Study on early warning of instability failure of corroded yellow sandstone under freeze-thaw cycle

In order to study the mechanical properties and failure early warning of prefabricated fractured yellow sandstone, the biaxial compression test was carried out on the yellow sandstone specimens with two penetrating parallel cracks which treated by chemical corrosion under different freeze-thaw cycles. Digital image correlation technology (DIC) and infrared thermal imaging technology were used to monitor the deformation and failure process of rock samples in real time. The results show that: the strength of the yellow sandstone specimen decreases with the increase of the number of freeze-thaw cycles. The alkaline solution inhibits the deterioration caused by the freeze-thaw cycles. The failure mode of the yellow sandstone specimen is mainly composed of airfoil cracks and shear cracks. The airfoil cracks are initiated at the end of the prefabricated cracks, and the shear cracks appear when the airfoil cracks expand and penetrate through the two ends along the axial direction. Combined with the potential location of cracks corresponding to the strain localization zone and the precursory anomalies of infrared radiation temperature, early warning of rock damage can be made.