building is very strong in the areas of Working Efficiency, Cost Effectiveness, Space, Culture, and particularly outstanding in Management Practice & Security. It is believed that the IBI Manual is the most up-to-date, objective and comprehensive assessment tool for auditing intelligent buildings of the world.

Hong Kong people live, work and spend leisure time in tall buildings. Nowadays 'green and sustainable' buildings are commonplace in the vocabulary and literature, although clear concepts tend to be absent. So-called building environmental assessment methods (BEAMs) provide some measure of the greenness of a building, but it remains to be clarified what measure of greenness is provided by an eco-label such as for example BREEAM-Excellent or HK-BEAM-Gold. Some BEAMs now includes aspects of building performance that go beyond environmental aspects to include assessment of social and economic issues, raising the question as to how a labelling system can provide a measure of sustainability. Based on an examination of several tools, this paper examines the extent to which a given BEAM assessment grade provides a measure of the 'greenness' and 'sustainability' of a building.

Hong Kong Building Environmental Assessment Method (HK-BEAM) was introduced to Hong Kong in 1996 and is an environmental performance based assessment scheme purpose designed for high rise buildings in Hong Kong. This scheme is completely voluntary and is owned by the HK-BEAM Society, a non-profit making organisation consisting of industry professionals. The latest HK-BEAM standards (Version 4/04 and Version 5/04) covers all "New" and "Existing" building types, including office, residential, mall, hotel, school, hospital, institutional and mixed complexes – centrally air-conditioned, naturally ventilated or mixed mode. The HK-BEAM assessment embraces a range of good practices into a pool of criteria using a life cycle approach. The comprehensive assessment framework encompasses exemplary environmental practices in planning, design, construction, commissioning, operation, maintenance, and management. However, more emphasis has now been placed on the wider attributes of a sustainable building, particularly safety, hygiene, security, amenity and overall quality. This approach encourages buildings that fulfil their intended functions whilst minimizing the resulting impacts on the environment. Finally, the scheme provides a benchmark for sustainable buildings and third party recognition to building performance excellence. This paper outlines the latest framework of HK-BEAM, including rationale on the assessment approach and criteria, and a synopsis of its achievements and benefits is also provided. Reference and correlation will be drawn to case studies of buildings which have been submitted for certification.

Sustainable development is a continuous career and a forward-looking business for the future development of human society. Developing a sustainable society requires the recognition and support of all members of the community. It is a top down movement from policy making, system development to task implementation. Recognition of the importance of sustainability starts with the development of a sustainable culture in provision of goods and services. A systematic measurement of the trend of cultural changes would provide valuable information for decision makers, system developers and stakeholders of every industry to formulate their strategy in meeting with the requirement for a sustainable society. This paper provides a method, the T-model, to survey and measure the cultural movement among stakeholders in response of the requirement of sustainable development. The T-model is a mechanism that converts abstract elements of cultural factors into numerical scores and synthesizes them by using a space diagram. The method is verified applicable in a pilot test proceeded in the construction industry of Hong Kong. Data obtained from a questionnaire survey of the pilot test were analyzed by the T-model and provided the result of cultural shift of the construction industry of Hong Kong.

The article pays close attention to the regional climate features and the particularity of the community in Shanghai and cities around. In order to realize ecologicalization in the mass construction of high-rise housing, the multi-objective programming strategy is put forward which enables us to meet the demands of different time, season and residence in different high-rise houses. The optimization strategy grades, rearranges and serializes energy consumption to raise its efficiency. In this serialization, the use of new energy resources ensure the enhancement of comfortableness of high-rise housing, creation of healthy, harmonious and comfortable community and while reducing the conventional energy consumption simultaneously.

Throughout history, buildings have been interrelated with certain indigenous characteristics such as regional climate, culture and religions. In particular, the control of regional climate has been primarily a concern for compatibility with nature. In our modern age, technologies to control climate have been successfully developed in architecture but the consumption of large quantities of natural resources can also produce environmental problems. This study is based on the proposition that this negative trend can be minimized with architectural design that is motivated to coexist with a regional climate. This study develops these design strategies for tall office buildings by analyzing various combinations of building design configurations based on regional climates. The objective is to determine the optimum architecture of tall office buildings during the initial design process that will reduce energy consumption for regional climatic conditions. The eQUEST energy simulating program based on DOE-2.2 was used for this comparative analysis study of the energy use in tall office buildings based on architectural design variables and different regional climates. The results are statistically analyzed and presented in functional architectural design decision-making tables and charts. As a result of the comparison of architectural design consideration for tall office buildings in relation to regional climates, buildings physically need less energy consumption when the architecture is concerned with the regional climate and it produces a more reasonable design methodology. In reality, imbalanced planning which is architectural design's lack of regional characteristics requires additional natural resources to maintain desired comfortable indoor conditions. Therefore, the application of integrated architectural design with regional nature should be the first architectural design stage and this research produces the rational. This architectural design language approach must be a starting point to sustaining long-term planning.

