Finite Element Analysis Of Rectification Of Irregular Buildings With The Method Of Horizontal Drawing Out Soil

Due to the influence of factors such as the foundation,the building itself,the outside world and the environment,building tilting accidents have occurred from time to time.For the tilt of buildings,commonly used methods for rectification include: lifting method,resistance-sinking method,forced-down method,adjusted upper structure method,and comprehensive rectification method,among them,the method of drawing out soil in the forced-down method has a wide range of applications.Domestic and foreign scholars have done some research on the method of drawing out soil,mainly focusing on the treatment measures in a rectification process for a specific project,and did not provide the corresponding settlement change rules for key control parameters,nor did they give correct settlement formula under special foundations.Therefore,it is necessary to study the modified settlement formula of the collapsible loess foundation under the effect of uniform distribution and the settlement variation law under the joint action of the foundation and the superstructure,which will provide a certain basis for the study of the theory of follow-up soil rectification.In this paper,ANSYS finite element analysis software is used to establish the finite element model of the collapsible foundation under the uniform distribution force.Based on the 3D finite element model of the interaction between the foundation and the superstructure,the correlative study on the key control parameters of the soil rectification method was studied.The main research content is as follows:(1)Using the finite element model of the collapsible loess foundation under the uniform distribution force,the finite element simulation was performed for key control parameters of different hole diameter(0.1m、0.15m、0.2m、0.25m),hole spacing(1.2m、1.5m、2m、3m),and depth(4m、6m、8m),and the settlement of the measurement point under the influence of the key control parameters was obtained.Settlement change rule in correcting process.Meanwhile,The law of settlement change in rectifying process is analyzed.The correction coefficient is introduced on the basis of the theoretical calculation formula,and the correction coefficient of the correction settlement formula is given.(2)Using the three-dimensional finite element model based on the interaction between the foundation and the superstructure,the finite element simulation of the buildings in the use phase was carried out.The first principal stress,equivalent stress and shear stress in the X and Z directions of each layer of the building were obtained.At the same time,the first principal stress,equivalent stress,and displacement at the measuring point of the foundation and foundation are also obtained.By analyzing the displacementvariation of foundation and foundation in X,Y and Z,the slope of the building under uneven force is described.The influence of the structure on the internal force of the building is analyzed by the first principal stress,equivalent stress and shear stress.(3)In view of the method of drawing out soil to correct the use of buildings,the settlement changes under the influence of different control parameters such as hole diameter(0.1m、0.15m、0.2m、0.25m),hole spacing(1m、2m、3m、4m),depth(21m、23m、25m、27m)and buried depth(2.5m、3m、3.5m、4m)during the correction process of the Lou soil method were simulated and analyzed.By plotting the settlement change curve under the key control parameters,the linear regression equations for the settlement of each axis are obtained,and the problems that the borehole exceeds the neutral axis and the junction between the podium and the main building are proposed.