Study On Dynamic Characteristics Of Rubber Sand Based On Dynamic Triaxial And Shaking Table Test

With the rapid development of China's economy,China has become the world's largest auto production and auto consumption country.At the same time,a large number of scrap tires are produced every year.It is difficult to degrade the waste tires,which has been called "black pollution".Waste rubber particles have the characteristics of light density,high elasticity,convenient construction,etc.they can be used as a kind of light isolation backfill material,which can be used in slope reinforcement,highway subgrade,building isolation and other projects,and have the effect of isolation and shock absorption.At present,most of the houses in the rural areas of China are built by the villagers themselves,and the villagers' seismic consciousness is relatively weak,so they seldom adopt the technology of shock absorption and isolation.In case of earthquake disaster,houses in rural areas are seriously damaged.In this paper,the dynamic triaxial test of GDS and large-scale shaking table test are carried out to study the dynamic characteristics of rubber sand.The main research contents are as follows:(1)The rubber particles and sand particles were screened by vibration sieving apparatus.The rubber sand with different rubber particle size and content was prepared and the corresponding grading curve was obtained.The maximum dry density and the minimum dry density of rubber sand were measured by vibration hammering method and funnel measuring cylinder method respectively.(2)The dynamic characteristics of rubber sand,such as dynamic shear stress,dynamic shear modulus and damping ratio,are studied by using GDS dynamic triaxial method.The dynamic characteristics of rubber sand affected by rubber content,consolidation confining pressure and rubber particle size are analyzed.The dynamic shear stress-strain curve,dynamic shear modulus-strain curve and damping ratio-strain curve of rubber sand under different influence factors are obtained.(3)Three classical dynamic constitutive models,Hardin drnevich,Ramberg Osgood and davidenkov,are introduced.The Hardin drnevich dynamic constitutive model is used to fit the dynamic shear stress-strain and dynamic shear modulus ratio dynamic shear strain and damping ratio dynamic shear strain curves of rubber sand,and the test results and fitting results are compared and analyzed.(4)Through the large-scale shaking table test,simulating the effect of rubber sand cushion on reducing and isolating earthquake,the shaking table tests were carried out under three working conditions: free field,no rubber sand cushion with superstructure and rubber sand cushion with superstructure,respectively.Under different seismic waves and loading direction conditions,the change rules of acceleration time history and Fourier spectrum were analyzed.