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Research on nonlinear constitutive relationship of permanent deformation in asphalt pavements

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Science china(Physics,Mechanics & Astronomy) 2006年第6期49卷 671-682页

作者： PENG Miaojuan1 & XU Zhihong2 1. department of civil engineering,shanghai university,shanghai 200072,china 2. School of Transportation engineering,Tongji university,shanghai 200092,china 1. department of civil engineering Shanghai University Shanghai 200072 China 2. School of Transportation engineering Tongji University Shanghai 200092 China

To predict correctly the rut depths in asphalt pavements,a new nonlinear viscoelastic-elastoplastic constitutive model of permanent deformation in asphalt pave-ments is presented. The model combines a generalized Maxwell model with an elasto-plastic one. Then from the creep theory,the linear and nonlinear constitutive equations of the generalized Maxwell model are obtained. From the nonlinear finite element method for the rutting of the asphalt pavement,the rut depths of 4 asphalt-aggregate mixtures are obtained. And the results are compared with the ones from the finite element method by SHRP and the experiments by SWK/UN. The results in this paper are better than the ones by SHRP,and agree with the ones of the experiment by SWK/UN. This shows that the nonlinear viscoelastic-elastoplastic constitutive model,which is presented in this paper for the rutting of the asphalt pavement,is effective. The properties,such as nonlinear elastic-ity,plasticity,viscoelasticity and nonlinear viscoelasticity,which affect the rutting of an asphalt pavement,can be shown in the model. And the characteristics of the permanent deformation of the asphalt pavement can be presented entirely in the model.

关键词： asphalt pavement,permanent deformation,nonlinear viscoelastic-elastoplastic constitutive relationship,generalized Maxwell model,creep compliance.

Model test on sand retaining wall reinforced with denti-strip inclusions

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Science china(Technological Sciences) 2008年第12期51卷 2259-2269页

作者： ZHANG MengXi1 & ZHOU Huai1,2 1 department of civil engineering,shanghai university,shanghai 200072,china 2 shanghai Chengtou City Land(Group) Corporation,shanghai 200438,china department of civil engineering Shanghai University Shanghai 200072 China shanghai Chengtou City Land (Group) Corporation Shanghai 200438 China

In conventional reinforced soil structures,the reinforcements are often laid hori-zontally in the *** this paper,a new concept of soil reinforced with denti-strip inclusions was proposed and a series of laboratory model tests were carried out on sand retaining wall reinforced with denti-strip *** the horizontal displacements of the facing,the lateral earth pressures acting on vertical elements were measured.A microscopic measurement was performed to investigate the deformation and progressive failure of the sand within model retaining *** on the image analytical technique,the bearing capability and interaction mechanism of reinforced sand retaining wall were *** model of the initial shear failure and potential failure surface were also put *** the experimental results,it is shown that denti-strip inclusions can increase the bearing capability of retaining wall significantly and restrict the facing displacements efficiently,as compared with conventional horizontal reinforcement.

关键词： denti-strip inclusions reinforced sand retaining wall model test horizontal facing displacements lateral earth pressure on denti-elements failure surface

A study of mechanical behavior of rock-fill materials with reference to particle crushing

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Science china(Technological Sciences) 2007年第z1期50卷 125-135页

作者： HUANG WenXiong1?, REN QingWen1 & SUN DeAn2 1 department of engineering Mechanics, Hohai university, Nanjing 210098, china 2 department of civil engineering, shanghai university, shanghai 200072, china department of engineering Mechanics Hohai University Nanjing 210098 China department of civil engineering Shanghai University Shanghai 200072 China

In rock-fill dams of 200 to 300 m high, maximum compressive stress can exceed 6 MPa. At such a high stress level, rock-fill materials may experience particle crushing during shear. The material behavior is highly sophisticated exhibiting pressure and density dependency as well as particle crushing effects. Through scrutinizing the relevant experimental data on rock-fill materials and sands published in the literatures, this paper is focused on understanding basic mechanical characteristics of this sort of materials in the light of constitutive modelling.

