A comprehensive model for evaluating infrared radiation and acoustic emission characteristics of sandstone fracture

The rock failure precursor can be used effectively for monitoring purposes and execution of underground engineering projects in a better way. To effectively determine the rock failure precursor, it is essential to consider the discreteness of the data, which researchers have not considered during the determination of rock failure precursors in the presence of infrared radiation and acoustic emission. Therefore, in this research study, the biaxial experiments of sandstone under different lateral stresses are carried out in the presence of infrared radiation and acoustic emission using the self-designed loading rock multi-parameter monitoring system. The characteristics of acoustic emission and surface infrared radiation of loaded sandstone are explained. A new index of infrared radiation of high-temperature point scale factor and cumulative high-temperature point scale factor amplitude is proposed. A comprehensive evaluation model of acoustic and thermal damage in the process of sandstone loading and fracture is constructed using the principal component analysis method based on the stress, cumulative ring count, and average infrared radiation temperature after effective denoising. The sandstone probability function of damage in the process of loading and fracture is defined, and the quantitative analysis of the influence weight of each acoustic and thermal index on sandstone fracture is defined. On this basis, a new method to determine the failure precursor of sandstone based on the first derivative of the acoustic thermal comprehensive evaluation model is proposed. This overcomes the discrete analysis defect of acoustic emission and surface infrared radiation information of loaded sandstone.