中文摘要：

大面积采空区引起的地面沉降或沉陷严重影响地表土地的正常使用。某循环经济产业集聚区位于采空区上方,开挖基坑时发现2条宽度约4 cm的地裂缝,经过反复论证,对该区域的采空区进行了水泥粉煤灰注浆处理,注浆前后的沉降观测结果表明：注浆对地表沉降速率有明显的控制作用,平均沉降速率由注浆前的0.052 mm/d下降至注浆后的0.0059 mm/d,使地基稳定性达到了国家相关规范的要求。

英文摘要：

Ground settlement or subsidence caused by large-area mined-out areas would seriously influence the normal use of the surface land.A circular economy industry cluster is just located above mined-out areas,two ground fissures with wideness of about 4 cm were found during the foundation pit excavation.After several repeated demonstration,the underground mined-out areas in this area were treated by grouting with a mixture of cement and fly ash.The results of settlement observation before and after grouting showed that the surface subsidence rate were obviously controlled by the grouting,the averaged subsidence rate decreased from 0.052 mm/d before grouting to 0.0059 mm/d after grouting,and the foundation stability met the national requirements of the national relevant specification.