dunn bass

This paper analyses main facts that influence the caving and drawing characteristics of top-coal, such as underground deep , intensity and joint crack of coal seam ; layer relations , thickness and intensity of rock parting .

本文深入研究了煤层的埋深、强度和裂隙发育程度以及夹石层的层位、厚度和强度对综放面顶煤可放性的影响，运用数值与经验相结合的分类方法对顶煤进行了可放性分类。