综放面覆岩运动“时-空-强”演化规律分析

Analysis on “spatio-tempo-intension” evolution rules of overburden strata movement in fully mechanized top-coal caving face

综放面覆岩运动是制约安全开采的关键问题之一。以新疆大南湖一矿1303综放工作面开采为工程背景,基于对工作面覆岩运动"横三区"与"竖三带"经典理论的理解,将区块链式演化思想应用于综放覆岩运动数值模型构建与链式演化过程精细计算,构建开采扰动区覆岩物理与数值计算模型,并将其植入三维有限差分计算FLAC^(3D)程序,揭示综放面覆岩运动"时间-空间-强度"链式演化与失稳破坏规律。结果表明:大南湖一矿综放面覆岩垮落带与裂隙带分别约为16.8 m与115 m.具有承载性的岩层受到外力破坏,均会出现应力集中;岩层垮落根据承载层和开挖尺寸不同,出现"分离-协同"运动现象,应力呈现"集中-分离-集中"规律,重合后的应力演化集中,造成工作面强矿压作用,这对现场安全开采提供了科学指导作用。

Overburden strata movement of fully mechanized top-coal caving face is of the key problems restricting safe mining.Based on“horizontal three zones”and“vertical three belts”theory of the overlying strata movement of working face,this paper takes No.1 Dananhu coal mine as engineering background,the blockchain evolution is applied to the numerical model construction of the overburden rock movement and the detailed caculation of the chain evolution process.Meanwhile in order to reveal“spatio-tempo-intension”chain evolution and instability failure law of overburden strata movement in fully mechanized caving face,physical model and numerical calculation model of overlying strata in the mining disturbance zone is constructed and implanted into the 3D finite difference calculation program(FLAC 3D).Results shows that overburden strata and fracture zone of top-coal caving working face in the Dananhu No.1 Mine are 16.8 m and 115 m respectively.Stress concentration occurs and bearing rock layer is damaged by external force.Rock layer collapses with different bearing layer and excavation size,and“separation-coordination”occurs.The stress present“concentration-separation-concentration”also stress concentration results in strong mining pressure on the working face.This provides scientific guidance for safe mining on site.