上游式尾矿坝动力响应及参数敏感性研究OA

As a key mine facility,the anti-seismic stability of tailings dam directly affects the safety of downstream area.In order to reveal the seismic dynamic response law of the upstream tailings dam dump coupling system,the influence mechanism of the peak ground acceleration(PGA)and shear strength parameters on the dynamic characteristics and stability of the system is mainly explored.Taking an upstream tailings dam in Qinghai Province as the research object,a three-dimensional finite element model is established,and the dynamic time history analysis method is used to systematically study the acceleration response characteristics,dynamic displacement distribution law,permanent deformation mode,liquefaction development area and slope stability under the action of design earthquake,and the sensitivity analysis of the PGA and shear strength parameters is carried out.The results show that:(a)under the design earthquake,the acceleration response of the system presents significant elevation amplification effect,and the peak acceleration along the valley reaches 2.13 m/s2;(b)the permanent deformation is mainly manifested in vertical settlement,and the maximum seismic subsidence of the accumulation dam is 363.2 mm;and(c)the minimum safety factor of the slope meets the requirements of specification and has good stability.The sensitivity study shows that:(a)the PGA is positively correlated with the dynamic response of the system,and the increase of PGA will significantly reduce the seismic stability of the system;and(b)improving the shear strength parameters of the waste dump can effectively improve the instantaneous minimum safety factor,inhibit the displacement development of the downstream side,and enhance the overall seismic performance of the system.