桂林红黏土的失水收缩变形特征研究

失水收缩是土体发生开裂的原因之一。以桂林红黏土为研究对象，开展了室内自然蒸发条件下干密度ρd=1.3 g/cm3的无侧限收缩试验。试验结果表明:桂林红黏土土体失水收缩经历了未收缩、正常收缩、残余收缩和零收缩4个阶段；在正常收缩和残余收缩阶段，土体含水率处于19%～31%，随着土中水分蒸发，含水率逐渐减小，土体发生收缩；在未收缩和零收缩阶段，土体体积形变不受含水率减小的影响；当土体含水率处于31%～41%时，土体不发生收缩；当土体含水率处于41%时，从开始失水那一刻即可认为其处于非饱和状态。

On Shrinkage Deformation Characteristics of Guilin Lateritic Clay due to Water Loss

Water loss shrinkage is one of the reasons why soil mass cracks. Taking Guilin lateritic clay as the study object, unconfined shrinkage test was carried out on condition that the dry density ρd is=1.3 g/cm3 under natural evaporation indoor. The test result shows that the water loss shrinking of Guilin lateritic clay experienced four stages:none, normal, residual and zero shrinkage; in the stage of normal and residual shrinkage, the moisture content of soil mass stays between 19%~31% and, as the water therein evaporates, the moisture content decreases and the soil mass shrinks; in the stage of none and zero shrinkage, the deformation of soil mass will not be affected by the decrease of moisture content; and the soil mass will not shrink when the moisture content is 31%~41%. The soil mass, while the moisture content is 41%, may be deemed as being in the state of unsaturation at the moment when the water is lost.