Risk Identification And Safety Evaluation Of Tailings Dam Under Seismic Action

Tailings reservoir is a place for storaging tailings,a large number of saturated tailings storaged prone to liquefaction,which is a high potential artificial debris flow.In the event of an accident,it will cause great losses to the people's lives and property safety and causing serious pollution to the environment around the reservoir area under earthquake action.Therefore,ascertaining relevant parameter through a series of tests and the dynamic characteristics of each part of the tailings dam with numerical simulation method is important.It has very important practical significance to study the dynamic response,dynamic stability,seismic liquefaction and propose seismic reinforcement measures of tailings dam under seismic action.In this paper,the research on the upstream tailings dam,mainly include the soil test for physical and mechanical properties of tailings sand,study on seepage and static stability,seismic dynamic response and seismic liquefaction evaluation,seismic strengthening measures and evaluation.The main content of this paper is:(1)Tailings dam is used as the main risk identification unit,identifies the risks under earthquake and propose five risk function models with related risk index monitoring methods.(2)To carry out indoor soil test of tailings material,consolidated drained test(CD)then gain the shear strength index of tailings.Carry out three axis dynamic test of tailings and establish the relationship between dynamic shear modulus ratio and damping ratio and dynamic shear strain,liquefaction stress ratio and vibration time.(3)Studied on the seepage law of tailings dam and using finite element strength reduction method to study the static stability of tailings dam.Carried out the seismic dynamic response analysis of the tailings dam at present situation,the maximum displacement of tailings dam presents to central position of middle slope of dam,liquefaction zone in upstream approaching waterside,Permanent deformation and permanent displacement are small.(4)Studied on the evaluation methods of tailings sand liquefaction and choosed various methods to evaluate the safty for the potential liquefaction area of tailings reservoir.(5)Studied on the different seismic strengthening measures,this paper puts forward relative effective seismic strengthening measures for the upstream tailings dam and analyzed the effects of anti-seismic measures.