Lei Gang, Wu Dawei, Zhu Shengyan
Faculty of Quality Management and Inspection, Yibin University, Yibin, Sichuan, China.
Department of Civil Engineering, Chengdu Technological University, Chengdu, Sichuan, China.
PLoS One. 2023 Sep 28;18(9):e0286005. doi: 10.1371/journal.pone.0286005. eCollection 2023.
To study fracture mechanisms and initiation of stress fields in the rock mass around a roadway subjected to cyclic stress, a series of loading and unloading tests were conducted on the rock mass around the roadway by using high-precision acoustic emission (AE) monitoring. The results show that intense AE activities occur in a specimen during cyclic load-holding at different levels. With the increase in the number of cycles, the overall stability of the specimen gradually decreases. In the cyclic loading and unloading process, the specimen exhibits a Kaiser effect. As the number of cycles increases, more AE events occur in the unloading stage and a Felicity effect is manifest. The spatial distribution of AE events is related to the stress regime and structure of the specimen, crack propagation in the roadway exhibits directionality due to effects of the principal stress. High stress is conducive to microcrack initiation and propagation in the specimen, which accelerates damage accumulation and macrofracture formation in a rock mass. The research provides a reference for roadway support work and disaster prevention and control in deep mines.
为研究受循环应力作用的巷道围岩的断裂机制及应力场的起始，采用高精度声发射（AE）监测对巷道围岩进行了一系列加卸载试验。结果表明，在不同水平的循环持载过程中，试样中会出现强烈的声发射活动。随着循环次数的增加，试样的整体稳定性逐渐降低。在循环加卸载过程中，试样表现出凯泽效应。随着循环次数增加，卸载阶段发生更多声发射事件，呈现出费利西蒂效应。声发射事件的空间分布与试样的应力状态和结构有关，由于主应力的作用，巷道中的裂纹扩展具有方向性。高应力有利于试样中微裂纹的萌生和扩展，加速了岩体中损伤的积累和宏观断裂的形成。该研究为深部矿井巷道支护工作及灾害防治提供了参考。
