The maximum dynamic shear modulus

shear strain amplitude and damping ratio of soil are important mechanical parameters for dynamic response analysis of soil layer.The influence of confining pressure on the dynamic parameters of silty clay in Dujiangyan region was researched by RCA resonant column apparatus of British GDS Company.Studies show:Under the same confining pressure conditions

the maximum dynamic shear modulus

shear strain amplitude and damping ratio are essentially not change with repeat count

which show that the test process is reproducible.The maximum dynamic shear modulus

shear strain amplitude and damping ratio are greatly influenced by confining pressure.The maximum dynamic shear modulus and damping ratio are increasing

and the shear strain amplitude is decreasing with confining pressures increasing.The empirical formula of the dynamic parameters of silty clay in Dujiangyan vs.confining pressures is formed.The study can provide a reference to dynamic response analysis of soil seismic and accumulate basic data.