单轴压缩下相似材料煤样破裂过程研究

Research on Crack Process of Similar Materials Coal Sample Under Uniaxial Compression

为研究巷道煤体的破裂演化过程,以平煤股份二矿庚一轨道巷为背景,采用水泥、石膏及全粒径煤粉等材料,制备不同配合比的相似材料煤样,通过单轴压缩试验及颗粒流(PFC^(2D))数值模拟,分析相似材料煤样的破坏模式及裂纹演化过程。结果表明:相似材料煤样的应力-应变曲线特征与原煤的曲线特征相似,试件破坏模式主要是沿斜截面剪切破坏;煤粉含量多的试样(水泥∶石膏∶全粒径煤粉=1∶1∶1.25)其破坏模式更接近原煤的破坏模式,PFC^(2D)数值模拟与室内试验得到的应力-应变曲线具有较好的一致性,最终破坏模式相似;根据裂纹累积曲线将裂纹演化过程分为裂纹产生、裂纹扩展、裂纹贯通3个阶段。研究结果为后期相似材料模型试验及巷道支护提供了技术指导。

To analyze the crack evolution process of coal mass in roadway,taking the Gengyi track roadway in No.2 coal mine of Pingmei Co.,Ltd.,as the background,similar material coal samples with different mix proportions were prepared by using cement,gypsum and full particle size pulverized coal as raw materials.The failure mode and crack evolution process of similar material coal samples were analyzed through uniaxial compression test and particle flow(PFC^(2D))numerical simulation.The results show that the stress-strain curve characteristics of similar materials coal samples are similar to those of raw coal.The failure mode of the specimen is mainly shear failure along the inclined section.And the failure mode of the specimen with high pulverized coal content(cement∶gypsum∶full particle size pulverized coal=1∶1∶1.25)is closer to the failure mode of raw coal.The stress-strain curve obtained by PFC^(2D) numerical simulation is in good agreement with that obtained by laboratory test,and the final failure mode is similar.According to the crack accumulation curve,the crack evolution process is divided into three stages,including crack generation,crack propagation and crack penetration.The research results can provide a technical guidance for the later similar material model test and roadway support.