煤层采后覆岩中的导水裂隙带之上存在离层带。多层位注浆时注浆体在离层中呈多层凸透镜状。地表减沉率与注采比成正比,其比例系数取决于地表的开采充分程度。多层位注浆的工程实验其注采比达到了37％,减沉效果显著。注浆减沉必需与井下开采协调配合。将注浆减沉技术有效应用于建筑物下开采,应具备一定的地质、开采等条件。 Seam above the water-bearing fracture zone in the overlying strata. Multi-layer grouting injection grouting layer in the multi-layer lens lenticular. The rate of surface subsidence is proportional to the ratio of injection to production, and its proportionality coefficient depends on the adequacy of surface mining. Multi-level grouting engineering experiment its injection-production ratio reached 37%, the sinking effect is remarkable. Grouting sinking must be coordinated with the underground mining. The grouting sinking technology effectively applied to the mining of buildings, should have some geological, mining and other conditions.