饱和砂土静动力剪切特性对比分析

在相同的初始应力条件下,通过进行循环扭剪试验和单调剪切试验,对比了初始固结应力状态完全相同时,饱和砂土的静动力剪切特性的相关性。试验结果表明,在初始固结应力状态相同的情况下,单调剪切和循环扭剪过程中,应力-应变关系的应变软化和硬化特性与流滑变形和循环流动特性具有密切的相关性,尽管在两种加载模式下都出现应变软化特性,但偏应力比增长均表现出硬化特性,增长模式也几乎一致,能作为静动力本构模型的物理基础。这一结果为对静力条件下的弹塑性模型进行修正和推广,从而进一步描述动荷载条件下的应力-应变特性的本构模型的建立提供了依据。

Comparative analysis on static and dynamic shear behaviors of saturated sands

A comparative experimental study on monotonic shear and cyclic torsion shear behaviors of standard loose sand under the same stress condition is carried out by using the soil static-dynamic universal triaxial and torsional shear apparatus. The correlation between static and dynamic characteristics of saturated sand under the same initial consolidation stress is investigated.The result shows that the strain softening and hardening characteristics of stress-strain relation is closely related to flow-slide deformation and cyclic flow characteristic.Although the strain softening characteristic appears under both loading mode,the increase of deviatoric stress ratio exhibits hardening characteristic in both cases,even the variation modes are approximately the same.It extents the plastoelastic model for static stress condition to dynamic condition and provides the physics basis of establishing the constitutive model for describing the stressstrain characteristics of sand under dynamic loading.