摘要
土工动力非线性分析中的等价线性化法通常采用由土样动态试验得到的动剪切模量G_s及等效粘性阻尼比ζ_(eq)与剪应变γ之间的关系曲线,而以定常参数的Ramberg-Osgood或Hardin-Drnevich模型为骨架曲线、以Masing加卸载准则为基础的真非线性分析法并不能同时拟合各种应变水平下G,-γ与ζ_(eq)-γ两方面的经验规律。为获取一个与实验结果相一致的动态本构方程,本文将Ramberg-Osgood模型及相应的Masing准则进行改造,即把原模型中的定常参数取为剪应变水平的函数,并由常规给出的G,-γ与ζ_(eq)-γ关系直接推求这些变参数的变化规律。通过对Seed-Idriss统计平均曲线与Hardin-Drnevich等效线性模型的具体计算表明所建议的方案简单可行,符合实际。
The empirical relations between equivalent parameters Gs, ξeq and shear strain 7 obtained experimentally are widely used for conducting equivalent linearization analysis. On the other hand, the truly nonlinear technique, which is based on Ramberg-Osgood or Hardin-Drnevich skeleton equation and Masing's loading/unloading criterion, usually cannot agree well with experimentally-obtained data on both Gs-γ and ξeq-γ curves. To obtain a reasonable dynamic constitutive relationship which would be in consistent with the observed results, Ramberg-Osgood model and corresponding Masing's rules are modified in this paper. The parameters in R-0 model are taken as functions of shear strain. Their dependence on strain level is determined according to the Gs-γ and ξeq-γ curves.
出处
《地震工程与工程振动》
CSCD
北大核心
1992年第2期69-78,共10页
Earthquake Engineering and Engineering Dynamics