Natural lighting and ventilation have long been a primary consideration in building design, particularly for those high-rise and densely packed apartment blocks where mechanical ventilation is normally secondary. In Hong Kong, there are prescriptive legal requirements governing the provision of natural lighting and ventilation in private buildings. This, coupled with developers' profit-maximizing incentives, often gives rise to re-entrant designs commonly found in apartment buildings in Hong Kong. Despite the popularity of re-entrants, little research has been done to evaluate the preference of homebuyers for them. Moreover, the revelation of the chimney effect of re-entrants by the mass outbreak of Severe Acute Respiratory Syndrome (SARS) in Amoy Gardens in 2003 might have influenced homebuyers' preferences. This paper aims to study the economic impact of the disposition of re-entrants on property prices. Based on the hedonic pricing analysis, we found that the preference for re-entrants is floor-dependent. Before SARS, homebuyers were not fond of re-entrants on low floor levels, but they were willing to pay more for re-entrants as the floor level increased. Yet, the outbreak of SARS did not significantly change their preferences for re-entrants.

This paper seeks to address the potential of the bioclimatic approach for improved energy efficient design and better comfort condition for the occupants in a hot humid climate in typical high-rise office buildings. An awareness of the need to conserve and minimise energy needs for heating and air-conditioning of buildings has arisen as a result of the energy crises. High-rise buildings which originated from North American are now found in almost every major city around the world, especially in the developing countries of Asia. The bioclimatic approach is concerned with problems of energy usage, air quality, amenity provided by the building to its users, and productivity, which can be affected by the environmental conditions in the building. The synthesis of all these listed important aspects is directly linked to the comfort criterion for the occupants.

The development of lift technology has contributed significantly to the history of tall building. Lifts are used in almost all buildings of more than a few stories high throughout the world as an effective and quick means of vertical transportation. To meet the demand of building's occupants on vertical transportation particularly in tall buildings, good vertical traffic analysis and planning as well as proper selection of vertical transportation equipment are very crucial. Apart from these, there are other important standards like lift ride comfort, fire safety in lift as well as monitoring of lift services that require to be addressed to. This paper discusses the recent development in the aspects of lift ride comfort, insulated lift doors for improving fire safety, and common protocol for communication with the central control and monitoring system.

High-energy-consumption (mainly for air-conditioning and heating) now is one of the general problem in high-rise buildings in cities of China. With the increasing number of high-rise buildings year after year, a new architectural design and research subject is that how to use advanced and applicable technology to high-rise buildings turning high-energy consumption to low-energy consumption, promoting energy efficiency, and solving the problems such as light and thin exterior cladding, poor insulation property, small thermal capacity and storage coefficient and poor thermal stability. This article tries to put forward an energy-saving technical system of improved thermal environment and low energy consumption with research of architectural design building construction and thermal and equipment system.

Organisations can develop and implement a range of strategies, from reactive to proactive, to address environmental issues. This paper examines how the firms perceive the expectation of different stakeholders and integrate them into their company strategies to enhance the competitive advantages. Stakeholders do not only include shareholders, customers, employees but also government and communities. Effective stakeholder management can constitute intangible, socially complex resources that may allow the firm to outperform competitors in terms of long-term value creation.

Maintaining acceptable indoor air quality (IAQ) has become a public issue, policymakers have had developed strategies to address the performance of it. Pollutant concentration measured during the occupied period of a space is a key parameter to determine IAQ. Apart from a number of sampling schemes concerning the measurement time of the average pollutant level, an 8-hour continuous measurement has been widely adopted in local IAQ assessments, with a balance of accuracy and measurement effort. It is believed that the longer the measurement time, the higher the accuracy and confidence level of the measurement can be achieved. However, the probable errors of the measurement, regarding the number of measurement points, were not addressed clearly in those assessments. This study, taking a long-term carbon dioxide measurement in a typical open-plan office building as a reference, develops a database to examine the probable errors of the measurement at different sampling point densities. The results showed that there was a strong correlation between the sampling point density and the probability of obtaining the measured quantity at certain confidence levels, Moreover, the confidence level in determining the indoor air quality in the occupied period for a ventilated space could be increased from 70% to 90% at a 5% error set limit when the sampling points were doubled to the one recommended in the HKEPD certification scheme.

