摘要:
针对强动压影响下三软煤层巷道围岩控制难的问题，以仲恒煤矿三软煤层115-101回风巷为工程背景，通过现场调查、围岩松动和地应力测试，采用UDEC数值软件根据实际建立数值模型，研究了巷道变形破坏原因，并基于应力控制原理，提出受强动压影响的三软煤层巷道卸-转-固围岩综合控制理论。研究结果表明：115-101回风巷围岩松动圈范围0～5 m，应力峰值在深入围岩5～6 m处，采用卸-转-固围岩控制技术，在原有的29U型钢支护条件下，降低支护排距，根据煤层倾角及厚度设计并施工爆破卸压孔，在孔底连线安装炸药，利用自制的封孔设备将加固材料通过高压风压入钻孔进行封孔，实施爆破。爆破后，围岩应力重新分布，重新形成破碎区、塑性区和弹性区，并使应力集中的弹性区转移到围岩更深处，降低巷帮及底板浅部围岩应力集中，在巷道周围表层一定范围内形成低应力卸压圈，而在围岩深部形成了应力集中的自承载圈，集中应力主要由该自承载圈的岩体承担。该自承载圈的岩体处于围岩深部，基本处于三向应力状态，降低集中应力对巷道的破坏作用，稳定性得到很大提高。巷道围岩顶底板移近速率降低了79.43%，两帮移近速率下降了54.17%，巷道围岩变形量明显减少，有效控制了强动压影响下三软煤层巷道围岩变形。
Abstract:
Aiming at the technical problem of difficult control of surrounding rock in the three-soft coal seam under the influence of strong dynamic pressure, taking the No.115-101 tail entry in the three-soft coal seam of Zhongheng Coal Mine as the engineering background, according to the actual situation, UDEC numerical software was used to establish a numerical model by field investigation, loosening of surrounding rock, and in-situ stress test, the causes of roadway deformation and failure are studied, and based on the principle of stress control, a comprehensive control theory of pressure relief stress transfer reinforce surrounding rock in three-soft coal seam roadway affected by strong dynamic pressure is proposed. The research results show that the loose circle of surrounding rock of No.115-101 tail entry is in the range of 0～5 m, and the stress concentration range is 5～6 m of surrounding rock. The surrounding rock control technology of pressure relief stress transfer reinforce is adopted, which is under the condition of profiled original 29U steel support, reduce the support row spacing, design and construct blasting pressure relief holes according to the inclination and thickness of the coal seam, install explosives at the bottom of the hole, and use self-made hole sealing equipment to press the reinforcement material into the hole through high pressure wind to seal the hole and implement blasting. After blasting, the surrounding rock stress is redistributed to re-form the broken zone, plastic zone and elastic zone, and the elastic zone of stress concentration is transferred to the deeper surrounding rock, reducing the stress concentration of the surrounding rock in the shallow part of the roadway and floor, a low-stress relief ring is formed in a certain range of the surface around the roadway, and a self-supporting ring with concentrated stress is formed in the deep part of the surrounding rock, and the concentrated stress is mainly borne by the rock mass of the self-supporting ring. The rock mass of the self-supporting ring is in the deep part of the surrounding rock and is basically in a three-dimensional stress state, which reduces the destructive effect of concentrated stress on the roadway and greatly improves the stability. Finally, the approaching rate of the roof and floor of the roadway surrounding rock was reduced by 79.43%, and the approaching rate of the two sides was decreased by 54.17%, the deformation of the surrounding rock of the roadway was significantly reduced, effectively controlling the surrounding rock deformation of the three-soft coal seam under the influence of strong dynamic pressure.
百度学术
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