基于PFC3D磷石膏尾矿库溃坝数值模拟研究

Numerical simulation of phosphogypsum tailings dam failure based on PFC3D

为探究尾矿库溃坝灾害作用对下游区域的影响,利用GOCAD/Rhino软件对某磷石膏尾矿库地形进行建模,采用颗粒流离散元方法研究设计140 m堆积高度尾矿库在4个不同方向上溃决砂流演进过程,分析了尾砂的位移和流速随溃坝时间的变化规律,为尾矿库下游合理规划、企业应急处置和科学防控提供依据。结果表明:140 m堆积高度初期坝溃决工况为溃坝影响最大、下泄体量最大的工况,下泄体最大宽度428 m,最大深度15 m左右,体积达2.017Χ10^(6)m^(3),尾砂最终滑移距离为1229 m,途中淹没回水泵房及多处房屋,对下游居民造成严重影响;140 m堆积高度北部、西部堆积坝溃决对下游影响较小;140 m堆积高度东部堆积坝溃决,未影响任何下游建筑物。

In order to explore the impact of tailings pond dam break disaster on the downstream area,the terrain of a phosphogypsum tailings pond was modeled by GOCAD/Rhino software,and the particle flow discrete element method was used to study the design of tailings ponds with a stacking height of 140 m in four different directions.The evolution process of the burst sand flow is analyzed,and the variation law of the displacement and flow velocity of the tailings with the dam burst time is analyzed,which provides a basis for the rational planning of the downstream of the tailings pond,emergency disposal of enterprises and scientific prevention and control.The results show that the dam failure condition at the initial accumulation height of 140 m is the condition with the greatest impact of dam failure and the largest discharge volume.The discharge body has a maximum width of 428 m,a maximum depth of about 15 m,a vol-ume of 2.017Χ10^(6)m^(3),and a final sliding distance of tailings of 1229 m,the backwater pump house and many houses were submerged on the way,which had a serious impact on the downstream residents;the collapse of the northern and western accumulation dams with the 140 m accumulation height had little impact on the downstream;the 140 m ac-cumulation height of the eastern accumulation dam collapsed and did not affect any downstream buildings.