由于高水压松散含水层的载荷传递作用,使覆岩关键层复合整体破断,导致了祁东煤矿7121工作面开采过程中压架事故的发生。防止压架事故需要从防止顶板整体破断入手,顶板超前预裂爆破是一种合适的方法。根据7121工作面地质开采条件和覆岩结构特征,确定了顶板预裂爆破的方案及相关技术参数。实践结果表明,在保障工作面良好支护质量的基础上,采取顶板预爆破措施,使工作面中下部支架平均阻力减小了246 kN,周期来压步距由34.1 m减小为23.0 m,来压持续长度由20.2 m减小为5.0 m,从而降低了覆岩关键层复合整体破断的可能性,对防范压架事故起到了积极作用。

Due to the load transmission role of the high water pressurized loose aquifer, the key stratum in the overburden strata would be completely broken and t hus the hydraulic powered supports jammed accident occurred during the mining operation period of No.7121 coal mining face in Qidong Mine. The prevention and contr ol of the hydraulic powered supports jammed accident should prevent the roof completely broken and the roof pilot pre-fracturing blasting would be a suitable method to prevent and control the hydraulic powered support jammed.According to the geological mining conditions and the overburden strata structure features of No.7121 coal mining face, the roof pre-fracturing blasting plan and the related technical parameters was set up.The practice results showed that based on the good support quality pr otected in the coal mining face, the roof pre-blasting measures applied could reduce the average resistance of the powered support at the central and down parts of the coal mining face by 246 kN, the periodical pressurized distance could be reduced from 34.1 m to 23.0 m and the pressurized sustained length would be reduced from 2 0.2 m to 5.0 m.Therefore, the possibility of the overburden stratum completely broken could be reduced and the active role would be played to prevent the powered sup port jammed accident.

国家自然科学基金资助项目(50974116)；国家重点基础研究发展计划(973计划)资助项目(2007CB209403)；