An Analysis Method Of Foundation Settlement Considering Soil Anisotropy

Foundation settlement analysis is one of the most important problems in soil mechanics.There are many methods to calculate the settlement of foundation.The simple and practical layering summation method is widely used in engineering practice and is still the most commonly used settlement calculation method.In recent years,the settlement calculation method based on soil constitutive model has developed rapidly,among which the settlement calculation method based on linear elastic constitutive model has higher practicability because of its simple parameters and convenient calculation.Soil anisotropy can be divided into primary anisotropy and stress-induced anisotropy.Anisotropy is an important factor affecting foundation settlement,which is often neglected in conventional calculation and analysis methods of foundation settlement,which has a great influence on settlement calculation results.Thus,this paper will improve the constitutive model of the pore medium,establish the pore medium model that can reflect the anisotropy of deformation mechanical parameters,and then introduce the idea of layering summation method and grading loading to deal with the nonlinear problem,and establish the calculation and analysis method of foundation settlement considering the anisotropy of soil mass.Firstly,the influence of anisotropy on settlement deformation and additional stress coefficient is analyzed by finite element method.The finite element analysis model of foundation settlement is established and the parameters are analyzed by anisotropic soil constitutive model.The influence of anisotropic parameters(horizontal deformation modulus,horizontal poisson's ratio,anisotropic coefficient,shear modulus)on foundation settlement,lateral deformation and additional stress coefficient of each soil layer is studied,and the main parameters affecting the settlement deformation and additional stress coefficient of foundation are determined.Then,a pore medium model considering soil anisotropy is established.Considering the spatial distribution of soil particles and the characteristics of the flat surface orientation,introducing the concept of horizontal and vertical porosity porosity,different compression model is set up in different direction,establish macro mechanics parameters and foundation deformation mesoscopic soil particle skeleton model of the relation between pore parameters,the improved soil pore medium model can't reflect the anisotropy of the defects and deficiencies.Based on the improved analysis model of pore media,the idea of treating nonlinear problems by graded loading and the method of layering summation are introduced.Because of the influence of initial geostress and additional stress,the relation formula reflecting the change law of mechanical parameters of deformation is established,and the settlement calculation method of foundation considering soil anisotropy is put forward.This method can not only reflect the characteristics of deformation mechanics parameters of foundation soil with the change of initial stress and additional stress,but also consider the influence of soil anisotropy on settlement,which has certain advantages.Finally,the calculation method of foundation settlement in this paper is applied to practical engineering,and is compared with other settlement calculation methods and settlement values measured on the foundation to verify the rationality of this method.