重复荷载作用下非饱和黄土的动力特性研究

通过对神河高速非饱和黄土在不同围压下进行振动三轴试验,测定了非饱和黄土的动弹性模量和阻尼比,以及黄土的动本构关系。结果表明,动弹性模量随动应变值增大而减小;在相同固结比条件下,动弹性模量随固结压力值增大而增大;随着动应变增大,非饱和黄土的阻尼比随之增大;非饱和黄土的动应力-动应变关系可近似用双曲线模型表达。同时分析了动弹性模量随动应变的规律,进一步验证动三轴试验中动弹性模量的变化规律的合理性。

The Dynamic Characteristics Tests of Unsaturated Loess under Cyclic Loading

According to the dynamic triaxial test under different confining pressures of unsaturated loess samples from Shenhe expressway, the dynamic elastic modulus, the damping ratio and the dynamic constitutive relationship of the unsaturated loess were determined. The dynamic elastic modulus of unsaturated loess decreases with the dynamic strain increasing. Under the same consolidation ratio, the dynamic elastic modulus of unsaturated loess increases with the increasing of the consolidation pressure. With the increasing of the dynamic strain, the damping ratio of unsaturated loess increases. The relationship analysis between the dynamic stress and the dynamic strain was expressed by the hyperbolic model, and analyzed the dynamic elastic modulus with the regularity of dynamic strain, further verified the rationality of the variation of the dynamic elastic modulus.