Monitoring and numerical simulation of deformation of retaining structure in subway station foundation pit

Based on some urban subway station foundation-pit project,retaining structure of the foundation pit and its deformation monitoring program are designed;in-situ monitoring data of the retaining structure deformation in the foundation pit are analyzed.The laws of the horizontal deformation of the retaining structure changing with the excavation depth and time are studied.Elastoplastic finite element model is built to do construction simulation calculation of the station foundation pit;FEM results and in-situ monitoring results of retaining structure deformation are compared;and sensitivity factors analyses of the foundation pit deformation are done with a variety of retaining structure form.The results showed that:the retaining form with steel support and supporting pile has good limit to the lateral deformation of the foundation pit soil.The results calculated by FEM are consistent with the in-situ monitor results;it is shown that the results of finite element analysis is credible;it plays an important role in limiting lateral deformation by change the position of steel support;with the increase of supporting pile insertion depth;the soil deformation trending to the foundation pit inside is slowed down somewhat.