充填是煤矿减损开采与固废减排的技术，覆岩隔离注浆充填是在深入揭示覆岩卸荷膨胀累积效应基础上提出的绿色开采新方法。该项技术通过确定控制岩层移动与地表沉陷的关键层，采用压实注浆新工艺，在关键层下的主层位实施高压注浆，将下方覆岩的卸荷膨胀量重新压缩转化为可充填空间，大幅提高了注采比，在采空区形成压实承载结构，支撑关键层，实现岩层沉陷控制与建（构）筑物保护。覆岩隔离注浆充填采用粉煤灰、煤矸石、煤泥等作为注浆材料，充分利用了煤矿采动空间与空隙，实现固废减排。介绍了不同类型固废制浆的工艺及特点，论述了充填浆液从固体－浆体－压实体的转变过程，以及浆液流动泌水固结特征。浆液由钻孔进入覆岩裂隙腔体内快速泌水，并在压力作用下不断固结压实，泌出水向注浆层围岩渗流。岩层饱和度对泌出水向工作面的流动产生影响。注浆充填体最终在地层内形成压实体，保证了地表沉陷控制的长期效果。除沉陷控制、固废减排之外，覆岩隔离注浆充填还可用于减震防冲、保水采煤等领域，并在无煤柱开采、相邻采空区开采、多煤层开采等复杂地质采矿条件中得到了成功应用。该技术的适用条件是工作面具有一定的基岩厚度，能够找出可作为注浆层位的关键层。未来该技术仍需在减震防冲、保水采煤中开展进一步试验研究。

Backfilling is a technology for reducing both mining damage and solid waste emission in coal mines. The o⁃ verburden isolated grout injection technology was proposed based on the accumulative effect of strata expansion induced by stress relief. By identifying the key strata controlling surface subsidence and overburden movement， this technology utilizes the new method of compaction grouting into the main injection horizon below a key stratum， which transfers the expansion volume of overburden strata into injectable zone. The injection ratio is significantly in⁃ creased，and a compaction zone that supports the overburden key strata and reduces subsidence is then generated，thus allowing the strata control and protection of surface buildings and infrastructures. The overburden isolated grouting uses fly ash，coal gangue，and coal slime as the injection material，allowing the reduction of coal waste by utilizing mining⁃ induced voids and fractures. The process and characteristics of slurring were proposed for different types of solid wastes. The transformation process of solid⁃grout⁃fill and the characteristics of grout flowing， bleeding， and consolidation were discussed for the injection material. The grout bleeds as soon as it flows into the overburden fracture from the borehole. Under the injection pressure，the grout is compacted continuously，and the water flows into the sur⁃ rounding rock layers. The saturation of the strata play a vital role in the seepage of bleeding into the underground long⁃ wall face. The grout is finally transformed into a compaction fill，which ensures the long⁃term stability of surface sub⁃ sidence control. In addition to subsidence control and solid waste emission reduction，the overburden isolated grou⁃ ting can also be used for mine quake reduction and outburst prevention. It has been successfully applied in some com⁃ plex geological and mining conditions such as non⁃pillar mining，adjacent gob mining and multi⁃seam mining. A cer⁃ tain thickness of bedrock in the overburden is needed for the application of this technology，which allows a key layer that can be determined as grouting horizon. This technology still needs to be further tested in mine quake reduc⁃ tion，prevention of outburst，and water conservation mining.