大倾角煤层群采动覆岩愈合阻水特性研究

项目名称： 大倾角煤层群采动覆岩愈合阻水特性研究

项目编号： No.41302273

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 天文学、地球科学

项目作者： 冯锦艳

作者单位： 北京航空航天大学

项目金额： 22万元

中文摘要： 通过对某大倾角煤层的研究发现，随着开采深度的增加，上部破裂覆岩愈合起到了一定的阻水作用，且阻水岩层恰为破碎覆岩重新形成的承载结构。本课题拟通过变换煤层群角度的方法验证大倾角煤层群开采其破碎覆岩重新形成的承载结构即为破碎覆岩愈合阻水带。通过相似材料试验以及电阻率响应试验反演煤岩层物理力学参数，在此基础上采用数值模拟计算方法计算煤层倾角、断层、煤岩层组合以及雨强、雨水持续时间多个因素影响下的覆岩裂隙分形维数，探讨裂隙分形维数与雨水渗流之间的动态关系，进而可评价不同因素影响下的覆岩愈合阻水效果。在已有的完善煤层破碎覆岩承载结构理论基础上，建立覆岩裂隙分形维数、孔隙水压力、采深与渗流量之间的动态关系式，可计算出覆岩起到愈合阻水作用所需的最小采深，为现场水害治理提供理论依据。

中文关键词： 大倾角煤层；采深；采动裂隙；分形维数；阻水作用

英文摘要： It is found in a research on steeply dipping seam that the top crack overlying strata closes up and stops water to some extent with increase of mining depth, and water-stop strata are just the bearing structure formed newly by broken overlying strata. This research task intends to verify that by transforming coal seam groups, the formed-newly bearing structure is just the waterstop belt closed up by the broken overlying strata with mining in the steeply dipping coal seam group. The physical mechanical parameters of coal bed are inverted in similar materials and resistivity response tests. On the basis of that, the fractal dimensions were calculated by numerical simulation for the overlying strata fracture under influences of factors such as coal bed angle, fault and coal bed combination as well as raininess and rainwater duration, and the dynamic relation between fracture fractal dimensions and rainwater seepage was explored, so as to evaluate the waterstop effect of overlying strata close-up. On the basis of previous broken overlying strata bearing structure theory on coal bed, the task intends to establish a dynamic relation expression of fractal dimension, pore water pressure, and mining depth and seepage discharge of the overlying strata fracture, calculate the minimum mining depth required for waterstop rol

英文关键词： steep coal seam；mining depth；mining-induced fractures；fractal dimension；block water effect