摘要
通过观测分析冻土单轴及三轴蠕变过程中细观结构的变化情况，发现蠕变过程中结构缺陷的增生与扩展制约着土结构的强化与弱化作用，控制着蠕变变形形态特征。易破坏区首先发生在样品的低密薄弱层面的薄弱区，对于单轴蠕变，在薄弱层面形成一环状低密带，然后向外扩展，最终导致整体结构的破坏；而对于三轴蠕变，在样品薄弱段的表面形成拉伸裂缝，然后向内扩展，最终导致整体结构的破坏。在单轴蠕变过程中冻土的体积随时间的发展而持续增加；三轴蠕变过程中冻土的体积随时间的发展而持续减小，仅当进入第三蠕变阶段后其体积有相对增大的趋势，但仍小于起始值。
In this paper, computerized tomography (CT) is used to measure and analyze the change of submicrostructure of frozen soil in uniaxial and triaxial creep process. The study reveals that the strengthening and softening actions of structure, as well as the form characteristics of creep process in frozen soil are controlled by growing microcracks, and growing and extending structural damage in creep process. The broken structure was appeared firstly in weak area of low density layer of sample. In uniaxial creep process of frozen soil, a ringlike zone of low density was formed in weak layer of sample and then extended outward to result in failure of integral structure. And the volume of frozen soil increased continuously with time. In triaxial creep process of frozen soil, the tensile cracks was formed in surface of low density part of sample and then extended inward to result in failure of integral structure. Meanwhile, the volume of frozen soil decreased continuously and increased slightly at the third creep stage, but it was still smaller than the initial value.
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
1997年第3期1-6,共6页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金
冻土工程国家重点实验室资助
