A new failure criterion for determining the cyclic resistance of low-plasticity fine-grained tailings

摘要

Reasonable determination of the cyclic resistance of low-plasticity fine-grained tailings is important for the engineering design of new tailings dams. In this paper, a series of monotonic and cyclic triaxial undrained tests were conducted to investigate the mechanical response of low-plasticity fine-grained tailings (Taiping tailings). A unified Viscous Energy Dissipation Ratio (VEDR) was then used to develop an energy-based method to study the failure mode under cyclic loading. The VEDR is a normalized energy ratio based on the relationship between cyclic stress and strain. Collapse failure was observed when the dynamic properties suddenly changed beyond the peak point of VEDR (VEDRpeak). These changes included a sudden decrease in VEDR, an abrupt increase in cyclic amplitude strain (epsilon(cyc)), and the prominent failure pattern of hysteresis curve. In this regard, VEDR failure criterion was proposed by considering VEDRpeak as the failure point. Comparisons based on the effective stress path and the cyclic resistance ratio (CRR) indicate that the VEDR failure criterion is more suitable for determining the CRR than conventional strain-based failure criteria for Taiping tailings. Furthermore, a relationship between the VEDR failure criterion and strain-based failure criterion was introduced. In general, the VEDR failure criterion will provide an insight into the determination of CRR for low-plasticity fine-grained tailings.