矿山开采过程中顶板冒落冲击振动规律相似试验研究

Similar Experimental Study on Roof Caving Shock Vibration Rules in Mining Process

以某矿山无底柱分段崩落法采场结构参数为参照,以相似理论为基础,设计相似试验物理模型,研究采空区顶板在不同冒落高度、不同冒落量、采场有无安全垫层以及不同材料强度4种情况下顶板冒落冲击下部采场的振动变化规律。试验结果表明:①振动速度大小和冒落高度、冒落量、材料强度呈正相关的关系;②振动速度大小随着冒落高度的增加存在一个突变期,在突变期内振动速度增长最快;③采场内存在适当厚度的散体垫层对冒落体具有良好的缓冲作用;④在各个试验条件下,距离冲击位置越近的测点速度变化越明显;⑤随着振动波在岩体中的传播,存在某一临界深度,当超过这一临界深度时,上部采场顶板冒落造成的冲击振动影响很小。

Taking the structural parameters of a mine stope with pillarless sublevel caving method as a case,based on the similarity theory,the similarity test physical model is designed to study the vibration change rule of the roof caving impact on the lower stope under the conditions of different caving height,different caving amount,whether the stope has safety cushion and different material strength.The results show that:(1)Vibration velocity is positively correlated with falling height,falling amount and material strength.(2)With the increase of falling height,the vibration velocity has a sudden change period,during which the vibration velocity grows the fastest.(3)The cushion with appropriate thickness in the stope has a good buffer effect on the falling body.(4)Under various test conditions,the velocity change of the measuring point closer to the impact position is more obvious.(5)With the propagation of vibration wave in rock mass,there is a critical depth,when it is beyond the critical depth,the impact of upper stope roof caving is minimum on impact vibration.