关于持水特性曲线研究的几个问题

On some problems of researches on soil-water retention curve

对持水特性当前的研究中存在的3个问题进行了分析讨论,指出持水特性是非饱和土的本构关系之一,它不能代替其他本构关系;用研究本构关系的观点、理论和方法探索持水特性可提升研究水平;不同类别、不同地区土的持水特性曲线形态差异很大,用现有文献中的任一经验公式都难以描述,用试验方法确定具体对象的持水特性曲线是有效可靠途径;通过改进测试吸力技术和试验方法可以显著缩短测定持水特性曲线的历时;工程中经常遇到的填土、黄土、膨胀土、红黏土等在工作环境下的实际吸力不超过1500k Pa,而对土的变形和强度影响比较显著的吸力范围就更窄,没有必要花费很长的时间去测定全吸力范围的完整持水特性曲线。

Three problems in the current researches on soil-water retention characteristics are analyzed and discussed,and the following main conclusions are drawn.The soil-water retention characteristics are one of the constitutive relations of unsaturated soils,and they cannot replace other constitutive relations.Exploring the soil-water retention properties with perspectives,theories and methods for studying the constitutive relations can improve the research level.The forms of the soil-water characteristic curve of soils with different types and in different regions are very different,and it is difficult to describe them with the same empirical equation in the existing literatures.The testing method is an effective and reliable way to determine the soil-water characteristic curve.The time required to measure the soil-water retention characteristic curve can be dramatically shortened by improving the suction-measuring technology and the testing method.The actual suction magnitude of filling soil,loess,expansive soil,red clay,etc.,which are often encountered in projects,does not exceed 1500 kPa in their working environment.The reasonable suction range,which has a significant effect on deformation and strength of soils,is narrower.So there is no need to spend a long time to obtain the complete soil-water retention characteristic curve for the full suction range.