Study of Water-Controlled and Environmentally Friendly Coal Mining Models in an Ecologically Fragile Area of Northwest China

Striking a balance between high-intensity coal mining and environmental protection has been a challenge in the Yushen mining area, which is an important coal production base in China located in an arid and semi-arid ecologically fragile environment. The 122,109 working face of the Caojiatan coal mine was used as a model to coordinate coal production with ecological protection. Theoretical analysis and field monitoring revealed that the maximum surface subsidence was 5.6 m, and the development height of the diversion fracture zone was 21 times the coal seam thickness. The influence of mining process parameters and mining methods on surface ecological damage and water loss was further analyzed using the fluid–solid coupling method. The results showed that exclusive pursuit of high-intensity mining would induce irreversible disasters including aquifer water loss and cultivated land damage; the degree of influence was directly proportional to the working face length, mining height, and mining method. Proper adjustments of these parameters could help realize water-controlled coal mining. The results provide an empirical basis for allowing both exploitation of coal resources and protection of the environment in ecologically fragile areas.