微地震监测揭示的采场围岩空间破裂形态

Spatial fracturing progresses of surrounding rock masses in longwall face monitored by microseismic monitoring techniques

中澳联合课题组采用微地震定位监测技术,观测和研究了煤矿长壁工作面围岩的空间破坏规律,分析得出:地层进入充分采动阶段前,岩层的破裂高度近似为采空区短边长度的一半;证实了采空区"见方"时顶板破裂高度达到最大值,且采场顶板容易来大压(异常压力),解释了国内外部分综采、综放采场支架压坏的岩层运动机理;根据微地震监测结果,提出了工作面长度为200～250m时底板破裂深度的估计曲线以及岩层离层与破裂的微地震显现的差异;初步描述了采场围岩空间破裂的形态,即在采空区周围顶、底板及四周煤体破裂后形成的三维空间破裂形态.

By using microseismic monitoring techniques, China-Australia cooperation research group observed and researched the spatial fracturing rules of surrounding rock masses in longwall faces. After analyzing the observation results, the authors come to the conclusions as follows: when working face advanced from open to the enough mining period, the fracturing height of overlying strata is about the half length of the shorter edge of goaf. When the shape of goaf is approximate to square, the supports in longwall face would be bearded the extreme load of roof, it explains the facts happen in many coal mines in China. The authors present the curve of evaluating fracturing height of floor when the width of longwall face along dip being from 200 to 250 m, and discuss the difference of microseismic events between strata separating and fracturing. At last, the authors describe the spatial fracturing shape of surrounding rock masses above longwall face monitored by microseismic monitoring techniques, it is threedimension spatial fracturing shape after the rooffloor around goaf and coal fractured.