Acta Geodynamica et Geomaterialia

Title: EXPERIMENTAL INVESTIGATION INTO DYNAMIC DAMAGE MECHANISM OF ROCK-COAL-ROCK COMBINATIONS BASED ON DIGITAL IMAGE CORRELATION METHOD
Authors: Miao Leigang, Niu Yuanyuan, Shi Biming and Pan Yangbo
DOI: 10.13168/AGG.2024.0006
Journal: Acta Geodynamica et Geomaterialia, Vol. 21, No. 1 (213), Prague 2024
Full Text: PDF file (1.7 MB)
Keywords: Digital image correlation method, Rock-coal-rock combination, Impact load, Strain field, Crack propagation
Abstract: In recent years, the dynamic damage of coal rock mass induced by deep mining disturbance has become increasingly serious. To study the mechanical properties of coal-rock combination under SHPB impacts, digital image correlation technology was used to investigate the dynamic evolution laws of strain field, displacement field, crack initiation and propagation of rock-coal-rock combination at different loading rates. Through qualitative and quantitative analyses, the following research results are obtained. It is concluded that different crack evolution and propagation of the composite are presented due to the increase of load, which have three stages: uniform deformation, local deformation and overall crushing. With the increase of strain rate, the shorter the time to reach the uniform strain, the faster the crack evolution and propagation, and the more obvious the degree of fracture of the specimen. Under the impact load, the specimens of rock-coal-rock assemblage show axial splitting failure, and the cracks in the middle coal body appear first and the damage is the most serious, and the coal body also shows ejection phenomenon under high-speed impact. The experimental results can improve the occurrence mechanism of dynamic phenomena such as rockburst and coal and gas outburst, and provide data accumulation and reference for coal mine safety production and mine disaster prevention and mitigation.