To reinforce the position as Asia's World City, it is a critical time for us to organize Hong Kong as a Super Sustainable City. The key to fuse the three elements of a Super Sustainable City is by utilizing nature-connecting environmental technologies to maximize the sustainable use of resources. The technology of microorganisms, geothermal heat pump, mechanical biological treatment together with a few kinds of renewable energy are introduced in this paper to demonstrate a road for us to move towards a Super Sustainable City.

This paper describes the development of a Life Cycle Assessment tool for commercial buildings in Hong Kong. The study was commissioned by the Electrical and Mechanical Services Department in the interest of promoting sustainable construction. A computing tool was developed that facilitates building professionals to input the required data to model building design; perform calculations of the environmental impacts, operating energy and life cycle cost of the building; and to compare the impacts and costs of alternative designs. The tool features a user-friendly processing template, with design-oriented data-entry sheets and informative reporting documents for the application of the construction industry in Hong Kong.

Over the last ten years issues of sustainability, energy efficiency and pollutions have become increasingly popular within the building industry. However, since the major energy efficiency involves large scale of investment in which various risks induced, the success generally depends on the leadership, top level commitment, technological and legal support both from private to public sectors. This paper discusses the prerequisites for introducing a successful energy saving performance contracting (ESPC) in hospitals. The paper also explores the considerations of applying the ESPC and the cost-benefit analysis of implementation of ESPC while comparing with the concept of sustainable buildings.

Set against background literature from disciplines as diverse as health, housing, urban development and the natural environment, this paper draws on the findings of an Australian study to explore the impacts of differential levels of access to nature on the health and wellbeing of inner city highrise residents. The paper identifies key factors influencing health and wellbeing outcomes, and suggests that access to nature is essential if health and wellbeing is to be optimized.

The supply of super-tall living units in Tokyo area in 2005 is estimated as over 10,000 household units and the total number of supertall livings equal to or higher than 30 stories will be already over 60,000. This paper will point out the problems of supertall living such as the difficulty of evacuation in emergency, isolation of children and aged people from the surface community, some other physical and mental bad effects on the human health, and so on, and also introduce the technological efforts to overcome those problems.

In Asia, Hong Kong and Singapore are distinguished by their high-rise public housing development. While high-rises are criticised and often viewed as unpopular places for family living elsewhere, these cities have consistently registered high residential satisfaction. Over time, an increasing proportion of the population has moved to live high-rises and at ever-increasing height. In Singapore, for example, the current plan is to continue to build more 40-, 50- and 70-storey housing. More people will in the near future be living on higher floors. Drawing on research findings of Singapore public housing residents' lived experience in the 30-storey blocks, this paper aims to explore the occupants' willingness and preference to live higher.

The paper attempts to ascertain the impact of age segregation on the quality of life of the elderly who are living in high-rise studio apartments in Singapore. After a review of the relevant literature and statistical analysis of a survey data for 390 elderly respondents in high-rise studio apartments, it was found that age segregation have a deleterious impact on the quality of life of the elderly. Furthermore, it was found that the perception of the elderly in relation to factors that are most significant to their quality of life is at variance with that of the policy makers. This implies that there is a need for policy makers and service providers to review their existing policies, products and services so as to be more effective in providing housing options for the rapidly aging population of Singapore. Although the elderly are comfortable with high-rise living, super high-rise living may cause affordability and safety concern.

Views are elusive entities that have positive values but difficult to define. Absence of a legal instrument by which the value of view rights can be optimized, rapid development of an area can bring the tragedy of common to views in that even though a view can always be recreated by being the first in the front, the view of each location will have a lower expected life. View rights, on the other hand, may not be practical to implement both because of the high cost of defining it, as well as the possible subsequent transaction costs of negotiating for development rights from the prior holders of view rights. City ordinances may or may not explicitly address to this issue, ranging from a regime of no recognition of any form, to a blanket prohibition of any new developments. Regulatory measures can also be set in place; but if view regulations are legislated vaguely, they can lead to rent seeking behavior. The city of Vancouver in B.C. Canada will be hosting a Winter Olympic in year 2010. Ranked by several magazines as the most livable city in the world, the rapid development of waterfront downtown area poses a challenging problem for the city planner and the developers in the city. A case study of how various issues on views are handled and resolved for the waterfront view of Vancouver will be useful for other cities of the world to be used as reference.

