摘要
Abstract
The cofferdam of the No.2 bridge pier of the E ramp of the Qijiang New Bridge on the South Zhongshan Expressway is a steel sheet pile cofferdam in water,with a planar dimension of 9.6m×9.6m.It is basically located in the silt soil layer,with a digging depth of 8.7m,which belongs to deep foundation pit construction,and the safety risk is classified as a first-level foundation pit.The planar dimension of the foundation pit is not large and it is a square foundation pit,so the support structure is simplified.However,the geological conditions in the bridge site area are complex,with thick silt layers and high water content.Therefore,the stability of the foundation pit and the support struc-ture needs to be verified from aspects such as foundation pit stability and the safety of the support structure.According to the design drawings,a finite element model is established to simulate the foundation pit excavation conditions,and the stability of the foundation pit and the support structure is analyzed from aspects such as the displacement of the surrounding soil,the deformation and stress of the steel sheet piles,and the axial force of the supports.The results show that the maximum horizontal displacement of the soil during excavation is 9.48 mm,the maximum deformation of the steel sheet piles is 13.7 mm,the maximum stress of the steel sheet piles is 81.3 MPa,and the maximum axial stress of the supports is 18.2 MPa.All are in a safe state.The results indicate that the foundation pit and the support structure are in a stable state,and the support scheme is safe and feasible.关键词
钢板桩/软土基坑/安全性验算Key words
Steel sheet piles/Soft soil foundation pit/Safety verification分类
交通工程
