穿采空区巷道围岩特性分析及稳定性控制

Characteristics Analysis and Stability Control of Surrounding Rock in Crossing the Mined-out Area Roadway

针对芦岭煤矿穿采空区巷道围岩工程环境特性问题,采用现场测试,钻孔窥视,数值模拟等方法,分析巷道在穿采空区不同区段围岩损伤区及矿压显现规律。研究结果表明,巷道穿采空区不同区段围岩具有明显分区特性,采空区上段巷道在逐渐靠近采空区时,损伤区范围逐渐扩大,完整性变差,围岩压力却较小;远离采空区下区段巷道围岩,裂隙发育程度较低,但是围岩压力表现更为明显。因此,结合巷道围岩的工程环境特点提出分区段控制技术方案,远离采空区卸压范围的围岩,主要采用锚杆、锚索加喷层的联合支护技术,改变浅层裂隙岩体的力学性能与围岩形成整体性结构,抵抗更大的围岩应力;采空区及附近围岩采用以U型钢为主体的刚性支护,防止裂隙岩体进一步碎胀扩容而产生的变形。现场支护表明,巷道顶底板及两帮位移量均小于30 mm,现场支护效果明显。

Aiming at the environmental characteristics of the surrounding rock engineering of the mined-out area in the Luling Coal Mine,the field test,borehole imaging,and numerical simulation were used to analyze the surrounding rock damage zone and the mining pressure behavior of different sections of the mined-out area.The research results show that the surrounding rock of different sections through the mined-out area has obvious zoning characteristics.When the upper roadway is gradually approaching in the mined-out area,the area is gradually expanded and destroyed,and the integrity is weaker,but the rock pressure is smaller;away from the surrounding rock of the lower mining area,the crack is to a lesser extent,but the surrounding rock pressure is more obvious.Therefore,combined with the environment characteristics of the roadway surrounding rock,a sub-section control technical scheme is proposed.When the surrounding rock is far away from the pressure relief area of the mined-out area,the joint support technology of anchor bolt,anchor cable,and spray layer is mainly used to change the mechanical properties of shallow fractured rock mass and the integral structure of surrounding rock to resist greater surrounding rock stress;the mined-out area and nearby surrounding rock adopt rigid support with Ushaped steel as the main measure to prevent deformation caused by further expansion and expansion of the fractured rock mass.The on-site support shows that the displacement of roof,floor and,the two sides are less than 30 mm,and the supporting effect is obvious.