冻结粉土的动静蠕变特征比较

通过动、静荷载作用下冻结粉土的蠕变试验,发现在初始蠕变阶段和稳定蠕变阶段,动蠕变的应变值小于静蠕变,而由于稳定蠕变阶段动蠕变的蠕变速率大,应变迅速增加,导致动蠕变的稳定蠕变阶段很短,迅速进入渐进流阶段,此时其应变值大于静蠕变;动、静蠕变的破坏特征与加载应力的变化趋势相同,但数值不同,动蠕变的破坏时间、破坏应变都小于静蠕变,最小蠕变速率值大于静蠕变,且加载应力越小,二者的差别越明显。

Comparison between dynamic and static creep characteristics of frozen silt

The dynamic and static creep characteristics of frozen silt were studied based on the dynamic and static creep tests. During the initial creep stage and the steady creep stage, strain of dynamic creep was less than that of static creep. However, for a dynamic creep, due to its higher creep strain rate during the steady creep stage and consequently a considerable strain increment, after a much shorter steady stage, it moved into the tertiary stage quickly where the strain became larger than that of a static creep. It was also discovered that there was a similar trend of creep failure characteristic, but with different values, between dynamic and static creeps in response to the change of loading stress. Both failure time and failure strain of dynamic creep were smaller than those Of static creep, and the minimum creep strain rate was greater. More distinct differences between these two creep types would be observed as the loading stress decreased.