布尔台矿保留巷道顶板剧烈下沉机理及其控制

Mechanism and control of severe roof subsidence of retain roadway in Buertai coal mine

针对布尔台煤矿22205工作面辅运巷600~1850m出现顶板剧烈下沉现象,通过现场监测、数值模拟、理论分析等手段研究了巷道顶板围岩破坏特征及发生机理,研究表明:剧烈下沉段顶板普遍淋水,围岩破坏深度可达5m以上,顶板含水导致围岩强度软化,在侧方采空区高偏应力场作用下塑性区急剧扩展,并呈非对称性分布,导致塑性区与直接顶之上的夹煤层塑性区贯通,夹煤层塑性区释放膨胀压力作用于直接顶,进一步加剧了顶板的不稳定性。基于此提出巷道分段补强支护参数以及二次采动超前支护措施,保证了22205工作面回采期间巷道的安全使用。

Aiming at the phenomenon of severe roof subsidence in 600-1 850 m return air roadway of 22205 working face in Buertai coal mine,the failure characteristics and mechanism of roadway roof surrounding rock are studied by means of on-site monitoring,numerical simulation and theoretical analysis.The results show that the roof of severe subsidence section is generally flooded with water,the destruction depth of surrounding rock can reach more than 5 m,the roof water content causes the strength softening of surrounding rock,and the side goaf is mined out.Under the action of high deviatoric stress field,the plastic zone expands sharply and presents asymmetry,which leads to the penetration of the plastic zone and the soft coal-mixed plastic zone above the direct roof.The expansion pressure released from the plastic zone acts on the direct roof,further aggravating the instability of the roof.Based on this,the support parameters of sublevel reinforcement and the advanced support measures of secondary mining are put forward to ensure the safe use of the roadway during the mining period of 22025 working face.