“南水”双屈服面模型的两点修正

Two Modifications to the Shen Zhujiang's Double Yield Surface Model

摘要:

基于堆石料大型三轴试验数据，分析研究了其切线模量和切线体积比与应力状态的关系，建立了切线模量和体积比与应力比之间的函数关系式，并将其引入“南水“双屈服面弹塑性模型中.运用修正模型对不同应力路径下堆石料的大型三轴压缩试验结果进行了模拟，结果表明，修正模型在未增加参数的情况下较好克服了原模型在描述堆石料应力应变关系，特别是剪胀（缩）特性方面的不足，可更好地模拟堆石料的强度和变形特性.

关键词:双屈服面; 弹塑性模型; 切线模量; 切线体积比; 堆石料

Abstract:

Taking the original triaxial test data as the basis, this study analyzed the relationship between the tangential modulus, or the tangent bulk ratio and the stress state. The corresponding relational expression were proposed, respectively. Then, the two new expressions were introduced into Shen’s elastoplastic model with double yield surfaces to replace the old ones. The triaxial simulated results of rockfill materials showed that the modified model can overcome the disadvantages of using the damage stress ratio to control the final strength, especially the inadequate characteristics of shear dilatation (contraction). And the simulated results of different stresspath triaxial tests confirmed the new model can well simulate the strength and deformation characteristics of rockfill.

Key words:double yield surfaces; elastoplastic model; tangential modulus; tangent bulk ratio; rockfill