中国农村水利水电Issue(6)：214-221,8.DOI:10.12396/znsd.2501009
不同冷却速率下高温花岗岩微裂纹演化及力学性能仿真研究
Simulation Study on Microcrack Evolution and Mechanical Properties of High-Temperature Granite Under Different Cooling Rates
摘要
Abstract
Granite,as a typical rock mass of hot dry rock reservoirs,is often subjected to different refrigerant media during exploitation using Enhanced Geothermal System(EGS).In this study,a PFC-GBM simulation model was established by combining indoor experiments and simulation,and the evolution of microcracks distribution,number and formation mechanism of the specimens during the cooling process of air,water and liquid nitrogen were analyzed in depth.Furthermore,the changes in the mechanical properties and damage modes of high-temperature granite under different cooling rates were further explored.The results show that:with the increase of cooling rate,the total number of microcracks increased significantly,showing the trend of liquid nitrogen cooling>water cooling>natural cooling,concentrated in the boundary of the mineral particles and quartz grains;under high temperature conditions,intergranular tensile microcracks account for more than 60%,and intragranular tensile microcracks in quartz account for about 20%.The formation of microcrack network is mainly controlled by three minerals:quartz volume change dominates the network formation,feldspar nodal surface controls the expansion path,and mica structure regulates the stress.The cooling rate significantly affects the mechanical properties and damage mode of high-temperature granite.The higher the cooling rate,the greater the reduction range of compressive strength and modulus of elasticity,and the post-peak behavior is gradually shifted from brittleness to ductility,and the plastic deformation is enhanced,with the damage mode mainly characterized by complex multi-cracks and block-like structures.When the temperature is lower than 450℃,the damage mode and mechanical property degradation of granite under liquid nitrogen cooling are more obvious;while at higher temperatures,water cooling provides a more economical and practical alternative.The results of this study provide a reference for the effective exploitation of geothermal energy from dry-heat rocks.关键词
高温花岗岩/冷却速率/PFC-GBM模型/微裂纹/力学性能Key words
high-temperature granite/cooling rate/PFC-GBM model/micro-cracks/mechanical properties分类
建筑与水利引用本文复制引用
苗箫雨,荣冠,邱钦焱,吕祖豪,全军松,王顺..不同冷却速率下高温花岗岩微裂纹演化及力学性能仿真研究[J].中国农村水利水电,2026,(6):214-221,8.基金项目
国家自然科学基金面上项目(42472352、41772305). （42472352、41772305）