关键词： rock-fill materials granular materials compressibility shear dilatancy particle crushing

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沥青路面车辙预估方法

同济大学学报（自然科学版） 2004年第11期32卷 1457-1460页

作者：彭妙娟许志鸿同济大学道路与交通工程教育部重点实验室

车辙会造成大量的经济损失 ,影响到路面行车的安全性和舒适性 ,而且还会引起路面其他形式破坏的产生和加剧 .为此总结了国内外学者对高等级道路沥青路面车辙预估的研究方法 ,并讨论了各种车辙预估方法的优缺点 ,在此基础上提出了高等级... 详细信息

车辙会造成大量的经济损失 ,影响到路面行车的安全性和舒适性 ,而且还会引起路面其他形式破坏的产生和加剧 .为此总结了国内外学者对高等级道路沥青路面车辙预估的研究方法 ,并讨论了各种车辙预估方法的优缺点 ,在此基础上提出了高等级沥青路面车辙预估的研究发展方向 ,为以后沥青路面车辙方面的研究及其沥青路面的设计提供参考 .

关键词：沥青路面车辙层应变法弹性理论粘弹性理论有限元法

Hydro-mechanical behaviours of highly compacted sand-bentonite mixture

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Journal of Rock Mechanics and Geotechnical engineering 2010年第1期2卷 79-85页

作者： De＇an Sun Wenjing Sun Wei Yan Jie Li department of civil engineering Shanghai University Shanghai 200072 China School of civil Environmental and Chemical engineering RMIT University Melbourne VIC 3001 Australia

： This paper presents the results of laboratory testing on a heavily compacted sand-bentonite mixture. To measure the soil-water retention curve （SWRC） of the mixture over a large range of suction, a pressure plate apparatus and filter papers were used. The obtained SWRC shows that the measurements via the two methods consistently agree with each other. By using a suction-controlled oedometer for unsaturated soils, a series of one-dimensional compression tests were performed on the unsaturated compacted sand-bentonite mixture at different constant suctions. The testing results indicate that the yield stress increases and compression index decreases with the increase of imposed suction. The results also demonstrate that the mixture wetted to saturation and subsequently dried to a certain suction level has a lower yield stress than that wetted directly to the same suction.

关键词： sand-bentonite mixture buffer/backfill material soil-water retention curve compression curves

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高层隔震结构的风振响应分析

水电能源科学 2010年第5期28卷 74-77页

作者：郑士杰刘文光何文福刘阳广州大学土木工程学院广东广州510006 上海大学土木系上海200072

根据高层隔震结构的隔震支座和上部结构的力学特性,将结构离散化为质量集中于楼层的多质点系后,采用自回归模型模拟了作用在结构节点上的风速时程,采用时域分析法分析了在不同风速、不同屈重比时隔震结构支座的受力特性,并对比了风荷载... 详细信息

根据高层隔震结构的隔震支座和上部结构的力学特性,将结构离散化为质量集中于楼层的多质点系后,采用自回归模型模拟了作用在结构节点上的风速时程,采用时域分析法分析了在不同风速、不同屈重比时隔震结构支座的受力特性,并对比了风荷载和地震作用下上部结构的剪力反应。结果表明,隔震结构在风荷载作用下基底剪力较非隔震结构略有增大,当作用风速较大和屈重比较小时,隔震支座会产生屈服现象,其最大楼层剪力有可能超过多遇地震作用下的最大楼层剪力。

关键词：高层隔震结构时域分析剪力风振响应

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用拉压不同模量理论解静定平面刚架

上海大学学报（自然科学版） 2004年第6期10卷 605-611页

作者：姚文娟叶志明上海大学土木工程系

静定平面刚架为杆件组合结构,其各杆件均处于复杂应力状态.根据结构特点,该文给出了不同模量刚架的中性轴、正应力、剪应力计算公式以及用不同模量理论解此类结构的计算方法;对一实例进行计算分析,用编制有限元程序计算与解析解进行对... 详细信息

静定平面刚架为杆件组合结构,其各杆件均处于复杂应力状态.根据结构特点,该文给出了不同模量刚架的中性轴、正应力、剪应力计算公式以及用不同模量理论解此类结构的计算方法;对一实例进行计算分析,用编制有限元程序计算与解析解进行对比分析;最后对两种方法计算的差异进行分析并得出结论.

