充填弱化坚硬覆岩冲击地压灾害机制研究

Study on the weakening mechanism of hard overburden rock burst disaster by backfilling

坚硬覆岩作为诱发冲击地压的主要因素之一,已经严重威胁煤矿安全高效开采。通过分析坚硬覆岩条件下冲击地压灾害的灾变过程及诱冲关键层能量的关键控制因素,给出诱冲关键层的判定方法,提出利用采空区充填和离层注浆充填弱化诱冲关键层致灾能量的思路,以2个典型煤矿坚硬覆岩下工作面采矿地质条件为背景,研究不同充填条件下诱冲关键层变形规律及致灾能量演化规律,揭示充填弱化坚硬覆岩致灾能量作用机制并给出相应的工程设计方法,最后通过现场实测分析进行验证。研究结果表明,坚硬覆岩形成的诱冲关键层变形产生的能量积聚、释放和传递是诱发冲击地压灾害的关键,采空区充填和离层注浆充填能够有效控制诱冲关键层变形,降低致灾能量的积聚程度和释放速度,同时,充填体可吸收部分能量并降低致灾能量的传递效率,进而实现弱化坚硬覆岩诱发冲击地压灾害危险性的目的。

As one of the main factors that induce rock burst,hard overburden seriously threatens the safe and efficient mining of coal mines.This paper analyzes the catastrophic process of rock burst disaster of hard overburden and the key controls on the energy of the key stratum inducing rock burst,gives the determination method of the key stratum induced rock burst,and proposes the method of goaf backfilling and grouting bed separation so that weakening the catastrophic energy of the key stratum inducing rock burst.Taking the mining geological conditions of two typical coal mines under the hard overburden rock as a background,the deformation law of the key stratum induced rock burst and the evolution law of the disaster energy under different backfilling conditions are studied,the mechanisms of backfilling to weaken the disaster-causing energy effect of hard overburden rocks is revealed and the engineering design method is given.Finally,it was verified by field measurement analysis.The research results show that the energy accumulation,release and transfer caused by the deformation and rupture of the key stratum inducing rock burst formed by the hard-overlying rock are the key to inducing dynamic disasters.Goaf backfilling and grouting bed separation can effectively control the deformation of the key stratum inducing rock burst,reduce the accumulation degree and release speed of the disaster-causingenergy,meanwhile,the backfilling body can absorb part of the energy and reduce the transmission efficiency ofthe disaster-causing energy,thereby realizing the weakness of dynamic disasters caused by hard overburden.