Stability Analysis of Gentle Dip Thick Ore Body Mining Based on the Integration of SURPAC-FLAC3D

Abstract

Issues of large exposed roof area, poor stability, and significant roof support workload are prevalent in the mining of metal ores with gently inclined thick bodies. In response to these challenges, a downward cemented fill mining method has been proposed to enhance the stability of the surrounding rock and filling body. By integrating SURPAC and FLAC3D software, a three-dimensional numerical model that conforms to the actual geological morphology of the mining area was established. Numerical calculation results indicate that after the first stage of ore body excavation, the surrounding rock settlement mainly occurs in the roof and the hanging wall of the -65m level, with the hanging wall settlement primarily concentrated between the 3rd and 4th vertical exploration lines. The filling body demonstrates a weak compressive stress capacity, leading to a gradual transition of compressive stress to the surrounding rock of the mine stope. As the excavation level increases, the compressive stress on the pillars also increases, forming a compressive stress concentration area at the -65m level. A mixed plastic zone of shear and tension is generated in the roof and hanging wall, while a shear plastic zone is present in the inter-pillar area. The findings of this study offer valuable insights to ensure the safety of mining in gently inclined thick ore bodies.