Strain-rate effects of stress-strain-strength behavior of a soft clay

Five kinds of consolidated-undrained triaxial tests were conducted to investigate the strain-rate effects on the stress-strain-strength behavior of remoulded Hong Kong Marine Deposits (HKMD). The tests were done at constant strain rates ranging from 0.0025%/min to 0.33%/min. A specimen was isotropically or anisotropically (K-0) consolidated, and sheared under compression or extension state. The results show that the undrained shear strength, porewater pressure, effective stress path of HKMD are strain-rate-dependent. Higher strain rate results in higher undrained shear strength and lower excess porewater pressure. The dependencies of those parameters are related to the stress history and the stress state of shearing.