近距离煤层群叠加开采卸压效应的数值模拟分析

Numerical simulation on superposition mining pressure relief effect of near distance coal seam group

以金佳矿为工程背景,采用FLAC3D数值模拟软件对矿井中煤组11223和111811这2个工作面的先后叠加开采过程进行了数值模拟分析,得出了煤岩层的应力分布、位移变化规律及塑性区破坏形态.结果表明:叠加开采后在煤岩层中形成了的3个不同区域的应力,即煤柱、切眼及进回风巷的应力升高区、采空区中部的应力降低区和远离工作面的原始应力区;应力云图和位移云图的形态走向均为平顶梯形,倾向均为斜梯形;塑性区图走向为驼峰顶边梯形,倾向为圆顶斜梯形.叠加后形态基本未改变,但其范围有所加大.

Taking Jinjia mine as the engineering background, the overlapping mining process of two working face of 11223 and 111811 in the mine coal group was simulated by using FLAC3D software and stress distribution, and the displacement and plastic zone failure pattern of the coal and rock were gotten. Results showed that the stress in three different regions were formed in coal beds after overlapping mining, namely, the stress increasing region of coal pillar, cutting holes and the return air lane, the stress decreasing zone of the central mining goal, and the original stress zone away from working face. The form and trend of stress nephogram and displacement nephogram were fiat trapezoid and the tendency was oblique trapezoid. The trend of plastic zone graph was crest trapezoid and the tendency was dome inclined ladder. The pattern did not change after superposition, but the range increased.