Research On The Horizontal Bearing Capacity Of Pile-wall-anchor Combination Foundation Under Surcharge

For the viaduct,industrial plant and other buildings,due to the limitations of the surrounding environment and construction conditions during the construction and use,they are often stored in a large area around the buildings.The lateral surcharge will not only lead to the uneven settlement of the soil around the foundation,but also cause the compression deformation of the soil around the foundation under the influence of the surcharge,and then cause the additional horizontal force of the lateral displacement of the soil,resulting in the lateral displacement and deformation of the adjacent foundation.In view of the relevant research of the existing foundation,this paper proposes a new type of composite foundation-pile underground wall anchor composite foundation(hereinafter referred to as pile wall anchor composite foundation).Based on the overall stress analysis of the pile wall anchor composite foundation,and using the finite element calculation principle to compile matlab program to solve the stress and deformation of the composite foundation,this paper analyzes the influence of different factors on the stress and deformation of the composite foundation;further carry out the indoor model test of the pile wall anchor composite foundation,and use PLAXIS The 3D finite element software is used for numerical simulation,and the results of indoor model test are verified and supplemented by numerical simulation data,so as to reveal the horizontal bearing characteristics and deformation law of the new composite foundation under the action of surcharge load.The main work and achievements of this paper are as follows:(1)In this paper,the research status of pile foundation,diaphragm wall foundation and all kinds of composite foundation under surcharge at home and abroad are summarized,and the research methods and results are classified and summarized.On this basis,the pile wall anchor composite foundation is put forward,and its research content and method are clarified.(2)Based on the preliminary stress analysis of the pile wall anchor composite foundation,the displacement and internal force of the composite foundation are solved by using the finite element method and matlab program,and the parameter settings are further changed.The influence of different working conditions,such as load size,bolt length,bolt diameter and whether there is bolt,on the stress and deformation law of the composite foundation structure is analyzed.(3)Through the establishment of test scheme and the selection of appropriate test materials,the indoor model test of pile wall anchor composite foundation under the action of surcharge is further carried out,and the displacement characteristics,bending moment of pile wall body,axial force of anchor bolt and distribution characteristics of earth pressure of composite foundation under different load levels are monitored.(4)The numerical model of pile wall anchor composite foundation is established by using the finite element software PLAXIS 3D,and the numerical results are compared with the model test results to verify the accuracy of the indoor model test results.Further,the displacement of the composite foundation,the distribution of the bending moment of the pile wall body,the axial force of the anchor bolt and the displacement field of the soil around the composite foundation are analyzed.At the same time,the pile wall anchor composite foundation and the pile underground wall composite foundation are compared and analyzed,and the restrictive effect of the setting of anchor on the composite foundation is revealed.By changing the parameters of the numerical model,the influence law of the factors such as the loading level,bolt length,bolt diameter and bolt location on the horizontal bearing capacity index of pile wall anchor composite foundation is explained.