受载煤体破碎块度分布的实验研究

The experimental study on broken fragment distribution of coal mass under the load

实验研究支承压力 (采深 )、煤体强度和裂隙发育程度对煤体破碎块度分布的影响变化规律 .根据顶煤回收要求与可放块度原则得出预测临界采深的实用关系式 ,并以加权平均块度评价支承压力、煤体强度和裂隙发育程度三因素对顶煤可放性分类的影响 。

The interrelations among the broken fragment of coal mass and abutment pressure (mining depth), coal mass strength and fissures developed extent were studied by the exprimental method. Based on the demand of coal drawing rate and the principle of capable drawing fragment, the formula that can predict the critical mining depth being suitable for sublevel caving mining method was obtained, and the effect of abutment pressure, coal mass strength and fissures developed extent on top coal cavability can be evaluated by even fragment index. According to these research outcomes, three factors evaluating rule of top coal cavability was put down.