为确保多伦协鑫煤矿综放回采工作面不受上覆第三系含水层影响,确定留设安全煤(岩)柱的合理厚度,须掌握综放开采条件下白垩系覆岩破坏规律。基于覆岩破坏高度现场实测结果,结合实验室相似材料模拟试验,得出了综放开采条件下白垩系覆岩破坏"两带"高度与采高之间的比例关系,取垮采比5.61,裂采比12.21,作为7号煤上分层综放开采条件下合理留设安全煤(岩)柱的数值依据。经过与开采条件相似矿井的覆岩破坏相关数据对比分析,认为白垩系岩层覆岩破坏具有裂采比较小、垮采比较大的特点,符合软弱类型覆岩的破坏规律。

In order to ensure the fully mechanized top coal caving mining face not affected by the Tertiary System Aquifer in the overburden strata, to determine the rational thickness of the left safety coal (rock) pillar shall understand the failure law of the Cretaceous overburden strata under the conditions of the fully mechanized to p coal caving mining.Based on the site measured results of the failure height in the overburden strata and in combination with the lab similar material simulation, the rat io relationship between the failure "two zone" height of the Cretaceous overburden strata and the mining height under the condition of the fully mechanized top coal cavi ng mining was obtained.The failing and mining ratio of 5.61 and the cracking and mining ratio of 12.21 was applied to be the numerical basis of the rational left safety C oal (rock) pillar under the fully mechanized top coal caving mining in the top slice of No.7 seam.In comparison analysis on the related failure data of the overburden stra ta with the similar mining condition in the mine, the paper held that the overburden failure in the Cretaceous strata would have small cracking and mining ratio and the I arge falling and mining ratio features and could meet the failure law of the soft and weak type overburden strata.

国家重点基础研究发展计划(973计划)资助项目(2007CB209402)；国家自然科学基金资助项目(50834005)；