深部变面长采场顶板破断演化的力学机制分析  

Study on mechanical mechanism of roof fracture evolution in deep stope with variable face length

作　　者：王新丰 陆明远 WANG Xinfeng;LU Mingyuan(College of Environment and Resources,Xiangtan University,Xiangtan 411105,China;School of Energy and Mining Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China)

机构地区：[1]湘潭大学环境与资源学院,湖南湘潭411105 [2]中国矿业大学(北京)能源与矿业学院,北京100083

出　　处：《煤田地质与勘探》2022年第10期1-15,共15页Coal Geology & Exploration

基　　金：国家自然科学基金项目(51904266);湖南省教育厅优秀青年基金项目(21B0144);湖湘高层次人才聚集工程创新团队项目(2019RS1059)。

摘　　要：不规则煤层开采容易引发顶板应力集中、矿压显现异常等问题,为探究变面长采场顶板破断规律与结构演化特征,针对工作面斜长由小变大的突变型采场不同开采阶段的几何特征与力学成因,运用小挠度薄板弯曲理论依次建立并解析4种边界条件的顶板结构模型。根据变面长采场顶板矿压分区显现特征,采用MATLAB与FLAC数值模拟方法分析顶板破断规律与宏观力学响应。通过系统分析与总结归纳,构建了变长工作面“三场三区三结构”的覆岩结构传递演化模式,提出了“两场两规律”的顶板分区破断效应。并通过典型工程案例的矿压实测进行应用验证。结果表明:变面长采场分为小面采场、变面采场和大面采场,小面采场顶板为缓压型结构,发生的是传统“O-X”形破断;变面采场顶板为突变型结构,顶板断裂产生的延长形与漂移形“O-X”破断裂隙与大面采场增压型结构顶板的裂纹发育特征较为相似,故将二者整合为全大面采场;全大面采场顶板发生的是“X-O”形破断,裂纹继续发展产生延长形破断,形成“两场两规律”的顶板破断理论。研究结论为探明变面长采场的覆岩运移本质,加强深部复杂煤层赋存条件下的顶板灾害防控提供了重要依据。Irregular coal seam mining is easy to cause the problems such as roof stress concentration and abnormal ground pressure behavior. In order to explore the roof fracture law and the structural evolution characteristics of stope with variable length, the roof structure models with four types of boundary conditions were established and analyzed using the small-deflection thin plate bending theory in view of the geometric characteristics and mechanical causes of the abrupt stope with the inclined length of working face changing from small to large in various mining stages. Meanwhile,the roof fracture law and macro-mechanical response were analyzed by MATLAB and FLAC numerical simulation methods based on the zoning characteristics of roof ground pressure in stope with variable face length. Through systematic analysis and summary, the transmission and evolution model of overburden structure comprising “three stopes, three areas and three structures” in working face with variable length was constructed, and the regional fracturing effect of“two stopes and two laws” was put forward. Besides, the application was verified by the measured ground pressure of typical engineering cases. The results show that the stope with variable face length is divided into small-face stope, variable-face stope and large-face stope. Specifically, the roof of small-face stope is in a slow pressure structure, where the traditional “O-X” fracture occurs. The roof of variable-face stope is in an abrupt structure, where the cracks generated by the extended and drift “O-X” fractures have similar development characteristics to the cracks in the roof of large face stope in pressurized structure, and so they are integrated into a full-face stope. Besides, the roof of the full-face stope is fractured in “X-O” shape, with the cracks developing continuously to produce the extended fracture. Thus, the roof fracture theory of “two stopes and two laws” was formed. The research conclusion provides an important basis for exploring the

关 键 词：变面长采场 薄板弯曲 覆岩结构 “O-X”破断 失稳破坏 顶板防控 

分 类 号：TD821[矿业工程—煤矿开采]