煤矿开采导水裂缝发育高度及影响因素分析

Height of water-conducting crack and its influence factors in coal mine

煤矿开采形成的导水裂缝,一旦波及煤层上覆水体,则会导致水流入或溃入井下,直接威胁煤矿安全生产。在总结分析现有导水裂缝研究方法的基础上,以理论推导的方式并结合生产实际,分析了导水裂缝高度与煤层开采厚度、覆岩性质等因素的关系,明确了导水裂缝高度与采厚的平方根存在正比例关系。指出当基岩上覆有粘土冲积层或其他类似岩层时,极限曲率增量与岩层物理性质、厚度的关系对确定导水裂缝高度具有重要作用,当粘土冲积层厚度不小于2倍采厚时,粘土冲积层内下行裂缝穿透粘土层的可能性小,为特定条件导水裂缝分析提供了研究基础。

Once water-conducting cracks induced by coal mining contact an overlaying water body, water will flow and burst into mine, directly threating safe production in coal mine. The paper, on the basis of analysis and sum- ming up of existing research methods of water-conducting, from theoretical derivation and in combination with production practices, analyzed the relationship between the height of water-conducting crack and the mining thickness and stratum properties, found the clear proportional relation between the height of water-conducting crack and the square root of mining thickness. It was pointed out that the relationship between limit coverture in- crement and stratum properties and mining thickness plays an important role in determination of the height of wa- ter-conducting crack when mining is conducted below bedrock with clay alluvial soil or similar rocks. The bedrock with clay alluvial is impossible to penetrate by descending crack when its thickness is more than double mining thickness. The paper provides a basis for future research on crack in specific coal mining conditions.