摘要
将液化后的饱和砂土视为一种流体,其流动特性表现出类似剪切稀化非牛顿流体的特性。根据非牛顿流体力学理论分析液化后饱和砂土的流动特性发现,当处于零有效应力状态时,可以用纯粘性流动本构模型较好地描述砂土的剪应变率表观黏度关系。通过拟合动扭剪试验结果的流变曲线,对比分析了几种常用的纯粘性流动本构模型,发现Gross模型可以较好且较简洁地描述液化后砂土零有效应力状态时的流动特性。通过对拟合参数的分析,建立了基于Gross模型的液化后饱和砂土零有效应力状态的流动本构模型,得到时间量纲下的参数K以及零剪切表观黏度η0和极限剪切表观黏度η∞的函数关系。考虑相对密实度、固结应力和应力历史对模型参数的影响,阐释了模型参数的函数关系以及物理意义。
When the liquefied water-saturated sand is regarded as a fluid,it can be idealized as a kind of shear thinning non-Newtonian fluid.Based on non-Newtonian fluid mechanics,the theoretical analysis was conducted on the liquefied water-saturated sand.According to this,the relationship between the shear strain rate and the viscosity under zero effective stress state can be properly described by pure viscous flow constitutive model.The Gross model of liquefied water-saturated sand is established by fitting the flow curve of the dynamic torsional shear test results on the basis of predictions obtained from several commonly used pure viscous flow constitutive models.The representative model parameters include the relative density,the consolidation stress and the impact of stress history.The functional relationships among time dimension K,zero shear apparent viscosityη0 and limit shear apparent viscosityη∞are fitted based on the dynamic torsional shear test results,and the physical meanings of the parameters are introduced in the composed function.The research landmarks a theoretical foundation for further analysis of large deformation of liquefied flows based on fluid mechanics theory.
作者
吴海清
Wu Haiqing(Shanghai Shenyuan Geotechnical Engineering Co.,Ltd.,Shanghai 200002,P.R.China)
出处
《土木与环境工程学报（中英文）》
CSCD
北大核心
2020年第3期32-39,共8页
Journal of Civil and Environmental Engineering
关键词
饱和砂土
剪切稀化
零有效应力
流动本构模型
剪应变率表观黏度
water-saturated sand
shear thinning
zero effective stress
flow constitutive model
shear strain rate-apparent viscosity
