高放废物深地质处置库屏障系统的多场耦合数值分析  

Numerical analysis of multi-field coupling of barrier system in deep geological repository for high-level radioactive waste

作　　者：赵艺伟 吴志军 王旭宏 侯伟 杨球玉 吕涛 胡大伟[2,4] 周辉 魏天宇[2,4] ZHAO Yiwei;WU Zhijun;WANG Xuhong;HOU Wei;YANG Qiuyu;LÜTao;HU Dawei;ZHOU Hui;WEI Tianyu(School of Civil Engineering,Wuhan University,Wuhan 430072,China;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China;China Nuclear Power Engineering Co.Ltd.,Beijing 100840,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]武汉大学土木建筑工程学院,湖北武汉430072 [2]中国科学院武汉岩土力学研究所岩土力学与工程国家重点试验室,湖北武汉430071 [3]中国核电工程有限公司,北京100840 [4]中国科学院大学,北京100049

出　　处：《中南大学学报（自然科学版）》2021年第8期2557-2571,共15页Journal of Central South University:Science and Technology

基　　金：国家重点基础研究发展规划(973计划)项目(2018YFC0809601);国家自然科学基金资助项目(51779252);湖北省技术创新专项(2017AAA128)。

摘　　要：建立考虑围岩开挖损伤的高放废物处置库屏障系统的温度-渗流耦合数值模型,并验证其合理性;通过分析不同研究点的温度和饱和度演化规律,揭示温度梯度对缓冲/回填材料的饱和度演化规律的影响,同时,通过比较分析采用不同围岩初始渗透率时缓冲/回填材料中各研究点的饱和度和温度演化规律,揭示缓冲/回填材料的饱和过程对温度演化的影响;最后比较分析考虑和不考虑围岩开挖损伤时对屏障系统饱和度和温度演化规律的影响。研究结果表明:温度梯度会驱使水蒸气由高温端向低温端迁移,阻碍缓冲/回填材料的饱和过程;缓冲回填材料的饱和过程会促进屏障系统的热量传递,更有利于屏障系统的安全稳定;不考虑围岩损伤会延缓缓冲/回填材料的饱和时间,增大处置容器表面的最高温度,使得屏障系统的安全评估更为保守。A temperature-seepage coupling numerical model of the barrier system of high-level radioactive waste repository considering surrounding rock excavation damage was established and its rationality was verified. By analyzing the evolution of temperature and saturation at different research points, the influence of temperature gradient on the evolution of saturation of buffer/backfill materials was revealed. At the same time, the saturation and temperature evolution laws of each research point in the buffer/backfill material with different initial permeability of the surrounding rock were compared and analyzed, revealing the influence of the saturation process of the buffer/backfill material on the temperature evolution. Finally, the influence of the saturation and temperature evolution of the barrier system was compared and analyzed with and without considering the surrounding rock excavation damage. The results show that the temperature gradient will drive the water vapor to migrate from the high temperature area to the low temperature area, hindering the saturation process of the buffer/backfill material. The saturation process of the buffer backfill material will promote the heat transfer of the barrier system, which is more conducive to the safety and stability of the barrier system. Ignoring the damage of the surrounding rock will delay the saturation time of the buffer/backfill material, increase the maximum temperature of the surface of the disposal container, and make the safety assessment of the barrier system more conservative.

关 键 词：高放废物 多场耦合 开挖损伤 非饱和土 深地质处置 

分 类 号：TU452[建筑科学—岩土工程]