不同应变类型红黏土归一化特性分析

Analysis on Normalization Characteristic of Different Strain Type Red Clay

基于红黏土不排水三轴剪切试验,采用人工制备2种不同压实度红黏土试样,分别测定其变形特性,研究不同应变类型红黏土的应力应变曲线归一化特性。试验结果表明:试验过程中出现应变弱塑性与应变强塑性这2种应变类型曲线,压实度对红黏土应变类型存在较大影响;2种应变关系曲线皆可用双曲线函数模型进行拟合;利用主应力差渐近值对不同应变类型的红黏土进行归一化分析均取得了较为理想的效果,对应变强塑性红黏土的曲线拟合效果优于应变弱塑性红黏土;本次试验用红黏土在重塑过程中损失了部分结构性,宜继续对比原状红黏土即结构性红黏土的应力-应变关系,构建结构性土本构模型。

Based on the red clay undrained triaxial shear test,two kinds of red clay sample with different compaction degree were prepared using artificial system. Their deformation characteristics were determined to get the stress-strain curve characteristics of different types of normalized strain of red clay. The test results show that： the strain curves of weak plasticity and strong plasticity occur in testing process,and compaction degree has large influence on the red clay strain type; The two strain curves can both be fit by hyperbolic function model; The main difference values were normalized to the asymptotic analysis of red clay in different strain types and ideal effect was achieved; Fitting results were better for red clay with strain strong plasticity than that of week plasticity. The red clay used in experiment loss some structure in the process of reshaping. It is appropriate to contrast the stress-strain relationship of the red clay,i.e.,structural red clay,to build constitutive model of structural soil.