基底潜山对土体失水收缩开裂动态过程影响的试验研究

The Influence of a Buried Hill in Basement on the DynamicProcess of Cracking Due to Soil Desiccation

摘要:

利用失水收缩性强的黏土,进行含有基底潜山和无潜山两种情况下土体失水开裂特征试验。研究表明:(1)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Ⅲ三个阶段;(2)含有潜山的试验中裂缝发育演化时受到了基底起伏的显著影响;(3)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。饱和黏土表面开裂主要是由水分丧失引起的土体基质吸力和表面收缩率的变化产生的,边界条件和基底起伏对开裂有着显著控制作用。

Abstract:

The cracking of soil has resulted in significant geological engineering and environmental problems.Indoor experiments on water loss ratio and the desiccation cracking of clay were carried out at room temperature.The research results indicate that:(1) the cracking progress can be divided into pre-cracking, rapid cracking, and cracking stagnation stages, (2) the cracking process is influenced by the buried hill of basement, and (3) though the surface cracking persists, the pattern of cracking has not significantly changed.The later cracks were approximately perpendicular to the early cracks, especially in the basement zone.The change in metric suction and surface shrinkage through water loss leads to the desiccation and cracking of the clay and the cracking process is controlled primarily by the boundary and geomorphologic form of the basement.