Research progress on the microcrack evolution mechanism of High-temperature rock postprint

Abstract: The microcrack evolution mechanism of high-temperature rock has received widespread study.However，the systematic summary is still lacking.The research progress of the microcrack evolution mechanism of high-temperature rock is systematically summarized from four perspectives，including slow heating and cooling effect，thermal shock effect，stress effect，and the combined effects of high-temperature and stress.The evolution of microcracks in high-temperature rock is described in detail.The application of advanced experimental techniques into the study of microcrack evolution mechanism was introduced，including acoustic emission (AE)，ultrasound wave，mercury intrusion technology，nuclear magnetic resonance (NMR) technology，optical microscope，scanning electron microscope (SEM) and computer tomography (CT) scanning technology.The limitations of existing research are pointed out，including the lack of research on microstructural changes under the coupling effects of multiple physical fields and multiphase media，and the lack of research on establishing quantitative relationships between microstructural parameters and macroscopic physical and mechanical parameters.The research trend of microcracking properties in high-temperature rocks is described from two aspects，including the multi technology joint monitoring and the establishment of macro-micro quantitative relationships.