Numerical Simulation And Prediction Analysis Of Deep Foundation Pit Deformation

Deep foundation pit engineering has the characteristics of complex geological conditions,high technical difficulty,the risk of large,deep foundation pit excavation often lead to settlement of surrounding soils and supporting structure deformation,nearby building deformation phenomenon,if improper handling can easily lead to accidents,resulting in serious economic loss and bad social influence.There are many methods for the stability analysis of deep foundation pit engineering which numerical simulation analysis and deformation prediction are the two most common methods.The combination of finite element numerical simulation and time series prediction method to analyze and forecast the soil around the deep foundation pit supporting structure and Tianhuiproject.The deformation rules of foundation soil and supporting structure under different working conditions are studied.The prediction effect between different prediction methods is compared and analyzed,and some conclusions that have certain guiding significance for engineering practice are obtained.The main contents and conclusions are as follows:(1)The theory of soil and foundation retaining structure is summarized,and the design scheme of foundation pit is analyzed.The safety regulations for foundation pit excavation and the determination principles of various alarm values are introduced.(2)The geological conditions,design scheme and excavation process of deep foundation pit are introduced in this paper,which provide reliable basis for the follow-up numerical simulation.(3)The finite element software ABAQUS is used to simulate the foundation pit by numerical simulation,and the support structure and the deformation law of foundation pit soil under different working conditions are obtained.By comparing the numerical simulation results and monitoring data,the validity of the finite element numerical calculation is verified,and the basic deformation law of the foundation pit is summarized.(4)A time series analysis and prediction method based on improved least squares and BP neural network is put forward.It predicts the deformation of the soil around the foundation pit,the displacement of the slope and the displacement of Wacom beam.The prediction results are compared with the improved least square method,the BP neural network and the monitoring data,and the feasibility and accuracy of the prediction model are verified.