土工格栅蠕变特性及其黏弹塑性损伤本构模型研究  

Creep properties and viscoelastic-plastic-damaged constitutive model of geogrid

作　　者：周志刚[1] 李雨舟[1,2] 

机构地区：[1]长沙理工大学道路结构与材料交通行业重点实验室,湖南长沙410076 [2]长沙市城市建设科学研究院,湖南长沙410011

出　　处：《岩土工程学报》2011年第12期1943-1949,共7页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(50778027);湖南省自然科学基金项目(04JJ3033)

摘　　要：首先通过土工格栅蠕变试验,比较分析了不同荷载水平下的土工格栅蠕变规律。对以往典型的土工格栅蠕变模型进行归纳分类,并将之与蠕变试验结果对比,评价它们的适用性与可靠性。在此基础上提出了一种土工格栅黏弹塑性损伤本构模型,并应用最优化方法求解模型参数,论证了其合理有效性。研究指出,以往研究所提三类典型的蠕变模型都只适合于描述低应力水平下的衰减模式蠕变,不适合描述高应力水平下的非衰减模式蠕变;土工格栅三参数黏弹性模型,能够较准确地反映土工格栅在低应力水平情况下的两阶段衰减蠕变特性;而考虑材料黏塑性变形以及损伤而建立的土工格栅黏弹塑性损伤模型,能够准确地反映其在高应力水平情况下的三阶段非衰减蠕变特性。By carrying out the creep tests on geogrid,the creep properties under different loading levels are compared and analyzed.The typical creep models of geogrids suggested in previous studies are categorized and their adaptabilities and reliabilities are evaluated.Based on the results,one viscoelastic-plastic-damaged constitutive model of the geogrid is suggested,then the optimization method is used to determine the model parameters,and its reasonableness and validity are proved.Some conclusions have been drawn： the three types of typical creep models are only suited to describe the attenuation mode creep at a low-stress ratio but not the non-attenuation mode creep at a high-stress ratio.The proposed three-parameter viscoelastic model of geogrid can relatively accurately reflect two-stage attenuation creep properties of geogrid at a low stress.The proposed viscoelastic-plastic-damaged model of geogrid considering viscoplastic deformation and damage characteristics can accurately reflect the three-stage non-attenuation mode creep properties of the goegrid at a high-stress ratio.

关 键 词：土工格栅 蠕变特性 黏弹塑性 损伤 本构模型 最优化方法 

分 类 号：U414[交通运输工程—道路与铁道工程]