摘要
小应变弹塑性模型-HSS模型广泛应用于软土基坑工程分析中,为便于简化计算,建立一种与HSS模型主要参数相对应的小应变非线性弹性本构模型是必要的。本文首先从Benz提出的小应变Overlay模型出发,建立一个综合考虑土体小应变范围内的模量衰减特性、模量的应力路径相关特性,大应变范围内的剪切与体变耦合特性,以及全应变范围内应力-应变关系的非线性、模量应力相关性的非线性弹性本构模型。然后,基于ABAQUS的子程序UMAT进行二次开发实现三维有限元数值模拟,平行使用基于本文模型的ABAQUS和基于HSS模型的Plaxis程序对均质土层基坑开挖算例以及台北TNEC基坑工程案例进行分析对比,验证了本文模型的有效性。
Hardening Soil Small(HSS)model has been widely employed in analyzing numerically deep excavation performance in soft clays,due to its capacity to account for the non-linear stiffness variations of soils at small strains.HSS,however,is formulated with the framework of elastoplasticity,thus may suffer from convergence and computational efficiency issues.The goal of this work is to propose a simple hypoelastic model that is equivalent to HSS and share similar material properties.Based on Benz’s Overlay model,the hypoelastic model incorporates key engineering behavior of soils,including the dependence of small-strain stiffness on strain magnitudes and recent stress histories,the volume-distortion coupling at large strains,and stress-dependent moduli and nonlinearity in the fullrange stress-strain relationship.The proposed model is implemented through the UMAT subroutine of ABAQUS.Comparisons between three-dimensional simulations using the hypoelastic model and HSS model,with reference to a synthetic excavation in homogenous soil stratum and Taipei TNEC deep excavation project,validate the proposed model.
作者
刘磊
倪雨萍
黄茂松
时振昊
顾晓强
Liu Lei;Ni Yu-ping;Huang Mao-song;Shi Zhen-hao;Gu Xiao-qiang(Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China;Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education,Tongji University,Shanghai 200092,China)
出处
《建筑科学》
CSCD
北大核心
2020年第S01期191-197,共7页
Building Science
基金
国家自然科学基金重点项目(51738010)
国家重点研发计划项目(2016YFC0800200)
关键词
基坑开挖
三维数值分析
小应变特性
非线性弹性
deep excavation
three-dimensional numerical analysis
small strain behavior
hypoelasticity
