非饱和黄土的动剪模量与阻尼比

Dynamic shear modulus and damping ratio of unsaturated loess

本文对陕西杨凌地区的非饱和黄土在不同湿度条件下进行动扭剪试验,测定了非饱和黄土的动剪切模量和阻尼比。结果表明,非饱和黄土的动剪切模量随动剪应变的增加而减小,但减小的幅度愈来愈小;在其它条件相同时,最大动剪切模量随含水率的减小而增大,随固结应力的增大而增大;非饱和黄土的动剪切模量与黄土的结构状态及密实状态有关。在相同含水率、固结应力比和固结应力条件下,原状黄土的最大动剪切模量比重塑黄土的稍大,重塑黄土最大动剪切模量随试样干密度的增大而增大;非饱和黄土的阻尼比受含水率、固结应力比、周围压力、干密度等因素的影响,可以反映在其与动剪应变的关系上,在半对数坐标系中动剪切模量与动剪应变具有较为良好的线性关系。

The dynmaic shear modulus and damping ratios of unsaturated loess samples with various moistures gathered from Yangling area were tested by using dynamic torsional shear apparatus. The test results show that ： 1. the dynamic shear modulus of saturated loess decreases with the increase of dynamic shear strain, and maximal dynamic shear modulus will be elevated if the moisture is decreased and the consolidation stress is increased;2, the modulus is related to the structure state and the density state ; 3.the damping ratio is affected by the moisture, consolidation stress, refining pressure and dry density of the soil.