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通过不同温度、不同加载应力作用下冻结兰州黄土、黏土、砂质黏土的蠕变试验,分析了蠕变曲线、初始应变、流变起始应变与流变起始时间、破坏应变与破坏时间及相对蠕变指标.结果表明:3种土质冻土的蠕变曲线变化规律大致相同,加载过程中,应变非线性增加,且加载应力越大、温度越高,初始应变越大;流变起始时间与破坏时间都与加载应力、温度有密切关系,加载应力越大、温度越高,越先出现流变和破坏.对于相同的土质,加载应力和温度对流变起始应变、破坏应变的影响不大;对于不同土质的初始应变、流变起始应变和破坏应变,都是黏土最大、砂质黏土次之、兰州黄土最小.3种土质冻土的初始加载段和非稳定蠕变段所占的时间较短,但产生的应变却较大;同时,温度越高,相对流变时间越短、相对破坏时间越长,说明非稳定蠕变阶段所占的时间随温度的升高而变短、稳定蠕变阶段所占的时间随温度的升高而变长.
Through the creep tests of frozen Lanzhou loess, clay and sandy clay under different temperature and different loading stress, the creep curves, initial strain, initial strain of rheology and rheological start time, failure strain and failure time Relative creep index.The results show that the creep curves of the three kinds of soil are roughly the same, and the nonlinear strain increases during loading, and the larger the loading stress is, the higher the initial temperature is and the larger the initial strain is. The time and failure time are closely related to loading stress and temperature, and the higher the loading stress is, the higher the temperature is, the earlier the rheology and failure occur.For the same soil, the influence of loading stress and temperature on the initial strain and the strain of rheology Not much.The initial strain of different soil, rheological initial strain and failure strain are the largest clay, followed by sandy clay, Lanzhou loess smallest.The initial loading section and unstable creep section Accounting for a shorter time, but the strain generated is larger; the same time, the higher the temperature, the relative rheological time is shorter, the relative damage time longer, indicating that the unsteady creep phase of the time with the temperature rise And shorter, stable creep phase of the time occupied by the increase of temperature and longer.