Study On Effect And Mechanism Of Partition Wall In Protecting Adjacent Buildings From Deep Excavation In Soft Ground

Deep excavations take place mainly in the urban areas, where a large number of buildings or other structures exist, and environment problems due to excavation become increasingly serious. Although much progress had been made in the area of excavation, the attention mainly focused on the behavior of excavation and the optimization of the support system. The research on active protection methods on decreasing the influence of excavation construction is relatively less. As a technique for protection of adjacent buildings, partition wall has begun to get an application in deep pit engineering. Nevertheless, the design of its parameters still lacks effective theoretical guidance. The research of this thesis concentrated on the effect and mechanism of partition wall. The main works are as follows:(1) 2-D finite elements numerical model relevant to pit excavation was established and several constitutive models widely used in engineering were compared. It was shown that the modified Cam-clay model was more suitable for the analysis of deep excavation. The parameter sensitivity of the MCC model was also analyzed.(2) 3-D finite elements analysis on a excavation case was presented and the effect of the partition wall on ground settlement, horizontal displacement of ground along depths, the angular distortions of the adjacent building, the active earth pressure on the retaining wall as well as the bottom heave of the pit were analyzed in detail. It was shown that the partition wall played an important role in decreasing the response of the adjacent building.(3) Design parameters relevant to the partition wall such as h(depths of partition wall),s(distance between the retaining wall and the partition wall), L(the installation plane range of the partition wall) and EI(stiffness of the partition wall) were analyzed, which can be the basis for the optimization design of partition walls.(4) The 3-D FEA model was employed in a deep pit in soft ground in Hang Zhou. The comparisons between the calculated and measured data validated the effect of the partition wall.