Influencing Factors for the Instability and Collapse Mode of the Goaf Structure in a Gypsum Mine

Abstract

Large-area goafs in a gypsum mine tend to collapse after 10 or more years, but the influencing factors are still unclear, and the effects of multiple factors have not been comprehensively considered. In this study, the failure mechanism and collapse mode of the room-pillar goaf structure were analyzed, and the uniaxial compressive strength tests of the pillars under different conditions were carried out in a laboratory. The influences of water, temperature, and time on the strength of the gypsum rock were considered. These three factors weakened the gypsum rock in different degrees. After 120 days of immersion, water had the greatest effect with a strength-weakening rate of 52.61%. After 20 temperature cycles, changes in temperature had little effect with a strength-weakening rate of 12.60%. After 25 years of aging, the strength-weakening rate of time was 25.13%. These results show how different factors affect the instability and collapse of the goaf structure, which are of great significance for predicting and preventing this from happening.

Experimental Investigation of the Mechanical Behavior and Damage Evolution Mechanism of Oil-Impregnated Gypsum Rock

“…With the gradual increase in the exposed area and the influence of surrounding loads, accidents such as pillar deformation and roof collapse are prone to occur in the goaf [1][2][3]. Therefore, the gypsum mine goaf has become a major hidden danger in the field of mine disaster prevention and control and ecological environment governance, and how to control it has become a significant problem for mine safety production [4]. For many years, scholars around the world have been committed to replacing "government" with "management" of goaves, i.e., comprehensive utilization of the underground space of mines, giving full play to the resource attributes of this space [5].…”