特厚煤层综放强采动巷道围岩应力演化特征:以塔山矿为例

Stress evolution characteristics of the intensively mining-induced surrounding roadways within an extra-thick coal seam:A case study from the Tashan coal mine,China

特厚煤层上下区段综放工作面两次开采形成的强采动应力易诱发煤与瓦斯突出、冒顶、塌陷等灾害,开展强采动应力演化和作用特征研究是关键。本文主要通过建立几何相似比1:100的物理模型,研究采动应力演化特征、强采动巷道围岩失稳机理和高应力卸压方法。实验结果显示上下区段综放面两次开采过程中,特厚煤层综放强采动巷道煤柱帮均为所监测围岩区域中最剧烈影响区;结合室内相似材料物理模型和现场钻孔应力监测结果比较,验证了特厚煤层综放开采利用窄煤柱布置方法进行高应力卸压的可行性。研究结果可为特厚煤层开采中区段煤柱设计、巷道布置,支护方案等优化确定提供一定的理论参考基础。

The combined intensive mining effect of sequential-mining-process of two adjacent longwall top coal caving faces is prone to inducing disasters such as coal and gas outburst,roof caving and surface subsidence.However,it remains a big challenge to explore the mining-induced vertical stress evolution and its role played during such complex mining condition.A physical model with the geometric similarity ratio of 1:100 was established to explore the mining-induced vertical stress characteristics,their influence on the surrounding rock failure mechanism and the high stress relief method.The results indicated that both coal ribs are the most intensive region of the surrounding roadway in the previous and next working faces.In addition,based on the experimental physical model and field monitoring results using borehole drilling stress device,the feasibility of high stress relief method using narrow pillar layout was technically proven.The research results can shed lights on optimization of coal pillar design,layout of roadways,the supporting schemes within extra-thick coal seam.