云冈石窟外壁面底部表层风化病害的形成与夏季降雨引发的毛细水上升密切相关。然而，冬季的反复冻融循环作用会使砂岩微观结构产生不可逆破坏，进而影响毛细作用，改变水分的迁移规律和分布范围等。本项目着眼于文物劣化现状，拟以云冈石窟砂岩为研究对象，开展冻融循环试验和一维竖直毛细上升试验，综合使用传统与新型无损检测技术，从多尺度角度研究砂岩冻融损伤演化规律，探索结构损伤砂岩的毛细迁移特性，并在此基础上建立考虑冻融损伤影响的砂岩毛细吸水动态理论修正模型。预期成果对于揭示砂岩劣化机理，拓展无损检测技术的应用等具有重要意义，同时也为我国类似石窟寺文物的科学保护提供理论依据。

In Yungang Grottoes, the formation of weathering pathologies at the bottom of outer wall surface is closely correlated to capillary rise after rainfall in summer season. However, repeated freezing-thawing cycles during winter induce irreversible damage on microstructure of sandstone, which alters the moisture transportation and distribution in the wall by influencing capillary migration. .Based on such current situation of deterioration, in this project, freezing and thawing tests and one-dimensional capillary rise tests are conducted on Yungang sandstone, adopting both traditional and nondestructive new techniques for measurement. Key questions including the law of frost damage evolution as well as the dynamics of capillary migration in sandstone with structural damage, are investigated and interpreted from different scales. Moreover, a modified theoretical model of capillary absorption of sandstone considering the impact of frost damage is established. The results are significant in revealing the deterioration mechanisms of sandstone, expanding the application of nondestructive techniques and providing theoretical basis for scientific conservation of similar grottoes in China.