Study On Passive Earth Pressure Of Retaining Wall In Transversely Isotropic Soil

Because the predecessors studied the earth pressure,the soil is usually considered as an isotropic medium.However,under the influence of gravity,the long axis tends to be deposited and arranged horizontally to exhibit anisotropic characteristics.Recently,there are Many scholars analyze the earth pressure through the angle of strength anisotropy,and obtain different strength parameters by different large principal stress direction angles(the angle between the large principal stress action surface and the normal of the deposition surface),and then analyze different corners.At the time of the earth pressure value,each time the soil model is selected,the intensity parameter corresponding to the same angle value is selected.Based on the previous research,this paper explores the cross-section by using the block processing method in the same model.Passive earth pressure under the same-soil filling,based on the theory of fabric tensor and the principle of least squares,two methods are applied by one displacement application and multiple displacements to make the direction of the large principal stress of the fill and the normal direction of the deposition surface.The angle parameters are changed to obtain the strength parameters c_i and?_i after the model is divided,and then the passive earth pressure values under anisotropy are analyzed.The following conclusions were obtained:(1)The theory of anisotropic strength of soil is introduced from the point of view of inherent anisotropy and stress-induced anisotropy of soil.In this paper,the earth pressure under transverse anisotropy of soil is studied.The anisotropy involved in this paper refers to transverse anisotropy.Because the earth pressure of retaining wall is essentially the strength of soil,the anisotropic strength of soil is emphasized.The influence of degree.On the basis of the fabric tensor and Mohr-Coulomb strength criterion,and referring to the anisotropic state parameter A defined by the predecessors,an expression considering the shear strength index C and_anisotropy is proposed.The validity and superiority of the fitting effect of the formula are verified by the experimental data.(2)After selecting the appropriate power for the anisotropic state parameters Ac and A?,the mathematical principle of the least squares method is used to fit the shear strength parameters when the direction of the large principal stress is different from the normal direction of the deposition surface Flexibility and applicability(3)In order to make better use of ABAQUS for soil pressure research under soil anisotropy,in the third chapter,the isotropic soil pressure research was carried out,and the MC criterion and D-P4(equal area circle)criterion were calculated.The D-P7(Matsuoka-Nakai)criterion and the corresponding earth pressure under the D-P8(Lade-Duncan)criterion,in which the excel function and the matlab program are used to find the integral method,the MN yield criterion and the LD yield are respectively obtained.According to the soil pressure value under the criterion,the comparison of the soil pressure under the four yield criteria can be obtained from Fig.3-17,which corresponds to the yield criterion theory.ABAQUS finite element analysis of the earth pressure is verified.A comparative reference is provided for analyzing the anisotropy of the soil.(4)In order to pursue a more realistic stress field inside the soil,the fourth chapter divides the displacement application and the multiple displacement application when doing the passive earth pressure wall translation.The multiple displacement application is after the last displacement is applied.Obtaining the new intensity parameter is based on the next displacement application,which is more realistic than the one-time application of the first displacement.By analyzing the results of 4.2.3,it is found that the results obtained by the anisotropy after one displacement application are closer to the results of the intensity isotropic than the results obtained by multiple displacements.The results obtained after multiple displacements are applied more than the one displacement.The situation with isotropic is small,and the total passive earth pressure obtained with the increase of the number of displacements is smaller,the closer the result is to the theoretical value,but the overall difference of the passive earth pressure is not very large,and the other is through Figure 4-2 and Fig.4-15,it can be found that as the number of applied displacements increases,the stress vector distribution in the soil becomes more scattered and irregular.