Numerical Simulation And Application Research For Seepage Field Of Tailing Pond Included Ice Layer In The High And Cold Area

As an important facility of mine production,tailing pond is significant hazard and pollution source,and its safe operation directly relates to the security of the downstream people's lives and property and public facilities.When tailing pond is operating in the high and cold area,the ore-drawing in low temperature will cause tailing sand to freeze,which leads to the reduction of permeability and the lift of saturation surface and is adverse to the seepage stability of tailing pond,so the study for the influence of ice layer to the seepage field has theoretical guidance significance for the construction and operation of tailing pond in the high and cold area.The frozen tailing sand's physical mechanical properties changed,its permeability coefficient reduced.In order to analyze the seepage filed of tailing pond included ice layer exactly,and provide reliable parameters for numerical simulation,saturated and frozen tailing sand's permeability coefficient is measured by falling head permeability test.Ice layer is affected by climate environment,topography condition,pulp concentration,and takes shape different number of layers,positions,species or permeability coefficients,all of which affect tailing pond's seepage stability in different degree.Because of the unfavorable influence brought by ice layer,respective saturation surface distributions in different number of layers,positions,species or permeability coefficients of ice layer are simulated,then,the seepage filed distribution rules due to different change of ice layer are obtained.For the engineering example with the tailing pond inc luded ice layer in Hebei province,its three-dimensional numeral model is built based on engineering data and its seepage stability analysis and anti-slide stability analysis are carried out by combining the fluid-solid coupling method with the strength reduction method.The analysis of seepage stability is carried out to obtain the distributions of total head,saturation surface and seepage flow velocity and draw the conclusion that min-depth of saturation surface and seepage stability meet requirement;The analysis of anti-slide stability is carried out to obtain three-dimensional dam's minimum safety factor and plastic breakthrough zone.The analysis of stability of dam's main cross-section by making use of limit equilibrium method are carried out in order to show the feasibility of the stability analysis for tailing dam by strength reduction method.Final,measures are given to avoid the occurrence of ice layer,which provide important scientific basis for the safe operation of the tailing pond.