基于三轴剪切试验的原状黄土结构性研究

The Intact Loess Structural Research Based on the Conventional Triaxial Compression Test

利用常规三轴剪切试验对陕西杨凌原状黄土的结构性进行研究。基于邓肯-张双曲线模型,对邵生俊提出的结构性参数进行改造,这样就避免了计算时人工插值求参数的繁琐和不准确性,以及克服了该公式在ε1=0和ε1=15%时没有意义的缺点。然后以此改造后的结构性参数为基础分析围压和含水率对黄土结构性的影响。结果表明:非饱和原状黄土的结构性参数随应变增大先降低后趋于稳定。在相同的含水率下,围压越小,结构性参数越大;在相同的围压下,含水率越低,结构性参数越大。最后,在原状黄土的应力应变关系中引入结构性参数后该曲线表现出了较好的归一性,说明了此结构性参数的合理性和可靠性。

Conventional triaxial compression test is conducted to research the intact loess structural in Yangling,Shaanxi Province.We,based on the Duncan-Chang hyperbolic model,have improved the structural parameters proposed by Shao Sheng-jun.It can avoid the tedious and inaccuracy when parameters are calculated in the artificial interpolation way,and furthermore overcomes the shortcoming of no meaning as ε1=0 and ε1=15%.Then on the basis of the above work,the influence law of consolidate pressure and water content on structural characteristic of loess are analyzed.The results show that：the structural parameters of unsaturated intact loess firstly decrease with the increase in strain and then remain at a stable level.In the same water content,the smaller the consolidate pressure,the greater the structural parameters and under the same consolidate pressure,the lower water content,the greater the structural parameters.Finally,after the structural parameters are introduced into stress-strain relationship of the intact loess,better normalization of the stress strain curve is got,which shows that the structural parameters are reasonable and reliable.