在干燥条件下土体逐渐失水产生收缩变形,对土体开裂、地基承载力及边坡稳定性产生重要的影响.因此,有效预测含水量变化下土体的体积收缩变形具有重要的意义.本研究提出了能考虑土水吸附效应的全含水量范围内的土体收缩曲线数学方程.该方程能够同时描述脱湿过程中结构性与非结构性黏土的收缩体变.通过考虑土水吸附效应对土体收缩变形的影响,引入1个参数描述低含水量条件下土体收缩斜率,仅用1个方程即可预测从饱和到干燥条件下土体的完整收缩行为,尤其是低含水量条件下土体的体变特性.通过方程的预测曲线与文献中实测数据的对比,证实了所提出黏土收缩曲线方程的可靠性.同时,与现有方程的预测能力进行对比,表明提出的方程能够很好地描述低含水量条件下黏性土的非0收缩段与非0收缩斜率行为,证实了低含水量条件下土体收缩变形预测中考虑土水吸附效应的必要性与重要性.

Soil shrinkage occurs with the decrease of water content in soils under dry conditions, which has a great influence on soil cracking, bearing capacity, and slope stability. Hence, it is important to predict soil shrinkage effectively under the change of water content in soils. A novel mathematical equation is proposed for describing the soil shrinkage behavior within the full water content range considering the soil-water adsorption effect. The proposed equation can be used to characterize the soil shrinkage behavior of structural and non-structural clayey soils under dry conditions. An additional parameter is introduced into the proposed equation for characterizing the slope of soil shrinkage in low water content ranges, in which the effect of soil-water adsorption is considered. Only one equation is needed to predict the complete shrinkage behavior from saturated to zero water content conditions, especially for describing the volume change of soils under low water content. The proposed equation has been validated by comparing the results between the predicted curves using the proposed model and the measured data in literatures. Comparing with existing equations for soil shrinkage curve, the results show that the proposed equation can describe the non-zero shrinkage and non-zero shrinkage slope behaviors very well under low water content conditions. Furthermore, the results show that the soil-water adsorption effect is important and necessary for prediction of soil shrinkage behavior under low water content conditions.