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Rock fracture toughness is a critical parameter for optimizing reservoir stimulation during deep resource extraction. This index characterizes the in situ resistance of rocks to fracture and is affected by high temperature, in situ stress, thermal shock, and chemical corrosion, etc. This review comprehensively examines research on rock fracture properties in situ environments over the past 20 years, analyses the influences of various environmental factors on rock fracture, and draws the following conclusions: (i) Environmental factors can significantly affect rock fracture toughness through changing the internal microstructure and grain composition of rocks; (ii) While high temperature is believed to reduce the rock strength, several studies have observed an increase in rock fracture toughness with increasing temperature, particularly in the range between room temperature and 200 degrees C; (iii) In addition to a synergistic increase in fracture toughness induced by both high temperature and high in situ stress, there is still a competing effect between the increase induced by high in situ stress and the decrease induced by high temperature; (iv) Thermal shock from liquid nitrogen cooling, producing high temperature gradients, can surprisingly increase the fracture toughness of some rocks, especially at initial temperatures between room temperature and 200 degrees C; and (v) Deterioration of rock fracture toughness occurs more rapidly in acidic environments than that in alkaline environments. In addition, this review identified current research trends and suggested some potential directions to provide suggestions for deep subsurface resource extraction. (c) 2024 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/

来源平台：JOURNAL OF ROCK MECHANICS AND GEOTECHNICAL ENGINEERING