基于颗粒离散元法不同岩性巷道围岩声发射特性和能量演化规律研究

Particle-discrete-element-method-based research on acoustic emission characteristics and energy evolution laws of surrounding rock in different lithologic roadway

为分析不同岩性巷道围岩声发射特性和能量演化规律,对巷道围岩进行钻孔取样并试验,基于离散单元法的颗粒流程序建立不同岩性岩石单轴压缩数值模型,获得描述岩石的细观力学参数,并在此基础上建立3种岩性(硬岩、软硬互层和软岩)巷道颗粒流分析模型,系统分析单轴压缩试验及不同岩性状态下巷道围岩的声发射特性和能量演化规律。结果表明:单轴压缩模型下硬岩的声发射数小于软岩,最大声发射事件数滞后于峰值强度出现,且在峰前阶段外界做的总功基本上转化为应变能。开挖扰动下巷道围岩声发射特性和能量演化规律与岩性密切相关,硬岩巷道声发射事件数最小,软硬互层次之,软岩最大;3种岩性状态下软岩开挖巷道释放的动能最大,巷道围岩变形严重。

To analyze acoustic emission characteristics and energy evolution laws of surrounding rock in different lithologic roadway, samples drilled from the roadway surrounding rock were tested, the uniaxial compression numerical model of different lithologic rock was established based on the particle flow code （PFC） of the discrete element method, and the meso-mechanical parameters of the rock were obtained, based on which the different roadway particle flow analysis models of three kinds of lithology （hard rock, soft-rock interbed and soft rock） were established, and the uniaxial compression tests, acous- tic emission characteristics and energy evolution laws were systematically analyzed. The results have shown that under the uniaxial compression model, the number of acoustic emission in hard rock is less than that in soft rock, the maximum number of acoustic emission appears after the peak intensity, and the total energy of the outside is basically converted into strain energy in the pre-peak stage. Under the excavation disturbance, the acoustic emission characteristics and energy evolution laws are closely re- lated to the lithology： the event number of hard rock is the minimum, soft-rock interbed stays medium, and soft rock is the maximum; the kinetic energy released by soft rock excavation roadway is the largest, which results in severe deformation of roadway surrounding rock.