College of Mining Engineering, Liaoning Technical University Xiaqing Coal Mine, Tiefa Energy Company

针对特厚煤层和多层坚硬顶板赋存条件下,工作面易出现液压支架压死、煤壁片帮和沿空巷道围岩变形严重、矿压显现强烈的问题,以同忻煤矿特厚煤层综放工作面为工程背景,对回采巷道和工作面进行矿压显现监测,分析多层坚硬顶板作用下的围岩应力和变形规律。研究表明:工作面开采引起的采动应力影响范围较大,多层坚硬顶板作用下覆岩形成了大结构,在其作用下围岩应力和变形表现为“上升突变”和“下降突变”交替出现。研究结果说明了特厚煤层大采出空间和多层坚硬顶板的共同作用是综放工作面强烈矿压显现的主要原因,据此提出了坚硬预裂爆破切顶和沿空巷道恒阻大变形锚杆吸能支护控制技术,可对强矿压进行有效防治。

Geological conditions of thick coal seam and multi-layer hard roof tend to result in the hydraulic support being crushed and rib spalling at the working fac e, as well as serious deformation of surrounding rock of the gob-side roadway together with dramatic strata behavior. The focus was laid on the fully-mechanized top co al caving mining face at Tongxin Mine, where the stress and deformation of surrounding rocks under the influence of multi-layer hard roof were monitored and analyzed. The results show that the mining stress generated by mining face has a large influence range. Under the impact of multi-layer overlying hard roof, the large overburden structure is formed, and the stress and deformation of the surrounding rock are"abruptly ascending"and" abruptly descending", alternately. The synergy of the large coal mining space and the multilayer hard roof are the main reason for the serious deformation in the fully-mechanized top coal caving face. The control technology of ener gy dissipation and bracing with constant resistance and large deformation of anchor in hard and long-stay tunnel with hard pre-fracturing blasting is proposed, which ca n effectively prevent and control the strong mining pressure. Keyword: extra-thick seam; multi-layer hard roof; strata behavior; overburden large structure;