Analysis Of Displacement And Soil Pressure Of Pile-anchor Supporting Structure For Deep Foundation Pit

The pile-anchor supporting structure system is applied in the field of deep foundation excavation support because of its good mechanical properties and deformation control function of deep foundation pit.At present,the construction of deep foundation pit is effected by many factors,such as the surrounding environment,supporting structure,it will lead to different deformation of deep foundation pit during the excavation,and it has a strong regional and risk.For the pile-anchor supporting structure system,its stress and deformation are not each other isolated,deformation and soil pressure are coordinate with each other factors,but they are not merely a linear relationship.Therefore,it is the key content to study the development of the deformation,it has a great significance to select reasonable supporting structure and analyze the change of soil displacement and supporting structure and soil mechanics effect during the excavation.Based on the engineering of deep foundation,the author established a 3D FE model by using the large finite element software ADINA.First,the distribution and variation rule of the soil pressure on the pile-anchor supporting structure are analyzed and studied,which include the different prestressed anchor and anchor angle and different parameters of soil;Then,analysis considering the interaction of pile,anchor and soil,using the relationship between the deformation coordination and failure mode on the pile-anchor system,considering the displacement variation rule of horizontal and vertical direction of soil during the foundation pit excavation,analyzed the displacement of pile top due to the different prestressed anchor and anchor angle.This paper mainly from the following aspects:(1)First,based on a practical foundation pit engineering model,simulating and analyzing the foundation pit under different working conditions,analysis for the distribution of soil pressure due to prestressed anchor and anchor angle,and summarizes their respective conditions and the distribution rules;Then,through the simulation analysis the effect of soil pressure due to the cohesive soil strength,elastic modulus,internal friction angle and poisson's ratio,and get the sensitive degree and the distribution variation rule for the soil pressure,in order to provide reference for simulating the stress change of soil in the same area.(2)Numerical model of deep foundation excavation is established using ADINA software,Mohr-Coulomb model is put to use for constitutive model of soil,pile and anchor are stimulated by structure element.Analysis for the horizontal and vertical displacement of soil during the foundation pit excavation,the influence on displacement of pile top due to different prestressed anchor and anchor angle and get the change regulation according to the horizontal and vertical displacements of foundation pit under different working conditions,the change rule of the influence of anchor prestress and anchor angle on the displacement of supporting structure,it provides a reference for the reasonable selection of prestressed anchor and anchor angle of pile-anchor supporting structure for deep foundation pit.