基于不同溃口形态的尾矿坝溃决泥浆流动特性试验研究

Study of tailings dam-break surges with floating slurry in model experiment in different collapse gates

以云南玉溪矿业有限公司秧田箐尾矿库设计资料为依托,依据相似原则,采用重庆大学自行研制开发的尾矿坝溃决破坏模拟试验台,基于尾矿坝溃决的口门形态,探索了坝体在1/4、1/2以及全部瞬间溃决3种情况下的下泄泥浆流动特性。试验结果表明:(1)溃坝口门形态对下泄泥浆的冲击力、淹没范围以及演进规律有较大的影响;(2)泥浆在下游各特征过流断面处的演进规律具有较明显的龙头衰减过程,龙头速度较大,泥深以及泥浆冲击力呈现小-大-小的分布,具有较长的拖尾衰减现象;(3)随着溃口逐渐加大,泥浆在下游同一过流断面处的冲击力和泥深呈明显增大趋势,其增大趋势表现为非线性;(4)泥浆流态在下游90°弯道处发生强烈扰动,在弯道内侧出现涡流现象,而在外侧出现反射现象,瞬间全溃下泄泥浆形成的涡流范围和反射波强度较坝体1/2和1/4溃决情况明显;(5)受溃口形态影响,下泄泥浆龙头到达同一过流断面的时间也不同,全溃泥浆龙头到达下游同一过流断面处的时间远小于坝体1/2和1/4溃决情况。同时,随着溃口的不断减小,同一断面处泥浆冲击力峰值呈减弱趋势,到达峰值的时间也相应推迟。研究成果为不同溃坝口门形态下的尾矿坝溃决泥浆流动特性的深入认识提供了参考。同时,对指导矿山企业的防灾减灾工作具有重要的现实意义。

Based on the similarity theory and the design data of Yangtianqing tailings impoundments of Yuxi Mining Co.,Ltd.in Yunnan province,a series of laboratory simulation model experiments of tailings dam-break surges with floating debris in different collapse forms（1/4,1/2 and the entire instantaneous collapse） were carried out in a uniform geometry flume of College of Resources and Environmental Science.The flow characteristics of slurry from tailings dam-break had be explored in the simulation model experiments.The experimental results show：（1） The collapse gate of tailings dam has an obvious influence on the impact stress,depth and evolution characteristics of slurry from tailings dam-break.（2） The slurry evolution course at the sections of downstream has an obvious attenuation phenomenon,and the slurry flows faster in the front,the depth and the impact stress vary along the long trail.（3） With the collapse gate augmenting,the impact stress and the slurry depth is increased obviously at a same section and the law of increase tendency is nonlinear.（4） The flow pattern of slurry has undergone great changes at the sharp bend flume;the vortex appears at the inner side and the reflection phenomena appear at the outside,the vortex and reflection phenomenon in entire instantaneous collapse condition are greater obviously than which of 1/2 and 1/4 instantaneous dam-break.（5） The time of the front slurry arriving at a same section of downstream in entire instantaneous collapse condition is far less than that of 1/2 and 1/4 instantaneous collapse conditions.With the collapse gate diminishing,the peak of impact stress is weakened and the time that the impact stress gets to the peak value is delayed.The results can provide some references to study of the characteristics of slurry flow in different collapse gates deeply and there is an important real significance to conduct the mine enterprises to take some corresponding actions to prevent and control the disaster of tailings dam-break.