Study On Seismic Residual Deformation Of Reinforced Soil In Experimental Model

The residual deformation of soil and rock is an important factor to evaluate the seismic safety and stability of earth-rock dams.In this paper,the effectiveness of seismic reinforcement measures and deformation control means for earth-rock dams is studied by studying the seismic residual deformation characteristics of reinforced soil and rockfill,and the seismic residual deformation model of reinforced soil is established.(1)A large dynamic triaxial test was carried out to study and verify the seismic residual deformation characteristics and deformation inhibition effect of reinforced soil.By changing different confining pressures,consolidation ratios and dynamic stress conditions,the residual deformation characteristics of reinforced soil and prototype soil(refer to corresponding unreinforced soil,the same below)were investigated.The results of reinforcing soil under different conditions are compared to provide reference for engineering application.The results show that the axial residual deformation and volumetric residual deformation of the reinforced soil decrease to different degrees under the same consolidation ratio,confining pressure and dynamic shear stress ratio.The average reduction of axial residual deformation is up to 40%-50%of the original soil deformation,up to 60%,and the average reduction of volume residual deformation is up to 30-40%.The experimental results show that the geogrid material has a good inhibitory effect on the residual deformation of earth and rock.(2)The influence factors and law of residual deformation of reinforced soil were studied and revealed.Under the same confining pressure and consolidation ratio,the residual deformation of reinforced soil increases with the increase of dynamic shear stress ratio.Under the same confining pressure and dynamic shear stress ratio,the axial residual deformation and volumetric residual strain of reinforced soil increase with the increase of consolidation ratio.Axial residual deformation is greatly affected by consolidation ratio,while residual volume strain is less affected by consolidation stress ratio.Under the same consolidation ratio and dynamic shear stress ratio,with the increase of confining pressure,the axial residual deformation and volume residual deformation of reinforced soil decrease greatly.The experimental results of the above reinforced soil are consistent with the research conclusions of the prototype soil samples.The strengthening effect of geogrid material on soil samples under different conditions was studied and analyzed.The results show that the lower the dynamic shear stress ratio,the higher the consolidation ratio,the better the reinforcement effect.The lower the confining pressure is,the lower the ratio of reinforcement to strain reduction is.(3)This paper discusses and analyzes the different finishing methods of the seismic residual deformation model of earth and rockfill DAMS based on strain potential,and improves the residual deformation model of hydrology based on strain potential.In this paper,two kinds of residual deformation calculation models based on strain potential are analyzed.By comparing and analyzing the conditions and the degree of difficulty of each parameter,the characteristics of each model are discussed.At the same time,based on the power function relationship between residual deformation and dynamic stress,the inverse proportion relationship between residual deformation and the first stress invariant,and the relationship between residual deformation and consolidation ratio,an improved residual deformation model of the Academy of Water Sciences was proposed.The simulation effect of the model is good for the prototype soil and it is ready for the application in reinforced soil.(4)The residual deformation model of reinforced soil is established.The improved model is applied to the simulation of the experimental results of the residual deformation of reinforced soil.The results show that the values of Kp and Kv are stable in a straight line when the vibration cycle is added into the coefficient of axial strain calculation parameters.When the effect of vibration cycle is added to the coefficient of volume strain calculation parameters,np and nv show the best results under the logarithmic curve.