循环荷载作用下饱和软土的各向异性边界面模型

发布时间：2018-04-27 13:11

本文选题：软黏土 + 循环荷载　；参考：《岩土力学》2016年S1期

【摘要】：在临界状态弹塑性力学的框架内,建立了可以考虑循环荷载作用下各向异性对饱和软土力学特性影响的边界面塑性模型。该模型采用非关联的流动法则,引入了反映土体各向异性的内变量,利用该内变量的初始值描述初始各向异性,采用一种理论更为严谨、模型参数确定更为恰当的旋转硬化法则描述循环加载过程中各向异性的演化,利用更新映射中心的径向映射法则和与塑性偏应变路径长度有关的塑性模量插值规律,保证模型能够模拟循环加载时应力-应变响应的非线性、滞回性、应变累积性等基本特性,解释了模型参数的物理意义和确定方法,特别是给出了一种合理确定描述土体初始各向异性状态变量方法。通过文献中等压固结和偏压固结饱和黏土的循环三轴试验结果与模型预测结果的对比验证了模型的合理性。
[Abstract]:A boundary surface plastic model considering the effect of anisotropy on the mechanical properties of saturated soft soil under cyclic loading is established within the framework of critical state elastoplastic mechanics. In this model, an internal variable reflecting the anisotropy of soil is introduced, and the initial value of the internal variable is used to describe the initial anisotropy. The rotation hardening rule, which is more appropriate for determining the parameters of the model, describes the evolution of anisotropy during cyclic loading. The radial mapping rule of the updated mapping center and the interpolation law of the plastic modulus related to the length of the plastic strain path are used. It is ensured that the model can simulate the nonlinear, hysteretic and strain accumulation properties of the stress-strain response under cyclic loading, and explain the physical meaning and determination method of the model parameters. In particular, a reasonable method for determining the initial anisotropic state variables for describing soil is presented. The rationality of the model is verified by comparing the cyclic triaxial test results of isobaric consolidation and partial consolidation saturated clay with the results of model prediction.
【作者单位】：天津大学水利工程仿真与安全国家重点实验室;天津大学岩土工程研究所;
【基金】：国家自然科学基金(No.51579174) 博士点基金(No.20130032110045)~~
【分类号】：TU447

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