Experimental study of crack evolution in prefabricated double-fissure red sandstone based on acoustic emission location
Experimental study of crack evolution in prefabricated double-fissure red sandstone based on acoustic emission location
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DOI：
10.1007/s40948-021-00219-8
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发表时间：
2021-01
影响因子：
5
通讯作者：
Jing Yang;Sheng-qi Yang;Guangli Liu;W. Tian;Ye Li
中科院分区：
文献类型：
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作者：
Jing Yang;Sheng-qi Yang;Guangli Liu;W. Tian;Ye Li
岩石损伤过程中微裂纹的发展影响着表面宏观裂纹的扩展。为了探究岩石中既有缺陷的裂纹演化过程，基于声发射（AE）源定位结果，分析了微裂纹发育对破坏模式的影响。通过分析声发射特征参数，确定了影响微裂缝发育的主要控制因素。结果表明：(1)岩样微裂纹的发育呈现出高能量断裂点、低能小断裂区、大面积断裂区、宏观断裂带的发展趋势。(2)岩石破坏模式的差异源于岩石桥对高能裂缝数量、位置和延伸方向的影响，从而导致岩石样品中主损伤区形成的差异。(3)随着岩桥倾角的增大，微裂纹总数、剪切裂纹比例和混合裂纹比例逐渐增加，导致岩样从简单的拉伸破坏模式逐渐演化为复杂的裂纹贯通模式。岩桥倾角的变化在微观上影响岩石颗粒的应力方向，在宏观上影响宏观裂纹扩展方向。
The development of micro-cracks during damage to rocks affects the propagation of macroscopic cracks on the surface. To explore the crack evolution among pre-existing flaws in rocks, based on the acoustic emission (AE) source location results, the paper analysed the influences of micro-crack development on failure mode. By analyzing AE characteristic parameters, the main controlling factors affecting the development of micro-fractures are determined. The results show that: (1) the development of micro-cracks in rock samples presents a trend of having a high-energy fracture point, the low-energy and small fracture region, the extensive fracture region, and a macroscopic fracture zone. (2) The difference in rock failure mode arises from the influence of rock bridge on the number, location, and extension direction of high-energy fractures, which results in the difference in the formation of main damage zone in rock samples. (3) The total number of micro-cracks, the proportion of shear cracks, and mixed-mode cracks gradually increase with the increase of the rock bridge inclination angle, leading to the gradual evolution of rock samples from simple tensile failure mode to complex crack penetration mode. The variation of the rock bridge inclination angle affects the stress direction of the rock particles at a microscopic level, while it affects the direction of macroscopic crack propagation at a macroscopic level.