摘要
利用ＣＴ手段观测分析了冻土三轴压缩蠕变过程中结构的变化情况，结果表明，蠕变过程中围压的作用抑制了冻土体中裂隙的增长，加强了结构的强化作用，致使冻土在不稳定蠕变阶段和稳定蠕变阶段表现出结构强化占优势。随着非弹性变形的进一步累积，如果结构强化仍然占优势，则变形具有衰减特征；如果弱化作用克服了围压效应占主导，则发展以破坏而告终的非衰减蠕变。破坏首先发生在样品低密段的薄弱区，在样品表面形成拉伸裂缝。
In this paper, monitoring and analyzing the change of structures of frozen soil in triaxial creep process by CT is presented. It is found that the confining pressure restrains the increase of cracks in frozen soil and enhances the strengthening action of structure so that the strengthening of structure occupies a dominant position at unstable and stable creep stages of frozen soil. With a further accumulation of non-elastic deformation in frozen soil, if the strengthening of structure still occupies a dominant position, the creep deformation attenuates, and if the softening action can overcome the action of confining pressure, the creep deformation becomes an unattenuated one. The breaking appears firstly in the weakened area with low density within the sample, and the tensile cracks is found in the sample surface and then propagates inwards to cause an integral failure of the structure at last.
出处
《冰川冻土》
CSCD
北大核心
1997年第1期52-57,共6页
Journal of Glaciology and Geocryology
基金
国家自然科学基金
中国科学院兰州冰川冻土研究所冻土工程国家重点实验室资助
