【作者】 鞠文君；

【导师】 王梦恕； 张顶立；

【作者基本信息】 北京交通大学 ， 岩土工程， 2009， 博士

【摘要】 甘肃华亭煤矿开采急倾斜特厚煤层,采用水平分层综合机械化放顶煤开采方法,近年来回采期间巷道中多次发生严重的冲击地压,造成人员伤亡和巨大的经济损失。华亭煤矿发生的冲击地压,是在特殊煤层条件和特殊开采方式下的巷道冲击地压新问题。本文以华亭煤矿巷道冲击地压为背景,综合运用理论分析、实验室和现场测试、相似材料模拟、数值模拟等研究手段,对华亭煤矿的煤层冲击倾向性和井下地应力进行了测试,对急倾斜特厚煤层水平分层综放开采条件下上覆岩层活动规律及矿压显现规律进行了比较深入的研究,在此基础上分析得出了华亭煤矿巷道冲击地压的成因,进而提出了华亭煤矿巷道冲击地压的防治对策,特别对冲击地压巷道支护技术进行了比较深入的研究。论文取得的主要研究成果有:(1)得出急倾斜特厚煤层水平分层开采上覆岩层移动和矿压显现特征:上覆岩层移动幅度大、动态性强;开采形成的采空区是一个随采动不断扩大和移动的动态陷落漏斗;多分层开采后,基本顶岩层形成“悬臂梁”结构;周期来压表现为分别沿走向和倾向的“双重性”特征;采场周围应力集中程度高、积聚能量大、易形成冲击载荷。(2)确定了华亭煤矿的冲击地压的成因。华亭煤矿的冲击地压是多种因素共同作用的结果:煤层及其顶板具有一定的冲击倾向性是冲击地压发生的内在条件;深部开采及向斜构造应力致使原岩应力已经达到较高水平;采出煤量多、上方岩层移动幅度大,造成采场周围巨大的采动附加应力;多工作面同采的高强度的开采方式,使多分层采动的附加应力叠加,形成畸高的动态集中应力;“悬臂梁”断裂形成的冲击载荷具有诱发和加强冲击地压的作用。(3)提出“避免形成和降低高应力是解决华亭煤矿冲击地压的有效途径”,并据此制订了“降低开采强度、深孔断顶爆破和加强巷道支护”的综合防治思路。(4)基于急倾斜特厚煤层顶板“悬臂梁”结构模型,提出了华亭煤矿顶板深孔爆破断顶技术并在华亭煤矿井下实施,取得了良好的技术效果。(5)论证得出锚杆支护是冲击地压巷道最有效的支护方式,并分析了冲击地压巷道锚杆支护的作用原理,提出了“抗冲击锚杆支护系统”及其支护理念—“高强度、强让压、整体性”。(6)建立冲击地压巷道支护设计方法—能量校核设计法:首先对巷道的冲击危险性进行预测:根据工程类类比提出初步设计,并采用数值模拟方法对各参数进行优化;最后根据冲击地压能量理论对支护系统的吸能指标进行校核。更多还原

【Abstract】 To mine the extremely thick and steep-inclined coal seam, a multiple-level sub-level caving method has been utilized in Huating mine of Gansu Province. Frequent rock-burst occurred in recent years have incurred serious casualties and economic loss. The rock-burst is a new project for Huating mine stemming from the specific coal seam sentimental condition and mining method.Based on the rock busting conditions of Huating mine, the overburden’s movement and rock pressure behavior characteristics have been deeply studied by comprehensively utilizing theoretical analysis, laboratory and site testing, similitude material simulation, and numerical modeling while accomplishing the testing of the rock-burst proneness of the coal seam and site-situ stress.The main achievements obtained in the dissertation are:(1) It was studied and verified that, under Huating mine geological conditions, the multiple-level sub-level caving method can typically cause large overburden displacement, rock proneness, high level of stress concentration, and high energy accumulation. It was also found that the development of the gob in the steep-inclined coal seam is a progressively dynamic and subsidiary funnel; a cantilever structural model was advanced and established according to the steep-inclined seam in Huating mine and mining method; a dual feature of the periodic pressure occurring in both longitude and dip was analyzed and demonstrated; high stress concentration and energy accumulation around the longwall panel causing rock burst proneness.(2) The rock burst results from multiple factors: roof and coal seam with burst proneness; high field stress level caused by deep mining and a syncline; additional mining stress around the panel caused by the high coal production and large overburden displacement; dynamic stress concentration caused by the superposition from multiple workings; the dynamic load yielded from the cantilever failure inducing and strengthening the rock burst..(3) An effective way has been established in preventing and reducing the rock burst for Huating mine. Accordingly, a comprehensive method, including mining intensity reduction, deep hole roof exploration, and entry support reinforcement, has been formulated as well.(4) Based on the model of the cantilever beam established for the steep-inclined thick coal seam, the stress-relieve method via deep hole exploration has been implementing underground.(5) It was found that rock bolting is the optimal way in preventing and reducing the rock burst. A rock-burst resistance rock bolting system been put forward while analyzing the rock bolting principle in rock burst entry. Meanwhile, a theory of rock bolting system specifically in resisting the rock burst, high bolt strength, pressure relieve at a high stress level, and integrity, has been developed.(6) The methodology, energy calibration, of rock bolting design for resisting rock burst has been developed: First of all, proneness prediction of the entry; Secondly, parameter optimization via numerical modeling; Finally, parameter calibration based on the rock burst theory.更多还原