带压开采煤层底板破坏深度理论分析及数值模拟——以陕西澄合矿区董家河煤矿5号煤层为例

随着煤矿开采深度的不断增加，带压开采已经成为深部矿井普遍应用的一种采煤方法，而带压水上采煤的关键问题之一是确定采动引起的底板破坏深度。针对董家河煤矿5号煤层开采引起的底板采动破坏深度开展相关研究，以该矿的507综采工作面开采为工程背景，采用理论分析和数值模拟相结合的办法，动态再现了整个底板岩层渐进破坏过程，并得出底板岩层的最大破坏深度为10~11 m，该结果与现场实测结果一致；同时给出了该矿底板岩层破坏深度与工作面斜长和埋深关系的经验公式。该结论为董家河煤矿带压开采工作面煤层底板突水预测与防治提供了科学依据。

Theoretical analysis and numerical simulation of destroyed depth of coal seam floor during bearing mining:with seam No.5 in Dongjiahe mine, Chenghe mining area, Shaanxi as example

With increased mining depth, most coal mines will face the threat of high pressure groundwater. Bearing mining has already became a coal mining method commonly employed in China's deep mines, one of the key problems in coal mining above confined aquifer is how to determine the depth of destroyed floor due to mining influence. According to the relevant study of the depth of the broken floor during mining seam No.5 in Dongjiahe mine, taking fully mechanized coal mining face No.507 of Dongjiahe mine as engineering background, this paper analyzed a method which combines the numerical simulation with theoretical calculation, dynamically reproduced the development and failure process of the whole floor strata, found that the maximum depth of destroyed floor was 10~11 m, while the testing data are compared with those from the in-situ measurement. The empirical formula for the relationship between the depth of destroyed floor and equivalent length of combined coal face and buried depth were obtained. The results may be used to guide practice with similar water prevention work of a working face of bearing mining and design of the water control method, and also provides scientific and theoretical basis for forecasting and prevention of water inrush from the floor in Dongjiahe mine.