增(减)湿时黄土的湿陷系数曲线特征

分别采用单线法和双线法对原状 黄土进行了增、减湿情况下的单轴压缩试验。根据试验结果，总结出了黄土的湿陷变形随饱和度及压力变化的规律，分析了湿陷性黄土在增（减）湿过程中的湿陷变形性状及不同应力路径对黄土湿陷变形特性的影响，指出湿陷系数曲线因为试验方法的不同而表现出不同的规律性：初始含水量较低时，单线法的湿陷性大于双线法；当初始含水量达到某个值时，两者的湿陷系数曲线出现交叉现象；当初始含水量超过该值后，单线法的湿陷性小于双线法；这种交叉现象是由黄土本身的特殊结构性所决定的。最后对湿陷系数与初始含水量的关系进行了探讨。

Characteristics of collapsibility coefficient curves of loess during moistening and demoistening process

The behavior of undisturbed loess Q3 in the case of moistening or demoistening is investigated with single-line and double-line uniaxial compression test. According to the experimental results, the characteristics of collapsible deformation of loess changing with saturation level and pressure are presented. The collapsible deformation properties of loess during moistening or demoistening process and the influence of different stress-paths on collapse deformation characters of loess are analyzed. It is indicated that collapsibility coefficient curves can display different characteristics for different test method. The collapsibility of single-line method is larger than that of double-line method for lower initial moisture content, and is smaller than that of double-line method for higher initial moisture content. For certain value of initial moisture content in between, collapsibility coefficient curves of the two methods will intersect. This intersection phenomenon is caused by special structure of loess. Finally, the relation between collapsibility coefficient and initial moisture content is discussed.