胶结材料加载破坏的能量积聚与释放响应研究

STUDYON ENERGY ACCUMULATION AND RELEASE RESPONSE OF CEMENTED MATERIALS SUBJECTED TO LOADING FAILURE

为研究胶结材料在0.001 kN/s的速度缓慢加载达到峰值强度后出现的第二跌落特征,并伴随发生在第二跌落区出现的噪音分贝值的突增现象产生的原因,应用能量积聚与释放的总能量平衡理论,对胶结充填体轴向加载试验获取全应力应变曲线,并通过电子噪音测试设备测试加载过程中的噪音分贝值的大小,引入可表征试件全应力应变曲线的即时弹性模量与割线弹性模量比值,作为柔化正态张量和可表征试件不同等应变变化的应变能与总应变能比值作为应变能张量,通过柔化正态张量和应变能张量的变化大小,表征试件在能量积聚阶段和释放响应阶段的变化特点,特别是在第二跌落阶段的能量变化特点。同时通过噪音分贝测量方法试验,建立噪音分贝与试件能量释放大小之间的对应关系。研究结果表明,只要加载速度较小,达到0.001 kN/s左右时,胶结充填体才会出现明显的第二跌落区。通过电子噪音分贝测试第二跌落区破坏出现的噪音分贝突增15 dB,相较常规加载多增加了10 dB以上。同时将这种缓慢加载方式应用在矿岩加载试验中,其加载破坏时的噪音分贝值突增更加明显,增加值达到20~35 dB。表明试件在近似等压受载环境下,更易积聚能量,并在破坏时以突然释放的形式释放,说明能量释放的强度是以前期积聚能量为前提的,这将有助于指导金属矿山采场高应力区评价,维护采场安全。

To study the second drop characteristic that occurs after the peak strength of the cemented material at a rate of 0.001 kN/s,and the occurrence of the sudden increase in the noise decibel value occurred in the second drop zone,the application of energy accumulation.The total stress-strain curve was obtained by the axial loading test of the cemented filling body,and the size of the noise decibel value during the loading process was tested by the electronic noise test equipment.The real elasticity of the stress-strain curve,the ratio of the modulus of elasticity to the modulus of elasticity and the ratio of the total strain energy as the strain tensor could be used to soften the normal tensor and strain the size of the changes in the characterization of the specimen in the energy accumulation stage and the release of the response stage of the characteristics of change,especially in the second drop stage of the energy characteristics.At the same time,the corresponding relationship between the noise decibel and the energy release of the specimen was established by the noise decibel measurement method.The results showed that only the loading speed reaches about 0.001kN/s,the cementing body would appear obvious second drop area.Through the electronic noise decibel test the second drop zone damage noise generated by the sudden increase of 15dB,compared to the conventional load increased by more than 10dB.At the same time,this slow loading method was applied to the rock and rock loading test,and the noise decibel value of the loading was more obvious and the added value is 20-35dB.It was shown that the strength of the energy release was prerequisite for the accumulation of energy in the early period,which would help to guide the mining of metal mining for high stress area evaluation,maintenance stope safety.