特厚煤层综放采动底板变形破坏规律的综合实测

为了探究兖州煤田兴隆庄煤矿特厚煤层综放开采对底板岩层的变形破坏规律，应用钻孔应变感应法和超声成像技术对该矿某综放工作面进行了综合实测，获得了底板下不同深度应变增量随工作面推进的变化曲线和工作面推进过程中不同深度钻孔超声成像图片资料。通过5个应变传感器监测数据和大量钻孔超声成像图片的关联对比分析，基本确定了该工作面采动底板扰动深度和矿压作用下支撑压力的影响范围。研究结果表明：①该工作面底板采动扰动深度约为19 m，具有较明显分带性，即可分为采动扰动破坏带和采动扰动变形带，带厚分别约为16 m和3 m；②采动扰动破坏带属于整体塑性变形，其强度条件已基本丧失，但采动扰动变形带仍以弹性变形为主，具有良好的承载条件和较强的抗渗强度；③采动矿压超前和滞后显现明显，其对底板影响程度具有由浅及深而减小的特征。该综合实测方法的成功应用不但为综放开采巷道支护、老空水防治等提供重要信息，而且对深部即将开采的下组煤能否安全带压采掘研究也将具有重要参考价值。

Comprehensive measurement of characteristics of deformation and failure of extra-thick coal seam floor induced by fully mechanized top-coal mining

In order to study the characteristics of deformation and failure of fully mechanized top-coal seam floor under mining in Xinglongzhuang Coal Mine in Yanzhou Coal Field, comprehensive measurements are performed by means of the strain testing system and ultrasonic imaging technology in the fully mechanized top-coal working face, and the variation curves of strain increment and the ultrasonic imaging pictures at different depths are obtained in the monitoring boreholes with extending of the working face. Through the comprehensive comparison of monitoring data of five strain transducers and many hole wall pictures, the disturbance depth and underground pressure influence range are approximately ascertained. The results show that: (1) the disturbance depth of the coal seam floor is about 19 meters, and there are obvious belts, namely, the belt of mining disturbance failure and the belt of mining disturbance deformation, which are 16 meters and 3 meters in thickness respectively; (2) the belt of mining disturbance failure belongs to the whole plastic deformation, and the rock mass in the belt fails, but the belt of mining disturbance deformation still belongs to elastic deformation and has a good bearing capacity and strong anti-permeability strength; (3) the underground pressure of mining obviously emerges ahead and behind, which has the weakening characteristics to the coal seam floor from shallow to deep. The successful applications of the comprehensive measurements provide important information for roadway support for fully mechanized top-coal mining and for controlling of goaf water, and important reference value for safely mining lower coal seam in coal fields in North China above the confined aquifers.