Support Design Practice of Foundation Pit in Soft Soil Area in Nanjing
Based on a foundation pit construction project in Nanjing,this paper analyzed the optimization of the design methods under different external environmental protection requirements and excavation depth.According to the monitoring results of the foundation pit,the applicability of cast-in-place piles,soil-mixing walls with pipe piles,horizontal concrete supports,and steel pipe diagonal braces was evaluated.The results show that both soil mixing wall with pipe piles and cast-in-place piles can effectively restrict the deformation of the foundation pit,but soil-mixing walls with pipe piles have advantages in cost and construction period.The application of diagonal braces in soft soil areas should be cautious,by reason of which higher requirements of design and construction quality is needed.