煤矿高浓度胶结充填体能量演化特征试验研究

为了研究煤矿高浓度胶结充填体的能量演化特征，借助RTR-2000高压岩石三轴动态测试系统开展了高浓度胶结充填体不同围压下的常规三轴压缩试验，分析了试件变形破坏过程中的应变能演化规律及围压效应。研究结果表明:(1)对于围压不为0的试件，峰值强度对应的耗散应变能占吸收应变能的比例超过70 %，试件在达到峰值强度前已经发生剧烈的塑性变形和破坏；(2)试件变形破坏过程中，吸收应变能快速增加，弹性应变能先积累后释放，峰值强度时达到储能极限，耗散应变能自屈服变形阶段开始快速增长；(3)相同轴向应变条件下，围压越大，试件的吸收应变能、弹性应变能越大，高围压试件的耗散应变能随轴向应变的增加将超过低围压试件的耗散应变能，围压可以大幅改善试件的应力水平，限制试件的径向变形，提高试件的储能能力，抑制试件的变形破坏。

Experimental study on the energy evolution characteristics of high-concentration cemented backfill in coal mine

In order to study the energy evolution characteristics of high concentration cemented backfill in coal mine, conventional triaxial compression tests of high-concentration cemented backfill under different confining pressures were carried out with the help of RTR-2000 triaxial dynamic test system for high pressure rocks.This paper analyzed the evolution law of the strain energy and the confining pressure effect during the deformation and failure of the specimens.The results show that: (1) for the specimen whose confining pressure is not 0, the ratio of dissipated strain energy corresponding to peak strength to absorbed strain energy is more than 70 %. Before the specimens reached the peak strength, they have undergone severe plastic deformation and failure.(2) in the process of deformation and failure of specimens, the absorbed strain energy increases rapidly, the elastic strain energy accumulates first and then releases, reaching the energy storage limit at peak strength, and the dissipated strain energy begins to increase rapidly from the stage of yield deformation.(3) under the condition of the same axial strain, the larger the confining pressure is, the larger the absorbed strain energy and elastic strain energy of the specimens are.The dissipated strain energy of the specimen with high confining pressure will exceed that of the specimen with low confining pressure as the axial strain increases.The confining pressure can greatly improve the stress level of the specimens, limit the radial deformation of the specimens, improve the energy storage capacity of the specimens, and restrain the deformation and failure of the specimens.