摘要
为了揭示浅埋房式采空区对下位煤层开采矿压显现的控制机制,降低工作面过房式采空区的动压显现强度和压架风险,以神东矿区霍洛湾煤矿2-2煤层房式采空区下3-1煤层长壁开采工作面动压特征为研究对象,将3-1煤层覆岩结构分为四类,利用理论分析和相似材料模拟等方法,系统研究了不同覆岩结构类型运动特征、力学模型及对3-1煤层长壁工作面的动压控制机制。结果表明:房式采空区稳定房柱下易形成上下位关键层双悬臂梁结构,双悬臂梁结构协同失稳是形成动载矿压的主要原因;房柱失稳区主关键层形成的不稳定砌体梁结构及靠近大煤柱未失稳的房柱随下位煤层开采滑落失稳是导致长壁工作面动载矿压发生的原因;当3-1煤层工作面上覆前方为房柱失稳区时,工作面推出集中煤柱时的动载矿压是由于大煤柱两侧关键块已提前滑落失稳,两关键块间无作用力,倒梯形岩柱与亚关键层联合失稳作用结果;当3-1煤层工作面上覆前方为房柱稳定区时,工作面推出集中煤柱时,动载矿压是由房柱失稳所致。
In order to explore the control mechanism of pressure appearing in the lower coal seam of shallow-buried coal bed with room mining goaf, to reduce the dynamic pressure of the working face through the room mining goaf, and to mitigate the risk caused by the coal pillar due to removal of hydraulic support, dynamic pressure characteristics of the 3-1 coal bed working face with longwall mining under the 2-2 coal bed room mining goaf are studied. The overburden structure of 3-1 coal seam is divided into four types. The theoretical analysis and simulation of similar materials are adopted to analyze the structure and motion models for the overlying strata under dynamic load, and to reveal the mechanism of dynamic pressure. Conclusions are as follows: with the stability of the room goaf, the double cantilever beam structures easily lead to the upper and lower key layers, and the fracture of the key stratum is the main reason for the formation of dynamic load. The unstable masonry beam structure with the instability of the main roof and the room pillars near the large coal pillar are not unstable. The instability of the structure is caused by the collapse of the lower coal seam, resulting in the dynamic ground pressure. The key block firstly slides due to instability, and two key blocks without force and trapezoidal weight of rock pillar above the coal pillar are directly applied on the working face, which causes the roof to fall behind. When the coal pillar cannot effectively support the above inverted trapezoidal rock pillar, the instability of trapezoidal rock pillar and crack movement of roof collapse cause dynamic load in common.
作者
霍丙杰
荆雪冬
范张磊
谢伟
段志华
解振华
HUO Bing-jie;JING Xue-dong;FAN Zhang-lei;XIE Wei;DUAN Zhi-hua;XIE Zhen-hua(College of Mining Engineering,Liaoning Technical University,Fuxin 123000,China;Shendong Tianlong Group,Erdos 017000,China)
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2019年第6期1116-1123,共8页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金项目(51504127,51774174)
关键词
浅埋煤层
房式采空区
覆岩结构
动载机制
覆岩运动
shallow seam
room mining goaf
overburden structure
mechanism of dynamic load
overburden movement
作者简介
霍丙杰(1980-),男,博士,副教授,主要从事矿山压力与矿井动力灾害防治研究工作。Email:huobingjie@163.com.
