Deformation characteristics and control for foundation pits in floodplain areas of Nanjing, China

摘要

A comprehensive understanding of deformation characteristics and control measures for large-scale foundation pits in soft soil regions is of increasing importance to their risk assessment, design, and construction. In this study, the influences of the thickness of soft soil on the deformation of foundation pits are discussed based on statistical data from 24 foundation pits in floodplain areas of Nanjing, China. The mean maximum ground surface settlement around the pit in floodplain areas of Nanjing was 0.38%H, and the maximum ground surface settlement was observed at 0.48H. The maximum influence scope of ground surface settlement was about 3.5H, and the average maximum horizontal displacement of supporting structures was 0.23%H. On this basis, a model of ground surface settlement around the pit according to excavation depth for foundation pits in floodplain areas is derived. In addition, the influence scope around the pit and relevant control measures are proposed for the protection of surrounding underground structures and roads.