Destabilization damage characteristics and infrared radiation response of coal-rock complexes

Abstract

Abstract To investigate the characteristics of destabilization damage in coal-rock complexes. Mechanical property tests were conducted on coal, rock, and their complexes. An infrared thermal camera was employed to real-time monitor the infrared (IR) radiation response signals during the destabilization damage process. A numerical model of coal-rock destabilization damage was developed, and its validity was verified. Deformed stress fields and displacement contours were obtained during the destabilization damage process. Upon destabilization, numerous cracks form at the base of the “coal” section, extending towards the interface, resulting in the formation of a wave-like deformation region. The differentiation in infrared thermal images is more pronounced in the “coal” section compared to the “rock” section. A high-stress region is evident at the interface, resulting in an area of high stress differentials. However, the bottom of the “coal” section also exhibits a region with high stress differentials and a more pronounced tendency towards destabilization damage. Displacement contours revealed that numerous units at the bottom of the “coal” section had slipped and misaligned, leading to the accumulation of damage and an elevation in the local damage level. It is a crucial factor contributing to the notable phenomenon of IR thermal image differentiation.

Keywords

• Coal-rock complexes
• Damage patterns
• Infrared thermal image differentiation
• Stress field evolution
• Damage evolution