长壁胶结充填覆岩移动变化规律初探

Preliminary Analysis on Movement Law of Overlying Strata during Long-wall Mining with Cemented Backfilling

针对长壁工作面胶结充填开采后覆岩移动及矿压显现规律的理论研究亟待提高的现状，首先在实验室内对胶结充填体的力学性能进行了测试，测定了本次实验中充填体弹性地基系数的取值范围为0．015—0．167GN／m3；在综合分析岩层移动变形和充填体受力特征的基础上，应用弹性地基梁理论，建立了充填开采顶板岩梁移动变形的数学力学模型，求得了该模型的解析解；并通过数值求解的方法，详细分析了充填区覆岩移动变形的各影响因素和充填区支承压力分布变化规律。结果表明：在长壁胶结充填采矿中，应根据不同的采矿地质条件，制备具有一定强度和刚度的胶结充填体；合理的充填体地基系数对于覆岩下沉及其变形的控制起了决定性作用；该研究可对长壁胶结充填实践的工程应用提供理论指导。

Theoretical research on movement of overlying strata and strata behavior under long-wall cemented backfilling mining conditions need to be improved urgently; In view of this issue, mechanical properties of cemented backfill are firstly tested at laboratory, and the coefficient of elastic foundation was measured to range in 0. 015 - 0. 167 GN/m3. According to comprehensive analysis on the movement and deformation of overlying strata and the mechanical characteristics of fill body, a mathematical and mechanical model of movement and deformation of roof beam was established with the application of the theory of beams on elastic foundation. And analytical solution of this model was obtained. All factors affecting the movement and de- formation of overlying strata and the distribution law of abutment pressure in backfilling zone were analyzed in detail via the method of numerical solution. The result showed that cemented backfill with certain strength and stiffness needs to be prepared based on different mining and geological conditions under long-wall cemented backfilling coal mining conditions. Reasonable coefficient of elastic foundation of backfill plays a key role in controlling the deflection and deformation of overlying strata. This research provides a theoretical guide in the field practices under long-wall cemented backfilling mining.