土-水特征曲线的分形特性及其分析拟合

发布时间：2018-01-07 14:28

本文关键词：土-水特征曲线的分形特性及其分析拟合　出处：《岩土力学》2014年09期 　论文类型：期刊论文

【摘要】：为了建立一种参数有明确物理意义的土-水特征曲线拟合方法,基于分形理论,给出了一种直接通过土-水特征曲线实测数据求解分维数的计算方法,建议了一种土-水特征曲线拟合分析的分形模型。为验证所建议拟合方法的合理性,采用液压千斤顶制作了7个不同干密度黏性土试样,利用压力板仪测量了土-水特征曲线。基于土-水特征曲线实测值计算了分维数,在此基础之上对土-水特征曲线实测数据进行分析拟合。结果表明:分维数计算及拟合分析时,7个试样相关系数都集中在0.97~0.99之间,从而证明了土-水特征曲线具有良好的分形特性,建议的拟合方法效果较好。此外,研究发现,分维数、进气值随干密度几乎呈线性增加,据此建议了一种不同压实度下的土-水特征曲线预测方法,其预测结果与实测值吻合较好。
[Abstract]:In order to establish a fitting method of soil-water characteristic curve with definite physical meaning, based on fractal theory, a method to calculate the fractal dimension is presented, which is based on the measured data of soil-water characteristic curve directly. A fractal model for fitting and analyzing soil-water characteristic curves is proposed. In order to verify the rationality of the proposed fitting method, seven clay samples with different dry densities are made by hydraulic Jack. The soil-water characteristic curve was measured by pressure plate, and the fractal dimension was calculated based on the measured value of soil-water characteristic curve. On this basis, the measured data of soil-water characteristic curves are analyzed and fitted. The results show that the correlation coefficients of the seven samples are concentrated in the range of 0.97 ~ 0.99 when the fractal dimension is calculated and fitted. It is proved that the soil-water characteristic curve has good fractal characteristics, and the proposed fitting method is effective. In addition, it is found that the fractal dimension and air intake value increase linearly with dry density. A prediction method of soil-water characteristic curve under different compaction degree is proposed, and the predicted results are in good agreement with the measured values.
【作者单位】：中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室;湖北工业大学土木工程与建筑学院;
【基金】：国家自然科学基金(No.51209084) 教育部重点项目(No.2010133) 湖北省建设科技项目(鄂建文[2012]78号-48)
【分类号】：TU41
【正文快照】： 1引言土-水特征曲线表征的是基质吸力与含水率(体积含水率、饱和度、质量含水率)之间的关系,它在非饱和土工程性质研究中扮演着很重要的角色。土-水特征曲线试验测量获得的试验数据较离散,一般通过数学模型进行拟合。常用的数学模型有Campbell模型、van Genuchten模型等,但这

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