摘要 土-水特征曲线（SWRC）是非饱和土力学中的基础本构关系,在研究非饱和土强度、体变及渗透系数等方面具有重要作用。通过试验直接测量SWRC,耗时较长,且通常得到的只是离散数据点,缺乏连续性,不能完全满足非饱和土研究的需要,因此,通过间接方法快速预测SWRC的完整数学表达式具有实际意义。以无损伤的核磁共振（nuclear magnetic resonance）技术为基础,结合Young-Laplace理论,建立基质吸力ψ与T2值的关系式;利用分形理论,推导出质量含水率w与T2值的关系式,最终建立了预测SWRC的数学模型,研究结果表明其预测结果与实测值吻合较好。
Abstract：It has been recognized that the soil-water retention curve (SWRC) is a fundamental constitutive relationship of unsaturated soil mechanics, which plays a decisive role in the researches on the strength, volume change and permeability coefficient of unsaturated soils. The direct experimental methods for measuring the SWRC are time-consuming, and they usually provide some discrete data points which are short of sufficient continuity, thus they cannot completely meet the needs of researches on unsaturated soils. So, it is necessary to fast obtain the complete mathematical expression for SWRCs by using the indirect method. Based on the non-invasive nuclear magnetic resonance (NMR) technology, the relationship between matric suction ψ and relaxation time T2 is established by using the Young-Laplace theory. Then, by using the fractal theory, an expression for the relationship between mass water content w and relaxation time T2 is derived. On this basis, a specific NMR-fractal method is promoted to predict SWRCs. The experimental results show good agreement with the predicted values by the proposed fractal method.
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