野外土-水特征及其工程意义

为了研究非饱和土边坡的土-水特征，在香港某人工边坡坡顶1，2，3，4m等不同深度同时安装了含水量计及吸力计。根据土体体积含水量和吸力值的野外监测结果，得出了边坡坡顶土体不同深度的野外土-水特征曲线。同室内土-水特征曲线明显的滞后性相比，野外土-水特征曲线的滞后性可以忽略。野外土-水特征曲线滞后性可以忽略的原因可能是由于边坡坡顶土体在暴雨期间的非平衡效应或者是体积含水量和吸力在野外和在实验室内测定方法不同的缘故。此外，对野外土-水特征曲线的工程意义进行了探讨。

FIELD SOIL-WATER CHARACTERISTICS AND ITS ENGINEERING IMPLICATION

In order to study soil-water characteristics of unsaturated soil slope, moisture probe and tensiometers are installed simultaneously for the soils at depths of 1, 2, 3 and 4 m at the crest of a cut slope in Hong Kong. Based on the field monitored results of volumetric water content and matric suction, field soil-water characteristic curves for the soils at different depths at the crest are determined. Compared with the obvious hysteresis of laboratory soil-water characteristic curves,the field soil-water characteristic curve shows negligible hysteresis. The negligible hysteresis may be attributed to the non-equilibrium effect during the heavy rainfall or the different measurements of volumetric water contents and matric suctions in the field and laboratory. Furthermore,the engineering implication of the field soil-water characteristic curve is also discussed in this paper.