Tailings dams are in danger of liquefaction during earthquakes. The liquefaction process can be indirectly reflected by the evolution rule of the dynamic pore water pressure. To study the development law of dynamic pore water pressure of tailing sand under different consolidation conditions, the evolution equation of critical dynamic pore water pressure of tailings under isotropic and anisotropic consolidation conditions was derived based on the limit equilibrium theory. Moreover, the development law of dynamic pore water pressure was expounded theoretically. The dynamic triaxial tests of tailing silty sand and tailing silt under different dry densities, consolidation ratios, and confining pressures were performed. The dynamic pore water pressure ratio and vibration ratio curves of tailings under isotropic and anisotropic consolidation were analyzed, and a dynamic pore water pressure growth index model suitable for both isotropic and anisotropic consolidation was derived. The results showed that the critical dynamic pore water pressure was positively correlated with the confining pressure and average particle size of tailings under isotropic consolidation conditions. The tailings have a limit dynamic effective internal friction angle φdc under the anisotropic consolidation condition. The evolution law of critical dynamic pore water pressure can be judged according to the dynamic effective internal friction angle of tailing sand φd and φdc values. The consolidation ratio significantly affects the dynamic pore pressure growth curve while confining pressure and dry density do not. For different tailing materials, the dynamic pore water pressure ratio is positively correlated with tailing particles. The dynamic pore water pressure growth process of tailing silty sand and tailing silt can be divided into two stages: rapid and stable growths. The development law of two types of tailings can be described by the dynamic pore water pressure growth index model. The research results can provide a theoretical basis for the seismic design of tailings dams in practical engineering.

The objective of this study is to investigate the dynamic characteristics of tailings sand under different consolidation conditions. Through consolidated undrained triaxial tests under different dry densities, consolidation ratios and containing pressures, the dynamic shear stress, liquefaction stress ratio, dynamic strength index, dynamic pore water pressure, dynamic modulus and damping ratio of tailings sand under different consolidation conditions were analyzed. The test results show that: The dynamic shear stress of tailings sand is linear with the number of failure vibration. The influence of consolidation ratio on liquefaction stress ratio is obvious. The two correspond to a quadratic polynomial passing through the origin. The influence of consolidation ratio on dynamic internal friction angle is greater than that of dry density. The change of dynamic shear modulus ratio and damping ratio with dynamic strain is obviously influenced by consolidation ratio. The variation law of reference shear stress under different conditions is basically in accordance with normal distribution. The research results can serve as a theoretical reference for seismic liquefaction of a tailings dam in areas of high intensity seismic activity.