Integration of multi-physical signals for monitoring shear failure in jointed granite: insights from experimental study

Shear failure is the primary mode of failure in jointed rock masses. As such, in-depth examination of multi-physical signals is necessary to accurately monitor rock mass conditions throughout shear processes. This study employed direct shear tests on jointed granite specimens with different roughness levels, utilizing an advanced multi-physical field monitoring system. By applying computer vision technology, signal mode decomposition, and statistical analysis, the research explored the evolution of acoustic emission (AE), infrared (IR), and electromagnetic radiation (EMR) signals during shear testing. The investigation identified distinct stages in the shear process: compaction, elastic deformation, plastic deformation, post-peak failure, and stick-slip instability. AE signals displayed characteristic phases that corresponded with shear stress variations, whereas IR signals provided predictive insights into failure events through temperature field changes. EMR signals revealed electromagnetic responses at various shear stages. AE signals exhibited a stronger correlation with shear stress changes compared to IR and EMR signals, which showed varying degrees of temporal delay. The findings of this study emphasize the significance of integrating multi-physical signal analysis to enhance the understanding and monitoring of shear failure dynamics in jointed rock masses.