中文摘要：

巨厚冲积层薄基岩条件下，综放开采工作面经常出现异常来压，给顶板控制提出了较大的挑战。通过数值计算的方法，分析了600m厚冲积层、不同基岩厚度条件下的顶板变形破坏特征，得出基岩厚度小于120m时，覆岩可能出现全厚切落现象；揭示出巨厚冲积层在运动变形过程中具有整体性且难以形成稳定的强承载结构；现场实测出了工作面异常来压规律，证明了巨厚冲积层和薄基岩结构间的关系。该研究成果为类似条件下的综放面安全高效开采提供了借鉴。

英文摘要：

Under a condition of uhra thick alluvium and thin base rock, an abnormal roof weighting would be often occurred in a fully mechanized top coal caving mining face and would have a great challenge to the roof control. With a numerical calculation method, the roof deformation failure features under the condition of a 600m thick alluvium and different thickness base rock were analyzed. When a thickness of the base rock was less than 120m, a full thickness cutting and falling phenomenon could be occurred in the overburden strata. The ultra thick alluvium with a completed and hard to form a stable high loading structure was revealed during the movement deformation process. Abnormal roof weighting law of the coal mining face measured at the site measurement showed that a relationship between the ultra thick alluvium and the thin base rock structure was proved. The study results could provide references to the safety and high efficient mining of the fully mechanized top coal caving mining face under the similar condition.