We advocate that solving externalities problems is the key to sustainable development. In this paper, we demonstrate how innovations in architectural design can help to internalize externalities. In spite of modern advances in the washer/dryer technology, a cultural habit of Chinese families is to dry clothes in open or airy areas such as their balconies. For congested high rise buildings in Hong Kong, such activities may or may not be considered as nuisance (negative externalities) by neighbors who share similar cultural preferences, but they may create an unpleasant sight even for a building sparingly spotted with cloth drip drying in the outside. Cloth drip drying by hanging can cause negative values to the building and buildings close by, and can discourage potential buyers with strong aesthetic preferences. Condominium by-laws concerning the type of things that can be put in the balcony of a building are often found in western cities; but for communities that have large number of people in a building wanting to drip dry their clothes, by-laws prohibiting cloth hanging outside the building may not be easy to enforce. This paper argues that innovative architectural design can help improve aesthetic concerns without rejecting a "national flags" habit. In other words, externalities problems can be resolved by innovative design by "having the cake and eat it too". Designing institutions that rewards architects who produce design solutions that help to solve externality issues a major step forward towards creating sustainable cities.

Emergency evacuation is always a primary concern in the safety system design for high-rise buildings. Minimum requirements on egress provisions have been stated in prescriptive codes in different countries. These evacuation provisions for buildings are considered effective to cater for most of the traditional emergency situations like building fires. In recent years, the community becomes more concern about the possibility of total building evacuation under the terrorist attacks or natural disasters. Traditional code requirements and provisions in terms of evacuation are not sufficient to handle these new situations. There is a particular concern for high-rise buildings since the existing egress provisions may be difficult to ensure that total evacuation can be carried out effectively and in a timely manner. One of the solutions is the use of lifts as a means to escape. Although lifts have been proved to provide a safe form of vertical transportation during normal operation, there are some concerns about using lifts in emergency evacuation, such as the complex nature of lift operation and the perceived adverse effect by smoke, water and heat on lifts. This paper proposed and discussed a total building evacuation design using lifts as a supplementary means of escape. The proposed design consists of combining stair evacuation from typical floors to refuge floors with lift evacuation from refuge floors to street level. The effectiveness of the proposed design has been characterized on a proposed super high-rise building with the use of evacuation lifts in multiple floor zones. The results showed that the total building evacuation time could be shortened significantly for both cases using single deck or double deck evacuation lift. This total building evacuation design using evacuation lifts can be integrated into new buildings to enhance the safety without significant changes to traditional evacuation strategy and heavy investment in safety provisions.

Nowadays, small high-rising flats have become a hotspot in the real estate market. In the design of small high-rising flats, a challenging task is to fulfill the critical demands on high quality life of single white-collar people and DIINK families by creating cozy, comfortable and functional space. This paper looks into several typical small high-rising flat buildings in Shenzhen in terms of overall layout, model design and space usage to discuss the optimization of the space of small flats and the ways to fulfill the users' demands and to reach the developers' profit goals.

In many cities around the world, inner-city living is seen as a vital factor in the success of an urban centre. In recent decades in the UK, however, British cities have seen a migration of inhabitants away from the city to the suburban periphery. In an attempt to counteract this, several cities have recently created high-density/high-rise, inner-city schemes. The relationship of many of these buildings to their urban setting however – as with most tall buildings the world over – leaves much to be desired. This paper outlines the findings of experimental design research, under the directorship of the author, in the field of tall buildings and their essential relationship to 'place'. In doing this, it embraces essential strategies of mixed-use, environmentalism and increased urban connections.

Singapore is embarking its next phase of growth as the Urban Redevelopment Authority (URA) has initiated plans and goals of creating a more dense mix of uses in the business area of the city. A substantial portion of this growth is occurring on reclaimed land just east of the city's Central Business District — and will further strengthen Singapore's presence in the vast enterprise of Asia. This paper documents a major residential development project: The Sail @ Marina Bay — and will discuss the design of this iconic residential tower; its economic, social, and cultural implications and show how substantial transformations may occur as a result of a strong design vision.