走向工作面贯通上山与支架快速回撤技术

针对走向工作面停采线与上山之间的护巷煤柱造成煤炭损失，支架回撤工艺复杂、巷道掘进量大等问题，提出走向工作面贯通上山与支架快速回撤技术。工作面贯通采区上山，利用上山回撤支架。在贯通前，利用压力拱模型分析剩余煤柱应力变化规律，并结合极限平衡区公式，确定让压煤柱为8 m；对贯通前基本顶合理断裂位置、让压调节机制、末采阶段采高进行了分析确定，并采取上山巷内补强支护及挂绳铺网措施。贯通上山后，首先利用支架对上山留巷，完成留巷后，利用上山回撤支架，先将上部端头3架逆时针旋转90°作为掩护架，在对剩余支架逐架回撤时，3个掩护架呈现台阶型。提出的技术取消了护巷煤柱及回撤通道，提高了煤炭采出率，减少了巷道掘进量，简化了回撤工艺。

Technologies of uphill transfixion and rapid retracing of brackets in along strike working face

Aiming at the problems that the entry protection coal pillars between the stopping line and uphill in the along strike working face will cause the coal loss,the retracing process of brackets is complex and the excavation amount is large,the technologies of uphill transfixion and rapid retracing of brackets in the along strike working face were put forward.The working face transfixed the uphill,and the brackets were retracted by using the uphill.Before the transfixion,the change laws of residual coal pillar stress were analyzed by using the pressure arch model,and the yielding coal pillar was determined as 8 m with the formula of limit equilibrium area.The reasonable fracture position of basic roof,yielding adjustment mechanism and mining height at final mining stage before the transfixion were analyzed and determined,and the measures of reinforced support and lanyard and paving were adopted in the uphill roadway.After the uphill transfixion,the uphill entry retaining was conducted by using the brackets,and the brackets were retracted by using the uphill after completing the entry retaining.Three brackets at upper end were anticlockwise rotated 90° as the shield brackets,and they presented the step type when retracting the remaining brackets one by one.The technology canceled the entry protection coal pillars and retracement channel,improved the coal mining rate,reduced the roadway excavation amount and simplified the retracement process.