为研究覆岩离层注浆开采条件下关键层变形特征及地表沉陷控制效应,准确预计地表移动 变形值,对离层注浆开采关键层变形进行了力学分析,将关键层下方离层注浆充填体和煤岩体的组 合视为弹性地基,并将之划分为压实区、欠压实区和实体煤区 3 种不同的区段,基于弹性地基梁理 论,给出了关键层挠度方程和弹性地基系数计算方法;采用“ 两步法” ,通过分层模拟的方式开展了 离层注浆开采关键层变形与地表沉陷数值模拟,研究了不同工作面宽度条件下离层发育和关键层 破断特征,以及不同注采比条件下地表移动变形特征;借鉴等价采高理论,将离层注浆开采条件下 关键层弯曲下沉空间等效视为开采空间,结合概率积分法,建立了适用于离层注浆开采的地表沉陷 预计模型。 以淮北矿区袁店二矿 7221 离层注浆开采工作面为例进行了验证,结果表明:该地质条 件下,离层注浆开采工作面宽度宜设计在90~120 m;采用提出的预计模型和方法能够对离层注浆 开采条件下的地表沉陷进行有效预计,预计值与实测值平均误差 9 mm,在允许误差范围内;离层注 浆开采地表沉陷控制效果显著,减沉率约 83%。

In order to study the deformation characteristic of key strata and control effect of surface subsidence in min- ing with grouting into overburden bed-separation,and predict the surface movement and deformation accurately,the mechan- ical analysis of key strata deformation was carried out based on the elastic foundation beam theory,and the combination of filling body in bed-separation and coal-rock mass under the key strata was divided into solid coal area,under-compaction area and compaction area,of which the deflection equation of each section of key strata and the calculation method of elastic foundation coefficients were given respectively; By means of simulation layer-by-layer,numerical simulation on the deforma- tion of key strata and surface subsidence in mining with grouting into bed-separation was carried out,the development char- acteristics of bed-separation,the fracture characteristics of key strata,and the surface movement and deformation characteris- tics under different injection-production ratios were studied; The bending subsidence space of key strata in mining with grouting into bed-separation was regarded as the mining space with reference to the theory of equivalent mining height, and the surface subsidence prediction model suitable for mining with grouting into bed-separation was established,combined with the probability integral method. It was verified in a mining face with grouting into bed-separation in Huaibei Mining Area,the results showed that the face width should be designed within the range of 90-120 m under the geological condition in the study area; The average error between the predicted value and the measured value was 9 mm,within the allowable er- ror range; The surface subsidence control effect of mining with grouting into bed-separation was remarkable,and the subsid- ence reduction rate was about 83%.