特厚煤层开采形成了大空间采场，坚硬顶板断裂扰动波及范围广，工作面来压具有强矿压特征，尤其当煤层顶板“见方”开采期间，采场矿压作用更加强烈。据此，采用现场实测和物理三维相似模拟方法，探讨了特厚煤层开采覆岩扰动高度及坚硬顶板断裂特征。首先基于现场实测研究分析了覆岩破断失稳规律，实测结果表明，特厚煤层开采过程中，煤层顶板存在超前断裂现象。伴随工作面的推进，顶板初始运动主要是围绕断裂线近区基点旋转下沉，滞后工作面一定距离；地表岩移观测结果表明，特厚煤层顶板分层构成顶板群组并产生组合运动，具有层位运动特点，且伴随工作面推进，层位顶板运动存在阶跃现象。基于地表裂缝形态及钻孔多点岩移观测反演，揭示了特厚煤层开采过程中的顶板断裂及运动特征，认为特厚煤层开采覆岩扰动高度大，坚硬顶板断裂具有转向特征，伴随煤层开采推进，由低位顶板层位的横向“O-X”断裂逐渐向高位硬岩的纵向“O-X”断裂转向；特厚煤层坚硬顶板开始发生断裂转向的临界位置即所谓的煤层开采“见方”区，合理解释了工作面开采的“见方”来压现象；高位顶板纵向断裂尺寸大，扰动影响范围广，是诱发采场强矿压的主要因素，确定了特厚煤层采后覆岩“低-中-高”层位结构的合理性，为大空间采场大小周期及强矿压显现的准确解释提供了依据。

The mining of extremely thick coal seam form a large space stope, the fracture disturbance of hard roof spreads to a wide range, the working face weighting has the characteristic of “strong mine pressure”, it is obviously different from rock burst, especially when the coal seam roof “square” mining period, the stope mine pressure is more intense. Based on this, the disturbance height of overburden and fracture characteristics of hard roof in extremely thick coal seam mining are discussed by field measurement and 3D physical similarity simulation. Firstly, the fracturing law of overburden was analyzed based on the field measurement, the results showed that the hard roof was fractured advance the working face during the extra thick coal seams mining. The initial movement of the roof mainly revolved around the base point near the fault line and sinking, behind the working face for a certain distance. The observation results of ground sinking showed that the strata formed a roof groups and moved combined of extra thick coal seams, and there is a step phenomenon during strata movement. The study shows that the disturbance height of overburden in extremely thick coal seam mining is large and the fracture of hard roof has steering characteristics. With the advance of coal seam mining, the transverse “O-X” fracture of low roof layer gradually turns to the longitudinal “O-X” fracture of the high hard rock. The critical position of fracture turning of hard roof in extremely thick coal seam is the so-called “square” area of coal seam mining, which reasonably explains the phenomenon of “square” pressure in working face mining. The large longitudinal fracture size of the high roof and the wide range of disturbance influence are the main factors inducing the strong mine pressure in the stope. The rationality of the “low-medium-high” layer structure of the overburden in extremely thick coal seam after mining is determined, which provides a basis for the accurate interpretation of the large space stope size cycle and the strong mine pressure. 

0 引言
1 特厚煤层顶板断裂运移实测
1.1 工作面地质概况
1.2 特厚煤层覆岩扰动高度
1.3 特厚煤层覆岩成组运动实测
1.4 特厚煤层顶板沿煤壁断裂?
2 特厚覆岩层位结构及演化规律
2.1 顶板断裂转向的实测分析
2.2 特厚煤层覆岩层位结构特征
2.3 特厚煤层覆岩层位结构演化
3 结论