Analysis On Deformation And Internal Force Of Foundation Pit Of Pile Anchor Supporting Structure

Due to the increase in the number and density of urban populations,many problems have been brought to cities.Improving the efficiency of land use can alleviate these problems to some extent.Therefore,many large-scale underground buildings have been built in large cities in China.These projects involve deep foundation pit projects.At present,the traditional theories used in the design of foundation pits in China still have deficiencies.At the same time,the emergence of many professional calculation software can be used as a reference tool in the design of support for foundation pit projects.Based on the research background of a foundation pit project,this paper has done the following work:1.Through the analysis of the monitoring data of the foundation pit engineering,it is found that the displacement value of the slope top of the foundation pit continues to change after the excavation of the foundation pit.Therefore,it is necessary to pay enough attention to the time effect of the foundation pit when designing similar foundation pit cases.2.The FLAC3 D software is used to simulate the three-dimensional numerical simulation of the selected position of the foundation pit.The distribution changes of the soil displacement,the bending moment of the supporting pile and the axial force of the anchor rod under various working conditions are recorded.The simulation results and the monitoring results are compared and analyzed.Through the comparison,it is found that the results of the horizontal displacement of the slope top and the axial force of the anchor rod simulated by FLAC3 D software are in the change trend and variation It is in good agreement with the monitoring data.3.By changing the parameters of supporting structure and simulating the deformation of the foundation pit under different design conditions,the final deformation of the foundation pit is analyzed.It is found that when the diameter of the supporting pile increases,the maximum horizontal displacement of the side wall ofthe foundation pit can be reduced to a certain extent;when the horizontal displacement range of the soil behind the wall is large,the anchorage length and incident angle of the anchor rod can be effectively limited Development of horizontal displacement of side wall of foundation pit4.In this simulation of the foundation pit engineering,the soil displacement near the corner of the foundation pit is simulated and compared by two models.The simulation results show that the horizontal displacement value of the foundation pit slope top of the two models is very small at the end of the foundation pit excavation.The maximum error of the horizontal displacement value of the side wall of the foundation pit at the 5-5 profile is 3.7%,which proves that the soil around the corner of the foundation pit is improved The improved model can be used to predict the horizontal displacement of the side wall of the foundation pit.5.On the basis of the original simulation method,by adding the contact surface on the side wall of the foundation pit,changing the vertical displacement of the surrounding soil,taking the friction angle of the contact surface as the research object,the simulation results of different friction angles are compared with the monitoring results,which proves that this method is more reasonable in predicting the displacement of foundation pit.