考虑组构变化效应的饱和密砂循环本构模型

发布时间：2018-03-21 12:55

本文选题：饱和密砂　切入点：循环加载　出处：《岩土力学》2014年11期 　论文类型：期刊论文

【摘要】：为了真实地描述饱和密砂在循环加载过程中的变形行为,需要引入考虑剪胀阶段组构变化的宏观参量。在已有的基于状态参量的本构模型基础上,引入反映组构变化的剪胀内变量,简称组构-剪胀内变量z。以相变线PTL作为参考线,采用基于相变的状态参量判断砂土在初始时刻和任意时刻体积变形的变化趋势,并通过z对剪胀比d的影响,考虑反向加载过程中塑性变形的累积,建立了一个针对饱和密砂的循环加载的弹塑性本构模型。该模型根据试验现象将已有模型中的塑性剪切模量区分为首次加载模量与再加载模量,能较好地模拟排水情况下砂土循环加载的胀-缩变化过程。最后,针对密砂的三轴排水情况,利用文中模型进行预测,并把预测结果与试验结果进行比较,结果表明该模型能够总体反映砂土循环加载的变形行为。
[Abstract]:In order to truly describe the deformation behavior of saturated dense sand during cyclic loading, it is necessary to introduce macroscopical parameters that take into account the variation of fabric in the shear expansion stage. Based on the existing constitutive models based on state parameters, the deformation behavior of saturated dense sand during cyclic loading is described. The internal variable of shear expansion, which reflects the variation of fabric structure, is introduced. The phase transformation line (PTL) is used as the reference line, and the state parameter based on phase transformation is used to judge the change trend of the volume deformation of sand at the initial time and at any time. The accumulation of plastic deformation during reverse loading is considered through the influence of z on the shear expansion ratio d. An elastic-plastic constitutive model for cyclic loading of saturated dense sand is established. According to the experimental phenomena, the plastic shear modulus in the existing models is divided into first loading modulus and reloaded modulus. The process of dilatation and shrinkage of sand under cyclic loading can be well simulated. Finally, according to the triaxial drainage of dense sand, the model is used to predict, and the predicted results are compared with the experimental results. The results show that the model can reflect the deformation behavior of sand under cyclic loading.
【作者单位】：北京交通大学土木建筑工程学院;北京城市学院城建学部;
【基金】：国家自然科学基金(No.51278047,No.51208031)
【分类号】：TU441

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