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利用建立的煤岩体分级加载扰动试验系统,进行了煤系岩石典型单轴压缩实验、无扰动分级加载试验,以及分别施加不同速率及幅度的扰动载荷的分级加载试验,同步采集声发射(AE)信号,并利用加卸载响应比理论对AE信号进行分析.结果表明,扰动载荷能够使岩石的抗压强度显著降低,施加扰动载荷条件下9个岩样单轴抗压强度降低了20~60 kN(约为单轴极限抗压强度的10%~25%);扰动速率的变化(由650 N/s增至1 kN/s)较载荷大小的变化(由2.5 kN增至5 kN)对岩样强度影响明显;AE能量与加载路径对应良好,其加卸载响应比随载荷水平的增加存在先减小后增大的趋势.
A typical uniaxial compression test of coal series rocks, no-disturbance classification loading test and graded loading test with different rates and amplitudes of perturbation loads respectively were carried out by using the established grading and loading disturbance test system of coal and rock mass. Simultaneous acquisition of acoustic emission (AE ) Signal, and the AE signal is analyzed by using the theory of loading-unloading response ratio.The results show that the compressive strength of rock can be significantly reduced by the disturbance load, and the uniaxial compressive strength of nine rock samples decreases by 20 ~ 60 under the disturbance load kN (approximately 10% to 25% of the uniaxial ultimate compressive strength); change in perturbation rate (from 650 N / s to 1 kN / s) to load change from 2.5 kN to 5 kN The strength of rock sample has a significant effect. AE energy corresponds well with the loading path, and the loading-unloading response ratio tends to decrease and then increase with the increase of loading level.