Small strain stiffness and yielding property of cement-mixed soil in drained triaxial compression

摘要

To evaluate the effects of ageing and large-scale yielding on the small-strain stiffness of moist compacted cement-mixed soil, a series of drained triaxial compression (TC) tests were performed. The specimens were cured initially unconfined for different periods and at an anisotropic stress state during TC loading for two days. The small-strain stiffness was evaluated during otherwise TC loading towards failure. As the curing period increases, the small strain stiffness values obtained by static and dynamic measurements at respective stress states increase associated with development of yield locus (YL). The small strain stiffness increases with the confining stress until the current stress level reaches the current YL that has developed by strain-hardening and curing, while it starts decreasing when the current stress level exceeds the current YL. These trends are more clearly observed with dynamically measured values, which are generally higher than statically measured values reflecting more the stiffness of stiffer local parts in the specimen.