基于弹塑性理论的溃坝尾矿砂下泄冲击力研究

Study on Impact of Dam Break Tailings Sand based on Elastomer Collision Theory

为确定溃坝尾矿砂下泄冲击力,以弹塑性力学为基础,从微粒弹性碰撞入手,建立单尾矿砂微粒的冲击模型,并扩展至团聚尾矿砂的冲击力求解模型,推导出均匀级配、固液耦合的冲击力计算公式。结果表明:单尾矿砂微粒可通过弹性力学理论描述碰撞过程、求解碰撞力和碰撞时间;尾矿砂团聚微粒的碰撞模型的构建应考虑液相的粘聚力、颗粒间的接触和局部力系向空间转化三个方面;冲击速度、平均粒径和含沙量对冲击力的影响均呈幂函数型增加,干密度呈线性增加,相同边界条件下,冲击速度的改变对冲击力的影响最大,平均粒径和含沙量次之,干密度影响最小,该结果代表了尾矿砂所特有的细颗粒、级配均匀所展现的特征,为尾矿砂下泄冲击计算提供理论依据。

In order to determine the impact force of tailing sands advancing after dam-break,based on elastoplastic mechanics and starting from the elastic collision of particles,the impact model of single tailings particle is established and extended to the impact force solving model of aggregate tailing sands,in addition,the calculation formula for the impact force of uniformly-graded and solid-liquid coupling is derived.The results show that single tailings particle can describe the collision process,solve the collision force and collision time by means of elastic mechanics theory;The cohesion of liquid,the contact between particles and the transformation of local force system into space should be considered in the construction of collision model of tailings agglomerated particles;The influence of impact velocity,average particle size and sand content on impact force increases in power function,but that of dry density increases linearly,and under the same boundary conditions,the change of impact velocity has the greatest impact on impact force,average particle size and sand content are followed,and then finally the dry density,this reveals the characteristics displayed of fine particles and uniformly-graded that peculiar to tailing sands.And it provides a theoretical basis for the impact calculation of tailing sands advancing.