ABSTRACT
In urban areas, more and more underground space is utilized with the fast development of city construction, and thus a lot of excavation engineering appears. However, the pit deformations induced by excavation greatly influence the safety of not only the pit itself but also the buildings and municipal facilities around it. Therefore, study of the behavior of foundation pits has received much attention. Whittle et al. (1993) described the application of a finite element analysis for modelling the top-down construction of a seven-storey, underground parking garage at Post Office Square in Boston.The results demonstrated that reliable and consistent predictions of soil deformations and groundwater flow can be achieved by advanced methods of analysis without recourse to parametric iteration, but emphasized the need for adequate characterization of engineering properties for the entire soil profile. Vaziri (1996) described a simple, efficient and practical numerical model for analysis of cantilevered and strutted flexible retaining walls. The model had incorporated a variety of features that affected the performance of the retaining walls in the field such as installation and removal of struts, application of
surcharge, changes in groundwater table, changes in soil properties and simulation of staged excavations. The model can be used effectively to perform a broad suite of parametric studies in the design stage and also as a reliable tool for predicting performance. Ou et al. (1996) further proposed a nonlinear, 3D finite element technique for deep excavation analysis. The technique as well as the analytical procedures for modeling the excavation processes were coded into a computer program, and the accuracy of the program was assessed. The case of an irregularly-shaped excavation with field measurements of wall deflection was studied and the results showed close agreement with field measurements. Zdravkovic et al. (2005) studied the effect of excavation on the surrounding areas and provided a detailed assessment of wall and ground movements.
