| In civil engineering,the static and dynamic response analysis of saturated layered soil is a very common problem.It is difficult to determine reasonable constitutive relationship in static analysis,the settlement law of buildings is not perfect,the dynamic analysis focuses on the liquefaction phenomenon of single soil,and lacks of study on liquefaction characteristics of layered soil.At present,the deformation analysis of foundation soil is static or dynamic,The research on the bearing layer is basically concentrated,and few studies on the deformation of the soil layer below the bearing layer may cause the deformation of the underlying layer of the foundation soil to be too large or the bearing capacity is insufficient,and the overall damage will occur,which will bring serious engineering accidents.In view of the settlement of buildings,Liaoning cultural and Art Center and new museum of Liaoning Province are selected as the engineering background.Based on the principle of layered grid system calculation,the elastic-plastic Drucker Prager matrix constitutive model is derived by determining the reasonable yield criterion,loading criterion,flow rule and hardening law.The compression modulus is calculated,and the mathematical model of foundation deformation under saturated layered foundation is established.The paper uses FLAC3D software to simulate the engineering case,and extracts the vertical stress value and vertical deformation curve of each soil layer,and analyzes the relationship between the maximum load point and the maximum deformation point.The difference between the self-compiled program and the Mohr Coulomb and Drucker Prager constitutive model in FLAC3D is compared.The results show that the deformation error is within a reasonable range,and the numerical value is 0.92%and 7.61%respectively,which proves the feasibility of the calculation program.According to the liquefaction failure of layered soil,the influence of different seismic wave types(th2tg035,th3tg035,rh2tg035),different seismic wave directions(horizontal direction,vertical direction,bidirectional coupling),different peak acceleration(0.035g,0.1g,0.2g and 0.35g)on liquefaction is analyzed.It is found that the liquefaction is only affected by the seismic wave in horizontal direction(acceleration 0.035g),and The liquefaction phenomenon was not found in the vertical direction seismic wave(acceleration 0.023g),bidirectional coupled seismic wave(horizontal 0.035g,vertical 0.023g),and the acceleration peak value increased under the action of horizontal direction earthquake,when the peak acceleration was 0.35g liquefaction.Based on the static and dynamic analysis of engineering cases,the deformation of bearing layer and underlying layer is studied when different soil layers are set.It is found that the deformation of the lower lying layer is very large,and it can not be ignored in the calculation of deformation.The research conclusion can provide some reference value for the deformation calculation of saturated layered soil foundation. |
