dirt band meaning in English

冰川上的冻土
冰川碎石层
冰川碎屑层
夹石层
污层

Sub - level caving mining with seam of thickness dirt band
含厚夹矸煤层的综放开采
It was found that comparing with the case without dirt band the periodic weighting distance , median roof moving coefficient and support resistance all increased to different extent because of the influence of dirt band
发现由于夹矸的影响，与不含夹矸层工作面相比，其周期来压步距、平均动压系数和支护阻力都有不同程度的增大。
The in - situ measurement and analysis of support resistance and top - coal movement in fully - mechanized top - coal caving face of a thick coal seam with dirt band had been carried out in some coal mine , the strata behavior and movement law of top - coal were revealed
摘要对某煤矿含夹矸煤层综放面的支架工作阻力和顶煤移动进行了现场观测和分析，揭示了其矿压显现和顶煤运移的规律。