Study on Acoustic Emission Characteristics and Failure Mechanism of Basalt After High Temperature
To explore the failure characteristics and mechanisms of basalt after high tem-perature,the loading experiments and acoustic emission tests were conducted on basalt samples temperatures at 25℃,200℃,400℃,600℃,800℃and 1 000℃.The evo-lution laws of acoustic emission(AE)characteristics such as peak frequency and energy during the rock fracture process were analyzed,and the mechanism of the rock fracture was also explored.The results show that the high temperature has a significant influence on the AE signal characteristics.With the increase of temperature,the proportion of high peak frequency increased.Thermal damage shorten the development time of the microc-racks,while accelerating the expansion speed but reducing the expansion scale.The heat treatment of the rock has an additive effect on the burstiness.The AE localization points gradually converge from the dispersed state to the aggregated state.With the increase of temperature,the period of convergent nucleation of the AE localization sites is advanced,and the absolute AE energy before the peak stress is fluctuated.The high temperature has modified the failure pattern of basalt.With the increase of temperature,the failure mecha-nism of basalt transformed from shear failure to tensile failure.
rock mechanicshigh temperaturebasaltacoustic emission characteristicsfailure mechanisms