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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。
Coal and gas outburst is one of the geological disasters that threaten the safety of coal mines. In recent years, as the depth of excavation continues to increase, the continual increase of ground stress and gas pressure, the frequency of prominence is also increasing day by day. At the same time, due to the underground coal mining activities, the stress field in coal and rock body changes. In front of the area formed by the pressure relief zone, the stress concentration zone and the original stress zone composed of three zones, coal and gas outburst prevention and treatment more difficult. Taking Tianfu Sanhui No. 1 mine as the engineering background, the coal and gas outburst process under the condition of mining was simulated based on the similar theory test, and the temporal and spatial evolution of the barometric pressure during the salient process was analyzed. The results show that the prominent development is the gradual destruction and throwing of coal from the starting point to the periphery, the relative protruding strength is 8.79% and the salient process is paroxysmal, which is manifested as intermittent multiple throwing of coal body And the air pressure repeatedly rises and falls, in which the air pressure near the protruding mouth increases greatly, reaching 69.2%, while the air pressure far away from the protruding mouth drops sharply in a short time, then slowly drops and gradually tends to the atmospheric pressure; during the protruding air pressure isobaric surface The distribution of the gas desorption area is approximately spherical with a spherical shell. The expansion speed of the spherical shell is about 130 mm / s, and the pressure gradient near the spherical shell is larger.