浅埋近距离采空区下工作面矿压特征与顶板结构分析

Analysis on mine pressure characteristics and roof structure of working face under shallow buried and close goaf

以陕蒙神东煤田浅埋近距离煤层群开采为背景,采用实测统计、物理模拟与理论分析相结合的方法,研究了浅埋近距离煤层采空区下开采的矿压特征及影响因素,揭示了不同间隔岩层结构形态及演化条件。研究表明,随着上煤层采高增大,来压期间支架工作阻力及动载系数均呈正相关增长;下煤层采高与间隔岩层厚度之比越大,周期来压步距及支架最大工作阻力越大。层间仅存在单一关键层时,层间关键层周期破断可形成"砌体梁"和"台阶岩梁"两种结构;则当上煤层垮落顶板关键层重新形成"砌体梁"结构时,层间关键层与上煤层垮落顶板关键层可形成"砌体-砌体"和"台阶-砌体"2种组合结构形态。

Taking the mining of shallow buried and close distance coal seams in Shendong coalfield as the background,using the method of measurement statistics,physical simulation and theoretical analysis,the mine pressure characteristics and the influencing factors of the mining under shallow buried and close goaf are researched,and the structural morphology and evolution conditions of different interval strata are revealed.The results show that with the increase of the mining height of the upper coal seam,the working resistance and dynamic load coefficient of the support increase positively during weighting;the greater the ratio of the mining height of the lower coal seam to the thickness of the interval strata,the greater the periodic weighting step and the maximum working resistance of the support;when there is only a single key layer between the strata,the periodic failure of the key layer can form two kinds of structures:“voussoir beam”and“step voussoir beam”;when the key layer of the upper coal seam collapses to form the“voussoir beam”structure,two kinds of composite structure forms of“voussoir beam-voussoir beam”and“step voussoir beam-voussoir beam”can be formed between the key layers of interlayer and the key layer of upper coal seam.