原状黄土的压缩曲线特性

原状黄土是一种具有结构强度的欠压密土，其侧限压缩变形特性区别于一般土。为研究原状黄土侧限压缩变形的共性，对西安、兰州6个场地不同含水率的原状Q3、Q2黄土进行了侧限压缩试验，得到了相应场地不同含水率原状黄土的压缩曲线，分析了其压缩曲线的形态，通过曲线对应的压缩屈服应力及初始孔隙比，将各黄土不同含水率下的压缩曲线归一化为同一曲线，且形成时代相同的黄土归一化曲线位置相同，并利用复合幂?指数模式分别描述了Q3、Q2黄土归一化的曲线。将文献中试验黄土的初始孔隙比与压缩屈服应力代入归一化曲线的表达式，计算得其压缩曲线和压缩性指标。经对比，与文献实测压缩曲线及压缩性指标很接近，验证了黄土压缩曲线的归一化特性并对其进行了应用。结果表明：试验黄土压缩曲线具有可被其初始孔隙比和压缩屈服应力归一化的特性，此特性为黄土侧限变形性质的分析提供了一条便捷的途径。

Compression curve characteristic of undisturbed loess

Undisturbed loess is a type of under-consolidated soils with structural strength, and its confined compressive deformation characteristic is distinct from those of ordinary soils. To study the general character of confined compression deformation of undisturbed loess, confined compression tests were carried out on Q3 and Q2 undisturbed loess with different water contents sampled from six fields in Xi'an and Lanzhou. The compression curves of undisturbed loess at different water contents from corresponding sites were obtained. The shape of the compression curve was analyzed. Through the compressive yield stress and the initial void ratio corresponding to the curve, the compression curves of tested loess at different water contents were normalized into a same curve, and the positions of the normalized curves of loess with the same sedimentary period were the same. The normalized curves of Q3 and Q2 loess were respectively described by composite power-exponent model. The initial void ratio and compressive yield stress of the loess in the literature were substituted into the expression of normalized curve to calculate the compression curves and compressibility indexes. It was found that the curves tested in literature was close to the compression compressibility indexes, demonstrating the normalized characteristic of loess compression curve and its application value. The test loess compression curve has the characteristics that can be normalized by its initial void ratio and compressive yield stress, which provides a convenient way for the analysis of confined deformation properties of loess.