Numerical Simulation And Deformation Analysis Of Deep Foundation Pit Construction In Subway Station

With the continuous advancement of Chinese urbanization process,a lot of development of the space under the city,the deep foundation pit project keeps emerging.Under the influence of complex factors such as construction technology,hydrogeology and surrounding environment,how to ensure the safe and orderly construction of foundation pit construction is the focus of the research of foundation pit engineering.This paper,taking Dalian subway station subway line 5,Qingniwa bridge as the research object,proposed,using the deep foundation pit construction process numerical simulation method and the application of Markov chain prediction model for the deformation of deep foundation pit engineering in-depth analysis and research,in order to forecast the deformation of deep foundation pit,ensure the safety of deep foundation pit engineering orderly.The research contents of this paper include the following aspects:(1)According to the characteristics of the deep excavation of metro station itself and the surrounding environmental factors,through the analysis of the local common type of supporting structure and the suitable conditions,select the reasonable structure of deep foundation pit supporting.(2)In Dalian subway line 5 Qingniwa bridge subway station as engineering background,for supporting numerical simulation analysis of deep foundation pit excavation of a metro station,is mainly studied in the process of deep foundation pit excavation supporting force and deformation of retaining structure and deep foundation pit soil settlement,the apophysis,simulation results show that,in the process of deep foundation pit excavation supporting soil stress,deformation and the deformation of retaining structure can satisfy the requirements of the relevant specification;Will be compared with the measured data of simulation data analysis,results showed that the curve fitting is good,reasonable parameter selection in modeling process,the numerical simulation method can more accurately predict the stress and deformation in the process of deep foundation pit construction,to deal with in the construction process improper deformation has a certain guiding significance.(3)Based on the simulation model,using the method of control variables by analyzing the design parameters of pile embedded depth of solid,pile spacing,pile body stiffness and deformation of deep foundation pit support spacing in the impact analysis,concluded that the soil parameters on the deep foundation pit at the bottom of the surface settlement,the apophysis and the influence law of the lateral deformation of the supporting structure.(4)The deep foundation pit engineering measured data as the original data sequence,set up a variety of GM(1,1)model and Markov chain model to forecast the deformation analysis,and comparing the model relative to the relative error of the measured values,it is concluded that the optimal prediction model,predict the deformation of deep foundation pit.Research results show that the prediction error accuracy meets the actual engineering needs.The prediction method is helpful for the early detection of possible improper deformation in deep foundation pit construction.