干湿循环对膨胀土变形指标的影响

Wetting-Drying Cycle Influence on Expansive Soil Deformation

对经历室内干湿循环后的膨胀土进行胀缩性试验，研究了胀缩变形指标的变化规律，结果表明：除缩限外，其余胀缩性指标随干湿循环次数的增加发生衰减，前1～3次循环时衰减速度较快，此后逐渐趋于一稳定值，循环次数与胀缩性指标可用指数关系拟合，缩限在干湿循环过程中不发生变化。

Laboratory tests study change of swell-shrink properties of expansive soil in wetting-drying cycle and swell-shrink indices are calculated. It is shown that well-shrink indices except the shrinkage limit of expansive soil obviously decrease at the beginning of 1 to 3 wetting-drying cycles, and then tend to stable values. But the shrinkage limit maintains constant after wetting-drying cycles. The relationship between swell-shrink indices and wetting-drying cycle times can be fitted by exponential equation