Analysis Of Ground Deformation Caused By Foundation Pit Excavation And Precipitation In A Subway Station

Stress and deformation of the subway station deep foundation pit supporting structure is one of the important research topic in the construction of the subway deep foundation pit,and the settlement analysis of excavation and precipitation coupling of excavated subway station has important engineering application value.The engineering background of this paper,taking a subway station in Changchun,using theoretical analysis,finite element simulation and analysis of monitoring data and other methods to study the influence on the surface of the excavation and precipitation together,Based on the above method to research the get the following conclusion(1)The software of Lizheng deep foundation pit was used to calculate the settlement and deformation of surroundings caused by excavation of the subway station.The results were in accordance with the specification.And the influence of friction angle was analyzed by single factor experiment.With the increase of depth,the horizontal displacement of the pile body increases gradually.Secondly,the bending moment and shear force of the envelope are increased with the increase of the excavation depth,and the maximum moment and shear point are gradually decreased.(2)The three-dimensional model of subway station foundation pit was established by GTS NX software.The excavation and precipitation process were simulated according to the working conditions.The stress cloud and surrounding ground deformation were obtained under the combined action of excavation and precipitation.The results were compared with the monitoring data,the data roughly broadly consistent.The maximum point of surface displacement is 8-12 m away from the foundation pit,and the maximum horizontal displacement of pile is 9 ~ 11.0 m below the ground.Compared with the steel support actual value and the simulation value,the steel support simulation value is found to be larger than the actual value,because the actual steel support construction process,the application of steel support prestressed loss occurred.The forecasting model proposed in this paper is of value for a subway station in Changchun,and it has a certain reference value for predicting the deformation of adjacent excavation excavation of adjacent stations in Changchun area.