基于黏粒含量的黄河下游堤防土水特征曲线预测研究

Prediction of Soil-Water Characteristic Curve(SWCC)of Embankments in Lower Yellow River Based on Clay Content

通过探究黄河下游堤防在不同围压下的土水特征曲线,为汛期堤防安全预报预警提供实时建议。通过分析黄河下游堤防土体黏粒含量与土水特征曲线的关系,提出以黏粒含量及干密度为主要因素的简易参数模型,并基于该模型进一步研究了不同围压条件下土水特征曲线的测算方法。结果表明:黄河下游堤防土体的土水特征曲线根据黏粒含量的不同呈现不同的特点,脱湿曲线可根据黏粒含量分为不同的区域,黏粒含量越大,滞回效应越显著;简易模型对于黏粒含量为20%以上的壤土或黏土的脱湿曲线适用性较好;随着围压的增大,相同含水量对应的基质吸力逐渐增大。模型引入与围压相关的参数c,可实现不同荷载下的黄河下游堤防土水特征曲线预测。

In order to provide real-time suggestions for the safety of the lower Yellow River embankment,it was imperative to conduct a quantitative analysis of the SWCC for the Lower Yellow River embankments soils under varying confining stress conditions.By analyzing the relationship between clay content and SWCC of the embankment soil,a simple parameter model based on clay content and dry density was proposed.This model was then utilized to examine the SWCC under various confining pressures.The findings indicate that the SWCC exhibits distinct characteristics corresponding to varying clay content.Dehydration curves can be demarcated into different regions based on clay content,with an increase in clay content correlating positively with the magnitude of the hysteresis effect observed.The simple model based on clay content exhibits a good applicability to the dehydration curve of loamy and clayey soils with clay fractions exceeding 20%.As confining stress intensifies,the matrix suction associated with a given water content incrementally rises.The parameter c,associated with confining pressure,has been incorporated into the model,enabling the prediction of SWCC for the Lower Yellow River embankment under different load conditions.