土水特征曲线(SWCC)是非饱和土研究的重要内容,但其唯一性受到多种因素的影响.为此,试样的差异性将对孔隙结构,进而对SWCC的唯一性造成影响.基于湿捣法制作的4个重塑试样对试样差异性进行试验研究,利用压力板仪和称量法获得相关脱湿试验数据.基于试验结果提出由无序阶段平均值和线性阶段基试样的试验数据组成表征SWCC数据.对比SWCC模型的拟合结果,验证了数据选取的合理性,确定Fredlund&Xing模型更符合试验结果.通过体积含水率和失水量随时间变化研究发现:起始基质吸力对体积含水率差异的产生有明显影响;主排水量在2~3d内完成,应在主排水结束之后进行相关试验,以降低对SWCC的影响.
Soil-water characteristic curve (SWCC) is important content of the unsaturated soil study. However, past studies clearly indicate that there are different parameters that would influence the uniqueness of SWCC. Since the uniformity of specimen is difficult to be controlled by human, and therefore to the pore structure, which is the main influencing factor for the uniqueness of SWCC, the difference of specimens will be studied. Four reconstructed specimens based on the moist tamping technology are used for testing. Test data are obtained by pressure plate extractor and weighing method. The test results show that the representative SWCC should be made up of the average in the disorder stage and the data of basis specimen in the linear stage. Based on the fitting results, the representative SWCC is verified, and Fredlund ~ Xing model is more suitable for test results. The variation of volumetric water content versus time shows that the initial matrix suction has clear influence on volumetric water content. The variation of water discharge versus time shows that main discharge will be completed in 2-3 d, and then other tests can be done to decrease the influence on SWCC.