Subsidence Control Design Method and Application to Backfill‐Strip Mining Technology

Abstract

Intensive and massive coal mining causes a series of geological hazards and environmental problems, especially surface subsidence. At present, two major types of subsidence control technology are applied: backfilling technology and partial mining technology. However, the cost of backfill mining is high and partial mining has a low recovery ratio. Therefore, the backfill-strip mining is used to solve the problems of high cost and shortage of filling materials in coal mines at present. A subsidence control design method of backfill-strip mining was proposed in this paper based on the subsidence control effects and economic benefits. First, the stability of the composite support pillar of the filling body and coal pillars in the backfill-strip mining is analyzed, and the values of the main subsidence influencing factors that include the filling material, the size of the backfilling working face, caving mining face, and residual coal pillar are preliminarily determined. Then, the surface movement and deformation are predicted based on the equivalent superposition probability integral method (PIM). The subsidence influencing factors are optimized and determined by comparing the requirements of the safety fortification index of the antideformation ability of surface buildings, resource recovery rate, and coal mining cost. Finally, the mining scheme design parameters of the backfill-strip mining technology are determined. This method is applied in the subsidence control design of backfill-strip mining in the Ezhuang coal mine. Research results show that backfill-strip mining can ensure the safety of surface buildings, increase the resource recovery rate, and reduce coal mining costs through the reasonable design of this method. This study can provide scientific guidance for subsidence disaster control, prevention, and engineering design in backfill-strip mining.

Evaluation of disturbance by coal mining to groundwater and surface ecosystem

“…According to the International Energy Agency (IEA), coal remains as a major component of the global fuel supply, accounting for 27% of global energy use. China is the world's largest producer and consumer of coal, and the coal industry has played a supporting role in the social and economic development of the country (Dong et al 2021) The western regions represented by Xinjiang and Inner Mongolia are the main coal mining territories in China (Wang et al 2021a) However, coal mining has brought about serious ecological and environmental problems in these areas (Ren et al 2020, Tyulenev et al 2019, with surface subsidence being the most prominent issue (Zhu et al 2021). Surface subsidence is a ground deformation caused by the roof subsidence of underground goaf.…”

Mining‐induced failure characteristics and surrounding rock control of gob‐side entry driving adjacent to filling working face in the deep coal mine

“…To satisfy the need for sustainable development and to avoid surface subsidence, it is imperative to adopt effective technology to maximize the exploitation of these trapped coal resources. In recent years, with its unique advantages, a variety of backfill mining technologies has gradually been developed for backfill mining, including solids, pastes, and high‐water materials 18 . Zhou et al 19 tested the mechanical properties of backfill materials to determine a reasonable backfill material ratio for the driving roadway during longwall mining.…”

“…In recent years, with its unique advantages, a variety of backfill mining technologies has gradually been developed for backfill mining, including solids, pastes, and high-water materials. 18 Zhou et al 19 tested the mechanical properties of backfill materials to determine a reasonable backfill material ratio for the driving roadway during longwall mining. Jiang et al 20 presented an approach for evaluating, designing, and optimizing the gob-side entry driving and yield pillars by considering the results of numerical simulations and field practice.…”

Study of water-conducting fractured zone development law and assessment method in longwall mining of shallow coal seam

“…Singh et al 30 proposed a visco and elastic model to determine surface subsidence value in Indian mining area. In addition, Zhu et al 31 developed the backfill-strip mining to reduce surface subsidence and successfully applied Ezhuang coal mine. Wang et al 32 used the theory of fuzzy matter-element and the combined weight to control subsidence in thick loose layer.…”