Lateral Stress Concentration in Localized Interlayer Rock Stratum and the Impact on Deep Multi-Seam Coal Mining

To explore the impact of lateral stress concentration in interlayer rock stratum on the exploitation of protected coal seam, a field experiment was carried out in a multi-seam mining structure. Lateral stress redistribution and interlayer rock failure behavior were surveyed. Then an assistant numerical investigation was implemented to evolve the effect of liberated seam mining and its influence on stress reconstruction in surrounding rock mass. The cause of lateral stress concentration and its impact were discussed finally. Key findings turn out that a certain lateral stress increases in interlayer rock stratum and concentrates on its lower region. Lateral stress concentration and interlayer rock failure are interactional. The former is an inducing factor of the latter;the latter promotes the increase of concentration degree. Extent of lateral stress concentration increases to the maximum as seam distance is about 50 m. But the efficacy of liberated seam mining decreases as the seam spacing gets larger. Protected seam mining is then classified based upon the impact of lateral stress concentration, which helps to prevent the rock burst hazard and then to achieve a reliable mining in deep mines.

基于钻孔压水试验的岩层阻渗能力研究

现场压水试验是揭示岩层阻渗能力的可靠方法,以鲍店矿为背景,采用钻孔高压压水测试手段,对下组煤底板隔水层进行压水测试,获得底板3段岩层的压水测试数据并计算出底板岩体渗透系数。经过分析结果表明:不同岩性的渗透系数和压力的关系曲线均表现出明显的分段性,具有劈裂压力前的稳定性及劈裂压力后的线性变化性;渗透系数与压水流量具有较好的线性关系,继续增大流量,渗透系数有增大的趋势;可根据临界抗渗强度来评价底板岩层阻渗能力的高低,经计算得到底板岩体阻渗能力从高到低顺序为泥岩,粉细砂岩,细砂岩,灰岩。研究方法和结果可为矿区下组煤工作面的安全开采提供重要的参考依据。

大倾角煤层工作面底板岩层富水异常区探查方法研究

淮南矿区老区大倾角煤层工作面较多,其A组煤层开采过程中受到底板灰岩水的威胁,需提前进行探测与处理,但大倾角条件下直流电穿透方法适用性需要得到确认。论文结合大倾角A组煤层工作面开采地质条件,进行物理模型构建及测试实验,并通过现场探查实践,对双巷并行电透视成像方法进行研究,获得了三维电透视数据采集、处理与反演关键技术认识。认为通过三维全空间电穿透数据采集及处理,对底板岩层富水特征探查分辨具有良好的效果,可为大倾角煤层工作面防治水技术措施制定提供依据。