一维静载与频繁扰动共同作用下含铜蛇纹岩动力学特性

Dynamic characteristics of copper-bearing serpentine under combined action of one-dimensional static load and frequent disturbances

基于冬瓜山铜矿深部开采面临的高应力集中及爆破扰动的问题,采用改进的SHPB岩石动静组合加载试验系统,进行了含铜蛇纹岩在一维静载与频繁扰动共同作用下的动力学试验,研究其动力学特性。研究结果表明:预加轴压促使岩石内部微裂纹完全闭合时,岩石动态应力-应变曲线初始阶段不出现下凹现象,否则出现;岩石内部存储的弹性力大于扰动冲击应力时,岩石动态应力-应变曲线峰值应力后会出现回弹现象,否则不出现;动态峰值应力、动态变形模量随扰动冲击次数的增大而减小,60%单轴抗压强度的轴压时峰值应力最大;峰值应力均值随轴压的增大先增大后减小;最大应变、峰值应力对应应变随扰动冲击次数的增大而增大;累计扰动冲击次数最大值与均值都随轴压增大呈一元四阶多项式关系递减。

The dynamic tests of copper-bearing serpentine under one-dimensional static load and frequent disturbances were conducted to study dunamic properties of copper-bearing serpentine adopting an improved SHPB test system for rock static and dynamic combined loading aiming at the problems of high stress concentration and blasting disturbance in deep exploitation of Dongguashan Copper Mine.The results showed that a phenomenon of concave does not appear in the initial stage of the rock＇s dynamic stress-strain curve when the pre-axial compression makes the rock＇s internal micro cracks be completely closed,otherwise it appears;when the rock＇s internal stored elastic force is larger than the disturbance impact stress,the rebound phenomenon appears on the rock＇s dynamic stress-strain curve after the dynamic stress reaches the peak stress,otherwise it does not appear;with increase in disturbance impact times,the dynamic peak stress and the deformation modulus decrease while the maximum strain and the strain corresponding to the peak stress increase;the peak stress is the maximum when the axial compression is 60 percent of the uniaxial compressive strength;with increase in the axial compression,the average value of the dynamic peak stress increases firstly and then decreases;the maximum and average cumulative disturbance impact times decrease according to a fourth order polynomial with increase in the axial-compression.