冻融受荷岩石唯象损伤扩展特性探讨

Discussion on the enological damage propagation characteristics of rock under freeze-thaw and load conditions

针对工程地质和岩土工程中所涉及到的冻害问题,从细观力学机理出发,将冻融循环次数及应变和岩石的损伤变量联系起来,得到宏细观相结合的冻融受荷岩石损伤演化方程及损伤扩展本构关系;对冻融荷载作用后的岩石进行唯象损伤扩展特性分析.研究发现:岩石的冻融损伤是一个疲劳损伤破坏过程,在寒区岩体工程设计和施工中,必须考虑冻融损伤的影响;寒区工程结构受荷岩石的岩性、初始损伤状态及力学性质的不同,造成冻融循环和荷载对损伤扩展的影响差别非常大,并表现出终态的宏观差异.

The frozen disaster is a problem not to be ignored in Engineering Geology and geotechnique. Contacting the freeze-thaw cycles and strain with damage variable, the micro-macro damage evolution equation and damage propagation constitutive relation of freeze-thaw and loaded rock were established based on micromechanics mechanism. Then, the macro enological damage propagation properties were analyzed of the rocks under action of freeze-thaw and load. It is shown that the mechanism of rock injured by freeze-thaw cycles is fatigue damage, its impact to rock engineering design and construction must be considered. To the freeze-thaw and Loaded rock in engineering structures, the influence of freeze- thaw cycles and strain on the damage propagation is different from the lithology, initial damage state and mechanical characteristics of the rock, and performances final macro diversity.