Similar Physical Modeling of Roof Stress and Subsidence in Room and Pillar Mining of a Gently Inclined Medium-Thick Phosphate Rock
Table 3
Law of deformation and failure for stopes in various mine types.
Mine characteristics
Differences
Explanation
Gently inclined medium-thick phosphate rock (the present study)
The surrounding rock in the roof gradually evolves from stable to unstable and dynamic balance during the mining process In the present study, because of the unique characteristics of the ore, the overlying rock mass had obvious bending, fracture, and caving zones
The characteristics and range of the surrounding rock deformation are closely related to the rock mass quality, rock layer contact zone, and orebody burial depth
In the mining process, the surrounding rock in the roof exhibits a process of gradual caving, gradual caving, sudden caving, and then again gradual caving, sudden caving, and then surface collapses, which is repeatable and instantaneous
The coal seam is shallow; thus, the caving zone caused by deformation and damage to the overlying rock directly extends to the surface; there are no subsidence, fracture, or caving zones
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Similarities
For a certain room size, the larger the pillars, the less change in the stress and displacement of the overlying rock and the more stable the stope During mining, tensile stress forms in the roof of the stope, and the maximum tensile stress appears in the center area of the roof.
