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Erosion of the nourished beach in Bethany Beach in Delaware is examined using available beach profile, wave and tide data during September 2007 to September 2010. The volume of the placed sand with the median diameter of 0.31 mm was about 500 m³/m along the curved shoreline of 1.8 km length. The placed sand volume along this shoreline decreased to approximately 30% for the duration of 2.5 years. The nourished beach was attacked by two severe storms in May 2008 and November 2009. The eroded sand volume above the mean sea level (MSL) was about 70 m³/m for each of the two storms and emergency repairs were necessary. The recovery after the first storm was about 8 m³/m above MSL and much smaller than the eroded volume probably because the large placed sand volume resulted in the relatively steep eroded profile below MSL. The numerical cross-shore model with multiple cross-shore lines is used to compute the cross-shore and longshore sediment transport. The decrease of the placed sand volume is found to be caused partly by the increase of the longshore sand transport in the downdrift direction. The beach erosion by the two storms is shown to be caused by the offshore sand transport and the alongshore gradient of the longshore sand transport rate. The small recovery after the first storm is difficult to reproduce without increasing the onshore bed load transport rate by a factor of 2.

The UN defines 17 Sustainable Development Goals (SDGs). Quality Management (QM) should logically be an asset for sustainability in supporting systematic changes to achieve these goals. Synergies between quality and sustainability have been discussed but it seems that considerable synergies are yet to be realised. Finding practical examples for synergies will be essential. Buildings play an important role in sustainability. Most new buildings are constructed in developing countries. Buildings provide the basic need for shelter but are also a major source of carbon emissions. Africa, with the youngest population, will need large-scale building activities to comply with the UN SDGs. Buildings, globally and in developing countries, could be an interesting research area for identifying potential synergies between quality and sustainability. The purpose of this paper is to exemplify quality theory’s contributions to sustainability. Possible synergies are highlighted based on the processes of global cement manufacturing and building block production in Dar es Salaam, Tanzania. A brief review of suggested synergies between quality and sustainability was conducted. Chosen models used for describing synergies were reviewed. These models have then been applied to the global process of cement manufacturing and a regional process of block production. The resulting presentations are analysed and areas of synergies are identified. Our findings indicate that quality theory could provide strong support, generally for sustainability and specifically for better buildings. The work indicates several interesting areas of possible synergies between quality and sustainability. New insights are presented for how QM could support sustainable development.

The triaxial tests of sand were simulated by PFC3D (particle flow code in three dimensions). The slip model is used to constitute samples of sand. The slip model provides no normal strength in tension and allowes slip to occur by limiting the shear force. Preliminary study on mechanical properties of the sand is done by PFC3D numerical simulation through endowing appropriate micro-properties. Good agreement between the results of numerical simulations and laboratory tests is shown. Macro properties of sand samples with various input parameters of particle elements are presented, and the results are valuable for developing sand constitutive models. It is shown that the microscopic parameters of sands affected markedly the macroscopic response of sands. The meaning of this research lies in the fact that PFC mode could break through the limits of real lab tests and make the microscopic research of sand possible.

The steady state line, SSL for sandy soil moves downward with increasing fines content, f_c up to a limiting f_c, then it moves upward with increasing f_c. Thus, one cannot have a single framework within critical state soil mechanics, CSSM. However, equivalent granular void ratio, e* instead of e was proposed by many researchers to achieve a single framework based on the studies on a host sand with a single fines type. But, the effects of fines type have not been studied in details. This paper discusses the effects of fines type using triaxial tests on a host sand with two types of fines. The experimental results are then synthesized in terms of e*. The prediction approach is used to obtain e* instead of back analysis as reported in many publications. A single trend for SS data points is achieved in e*-log(p′) space irrespective of fines type. The effective stress path and stress-strain behaviour for clean sand and sand with two types of fines are consistent within a CSSM framework.

Natural disasters like landslide, mudflow and debris flow often cause catastrophic failures in civil infrastructure and may give rise to high rates of strain (10²-10⁴/sec) in soil. Rate of induced strain (or stress) plays a significant effect on the strength and stiffness of soil. In this paper, we investigate the high strain-rate behavior of sand by developing a rate-dependent, multi-axial, viscoplastic two-surface constitutive model. The model is based on the concepts of critical-state soil mechanics. Perzyna's overstress theory is incorporated in this model to reproduce viscoplastic behavior of sand under high loading rate. Nonassociated flow rule is considered. The rate-dependent model parameters are determined from experimental data of split Hopkinson pressure bar test under high rate loading. Model performance is demonstrated for different sands.

The main objective of this laboratory project is to investigate the effectiveness of using polyamide grout injection on sand improvement. Soil samples with different dry densities in their loose, medium and dense state (cylindrical shaped) with 5cm diameter and 10cm height are subjected to polyamide injection. In order to investigate the grout injection effect on soil's strength, the specimens are subjected to one dimensional unconfined compression tests. We know that polyamide doesn't mix with water and we should mix it with citric acid. It has been observed that by increasing the polymer percent in polymer-water-citric acid mixture grout, the soil compressive strength and elastic modulus has been improved significantly. In general denser sands presented higher compressive strength and elastic modulus in comparison with looser ones in same polymer percents.