传统测试土−水特征曲线（soil-watercharacteristic curve，简称SWCC）方法耗时较长，开发快速确定非饱和土的SWCC具有重要的实践意义。为了实现压实黄土SWCC快速预测，对不同干密度压实黄土进行了水势和水分测试，并且运用核磁共振（nuclear magneticresonance，简称NMR）技术对其孔径分布曲线进行了测试。根据测试结果建立了基于孔隙比的延安压实黄土土−水特征曲线快速预测方法，并利用实测数据验证了方法的准确性。结果表明：预测模型中的分形维数D可用孔径分布曲线上两点（峰值点和半幅点）的累计孔隙体积与孔径在双对数坐标中连成直线的斜率确定；基于孔隙比和优势孔径在双对数坐标中的线性关系，D可用孔隙比进行表示。SWCC进气值受大孔隙直径控制；过渡段斜率受中孔隙体积控制；压实黄土存在一个临界孔径，而残余含水率主要受孔径小于临界孔径的孔隙体积控制，并且提出了求取残余体积含水率的经验方法。与传统方法相比，所提出的方法可以在确定SWCC时节省大量时间。The traditionalSWCC test method is time-consuming

and it is of great practical significanceto develop a method that can quickly determine the SWCC of unsaturated soil. Inorder to predict the SWCC of compacted loess rapidly

the water potential andmoisture content of compacted loess with different dry densities were tested

and the pore size distribution curve was measured using nuclear magneticresonance (NMR) technology. Based on the test results

a rapid predictionmethod of the soil-water characteristic curve of Yan’an compacted loess wasestablished based on the void ratio

and its accuracy was verified by themeasured data. The results show that the fractal dimension D in the prediction model can be determined by the cumulative porevolume of two points (peak point and half-width point) on the pore sizedistribution curve and the slope of the pore size in a double logarithmiccoordinate; and it can be expressed by the void ratio based on the linearrelationship between void ratio and dominant pore diameter in logarithmiccoordinates. The inlet value of SWCC is controlled by the diameter of macropore;the slope of the transition section is controlled by the volume of mesopore. Thereis a critical pore size in compacted loess

the residual water content ismainly controlled by the pore volume whose pore size is smaller than the criticalpore size

and an empirical method is proposed tocalculate the residual volume water content.Compared with traditional methods

the proposed method can save a lot of timein determining SWCC.