基于热力学理论的超固结黏土边界面模型

发布时间：2018-01-24 10:04

本文关键词： 热力学理论 α-β屈服面超固结黏土临界状态边界面模型框架　出处：《岩土工程学报》2017年03期 　论文类型：期刊论文

【摘要】：基于热力学理论和临界状态土力学的框架,建立了耗散应力空间内的α-β屈服面。定义耗散势和背应力为应力的函数来实现在真实应力空间非相关联流动。基于边界面模型框架,准确模拟了超固结黏土在初始屈服面内的弹塑性响应。采用临界状态线与边界面交点在静水压力轴上的投影为映射中心,并定义剪胀函数,保证了"干侧"发生剪胀,而"湿侧"发生剪缩。与Boston Blue Clay,Lower Cromer Till和London Clay 3种土在不排水条件下的三轴试验数据进行对比,验证了模型的合理性和有效性。
[Abstract]:Based on thermodynamic theory and critical state soil mechanics framework. The 伪-尾 yield surface in the dissipative stress space is established. The dissipation potential and the back stress are defined as functions of stress to realize the non-associated flow in the real stress space. The elastoplastic response of overconsolidated clay in the initial yield surface is accurately simulated. The projection of the critical state line and the boundary point on the hydrostatic pressure axis is used as the mapping center and the shear expansion function is defined. The results show that the "dry side" and "wet side" are shear-dilated and shear-shrink respectively, which is similar to that of Boston Blue Clay. The results of Lower Cromer Till and London Clay triaxial tests under undrained conditions are compared to verify the rationality and validity of the model.
【作者单位】：浙江大学建筑工程学院;
【基金】：国家自然科学基金项目(51322809,51578499) 浙江省教育厅项目(N20110091)
【分类号】：TU43
【正文快照】： 近年来,随着高速公路、铁路、机场、堤防等基础设施建设,土的超固结现象普遍存在。在准确掌握超固结黏土力学特性的基础上,建立恰当的超固结土本构模型有利于工程问题的精细化分析。1958年,Roscoe提出临界状态理论,认为土在剪应力作用下会趋近于临界状态,体应变恒定,剪应变不

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