膨胀土边坡模型的含水量与变形特征

摘要

Indoor model tests were conducted to investigate the deformation mechanism of hydrophilic expansion and dehydration shrinkage,and the relation between them.Water content change and deformation characteristics of expansive soil slope under rainfall evaporation were analyzed.The results demonstrate that the direct reason of expansive soil slope deformation is the change of water content which occurs mainly in shallow soil.Slope expansion occurs at the beginning of rain tall,and its speed is fast and then slow.In evaporation stage,deep soil expands with the increase of water content by rain infiltration,whereas soil surface shrinks with the decrease of its water content.It can be concluded that slope deformation is closely related to its water content distribution.%采用室内模型试验,研究降雨蒸发条件下边坡模型的含水量变化和变形特征,并分析两者之间的关系,揭示降雨、蒸发条件下膨胀土边坡遇水膨胀,失水收缩的变形机制.结果表明:含水量的变化是导致膨胀土边坡变形最直接的原因；降雨期间,雨水下渗缓慢,含水量的改变主要发生在浅层土体；边坡的膨胀变形在降雨的第一时间发生,膨胀速度由快变慢；蒸发阶段,雨水入渗使坡体较深处含水量增高,深层土体继续膨胀,而表面土层由于含水量的降低已经开始收缩,因此边坡的整体变形与坡体含水量分布紧密关联.