Analysis On Three-dimensional Seepage Stability Of Chagou Tailings Pond

Tailings pond is an important facility to maintain the production of the mine concentration,meanwhile,it is also a artificial high potential energy debris flow dangerous source,once accident takes place,it will cause irreparable and heavy losses to the mine and downstream people’s lives and property security.A large number of research results show that phreatic surface position is one of the decisive factors affecting the safety and stability of tailings pond.According to this situation,this paper takes Chagou tailings pond in Pingquan County of Hebei province as engineering background,using the finite element analysis software MIDAS/GTS NX to carry out the three-dimensional numerical simulation of seepage field scientifically.According to the basic theory of seepage-Darcy’s law,first of all,the finite element analysis method and solving process of three-dimensional seepage are briefly introduced,then the method for determining the phreatic surface(line)position is summarized.According to the design documents of tailings pond,relevant basic data for the three-dimensional seepage stability analysis of tailings pond is refined.Using the finite element analysis software MIDAS/GTS NX to establish three-dimensional seepage numerical model of tailings dam,and to simulate phreatic surface(line)and hydraulic gradient change regulation of tailings pond in normal and flood working conditions when the tailings accumulation elevation is 580 m,608m,648 m and 714 m respectively,based on this,the seepage characteristics of tailings pond are comprehensively analyzed and evaluated.The main engineering measures to reduce the phreatic surface(line)of the dam body are introduced,and the characteristics,application conditions and seepage reducing effects of various kinds of drainage reinforcement measures are summarized.Using finite element analysis software MIDAS/GTS NX to carry out the seepage reduction effect calculation of the blind ditch and vertical-horizontal gravity drainage wall,the seepage reduction effect of the two kinds of drainage reinforcement measures are compared,finally the recommended drainage reinforcement scheme is given.