School of Mining, Guizhou University
Engineering Center of Safety Technology for Mining under Complex Geological Conditions
Institute of Mine Gas Disaster Prevention and CBM Exploitation, Guizhou University
China Coal Research Institute Co. , Ltd.

为研究近距离下煤层首采工作面开采对软弱煤岩破坏变形特征的影响,以熊家湾煤矿20903首采工作面为研究背景,基于数值模拟、理论分析和现场观测等手段分析近距离首采工作面开采对软弱煤岩(C8煤层)的裂隙发育、应力变化以及膨胀变形等特征的影响。研究表明:随首采工作面推进,煤体裂隙网格持续发育,表现为裂隙产生到裂隙稳定发育、裂隙稳定发育到弯曲下沉和弯曲下沉到裂隙压实阶段;C8煤层膨胀变形呈“压缩→膨胀→稳定”的变化规律,其煤层最大膨胀变形值为12.1mm和11mm,位于卸压膨胀稳定区内;根据现场观测可知,C8煤层软弱煤岩整体稳定,部分煤岩体存在破碎裂隙区,局部顶板岩石虽已发生松动,但对岩层稳定无太大影响。

In order to study the characteristics of the failure and deformation of soft coal and rock caused by the mining of the first working face in lower coal seam of contiguous seams, the 20903 working face of Xiongjiawan Coal Mine was taken as the research background, the influence of the first working face mining on the fracture development, stress variation, and expansion deformation characteristics of soft coal and rock ( C8 coal seam) was analyzed based on numerical simulation, theoretical analysis, and on-site observation.The results show that, as the first mining face advances, fracture grid of the coal body continues to develop, manifested in the following stages: generation and stable development of fractures, stable development of fractures and bending subsidence, and bending subsidence and fracture compaction. The first working face mining changed the maximum principal stress value and area of C8 coal seam, resulting in the failure and deformation of C8 coal seam. The expansion deformation of C8 coal seam shows the law of compression → expansion → stability. The maximum expansion deformation values of C8 coal seam are 12. 1 and 11 mm, which are located in the pressure relief expansion stability zone. According to the field observation, the weak coal and rock of C8 coal seam are stable as a whole, some coal and rock have broken fracture zone, and some roof rocks have become loose, which has no great influence on the stability of rock strata.

国家自然科学基金项目(51874107,52164015);贵州省省级科技计划项目(黔科合平台人才[2018]5781号,黔科合支撑[2022]一般231)

蔡俊杰, 李希建, 郭隆鑫, 等. 近距离下煤层首采面开采对软弱煤岩破坏变形特征的影响 [J]. 煤炭工程,2023, 55(6): 123-127.