武汉软土固结不排水应力-应变归一化特性分析  

Normalized stress-strain behavior of Wuhan soft clay

作　　者：张勇[1] 孔令伟[1] 孟庆山[1] 陈建斌[1] 

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学重点实验室,武汉430071

出　　处：《岩土力学》2006年第9期1509-1513,1518,共6页Rock and Soil Mechanics

基　　金：中国科学院武汉岩土力学研究所知识创新工程项目(No.Q110201)。

摘　　要：基于武汉软土的固结不排水三轴剪切试验,分析了武汉软土的应力-应变关系特性:在低围压下,土体表现出稳定型或弱应变硬化型;在高围压下,土体呈现出弱应变软化型;土体的应力-应变关系曲线为典型的双曲线。为实现武汉软土应力-应变关系的归一化,基于典型的双曲线方程,从理论上推导了为实现应力-应变方程归一化而必须满足的归一化条件,并提出了用主应力差渐近值作为标准归一化因子。通过运用标准归一化因子和常用的以固结围压为归一化因子,对武汉软土应力-应变特性进行归一化分析和比较,得出用主应力差渐近值作为标准归一化因子,软土的应力-应变特性归一化程度更高,效果更好。同时,运用标准归一化因子,建立了武汉软土固结不排水条件下应力-应变特性的归一化方程。Based on the consolidated undrained triaxial shear test of Wuhan soft clay, the behaviors of stress-strain relationship are analyzed. The soft clay appears to be strain stabilization or hardening under low confining pressure, but exhibits strain softening phenomenon under higher one. The stress-strain curves of Wuhan soft clay under various confining pressure conditions are all typical hyperbola pattern. The normalization of its stress-strain relationship is important for the study of stress-strain relationship of soft clay. In this paper, a new normalized condition is derived theoretically based on hyperbola function. In this condition, the concept of standard normalized factor, which is defined as the ultimate value of principal stress difference, is introduced. Compared with the confining pressure which is often adopted as the normalized factor, the standard normalized factor is much better at normalizing the stress-strain relationship of soft clay. Meanwhile, the normalized stress-strain relationship of Wuhan soft clay under consolidated undrained condition is established.

关 键 词：武汉软土 固结不排水三轴试验 应力-应变关系 归一化性状 归一化因子 

分 类 号：TU43[建筑科学—岩土工程] TU447[建筑科学—土工工程]