地应力方向与围岩稳定性关系研究

Research on Relationship between Direction of In-situ Stress andStability of Surrounding Rock

地应力方向与巷道轴向的夹角对围岩稳定性有重要影响,在三山岛金矿西山分矿深部某水平巷道开展研究,采用FLAC3D数值模拟软件模拟分析,研究最大水平主应力与巷道的角度约为0°、30°、45°、60°、90°的五种工况开挖后应力分布及围岩位移规律。研究结果表明:在其他工况条件相同时,当夹角α不同时,围岩变形趋势基本一致,最终都趋于稳定值,且夹角α越大巷道围岩稳定性就越差;当巷道走向与最大水平主应力方向夹角在0°~30°时,巷道边帮受影响较大,需注重边帮支护;当夹角α在30°~60°时,巷道边帮与顶板承载应力及围岩位移接近,此时需对顶板和边帮进行相同强度的支护;当α在60°~90°时,顶板位移明显大于两帮,易发生剪切破坏,应当注重顶板支护。

The angle between the direction of the in-situ stress and the roadway axial has a great impact on the stability of the surrounding rock.The research is carried out in a horizontal roadway deep in Xishan branch mine of Sanshandao Gold Mine,and FLAC3D numerical simulation software is used for simulation analysis.The stress distribution and surrounding rock displacement after excavation under five working conditions that angles of the maximum horizontal main stress and roadway are approximately 0°,30°,45°,60°and 90°are studied.The research results show that the maximum main stress of the roadway side is about half of the maximum main stress on both sides of the roadway roof.When the angle between the roadway strike and the direction of the maximum horizontal main stress is 0°to 30°,the most affected are the roadway sides,and attention should be paid to the side support.When the angleαis 30°to 60°,the bearing stress and surrounding rock displacement of the roadway side are close to those of the roof.At this time,the roof and the sides should be supported with the same strength.Whenαis 60°to 90°,the displacement of the roof is significantly greater than that of the two sides,which is prone to shear failure and attention should be paid to roof support.