采动覆岩离层多层位注浆地表沉陷控制技术

Surface subsidence control technology of multi-bed separation grouting

为了解决上覆岩层中无明显厚硬岩层、采动过程中难以产生较大尺寸离层空间、离层注浆充填率低的问题,提出采动覆岩离层多层位注浆技术。通过相似材料模拟实验对多层位离层注浆覆岩时空演化规律进行研究,并在淮北矿区某工作面进行现场试验。结果表明:在无较大采动覆岩离层情况下,采用增加钻孔数目的多层位离层注浆方法,在采动覆岩内部形成不同扩散半径的注浆充填体,共同叠加支撑上覆岩层,可以有效减小覆岩破坏程度。实施多层位离层注浆方法,可以有效提高注浆总量和注采比,地表减沉率可达79.92%。提出的离层注浆量计算公式可以精确预计浆液灌注量,准确率超过91%,可为覆岩离层注浆工程提供指导,并为注浆减沉率预计提供参考。这为解决煤炭资源开采引起的地表沉陷问题提供了一种有效和经济的方法,同时扩大覆岩注浆技术的应用范围。

In order to enhance the injection ratio to meet the surface subsidence controlling requirements without obvious thick-and-hard strata in overburden for generating large-scale bed separation,the multi-bed separation grouting method is proposed in this paper.The scale model test is used to study the spatiotemporal evolution of overburden due to multi-bed separation grouting.The field measurements is proven that multi-bed separation grouting can successfully mitigate overburden failure and subsidence by increasing the boreholes number,and multi-bed separation grouting has successfully applied in Huaibei mining area.Filling masses with different diffusion radii are commonly formed in the different bed separation,which can effectively support the overlying.The surface subsidence reduction ratio can reach 79.92%.The formula for injection quantity calculation can accurately predict the overburden grouting with an accuracy rate of over 91%,providing the beneficial guidance for the overburden grouting engineering and the reference for the prediction of subsidence reduction rate.This research presents an effective and cost-efficient approach for addressing the surface subsidence,and expands the application scope of overburden grouting is expanded.