Experimental Study of Slabbing and Rockburst Induced by True-Triaxial Unloading and Local Dynamic Disturbance
Experimental Study of Slabbing and Rockburst Induced by True-Triaxial Unloading and Local Dynamic Disturbance
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真三轴卸载和局部动力扰动引起的板崩和岩爆试验研究
DOI：
10.1007/s00603-016-0990-4
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发表时间：
2016-09-01
影响因子：
6.2
通讯作者：
Zhou, Jian
中科院分区：
文献类型：
--
作者：
Du, Kun;Tao, Ming;Zhou, Jian
片帮/剥落和岩爆是高应力环境下，在卸荷和各种动荷载作用下，硬岩的非常规破坏形式。在这项研究中，不同的岩石类型（花岗岩，红砂岩，水泥砂浆）的破坏行为进行了研究，使用一种新的测试系统耦合到真三轴静态载荷和局部动态扰动。利用声发射系统和高速摄像机对压裂过程进行了实时记录。真三轴卸荷试验结果表明，花岗岩和砂岩发生板状破坏，而水泥砂浆发生剪切破坏。在局部动扰动荷载作用下，在低幅局部动荷载作用下，试件均未出现明显的破裂，但随着局部动荷载幅值的增大，岩石的破坏程度增大。水泥砂浆在测试过程中没有出现故障，测试后显示出相当大的承载能力。砂岩经历了一个相对稳定的破裂过程，而在花岗岩标本发生了剧烈的岩爆。破裂过程似乎并不依赖于局部动态加载的方向，和岩石破碎过程中的声发射计数率表明，类似的裂纹演化发生在两个测试方案（真三轴卸载和局部动态扰动加载）。
Slabbing/spalling and rockburst are unconventional types of failure of hard rocks under conditions of unloading and various dynamic loads in environments with high and complex initial stresses. In this study, the failure behaviors of different rock types (granite, red sandstone, and cement mortar) were investigated using a novel testing system coupled to true-triaxial static loads and local dynamic disturbances. An acoustic emission system and a high-speed camera were used to record the real-time fracturing processes. The true-triaxial unloading test results indicate that slabbing occurred in the granite and sandstone, whereas the cement mortar underwent shear failure. Under local dynamically disturbed loading, none of the specimens displayed obvious fracturing at low-amplitude local dynamic loading; however, the degree of rock failure increased as the local dynamic loading amplitude increased. The cement mortar displayed no failure during testing, showing a considerable load-carrying capacity after testing. The sandstone underwent a relatively stable fracturing process, whereas violent rockbursts occurred in the granite specimen. The fracturing process does not appear to depend on the direction of local dynamic loading, and the acoustic emission count rate during rock fragmentation shows that similar crack evolution occurred under the two test scenarios (true-triaxial unloading and local dynamically disturbed loading).