结构性黄土湿陷性指标室内测定方法的探讨

对黄土湿陷性指标的室内测定，国内外都借助标准压密仪，采用单线法或双线法进行。由于多种原因，我国各部委编制的试验规程，对采用何种方法，意见尚未统一。本文首先从人工制备结构性黄土的试验成果出发，讨论了黄土的湿陷线问题，认为非饱和结构性黄土存在湿陷线，且该线与饱和结构性黄土的压密曲线重合。从而说明在此简单应力路径下，单线法和双线法是等价的。接着，从日本大阪海成粘土不同室内压密方法得出的试验结果出发，就天然结构黄土，探讨了常规标准压密试验方法的不足，提议采用等应变压密双线法，来测定结构性黄土的湿陷性指标，从而有利于实际工程应用。

Laboratory determination of collapsibility index of structural loess

It is a common way both in China and abroad to determine the collapsibility of loess in the standard oedometer by either single oedometer test or double oedometer test.However, it still remains unsolved whether the first method or the second one should be used and in the soil testing standards compiled by different administrative departments of the Chinese Government different statements can be found. In this paper it is obtained from test results of an artificially prepared structural loess that there exists an unique collapse line which coincides with the compression curve of the same sample but saturated preliminary. Therefore, it has been proved that both single oedometer test and double oedometer test will yield similar result if the tested samples have identical property, but this demand can hardly be satisfied for natural soils because of their heterogeneity. Next, from the analysis of test results of Osaka clay samples, the drawback of the standard oedometer test for natural loess is discussed, and a method of constant strain double oedometer test for determining the collapsibility of structural loess is proposed for practical use.