Abstract:

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 and dynamic shear modulus 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 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 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.

Key words: structural soft soil, dynamic triaxial test, constitutive relation, traffic loading, dynamic elastic modulus, damping ratio