关键词：拉压不同模量静定刚架中性轴应力

贯穿含深厚建筑垃圾土地基的预应力管桩承载力特性

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上海交通大学学报 2011年第S1期45卷 33-37页

作者：崔振清赵岗飞张孟喜杨德生王蛟洋山西潞安矿业集团有限责任公司山西长治430071 上海大学土木工程系上海200072

通过对表面粘贴应变片的管桩进行静载试验,分析沿轴向的管桩轴力及侧摩擦阻力的变化情况.结果表明:在竖向荷载作用下,桩身轴力沿深度方向呈现出倒三角的分布特征,其数值沿深度方向而逐渐减小;在含建筑垃圾土的土层中,管桩轴力随着深度... 详细信息

通过对表面粘贴应变片的管桩进行静载试验,分析沿轴向的管桩轴力及侧摩擦阻力的变化情况.结果表明:在竖向荷载作用下,桩身轴力沿深度方向呈现出倒三角的分布特征,其数值沿深度方向而逐渐减小;在含建筑垃圾土的土层中,管桩轴力随着深度的增加而快速降低,进入粉质黏土层后,其降幅较深层含建筑垃圾土的土层减缓;随着压桩力增加,管桩侧摩擦阻力逐渐增大,但其增幅减缓而最终达到极限值;浅层土与管桩之间的摩擦阻力较小,随着深度增加,摩擦阻力迅速增大;粉质黏土层与管桩之间的侧摩擦阻力小于底层含建筑垃圾土土层.

关键词：含建筑垃圾土预应力混凝土管桩承载力

A Criterion for Crack Initiation and Propagation of Intact Rocks under Creep Condition

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Journal of shanghai university(English Edition) 2002年第1期6卷 24-35页

作者：陈有亮岳中琦谭国焕李启光 department of civil engineering Shanghai University Shanghai 200072 China department of civil engineering The University of Hong Kong Pokfulam Road Hong Kong China

The mechanism and criterion of crack initiation and propagation of rocks were investigated by many researchers. And the creep behaviour of rocks was also theoretically and experimentally studied by some scientists and engineers. The characteristics of crack initiation and propagation of rocks under creep condition, however, are very important for rock engineering and still not paid enough attention by researchers. In this paper, the criterion and mechanism of crack initiation and propagation under creep condition were investigated using specimens collected from sandstone rock formations outcropping in the Emei Mountain, the Sichuan Province of china. Cuboid specimens under three point bending were used in this investigation. All specimens were classified into four sorts and used for Mode I fracture or creep fracture tests. The experimental result shows that due to creep deformation, rock crack will inevitably initiate and propagate under a load of K I , which is less than fracture toughness K IC but not less than a constant (marked as K IC2 ). K IC2 indicates the ability of rock to resist crack initiation and propagation under creep conditions and is less than fracture toughness K IC , defined as creep fracture toughness in this paper. K IC2 should be considered as an important parameter on design and computation of rock engineering. The microstructural mechanism for crack initiation and propagation of rock materials under creep condition was introduced based on competitive model between softening effect and hardening effect, and the validity of test result was explained. The test result was also verified in rheological theory. When K I is more than K IC2 but less than K IC , rock crack will initiate and propagate after a time interval of sustained loading under creep condition. In order to find the relation between duration of sustained loading, which can lead to crack initiation and propag

关键词： crack initiation and propagation sandstone creep gray prediction.