Strip Coal Pillar Design Based on Estimated Surface Subsidence in Eastern China

Excerpt

In order to ensure the safety of mining areas and reduce mining-induced surface subsidence, partial mining methods, such as room-and-pillar method and strip coal pillar mining, are practiced around the world. The design of pillars in coal mines has attracted much attention, with the aim of developing cost-effective recovery schemes while maintaining appropriate safety conditions. This means minimizing pillar dimensions while preserving sufficient stability (Wagner and Eng 1980). Studies of partial extraction methods used outside of China mainly discuss room-and-pillar mining in underground coal mines (Hustrulid 1976; Pariseau and Sorensen 1979; Fama et al. 1995; Gale 1999). To maintain a stable roof in a room-and-pillar mine, small pillars are left at regular intervals, although these pillars can be mined later during retreat when all panels have been mined out (Pariseau 1981; González-Nicieza et al. 2006; Shabanimashcool and Li 2013; Ghasemi et al. 2014a, b). …