Experimental study on precursor characteristics of rock failure based on strain and temperature changes

Early warning of natural disasters (earthquakes and landslides) and engineering disasters (mining and tunnel collapse) has always been a complex problem in the field of engineering. In the current paper, the uniaxial compression loading tests of rock specimens are methodically observed by employing strain data acquisition equipment and an infrared thermal imager. By examining the variation pattern of strain field and temperature field data before rock damage, a critical damage identification method in conjunction with the strain and temperature data analysis is proposed. The corresponding time of total failure under the action of uniaxial compression is rationally determined by the strain data variation from increasing to decreasing in a 45-degree direction, and the location of the crack is predicted based on the slope of the tangent line of the strain curve in x- and y-direction at the failure time. Additionally, the slowing down of the temperature growth trend at the monitoring point and the significant variation of the local temperature over a short period in the infrared thermal image could be utilized as precursory characteristics for the rock damage. These research findings could be very beneficial in predicting the early warning of the surrounding rock instability in geotechnical engineering.