氯盐渍土土-水特征曲线的试验研究

Experimental study of soil-water characteristic curve of chlorine saline soil

采用滤纸法和压力板法测定不同含盐量盐渍土的土-水特征曲线(SWCC),探讨土中含盐量对盐渍土土-水特征曲线的影响。试验结果表明,粉土中含盐量对基质吸力土-水特征曲线的影响不大。采用滤纸法测得的总吸力与基质吸力之间的差值随着土中盐溶液浓度的增加而增加,且该差值要大于相同浓度纯盐溶液的渗透吸力,其原因是由于土颗粒表面对溶液吸附作用引起的,用滤纸法测得的基质吸力土-水特征曲线处于脱湿曲线和吸湿曲线之间。采用蒸汽平衡法测定Whatman 42号滤纸在高吸力阶段的总吸力的率定曲线,使得高吸力时用滤纸法测定吸力更为精确。

Soil-water characteristic curves （SWCCs） of saline silt with different salt contents were measured by the filter paper and pressure plate methods, The influence of salt contents on the SWCCs was discussed. It was concluded from the experimental results that the variation in salt content in silt has little effect on matric suction; the difference between total and matric suctions measured by the filter paper increases with increasing salt content; and the difference is greater than osmotic suction of the pure saline solution with the same salt concentration due to the adsorption of the surface of soil grains to the solution; and the matric SWCC measured by the filter paper method is between the drying curve and the wetting curve. The calibration curve of Whatman No.42 filter paper was measured by the vapor equilibrium method for total suction at the high suction range; and thus the measured accuracy of total suction is improved at that range.