薄基岩采场覆岩破断机理及风氧化带整体注浆加固技术

Breaking mechanism of overlying strata under thick unconsolidated layers and integrated grouting reinforcement technology for wind oxidation zone

采用物理模拟、理论分析、现场实测等方法对厚松散含水层载荷传递作用下不同覆岩结构的采场覆岩运动规律、支架围岩关系及风氧化带整体注浆加固技术进行了研究。研究表明:采场覆岩仅有一层关键层时,随着工作面的回采,在松散含水层的载荷传递作用下覆岩大范围的垮落下沉作用于下方支架,支架受力较大,易发生压架事故;采场覆岩中有两层关键层时,垮落至高位关键层时形成"砌体梁"结构,该结构能将松散含水层传递的上覆冲积层载荷转移远离工作面支架,改善了液压支架受力状态;基于此,以顾北矿1512(3)工作面为例,针对松散含水单一关键层地质条件,从地面采用J型水平羽翼分支孔注浆方法对风氧化带进行整体注浆加固,人为的在采场上方构筑一层高位承载层,减缓了工作面来压时矿压显现程度,工作面安全开采,验证了研究结果的合理性。

With the method of physical simulation,theoretical analysis and field measurement,in the case of different overburden structures,this study investigates the law of overlying strata movement,relationship between support and surrounding rock under the load transfer of thick loose aquifer and integrated grouting reinforcement technology for wind oxidation zone.The results show that when there is only a key stratum in stope overlying strata,with the process of coal mining,in unconsolidated aquifer load transfer function,overlying strata large range collapse sink acting on the support below,and support force is bigger,and it is easy to occur support crushing accidents. When stope overlying strata has two key strata,its collapse to high key stratum form a ‘voussoir beam＇structure,the structure can make the transfer of aquifer overlying alluvium pressure shift away from stope support,and it improves the hydraulic support force status.Based on this,it takes 1512（ 3） working face of Gubei Mine as an example,according to the geological conditions of loose aquifer single key stratum,the method of J type horizontal wing branch hole is applied to reinforce the wind oxidation zone,aim to artificially build a high key stratum,this slows down the stress behavior when the working face is pressed,and the working face achieves the goal of safe mining,which verifies the rationality of the research results.