Dynamic response characteristics of a tailing dam determined by shaking-table tests

Upstream tailing dams, which are commonplace, can easily lead to major accidents under seismic excitation. However, the dynamic response characteristics and causes of instability failure of tailings dams are yet to be investigated fully. In the present study, shaking-table tests were conducted to determine the acceleration, pore pressure, soil pressure, and displacement of a dam body under a seismic wave with different values of the PGA peak ground acceleration. The peak acceleration of the dam exhibited the typical spatial effect. Because of the increased shear strain of the tailings in the dam, reduced stiffness, and increased damping, the acceleration amplification factor increased with increasing elevation and decreased with increasing PGA (peak ground acceleration. The free face of the dam underwent liquefaction more easily, and the pore pressure of the dam exhibited three phases over time, namely rapid increase, sharp decrease, and then slow dissipation. The soil pressure also exhibited three phases over time, namely slow increase, rapid increase, and peak fluctuation. Once the pore pressure had dissipated, the soil pressure exhibited an inflection point at Arias intensity release. The vertical displacement of the dam increased gradually, but it is less than horizontal displacement. The pore pressure, soil pressure, and displacement were closely related to the Arias intensity. The present results have practical importance for understanding the instability of dams and reinforcement under seismic effects.