特厚煤层综放开采顶煤成拱机理及除拱对策

Top coal arching mechanism and arch removal strategies in fully mechanized top coal caving mining of ultra-thick coal seam

通过现场实测对同煤集团塔山煤矿特厚煤层综放开采中放煤过程进行了分析,揭示了顶煤在放出过程中易形成阻塞放煤的成拱现象,研究了顶煤成拱机理,提出了"面接触块体拱"模型,得到了拱的轴线形式为抛物线,给出了影响放煤效率的高跨比参数,并对高跨比参数中的角度和摩擦因数影响进行了分析,明确了煤岩压缩强度与煤块尺寸之间的关系。在此基础上,提出并实施了顶煤注水软化,开发新型放煤支架及强扰动装置,优化放煤工艺等开采措施,顶煤采出率提高了6.92%。

Based on in-situ measurement and theoretic analysis,the top coal arch phenomenon and arch forming mechanism are elaborated in the fully mechanized top coal caving mining of ultra-thick coal seam in Tashan Coalmine,Datong,China. A top coal analytic model formed by arching blocks in face contact is proposed,which takes the axis of the arch in the form of parabola. The study derives the parameters of height-span ratio of top coal arch that affects the efficiency of top coal recovery,where the supporting plane angle and coefficient of friction involved in the height-span ratio are analyzed. The countermeasure strategies against the top coal arching effect are put forward and performed in practice. As a result,the recovery ratio of top coal increased by 6. 92% that shows the significance for the efficient recovery of coal resources.