水化-冻融耦合作用下大理岩单轴蠕变力学特性

Uniaxial Creep Mechanical Properties of Marble Under Hydration Freeze-Thaw Coupling

为探究岩石在水化-冻融耦合作用下的蠕变规律,以湖北地区某露天边坡大理岩为研究对象,设置酸性、中性、碱性3种溶液环境浸泡,开展不同冻融循环次数条件下的单轴压缩蠕变试验,并对比分析大理岩宏观破坏形态和断口细观特征。结果表明:1)在同一冻融循环次数条件下,酸性溶液环境中的瞬时、蠕变应变量及蠕变速率均最大,碱性溶液环境次之,中性溶液环境最小;2)大理岩长期强度为瞬时强度的0.685~0.812,长期强度折减较大;3)酸性溶液对大理岩颗粒结构的损伤劣化程度强于碱性溶液,但随着冻融作用的增强,碱性溶液对岩石结构的损伤程度逐渐接近酸性溶液。

In order to explore the creep law of rock under the coupling action of hydration,freezing and thawing,taking the marble of an open-pit slope in Hubei as the research object,the uniaxial compression creep tests under different freeze-thaw cycles were carried out by soaking in acid,medium and alkali solutions,and the macro failure morphology and fracture micro characteristics of marble were compared and analyzed.The results showed that:1)Under the same number of freeze-thaw cycles,the instantaneous,creep strain and creep rate in acidic environment were the largest,alkaline was the second,and neutral was the smallest.2)The average long-term strength of marble was 0.685-0.812 of the instantaneous strength,and the long-term strength was greatly reduced.3)The damage degree of acid solution to marble particle structure was stronger than that of alkaline solution,but with the enhancement of freeze-thaw effect,the damage degree of alkaline solution to rock structure was gradually close to that of acid solution.