长期循环荷载下粉细砂的累积变形特性

Character for Cumulative Deformation of Silty Sands Under Long Term Cyclic Loading

摘要:

在分析循环荷载下粉细砂轴向塑性累积变形受初始孔隙比、有效固结压力及动应力比等因素影响规律基础上,考虑动偏应力水平及初始固结压力影响,建立了一种参数具有明确物理意义的计算粉细砂在循环荷载作用下轴向塑性累积变形的显式模型.通过对上海地区粉细砂非等向固结排水循环三轴试验结果进行模拟,得到了相关参数,验证了模型的有效性和合理性.

关键词:动偏应力水平; 长期循环荷载; 塑性累积应变

Abstract:

Based on an analysis of effect of the initial pore ratio,effective consolidation pressure and dynamic stress ration on the axial plastic cumulative deformation of the silty sand and a consideration of the effect of the dynamic partial stress level and the initial consolidation pressure of the silty sand, an explicit model of which parameters were of physical significance was build up to calculate the axial plastic accumulative strain of silty sands under cyclic loading. Parameters of the explicit model were determined by undrained cyclic triaxial tests on anisotropically consolidated Shanghai silty sands and validity of the model was verified by the cyclic tested data.

Key words:dynamic deviator stress level; long term cyclic loading; plastic accumulative strain