双巷掘进留窄小煤柱布置方式及围岩稳定性控制技术

Arrangement of double entry driving with a narrow coal pillar in the middle and stability control technology of surrounding rock

为解决传统双巷掘进资源采出率低和沿空掘巷采掘接替紧张难题,以翟镇煤矿下组煤一采区11502工作面为工程试验对象,创新性提出留窄小煤柱双巷同时掘进巷道的布置方法,同时构建小煤柱高强复合加固支护技术。采用理论分析、试验测试结合数值模拟等综合研究方法,对留窄小煤柱双巷掘进布置原理及煤柱加固支护技术进行深入研究探索。结果表明,双巷掘进留窄小煤柱技术能够实现采区工作面顺序接替,有效提高采区采出率;提出的小煤柱综合加固支护技术以超前断顶卸压、对穿锚索提高煤柱自身承载力以及钢管混凝土墩柱高强辅助加强支护为主体,避免了小煤柱过早进入塑性状态而发生整体失稳破坏,能够有效保持长期稳定。基于覆岩组合结构理论建立煤柱–顶板结构力学模型,研究煤柱上方支承压力分布规律与大小,建立双巷掘进小煤柱加固支护设计方法。通过数值模拟验证,该技术与传统沿空掘巷相比,能够更好地控制巷道围岩变形,煤柱体的帮鼓变形量和巷道变形量均得到了有效降低。

In order to solve the problem of low resource recovery rate of traditional double entry driving and tight replacement of gob-side entry driving,taking the 11502 working face of the first mining area of Lower group coal mine in Zhaizhen Coal Mine as the engineering test object,this paper innovatively put forward an arrangement method of double entry driving with a narrow coal pillar in the middle,and constructed a narrow coal pillar high-strength composite reinforcement support technology.By adopting comprehensive research methods such as theoretical analysis,experimental test combined with numerical simulation,the arrangement principle of double entry driving with a narrow coal pillar and a narrow coal pillar reinforcement support technology are deeply researched and explored.The results show that the technology of double entry driving with a narrow coal pillar can realize the sequential succession of working faces and effectively improve the recovery rate in the mining area.The technology of narrow coal pillar composite reinforcement support is mainly based on advanced broken roof and relieved pressure,the improvement the bearing capacity of the narrow coal column side by anchor cable through coal pillar,and the high-strength composite reinforcement support of the concrete-filled steel tubular columns,which prevents the narrow coal pillars from prematurely entering a plastic state and then losing overall stability,and can effectively maintain long-term stability.Based on the combined structure theory of overburden rock,a coal pillar-roof structural mechanics model was established,the distribution law and magnitude of the abutment pressure above the coal pillar were studied,and a design method for the double entry driving with a narrow coal pillar reinforcement support was established.The numerical simulation proves that compared with the traditional gob-side entry driving,this technology can better control the deformation of surrounding rock of roadway,and the deformation of coal pillar body and roadway have been effectively reduced.