Abstract: The shear strength characters of mucky excessive soft soils were studied by using an improved true triaxial device SPAX200 under different a relative high impulse frequency (16Hz) with various confining pressures. The conclusions are presented in this paper: both the static and dynamic consolidation methods could have an obvious result of improving the soil shear strength. The results indicate that the soil samples with various impulse stress could have strength increase of 29%, 25% and 36%, respectively; 2) the strain softening effect was observed with intermediate or high confining pressures and the shear strength at the initial stage is higher than the samples under the conventional triaxial confining pressure. An optimum impulse frequency might exist for each sample under each overconsolidation ratio. Under this optimum impulse frequency, shear strength of the soil samples that under the same overconsolidation ratio can be improved throughout the dynamic and static consolidation action without strain softening effect.

Key words: Triaxial Tests, Impact Loading, Mucky Soils, Shear Characteristics