大采高小煤柱沿空巷道大变形机理与支护技术研究

Deformation mechanism and support of narrow coal pillar gob side entry with large mining height

基于采煤工作面上覆岩层运动规律和砌体梁平衡理论,分析了大采高工作面小煤柱沿空巷道上覆关键层顶板断块下沉运动特征,断块之间相互挤压形成的力学平衡结构及其对沿空巷道围岩产生的破坏作用,探讨了大采高条件下沿空巷道围岩的破坏特点和工程可支护性能。结果表明:沿空巷道上方关键层断块在相邻工作面回采期间已经形成了稳定的半拱形力学平衡结构,在巷道掘进期间和本工作面回采期间能对其下巷道围岩起到可靠的掩护作用,沿空巷道围岩的支护应围绕半拱形力学平衡结构来开展。提出了针对沿空巷道不同部位的围岩应采用不同的支护机理和支护参数,并在济三煤矿53下12工作面进行了试验,确保了巷道的安全使用,同时也取得了较好的经济效益。

Based on the law of overlying strata movement in working face and masonry beam balance theory,we analyze the overlying key strata roof block sinking motion characteristics of gob side entry under working face with large mining height and support of small coal pillar,and the mechanical equilibrium structure formed by the mutual extrusion of blocks and damage to surrounding rock of gob side entry. Discuss the failure characteristics of surrounding rock on gob side entry and engineering supporting performance under large mining height. The results show that a stable semi arch mechanical equilibrium structure is formed in the key fault blocks above gob side entry during the mining of adjacent working faces,this structure plays a reliable protecting role in the surrounding rock of roadway below it,during roadway excavation and the mining of the current working face. So,the support for surrounding rock of gob side entry should be carried out around the semi arch mechanical equilibrium structure. Put forward different parts for the surrounding rock of gob side entry should adopt different support mechanism and parameter,and experiments have been carried out in the coal mine to ensure the safe use of the roadway and achieve better economic results in 53 lower12 working face of Jining No. 3 Coal Mine.