海东地区原状黄土动剪切模量与阻尼比试验研究

使用英国GDS双向动态三轴试验系统对青海省海东地区原状黄土进行动力特性试验研究。试验结果表明:动应变ε_d 1%时,动剪切模量随动应变的增加急剧减小;动应变ε_d1%时,动剪切模量随动应变的增加减小缓慢,后期基本趋于稳定。动剪切模量随固结围压、固结应力比、加载频率的增大而增大,且增大幅值随应变的增大呈现减小的趋势。在动应变ε_d 0.5%时,阻尼比随动应变的增加迅速增大;在动应变ε_d0.5%时,阻尼比随动应变的增加缓慢增大;在较小动应变时,固结围压、固结应力比、加载频率对阻尼比无明显的影响,随着动应变的增大,阻尼比随围压、加载频率的增大而减小,随固结应力比的增大而增大。

Experimental study on dynamic shear modulus and damping ratio of undisturbed loess in Haidong area

The dynamic characteristics of the undisturbed loess in Haidong area of Qinghai Province are studied by using the British GDS bidirectional dynamic triaxial test system. The test results show that: when the dynamic strainε_d is smaller than 1%, the dynamic shear modulus decreases sharply with the increase of the dynamic strain, while it decreases slowly with the increase of the dynamic strain and tends to be stable at the later stage when the dynamic strainε_d is larger than 1%. The dynamic shear modulus increases with the increase of the consolidation confining pressure, consolidation stress ratio and loading frequency, in addition, the increasing amplitude decreases with the increase of the strain. When the dynamic strainε_d is smaller than 0.5%, the damping ratio increases rapidly with the increase of the dynamic strain. When the dynamic strainε_d is larger than 0.5%, the damping ratio increases slowly with the increase of the dynamic strain. When the dynamic strain is small, the consolidation confining pressure, consolidation stress ratio and loading frequency have no clear influence on the damping ratio. With the increase of the dynamic strain, the damping ratio decreases with the increase of the confining pressure and loading frequency, however, it increases with the increase of the consolidation stress ratio.