Study on Rock and Surface Subsidence Laws of Super-High Water Material Backfilling and Mining Technology: A Case Study in Hengjian Coal Mine

Abstract

Research on the rock and surface subsidence laws of super-high water material backfilling and mining technology can provide a scientific basis for liberating coal resources that are deposited under buildings, railways, and bodies of water. Using field measurements, numerical simulations, and theoretical analyses to study the geological mining conditions of the Hengjian Mine in Handan, Hebei Province, this research comprehensively analyzes the dynamic and static deformation laws of rock and surface subsidence, reveals the subsidence control mechanism, complements existing studies and helps improve the feasibility of new technology in engineering practices. This study shows that rock and surface subsidence values are smaller when the super-high water material backfilling and mining technology are used, and the surface movement parameters are smaller than those of the fully caving mining method. The backfilling material supports the rock load above the mining area and suppresses the rock and surface subsidence. In addition, the super-high water backfilling material limits the height of the developing stress arch above the mining area, thus reducing the range of deformation in the rock and surface movement. In engineering practice, the development of the stress arch can be controlled by increasing the backfilling rate and the strength of the backfilling material. With the above-mentioned discoveries, this research is of great significance to the promotion and application of super-high water material backfilling and mining technology and the liberation of deposited coal resources.