CAJ | 학술논문

针对工作面一侧采空边界条件,建立三边固支一边简支高位硬厚岩层板结构力学模型,推导出硬厚岩层破断能量释放公式;通过比较岩板上表面固支边和下表面中部最大拉应力,揭示了硬厚岩层的变形破断规律;并结合现场微震监测数据,分析了高位硬厚岩层下开采微震活动分布特征.研究结果表明:当悬露系数λ＜1.024时,硬厚岩层倾向固支侧与下表面中部同时断裂,呈固支侧侧向跨度大于简支侧的竖向偏"O-X"型;否则,硬厚岩层走向固支边首先破断,呈对称的横向正"O-X"型;工作面开采时,小能量微震主要分布在厚关键层下方岩体内,且下方岩体运动易引发相邻采空区的微震活动;大能量微震活动发生在厚关键层破断失稳过程中,主要分布在厚关键层断裂线附近,集中于其内部及下方附近.
침대공작면일측채공변계조건,건립삼변고지일변간지고위경후암층판결구역학모형,추도출경후암층파단능량석방공식;통과비교암판상표면고지변화하표면중부최대랍응력,게시료경후암층적변형파단규률;병결합현장미진감측수거,분석료고위경후암층하개채미진활동분포특정.연구결과표명:당현로계수λ＜1.024시,경후암층경향고지측여하표면중부동시단렬,정고지측측향과도대우간지측적수향편"O-X"형;부칙,경후암층주향고지변수선파단,정대칭적횡향정"O-X"형;공작면개채시,소능량미진주요분포재후관건층하방암체내,차하방암체운동역인발상린채공구적미진활동;대능량미진활동발생재후관건층파단실은과정중,주요분포재후관건층단렬선부근,집중우기내부급하방부근.
Aiming at the boundary conditions of one side mined working face, a plate model with three clamper edges and one simply supported edge was established as the mechanical model of high-position hard thick strata, and an energy releasing formula of hard thick strata fracturing was proposed. Defor-mation and rupture law of hard thick strata was revealed by comparing the maximum tension stresses in clamped edges of rock plate's upper surface and the middle of lower surface. In addition, characteristics of microseismic energy distribution during the mining operation under high-position hard thick strata were analyzed combined with the microseismic monitoring data in field. Research results show that fracture happens at the same time in both lateral clamper side and the central of the lower surface whenλ＜1.024, the fracture form is an offset transverse"O-X" type, while the lateral span of the clamper side is lager than that of the simply support side. Otherwise, fracture first happens along the strike clamper edge, and the fracture form is a symmetrical vertical"O-X" type. During the mining process, small energy seismic events are mainly distributed in the rock mass below the thick key strata, and seismic events are easily triggered in the neighboring gob by the movement of lower rock mass. The high ener-gy seismic events mainly happen in the fracturing process and losing stability of high-position thick key strata, mainly distribute near the fracture line of thick key strata, and concentrate in the vicinity of the internal and lower parts.