土工基础

›› 2012, Vol. 26 ›› Issue (1): 33-36.

• 工程实录 • 上一篇    下一篇

基于UH本构模型的软土深基坑数值分析

甄文战   

  1. (中铁二院工程集团有限责任公司，成都 610031)
  • 收稿日期:2011-07-01 出版日期:2012-02-20 发布日期:2012-03-23
  • 作者简介:甄文战，1982年生，博士，工程师，国家注册土木工程师(岩土)。主要从事地下结构设计及数值计算工作。

Numerical Analysis of Deep Excavation in Soft Clay Using Unified Hardening Model

ZHEN Wenzhan   

  1. (China Railway Eryuan Engineering Group Co., Ltd., Chengdu 610031)
  • Received:2011-07-01 Online:2012-02-20 Published:2012-03-23

摘要： 针对能反映超固结黏土的硬化、软化、剪缩和剪胀等应力应变特性及应力路径影响的UH本构模型，采用回映应力更新算法，编写了有限元材料子程序，实现了该模型在有限元ABAQUS软件中的应用；通过对单元试验进行三轴压缩及其它不同应力路径下的加载及卸载模型预测，再现了超固结土在不同超固结比和应力路径时的变形和强度特性，验证了子程序的正确性。最后，采用UH本构模型材料子程序，使用有限元软件ABAQUS，对软土地层中的某地铁车站深基坑进行了数值分析，讨论了基坑变形及支护结构土压力的变化，通过数值计算结果和实测值的对比，验证了UH本构模型在软土基坑数值分析中的适用性和正确性。

关键词: UH本构模型, 回映算法, 深基坑, 超固结土, 有限元子程序

Abstract: The Unified Hardening (UH) model can characterize many aspects of clay stressstrain behaviors, such as, straining hardening and softening, stress dilatancy, as well as the stress path dependent. A users defined material subroutine implementing the UH model was developed using the return mapping algorithm in the commercial finite element analysis software ABAQUS. The UH model was validated by simulating the loadingunloading process in the triaxial compression and other stress paths on a testing element. The results indicated that this constitutive model can reasonably characterize the soil behavior under different stress paths and overconsolidation ratio. This UH model was then applied to simulate a deep excavation of a subway station in cohesive soils. The numerical simulated deformation of the excavated area and the stress in the supporting structures were compared with the measured values. A satisfactory agreement was found between the measured and predicted values.

Key words: UH constitutive model, return mapping algorithm, deep excavation, overconsolidated soil, users defined subroutine