Numerical Simulation With FEM On Underground Continuous Wall Supporting Deep Foundation Excavation Of Metro Station

With the development of high-rise buildings and utilization of underground space,deep foundation pit engineering is increasing in depth and scale. Because close citybuilding, complex geological condition and stress redistribution, the deep foundationpit excavation step by step will affect the displacement field and stress field ofsurrounding soil, then will cause the soil surface settlement, horizontal displacement ofsupporting structure and pit uplift. Underground continuous wall with the economicalproperty and good work performance has been widely used in foundation pit.In this paper, by using the ANSYSY14.5large general finite element analysissoftware, using the two dimensional finite element model, the soil usingDrucker-Prager ideal elastic-plastic constitutive model and using the " Element Birthand Death ", in the geologicl condition of soft soil of Wuhan area, numericalsimulation analysis of the whole process of soft soil deep foundation pit engineeringenvironment. By comparing the stress and strain, the soil surface settlement, horizontaldisplacement of supporting structure and pit uplift of the different dig depth finds thechanging rule of in the process of foundation pit excavation the soil surface settlement,horizontal displacement of supporting structure and pit uplift, and the simulationresults are compared with the engineering monitoring data.Although deformation control of the pit dug has made more research in recently,but the study of the surface settlement, horizontal displacement of supporting structureand pit uplift is less. The results of this research can provide reference for practicalengineering design and construction and the related research. The main contents andresults are as following:1. Investigate deformation mechanism and calculation methods of the walldeformation, pit uplift and the soil surface settlement behind the wall, including thetype of retaining structure, deep foundation pit deformation theory and constitutive relation and the ANSYS finite element method.2. The elastic parameters simplifies physical model and modify the elasticparameters of soil to achieve the numerical convergence and soil and undergroundcontinuous wall deformation coordination, using ANSYS elastoplastic model.3. Derive from the displacement, stress nephogram, analyze the stress anddisplacement of support structure and the surrounding soil as a whole, find thefoundation pit uplift, the soil surface settlement, horizontal displacement and soil in theplastic zone development process and scope. Simulate data and actual projectmonitoring data analysis.