煤与瓦斯突出过程中气压时空演化规律

发布时间：2018-03-29 21:09

本文选题：煤与瓦斯突出　切入点：瓦斯压力　出处：《岩土力学》2017年01期

【摘要】：煤与瓦斯突出是严重威胁煤矿安全生产的地质灾害之一。近年来,随着采掘深度不断增加,地应力与瓦斯压力不断加大,突出次数也日益频繁,同时由于煤矿井下开采活动,使煤岩体中地应力场发生变化,在掘进工作面或回采工作面前方形成由卸压区、应力集中区和原始应力区组成的三带,给煤与瓦斯突出的预防与治理带来更大的困难。以天府三汇一矿为工程背景,基于相似理论试验模拟了采动条件下的煤与瓦斯突出过程,并分析了突出过程中气压的时空演化规律。研究结果表明:突出的发展是煤体由突出启动点向周围逐渐破坏并抛出的过程,相对突出强度为8.79%,且突出过程具有阵发性,表现为煤体的间歇式多次抛出和气压的反复升降,其中突出口附近气压的升幅较大,达到69.2%,而远离突出口处气压表现为短时间内急剧下降,之后缓慢下降并逐渐趋于大气压;突出过程中气压等压面近似以突出口为中心呈球面分布,且气体解吸区域近似呈球壳状逐渐向外扩展,球壳的扩展速度约为130 mm/s,球壳附近气压梯度较大。
[Abstract]:Coal and gas outburst is one of the geological disasters which seriously threaten the safety of coal mine production. In recent years, with the increasing of mining depth, the in-situ stress and gas pressure are increasing, and the outburst times are becoming more and more frequent, at the same time, due to the underground mining activities, The ground stress field in coal and rock mass is changed, and three zones are formed in front of tunneling face or stoping face, which consist of relief zone, stress concentration area and original stress zone. It is more difficult to prevent and control coal and gas outburst. The process of coal and gas outburst under mining condition is simulated based on similar theory test with Tianfu Sanhui No.1 Mine as the engineering background. The results show that the outburst development is a process in which the coal body is destroyed and thrown out from the outburst starting point, the relative outburst intensity is 8.79, and the outburst process is paroxysmal. It shows that the intermittent ejection of coal body and the repeated rise and fall of air pressure, in which the air pressure near the protruding mouth increases greatly, reaching 69.2, but the air pressure far away from the outburst decreases sharply in a short period of time, then slowly decreases and gradually tends to atmospheric pressure; In the process of outburst, the pressure isobaric surface is approximately spherical at the center of the bulge, and the region of gas desorption is approximately spherical shell. The velocity of expansion of the spherical shell is about 130 mm / s, and the pressure gradient near the spherical shell is larger.
【作者单位】：重庆大学煤矿灾害动力学与控制国家重点实验室;重庆大学复杂煤气层瓦斯抽采国家地方联合工程实验室;中煤科工集团重庆研究院有限公司;
【基金】：重庆市基础与前沿研究计划项目(No.cstc2013jj B90001) 中国博士后科学基金资助项目(No.2014M552323) 煤矿灾害动力学与控制国家重点实验室自主研究课题重点项目(No.2011DA105287-ZD201203)~~
【分类号】：TD713

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