考虑基底起伏的土体失水开裂动态过程试验研究

摘要

The soil crack resulted by desiccation leads to many engineering and environmental problems. Taking benton-ite with a high shrinkage rate for example,the soil desiccation and cracking tests are carried out. the results showed that the process of desiccation and crack were divided into three stages of pre-crackⅠ, rapid crackⅡ, and cracking stagnation Ⅲ. Cracking evolution is influenced by the boundary and relief of basement. At the early stage of rapid crackingⅡ,the cracking is mainly developing in the boundary of the model. However,in the late of crack,the cracking evolution is mainly influenced by relief of basement. In the stageⅢ,though the surface cracking still happens,the pattern of cracking development has not signif-icantly being changed. The later cracks are approximately perpendicular to the early cracks,especially in the zone of basement from the view of the cracking shape.%土体失水开裂会导致大量的工程和环境问题。利用失水收缩性强的膨润土，进行了土体失水开裂特征试验。研究表明土体失水开裂过程可划分为开裂前Ⅰ、快速开裂Ⅱ、开裂趋于停滞Ⅲ3个阶段，裂缝发育演化中受到了模型边界和基底起伏的显著影响。在快速开裂阶段Ⅱ前期裂缝主要发育在模型的角部，后期裂缝主要在基底起伏影响范围内发育。在Ⅲ阶段，尽管表面开裂仍在发生，裂缝发育的整体格局已经不再发生显著变化。从裂缝形态看，后期裂缝与前期裂缝主要呈现为垂直相交，特别是在起伏区范围内。