季节性河床不同沙样的水分特征曲线研究

发布时间：2018-05-22 18:44

本文选题：水分特征曲线 + MATLAB　；参考：《人民黄河》2017年01期

【摘要】：选取季节性河流大沽河上、中、下游3处代表性河床的沙样作为试验样品,采用张力计法测出不同沙样的脱湿和吸湿过程,采用Van Genuchten模型拟合不同沙样的水分特征曲线,利用MATLAB中的Nlinfit函数求得Van Genuchten模型参数。结果表明:土壤水吸力(水银柱高度)为0~10 cm时,沙样的质量含水率变化明显,随着土壤水吸力逐渐增大,质量含水率逐渐降低,当土壤水吸力为60 cm左右时,含水率变化减缓,逐渐趋于平稳;3种沙样均存在水分特征曲线滞后现象,粗沙的滞后现象较细沙的明显;实测水分特征曲线和拟合曲线基本吻合,Van Genuchten模型和MATLAB求参方法均适用于拟合季节性河床沙样的水分特征曲线。
[Abstract]:The sand samples from three representative river beds on the Dagu River, the middle and the lower reaches of the seasonal river, were selected as experimental samples. The desiccant and hygroscopic processes of different sand samples were measured by using the tensometer method, and the water characteristic curves of different sediment samples were fitted by Van Genuchten model. The parameters of the Van Genuchten model are obtained by using the Nlinfit function in MATLAB. The results showed that when the soil water suction (mercury column height) was 0 ~ 10 cm, the mass moisture content of sand samples changed obviously. With the soil water suction increasing, the mass water content decreased gradually, when the soil water suction was about 60 cm. The change of water content slowed down, and gradually tended to steady. The hysteresis of water characteristic curve existed in all three kinds of sand samples, and the lag phenomenon of coarse sand was more obvious than that of fine sand. The measured water characteristic curves and fitting curves are in good agreement with Van Genuchten model and MATLAB parameter calculation method, which are suitable for fitting the water characteristic curves of seasonal riverbed sand samples.
【作者单位】：青岛理工大学环境与市政工程学院;
【基金】：国家自然科学基金资助项目(51309137,51379097)
【分类号】：S152.7

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