摘要
为探究临近断层处孤岛工作面开采时断层煤柱的受力状态与动力显现的发生机理,理论分析了某矿7192工作面的覆岩结构及其运移规律,探讨了由断层错动导致的工作面动力显现及强矿震的发生机理,利用震动波CT技术对工作面冲击危险性进行动态预警。结果表明:1)工作面倾向覆岩结构将由以工作面煤体为承载主体的对称短臂"T"型结构转化为以断层煤柱为承载主体的非对称"T"型结构,走向上因工作面面长较短使中高位关键层出现较长悬顶,其上方为非对称"T"覆岩结构;2)工作面断层附近历次强矿震均受断层活动静止期影响,即矿震时隔越长,后续矿震能量越大;3)中高位关键层的突然破断与运动是工作面矿震活动的主要动力源,导致的断层煤柱承载能力失效使断层突然错动,产生的冲击动载与煤体高静载叠加诱发动力显现;4)震动波CT动态预警技术揭示了工作面区域的应力演化过程,且动力显现区域与强矿震位置也与反演结果吻合,证明了预警结果的可靠性。
To study the pressure status of fault pillar and the dynamic manifestation mechanism of min- ing on the island coalface along fault, the structure and movement law of overlying strata above work- ing face 7192 was analyzed theoretically, the mechanism of dynamic manifestation and strong mining tremor in the working face caused by fault dislocation was studied, and the dynamic pre-waming of rockburst hazard was also conducted with the technology of seismic tomography. The results have shown that 1） The overlying strata of working face in dip direction transforms from a symmetrical ＂I＂structure subjected to the coal mass of working face to an asymmetric ＂T＂ structure subjected to the fault pillar, and an asymmetric ＂T＂ structure is found in strike direction due to long hanging distance of middle and high key strata caused by short working face length; 2） The strong mining tremors occurring near the fault are influenced by.the interval of fault movement suspension： the released energy of latter mining tremor will be higher with the increasing time interval; 3） The strong mining tremors at the working face are mainly caused by the sudden rupture and movement of medium and high key strata, and the fault pillar failure results in sudden fault movements, which causes a dynamic loading combined with high stress loading in coal mass and triggers the dynamic manifestation; 4） The evolution process of stress redistributions in the working face area is revealed by the technology of seismic tomography dynamic pre-warning, and both areas of dynamic manifestation and strong mining tremors are consistent well with the tomography results, which proves the pre-warning reliability of seismic tomography.
出处
《采矿与安全工程学报》
EI
CSCD
北大核心
2017年第3期411-417,共7页
Journal of Mining & Safety Engineering
基金
国家自然科学基金项目(51674253)
国家重点研发计划项目(2016YFC0801406)
江苏高校优势学科建设工程项目(SZBF2011-6-B35)
关键词
动力显现
冲击矿压
覆岩运动
震动波CT
dynamic manifestation
rockburst hazard
overlying strata movement
seismic tomography
