Narrow Results

The design of lateral load resisting elements of tall buildings in regions of low to moderate seismicity is normally governed by the requirements to meet inter-storey drift limit under wind load. The key objective of the design of tall buildings is to provide adequate lateral stiffness to the buildings to limit their lateral deflections and inter-storey drifts under the lateral load. The current design practice assumes that only the structural skeleton provides lateral resistance against wind load. Although the effects of nonstructural elements on the lateral stiffness are widely acknowledged, the effects are often ignored in the analysis of the buildings. This paper presents a state-of-the-art of review on the effects of nonstructural elements on the lateral deflections and inter-storey drifts of buildings at serviceability limit states. It was found that ignoring the nonstructural elements could significantly underestimate the lateral deflection for certain types of buildings. However, the shape and form of the lateral deflection in the overall building is not significantly affected by the nonstructural elements.

Following the empirical-computational methodology, the contemporary investigations deal with inelastic stability and dynamics of concrete beam-columns. Even under service loads, the concrete structures exhibit physical nonlinearity due to presence of axio-flexural cracks. The objective of the present paper is to analyze the static and dynamic stability of conservative physically nonlinear fully cracked flanged concrete beam–columns. In this paper, using proper reference frames, analytical expressions are developed for the lateral displacement and stiffness of a flanged concrete cantilever under axial compressive and lateral forces. Two critical values of both the axial and lateral loads are identified. For constant lateral force smaller than its first critical value, the concrete beam–columns exhibit brittle buckling mode. Higher lateral forces lesser than the second critical value introduce alternate stable and unstable domains with increase in axial force. The lateral stiffness is predicted to vanish when the axial loads reach the critical values and when the limiting displacement is reached for axial load exceeding its second critical value. The load-space is partitioned into stable and unstable regions. Accessibility of these equilibrium states in the load space has been investigated. Such distinguishing aspects of the predicted behavior of elastic concrete beam–columns are discussed. Their dynamic stability is investigated in second part of the paper.

In regions of low to moderate seismicity, serviceability limits states such as inter-story drift under wind load govern the design of the lateral load resisting structural systems of high rise buildings. The key objective in this regard is to provide adequate lateral stiffness to control lateral deflections and inter-story drifts. Current design practice assumes that the structural system alone provides lateral resistance against wind, the dominant load considered for countries like Australia. The contribution of nonstructural components (NSCs) such as interior partition walls on lateral stiffness is generally disregarded in the analysis of the buildings, even though it is commonly acknowledged that the NSCs play a significant role on the lateral stiffness of buildings. This technical note presents the results of a parametric study on the effects of NSCs, in particular, the effects of masonry interior partition walls on the fundamental period of buildings. The parameters considered in this study include: the number and length of walls, their material properties, the number of parallel moment resisting frames and the height of buildings. The results of this study indicate that interior walls can have significant effects on the lateral stiffness of buildings.

Regarding as lateral problem that is occurred when heavy vehicle turns because of no transverse stability rod attached, lateral stiffness calculation and experimental were researched. The gas pressure, vertical stiffness and lateral stiffness formula were deduced through real gas state equation. By program anaylsis, it was concluded that vertical stiffness of interconnected structure was equivalent to that of independent suspension, but lateral stiffness was multiplied when turning. Through real vehicle tested, lateral angles of vehicle body of two suspension forms were compared. It was verified that vehicle handling and stability performance are improved when suspension system is interconnected.