不同年代黄土动剪切模量和阻尼比试验研究

为研究形成年代对黄土动力特性的影响,对Q_4全新世黄土、Q_3晚更新世黄土和Q_2中更新世黄土试样进行共振柱试验研究。结果表明:在相同条件下,动剪切模量G随形成年代的增加而增加;对动剪切模量采用两种常见的经验模型进行拟合对比,结果发现Davidenkov模型要比Hardin—Drnevich模型更加精确,并给出了模型的拟合参数;采用经验公式对不同年代黄土的最大动剪切模量和固结应力之间的关系进行了拟合,并确定了拟合参数;阻尼比也随形成年代的增加而增加,在半对数坐标系中,阻尼比与剪应变呈近似线性关系。

Experimental study on dynamic shear modulus and damping ratio of loess of different ages

In order to study the influence of the formation age on the dynamic characteristics of loess, the Q4 Holocene loess, the Q3 late Pleistocene loess and the Q2 Middle Pleistocene loess are studied by resonant column test. The result shows that under the same conditions, the dynamic shear modulus G increases with the formation age; the dynamic shear modulus fitting with two common empirical models shows that the Davidenkov model is more accurate than the Hardin-Drnevich model, and the fitting parameters of the models are obtained; the Davidenkov model is used to fit the relationship between the maximum dynamic shear modulus and the consolidation stress of loess of different ages and the fitting parameters are determined; the damping ratio D increases with the increasing of the formation time, and the damping ratio is approximately linear with the shear strain in the semi-logarithmic coordinate system.