摘要
介绍了以热力学为基础的土水特征曲线的滞后模型,该模型通过引入内变量来考虑与滞后有关的各种效应。由于满足了热力学定律,使这种模型更具有一般性和适用性。利用边界面理论,可以得到扫描线与边界面之间的关系,从而可以利用边界面来确定出其中的扫描线的情况。在前人工作的基础上,提出了一个修正的简化模型,把不可恢复的含水率作为其中一个内变量。修正后的模型对原有模型的不足之处进行了改进,使得扫描线在刚开始靠近边界面时的斜率不会出现无穷大,同时保留了原有模型的优点,只有一个参数,便于实际应用。通过与实验结果进行比较,可以看到修正后的模型能更好地反映非饱和土性质和实际情况。
Hysteresis is a well-known phenomenon in the soil-water characteristic curves.It plays an important role in many aspects of unsaturated soils.A thermodynamic model of hysteresis for soil-water characteristic curves was presented.Internal state variables were used in the model to simulate the effects related to the capillary hysteresis,and they made the model more reasonable than the empirical models or the domain models.By introducing the concept of bounding surface,a general theoretical framework for hysteresis was developed.A simple relationship between boundary curves and the scanning curves was proposed,the irreversible component of volumetric moisture content was introduced as one of the internal state variables.An improvement of this model was that the slope of the scanning curves would not become infinite when they started from the boundary surface.The simplified model had only one parameter which could be easily determined if the boundary curves and at least one data point on the scanning curves were given.Model predictions were compared with the experimental results,showing that the model agreed well with the existing data.
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2008年第3期399-405,共7页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金资助项目(50778013)
北京市自然科学基金资助项目(8082020)
关键词
土水特征曲线
滞后模型
非饱和土
soil-water characteristic curve
hysteresis model
unsaturated soils
