Study On Consolidation Simulation Of Foundation And Influence Factors Of Lateral Deformation By Vacuum Preloading Method

As an economical and effective foundation stabilization method,vacuum preloading method has been widely used in our country since 1980 s.The mechanism of vacuum preloading and the design calculation method of settlemen t calculation have been studied,but there is still a lack of systematic study on the size of lateral deformation and its influence factors.This paper briefly introduces the practical operation of the vacuum preloading method and the analysis of vacuum preloading reinforcement mechanism and strength change.Vacuum pumping can reduce the pore pressure in the soil boundary and form the pressure difference between the original pore pressure and the pore pressure in the soil boundary,thus occurs seepage,gradually reduces the pore water pressure in soil,so soft soil foundation reinforcement achieve the effect;the vacuum preloading method only when the deformation reinforcement area to lateral contraction,no lateral extrusion results;according to the Biot's consolidation theory,we can get finite element expression equation of plane strain Biot's consolidation;at the same time focus on the related problems of the vacuum preloading method for numerical simulation,including the selection of constitutive relation,the means of plastic drainage plate to the two-dimensional equivalent sand wall foundation.By using ABAQUS to establish the finite element model of the soft soil foundation,the Drucker-Prager model is used to calculate the effect of the vacuum preloading method,and the equivalent load and vacuum pressure are also researched.By means of the finite element method,the influence of these factors on the lateral deformation of the soil is analyzed,including permeability coefficient,modulus of elasticity,vacuum degree under membrane,etc.