Experimental Study on the Progressive Failure Zone of Non-Bolted Roadway with Infrared Radiation Detection

摘要

The thermal infrared (TIR) radiation in the deformation and progressive failure of coal roadway and the mechanism of thermo-mechanical coupling were investigated. The experimental achievements showed that the surface TIR temperature (TIRT) rose non-uniformly with the load increase before the stress peak and TIR radiation caused by stress concentration and fracture belt, was much stronger and higher than that caused by stress relaxation, week friction and tensile fracturing. The progressive failure zones were determined from the change ratios of TIR temperature of the different areas of the surrounding rocks. The infrared thermal image anomaly appeared with the macro-cracks development in the progressive failure of roadways, which reflected the spatial and temporal features of infrared precursor respectively. The infrared thermal image precursors were classified as TIRT increment region and TIRT constant region to disclosure the damage evolution and localization behaviors of roadways.