Deformation Characteristics of Deep Foundation Pit of Subway Station with Semi-covered Excavation in Sandy Cobble Stratum
The deep foundation pit engineering of subway stations constructed using the semi-covered excavation method often has the characteristics of large construction scale,complex support structure,large excavation depth,and narrow construction site.However,the stability of sandy cobble stratum is poor and it is easy to deform under load,which leads to the accident of foun-dation pit sometimes.Taking a semi-covered excavation station in Chengdu Metro as an example,the surface settlement and uplift,lateral displacement of the retaining structure,and column deformation during the excavation process of the foundation pit are simu-lated and analyzed by using finite element analysis software PLAXIS 3D.Due to the asymmetric excavation of the foundation pit,there are slight differences in the structure and surface settlement deformation on both sides of the foundation pit:The top of the open excavation side shows displacement towards the outside of the pit,while the deep horizontal displacement of the cover excava-tion side retaining pile is greater than that of the open excavation side;the cumulative surface settlement value on the open excava-tion side is smaller than that on the cover excavation side;the vertical displacement of the column during excavation is affected by the combined action of upper load,soil settlement in the pit,and uplift at the bottom of the pit,the upper structure of the column will experience a bow shaped horizontal deformation towards the open excavation side.
sandy cobble stratumsemi-covered excavationdeep foundation pitdeformation
万方数据
维普
