热损伤花岗岩力学劣化特性及损伤演化规律研究OA北大核心CSTPCD

The high geothermal environments encountered in deep mineral mining induce thermal damage to rocks,which can trigger geotechnical disasters in deep engineering projects.Therefore,explo-ring the degradation characteristics of rock mechanical properties and the damage evolution laws after high-temperature exposure is of significant importance for rock engineering in deep high-geothermal en-vironments.By subjecting granite to the temperature range from ambient to 1200 ℃ and conducting macro-microscopic studies using optical microscopy,the degradation characteristics of Young's modulus and compressive strength in granite samples post various high-temperature treatments were investigated.Additionally,an analysis was performed on the internal cracks and damage evolution in thermally damaged granite from a microscopic perspective.The experimental results demonstrate that high-temperature treatments significantly reduce the mechanical properties of granite.The granite's com-pressive strength and Young's modulus decrease with increasing treatment temperatures,and the extent of crack development increases with temperature.The mechanic cal properties of granite are highly cor-related with the development of internal crack structures.There is a power function relationship between the crack density and compressive strength in granite after different temperature treatments,indicating that crack density can effectively reflect the extent of thermal damage in granite.