浅埋坚硬特厚煤层综放开采顶煤冒放结构分析

为深入研究浅埋坚硬特厚煤层综放开采顶煤冒放结构特征，以主采3号煤层的榆阳地区千树塔煤矿作为研究背景，采用数值模拟、理论分析和现场实测等综合方法对坚硬顶煤冒放结构进行了研究，得出靠近工作面两端头位置坚硬顶煤容易形成“悬臂”结构。由悬臂顶煤内部应力解析和模拟得到顶煤不同的破断长度对其垮落放出有着重要影响，当其破断长度小于放煤口水平投影宽度时，垮落放出相对较为容易；当其破断长度大于放煤口水平投影宽度时，垮落放出较为困难，并且增加处理大块煤的时间，该结论解释了坚硬顶煤垮落放出困难的宏观结构因素。

Analysis on the top-coal caving structure of extra-thick hard coalseam with shallow depth in fully mechanized sublevel caving mining

In order to further investigate the top-coal caving structural characteristics of extra-thick hard coal seam with shallow bury depth in fully mechanized sublevel caving mining,authors studied the No.3 coal seam mined in Qianshuta Coal Mine at Yuyang District,China.The caving structure of hard top coal was studied by using numerical simulation,theoretical analysis,in-site measurement,etc.Cantilever structure of top coal exits at the face end position.The internal stress of cantilever top coal was analyzed,and the cantilever length was also simulated.The results indicate that different broken lengths have ansignificant impact on the caving and releasing of top coal.When broken length is less than the horizontal projective width of coal caving port,top-coal caving are relatively easy.On the contrary,it is difficult for top-coal caving,and the total time for handling big lump coalincreases.The results explains the macro-structural factors of difficulty on hard top coal caving.