摘要
为探究瓦斯抽采钻孔孔周煤岩体渐进性破坏过程中裂隙和应变能演化特征,设计了完整试样和含孔试样,开展渐进性破坏试验;通过VIC-3D观测系统,获取试样表面变形情况,计算并分析试样表面裂隙动态演化过程,裂隙分布情况及应变能演化特征。研究结果表明:含孔试样抗压强度较低,且钻孔孔周产生较多裂隙,孔上下两侧变形严重,表明在实际钻孔施工过程中,煤岩体抗压强度会大幅下降,钻孔周围产生较多裂隙,从而造成钻孔破坏,甚至塌孔;渐进性破坏过程中,孔周煤岩体表面裂隙发生动态演化,其动态演化过程与加载应力呈对应关系,同时通过对比裂隙张开量和错动量演化特征,判定试样破坏的主要裂隙类型为张开、错动混合型裂隙;在渐进性破坏过程中,孔周煤岩体表面裂隙演化过程与局部化区域变形能密度累积保持对应关系,不同局部化区域的应变能密度演化特征不同,体现出孔周煤岩体在渐进性破坏过程中存在内部能量调整。
In order to explore the evolution characteristics of cracks and strain energy during the progressive failure process of coal and rock mass around the gas drainage borehole,in this paper,complete samples and samples with holes are designed to carry out progressive failure tests.Through the VIC-3D observation system,we obtain the surface deformation of the sample,calculate and analyze the dynamic evolution process of the surface cracks,the distribution of the cracks and the evolution characteristics of strain energy,and obtain the following conclusion:the compressive strength of the sample with the hole is low,and there are many cracks around the drill hole,and the upper and lower sides of the hole are deformed seriously.It shows that:in the actual drilling process,the compressive strength of coal and rock mass will be greatly reduced,and many cracks will be generated around the drilling,which will cause the drilling damage and even the collapse of the hole.During the progressive failure process,the surface cracks of the coal and rock mass around the hole undergo dynamic evolution,and the dynamic evolution process corresponds to the loading stress.At the same time,by comparing the evolution characteristics of the crack opening and the dislocation amount,the main type of cracks for the sample failure can be determined.It is an open and staggered mixed type of fissure.During the progressive failure process,the evolution process of the surface cracks of the coal and rock mass around the hole maintains a corresponding relationship with the accumulation of deformation energy density in the localized area. The strain energy densityevolution characteristics of different localized regions are different, which reflects the coal and rock mass around the hole. There isinternal energy adjustment in the progressive destruction process.
作者
马德
赵育云
郭德龙
邰玉龙
MA De;ZHAO Yuyun;GUO Delong;TAI Yulong(Xiashijie Coal Mine,Tongchuan Mining Co.,Ltd.,Tongchuan 727101,China;Shaanxi Jianxin Coal Co.,Ltd.,Huangling 727300,China;Xunyi Zhongda Yanjiahe Coal Mine Co.,Ltd.,Xianyang 711300,China)
出处
《煤矿安全》
CAS
北大核心
2022年第3期16-23,共8页
Safety in Coal Mines
关键词
孔周煤岩体
渐进性破坏
裂隙动态演化
局部化区域
应变能演化
coal mass around gas drainage boreholes
progressive failure
fracture dynamic evolution
localization region
strain energy evolution
