深部开采松软煤层抽采钻孔变形特性研究

发布时间：2018-07-22 11:09

【摘要】：为了研究深部开采松软煤层抽采钻孔变形失稳特性,基于有限元理论和统计损伤理论数值模拟了深部开采松软煤层抽采钻孔变形失稳整个过程,分析了钻孔周围煤体应力及形变分布、卸压区演化和渗透特性。研究表明:钻孔破坏形式为上方发生垮塌,形成垮塌区;左右侧发生破坏,形成破碎区;钻孔周围煤体均向钻孔移动,钻孔附近煤体位移量较大,远处煤体位移量相对较小;钻孔形状由开始的圆形逐渐变成"类橄榄球形",然后钻孔"类橄榄球形"断面逐渐减小至坍塌。钻孔失稳过程中,钻孔附近煤体渗透率逐渐增大,钻孔周围煤体渗透率变化量及变化范围均不断增加;周围煤体渗透率分布均大致呈"V"字型变化规律,即煤体渗透率呈随着距钻孔距离的增加先减小后增加然后趋于稳定的趋势。研究结果可以为我国煤矿深部开采松软煤层瓦斯治理和煤层瓦斯抽采提供理论支撑,具有指导性意义。
[Abstract]:In order to study the deformation and instability characteristics of extraction borehole in deep mining soft coal seam, based on finite element theory and statistical damage theory, the whole process of borehole deformation instability in deep mining soft coal seam is simulated. The distribution of stress and deformation of coal around the borehole, the evolution of pressure relief zone and the permeability characteristics are analyzed. The results show that the failure of borehole is in the form of collapse in the upper part, failure in the left and right side, the coal body moves to the borehole, the displacement of the coal body near the borehole is larger, and the displacement of the coal body in the distance is relatively small. The shape of the borehole changes from the initial circle to the rugby shape, and then the section of the borehole reduces to collapse. During the process of borehole instability, the permeability of the coal body near the borehole increases gradually, the change amount and range of the permeability of the coal body around the borehole increase continuously, and the distribution of the permeability of the surrounding coal body is approximately the "V" shape change rule. That is, the coal permeability decreases first and then increases with the increase of the distance from the borehole to the borehole, and then tends to stable. The results can provide theoretical support for gas treatment and gas drainage of soft coal seam in deep coal mining in China, which is of guiding significance.
【作者单位】：煤炭安全生产河南省协同创新中心;河南省瓦斯地质与瓦斯治理重点实验室—省部共建国家重点实验室培育基地;河南理工大学安全科学与工程学院;
【基金】：国家自然科学基金项目(51174079) 教育部“长江学者和创新团队发展计划”创新团队项目(IRT1235) 河南省基础与前沿技术研究计划(142300413233)
【分类号】：TD712.6

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