Considering The Spatial Effect, The Foundation Pit Pile Anchor Support Deformation Study

The foundation pit is a3 D spatial structure system with length,width and depth.In the design process of foundation pit,designers often consider it as 2D plane problem.But the spatial effect of foundation pit excavation can not be completely reflected,so it's very important to analyze it from three dimensional perspective.In this paper,a three-dimensional model of foundation pit excavation is established by using the finite element software ABAQUS.The model takes into account the interaction between the soil and the retaining structure after the wall,and makes a systematic study of the spatial effect of the foundation pit.The horizontal displacement of the supporting structure and the distribution of the earth pressure with the space position are analyzed in the process of the excavation,and the different geometry is also studied.The size of foundation pit,its support structure displacement and earth pressure distribution.The results of the analysis show that:(1)The foundation pit excavation has a strong spatial effect.In the process of foundation pit excavation,the deformation of the foundation pit reaches the minimum value at the corner of the foundation pit.With the greater displacement to the middle of the foundation pit,the greater the deformation,the deformation reaches the maximum value in the middle,and the soil pressure of the supporting structure gradually decreases from the pit angle to the middle part.(2)The deformation of the foundation pit supporting structure and the distribution of soil pressure have obvious spatial effect: the deformation of the pit corner is smaller,the soil pressure is larger,the deformation in the middle of the foundation pit is larger and the soil pressure is relatively small.(3)The geometric size of foundation pit has great influence on the deformation of foundation pit.When the length width ratio of foundation pit increases gradually,the influence of spatial effect on the supporting edges of foundation pit gradually decreases.In the analysis and calculation,it is concluded that the ratio of the length to width of the foundation pit can be introduced.When the ratio of the length to width ratio of the foundation pit exceeds the critical length width ratio,the calculation results gradually become close to the fixed value,that is,the spatial effect is weakened.Finally,the numerical simulation of a partial support section of a practical projectis carried out by ABAQUS,and the results of the analysis are compared with the calculated results,and the applicability of the model is verified in a certain range.