Analysis of strata and ground subsidence in fully mechanized solid backfilling mining: a case study of Huayuan coal mine

Fully mechanized solid backfilling mining (FMSBM) is a mining technology that combines strata movement control and solid waste disposal. This technology can effectively reduce the damage to surface infrastructure. In this paper, field measurement subsidence data, physical modelling test and numerical simulation tests are used to study ground deformation, overlying strata movement and the predicting parameters of probability integral method of solid backfilling mining. The analysis shows that the process of strata movement has three stages and that the final and dynamic ground subsidence characteristics are significantly different from those of traditional longwall caving mining methods (without backfill). The ground subsidence values, subsidence velocity and damage height of overlying strata are smaller than those of caving mining, and no active subsidence phase is present in the dynamic subsidence. Among many factors that affect ground subsidence and overlying strata movement, the compression ratio of backfill materials is the key to controlling strata movement. On the basis of the results, several countermeasures are advised to ensure backfilling quality and control ground subsidence. The research results can provide clear guidance for subsidence disaster control, prevention and engineering design in FMSBM.