摘要
基于沿空留巷原理,分析了厚层灰岩直接顶板下巷旁充填沿空留巷和超前切缝断顶卸压法沿空留巷巷道顶板断裂位态,分别建立了2种不同顶板断裂位态下的结构力学模型,推导了巷道顶板支护阻力计算方法。研究表明:当切顶阻力Q≤ql时,巷道顶板沿煤壁内一定深度内断裂,沿空巷道侧向顶板悬臂结构可向沿空巷道围岩传递采场岩梁和上覆岩层移动压力;而当切顶阻力Q≥ql,巷内加强支柱+巷旁切顶墩柱+巷旁切缝的联合切顶作用时,可使得侧向坚硬灰岩顶板沿切缝结构面断裂滑落,实现顶板断裂位态主动控制,降低了坚硬灰岩顶板传递上覆岩层压力的移动变形压力,优化了顶板承载结构和围岩应力,降低了巷旁支护体承受的附加载荷。相关设计方法及研究成果应用到南屯矿厚层灰岩直接顶切顶留巷试验,取得了良好的应用效果。
Based on the theory of retained entry along gob-side with immediate roof of limestone, the roof fracture state of the roadway-side packing to retain gob-side entry and retaining gob-side entry by caving the roof and relieving pressure was analyzed, two different mechanical models of roof fracture states were established respectively, and the calculation method of support resistance in the roof was de- rived. Research has indicated that when the cutter roof resistance Q is less than or equal to ql, its roof breaks along the coal wall inside certain depth, and the cantilever beam structure of gob-side entry roof can transfer the pressure from stope rock beam and overlying rock movement to the surrounding rocks in the roadway; when the cutter roof resistance Q is greater than or equal to ql, and under the combina- tion action of reinforcing struts inside the roadway, pier stud along roadway-side and the cutting seam of the roadway-side cutting the roof, the direct hard limestone roof cut along the seam slides along therupture surface structure, which actively controls the roof fracture state, cuts off the stress of movement and deformation from the hard limestone roof to the overburden strata, optimizes the bearing structure in the roof and surrounding rocks, and reduces the additional load of bore by the support body of the roadside. The relative design method was applied in the experiment of gob-side entry formed by cutting the hard limestone roof sliding down in Nantun coal mine, and has demonstrated its effectiveness.
出处
《采矿与安全工程学报》
EI
CSCD
北大核心
2017年第3期488-494,共7页
Journal of Mining & Safety Engineering
基金
国家自然科学基金项目(51404278)
教育部高校博士点基金项目(20130023120011)
关键词
厚层灰岩
切顶留巷
顶板断裂
覆岩移动
矿压规律
thick-layer limestone roof
gob-side entry retained by cutting roof sliding down
roofbreak
overlying strata movement
mine pressure regularity
