滤纸法测定南阳中膨胀土土水特征曲线试验研究

Measurement of SWCC of Nanyang expansive soil using the filter paper method

介绍了滤纸法量测非饱和土吸力的工作原理,以及滤纸接触法量测土体基质吸力和非接触法量测土体总吸力的试验方法和注意事项。利用NaCl盐溶液法建立了国产＂双圈＂No.203型滤纸的总吸力率定曲线,得到了总吸力率定曲线的双线性表达式。分析了＂双圈＂No.203型滤纸的总吸力率定曲线和王钊等率定得到的基质吸力率定曲线的关系特性。应用滤纸法分别测试了不同含水率下南阳中膨胀压实土的总吸力和基质吸力值,分别给出了含水率介于16~30%之间的南阳中膨胀压实土的总吸力和基质吸力土水特征曲线。

The basic principle,approach and precautions for measuring both the matric and the total suction of unsaturated soils using the filter paper method are introduced.By means of sodium chloride solutions,the total suction calibration curve of the domestic filter paper,named as ＂Double-Circle＂ No.203,is established and a bi-line regression equation is proposed.As an application,the identical compacted samples of Nanyang expansive soil are tested under different water contents using the filter paper method,and the relationships among the total suction,matric suction,osmotic suction and water content of the expansive soil are established.Furthermore,the SWCC of the expansive soil,with the water content ranging from 16% to 30%,is obtained.