弱含水条件下巷道顶板变形特征及过程控制技术

Roof Deformation Features and Procedure Control of Mining Gateway Under Weak Water Bearing Condition

针对梅花井煤矿回采巷道顶板含水、直接顶厚度和岩性变化大、易风化,导致支护失效的问题,对煤层顶底板岩石物理力学性质进行了测试;对巷道掘进期间表面位移进行了观测,发现顶底板移近量是两帮移近量的2倍多,而且由于锚杆或锚索孔出水使顶板浅部围岩软化,顶底板变形一直不稳定;分析了水对巷道顶板岩体弱化机理,得出地下水不仅诱发顶板围岩节理裂隙面等发生剪切滑移,同时软化顶板自身强度。在此基础上,提出弱含水顶板动态过程控制技术,以顶为主,兼顾两帮的支护思路及锚杆支护设计,并应用于首采工作面巷道,巷道支护状况良好。

According to the support failure problems occurred by the roof water bearing, direct roof thickness and high variation and high weathered lothology of the mining gateway in Meihuajing Mine, the rock physics mechanics properties of the seam roof and floor in the mine were tested and measured. The surface displacement of the gateway was observed and measured during the gateway driving period. The convergence between the roof and floor was 2 times larger than the displacement value between the two side walls as found. Due to the water flow from the bolt boreholes or anchor boreholes, the surrounding rocks in the shallow section of the roof were often and the deformation of the roof and floor were always in unstable. The weaken mechanism of water to the roof rock of the gateway was analyzed. The un- derground water would not only cause the joint cracking face of the roof surrounding rock and cause the shearing sliding, but also soft the strength of the roof. Based on the circumstances, the control technology of the water bearing roof dynamic process was provided. The sup- port conception and bolt support design with the roof as the main and the two side walls as secondary was provided and had been applied to the mining gateway of the first coal mining face in the mine with a good support condition in the gateway.