Experimental study of dynamic constitutive relation of structural soft soils under traffic loading

Based on a lot of dynamic triaxial tests,the variation laws of dynamic stress-strain,dynamic elastic modulus and damping ratio of structural soft soils were studied;meanwhile,the influences of vibration wave,frequency and consolidation ratio were investigated.It is concluded that the influence of vibration wave on the type of dynamic stress-strain is not evident;the value between the maximum dynamic modulus E dmax and dynamic shear modulus Gd max is 2.5 times or so.The effect of frequency on the structural soft soil is evident;and there is a threshold vibration frequency.The maximum dynamic modulus E dmax decreases with the consolidation ratio increasing as the confining pressure is less than structural yield pressure;and when strain exceeds a certain value,the maximum dynamic modulus E d decreases with the consolidation ratio increasing.At a lower strain and deviatoric pressure,the higher the consolidation ratio is,the larger the damping ratio is;and when strain exceeds 0.004,the consolidation ratio increases,meanwhile the damping ratio decreases as the strain value increases.The conclusions can provide a useful guidance for the engineering application.