世界核地质科学2025，Vol.42Issue(5)：1055-1064,1080,11.DOI:10.3969/j.issn.1672-0636.2025.05.012
基于多物理参数的北山花岗岩热损伤评价
Evaluation of thermal damage of Beishan granite based on multiple physical parameters
摘要
Abstract
Granite serves as the surrounding rock for high-level radioactive waste repositories,the understanding of its thermal damage evolution is crucial for long-term engineering safety.This study systematically investigated the synergistic evolution of thermal conductivity,thermal diffusivity,P-wave velocity,porosity,and gas permeability of Beishan granite across temperatures ranging from 25 ℃ to 800 ℃.We employed a thermal constant analyzer,nuclear magnetic resonance(NMR),and ultrasonic pulse transmission techniques.Results reveals that:P-wave velocity shows accelerated attenuation between 300 ℃ and 700 ℃ due to mineral phase transformations,but stabilizes above 700 ℃ as melt-induced self-healing effects suppress further damage.Porosity evolution exhibits significant threshold behavior;its growth rate triples after 500 ℃ as quartz phase transition triggers fracture percolation.Thermal conductivity and thermal diffusivity respond asymmetrically:thermal conductivity decreases rapidly after 500 ℃ due to interconnected fracture networks,while thermal diffusivity temporarily increases between 300 ℃ and 500 ℃,regulated by enhanced mineral lattice ordering.Gas permeability increases slowly before 500 ℃ but surges steeply thereafter as fracture connectivity surpasses the percolation threshold;increasing confining pressure significantly suppresses this growth by closing fractures.The parameter sensitivity ranking is:P-wave velocity>porosity>gas permeability>thermal conductivity>thermal diffusivity.This indicates that P-wave velocity,owing to its high sensitivity to fracture topological evolution and the advantage of non-destructive testing,serves as the preferred indicator for thermal damage evaluation.These findings provide a key theoretical basis for the thermo-hydro-mechanical(THM)coupled design of repository surrounding rock,and could be valuable for the R&D of geothermal power.关键词
花岗岩热损伤/导热特性/纵波波速/气体渗透率/多物理参数敏感性Key words
thermal damage/thermal conductivity/P-wave velocity/gas permeability/sensitivity of multiple physical parameters分类
建筑与水利引用本文复制引用
王锡勇,吴云,王嘉敏,余俊桥..基于多物理参数的北山花岗岩热损伤评价[J].世界核地质科学,2025,42(5):1055-1064,1080,11.基金项目
国家自然科学基金(编号:42307244)和中国国家原子能机构核设施退役及放射性废物治理项目联合资助 Supported by National Natural Science Foundation of China(No.42307244)and China Atomic Energy Authority(CAEA)through the Geological Disposal Program （编号:42307244）
