中文摘要：

在现场实测统计分析的基础上,通过模拟实验和数值计算,揭示了大采高工作面直接顶变厚和覆岩结构铰接点上移的机理,给出了＂等效直接顶＂的定义。研究得出浅埋煤层大采高工作面顶板结构主要表现为双关键层结构,下组关键层为＂高位台阶岩梁＂结构,上组关键层为＂短砌体梁＂结构,工作面来压将出现大小周期来压现象。等效直接顶的破断为上部拉破断下部剪破断,等效直接顶的重量是工作面支架载荷的主要来源。大采高工作面支架初撑力应大于等效直接顶的重量,支架工作阻力主要由等效直接顶重量构成,占77%,支架额定工作阻力约为初撑力的1.3倍。

英文摘要：

Based on field measurement, simulation experiments and numerical calculation, the mechanism of immediate roof thickness increase and structure of overlying strata hinged point move up of large min- ing height face is explored, and the definition of ＇ equivalent immediate roof＇ is put forward. Study shows that the main roof structure has double layer structure. The lower key stratum has ＇ high step voussoir beam＇ structure and the upper key stratum has ＇ short voussoir beam＇ structure. There roof weighting will appear big and small periodic pressure phenomenon in shallow coal seam mining face. The breaking form of equivalent immediate roof is tension broken at its upper position and shear failure at its lower po- sition. The weight of thick equivalent immediate roof is the main source of support load in the large min- ing height face. The initial supporting resistance of support should be greater than the weight of the e- quivalent immediate roof, and the working resistance of support is mainly composed of equivalent imme- diate roof weight, accounting for 77% ,the rated resistance value is about 1.3 times of the initial support resistance.