基于材料非线性的多轴重载下沥青路面结构响应分析

发布时间：2018-01-14 17:29

本文关键词：基于材料非线性的多轴重载下沥青路面结构响应分析　出处：《东南大学》2015年硕士论文　论文类型：学位论文

【摘要】：为了满足大物流的运输需求,解决运输经济与车辆超载的矛盾,车辆多轴重载运输已成为交通发展的必然趋势。与此同时,车辆的多轴重载作用对路面结构与材料的要求也提出了新的挑战,尤其是在路基路面材料方面,在重载作用下路基路面材料呈现出较大的非线性特性。此外,随着近些年来柔性路面的增多,工程实践表明,在路面设计及研究中路面结构材料的非线性特性不容忽视。基于上述状况,本文采用现场车辆调查与资料分析、路基路面材料特性研究和数值模拟等方法,分析了碎石底基层和土基非线性对路面结构响应的影响,同时在材料非线性的基础上研究了多轴重载作用下路面结构的响应。本文对我国货车发展及现状进行了调查分析。调研分析表明,我国重载货车在过去十年实现了快速增长,在现行的城市快速路和省道中,多轴重载车辆可占到总货车数量的一半,随着大物流运输的发展,多轴重载车将是我国未来货车的发展趋势。为了系统分析基于路基路而材料非线性多轴重载条件下路面结构的响应,本文继而展开以下几个方面的研究。首先,在路基路面材料方面着重考虑了碎石底基层和土基材料的非线性,并对其非线性应力依赖模型进行了系统研究。本文选取了国内外常用的碎石应力依赖模型,通过对已有碎石回弹模量测试数据的分析拟合,得到了三种不同级配碎石的本构模型参数。对于土基材料,基于美国伊利诺伊州联邦公路局对柔性路面的调查评估和我国实际情况,针对双线性应力依赖模型的土基的本构关系,讨论分析了由强到弱的四种不同土基材料,选取了不同土基的本构模型参数。其次,在有限元原理的基础上,分别针对碎石材料和土基材料的本构模型,选取切线刚度算法编写了相应的材料子程序,通过UMAT子程序接口导入到ABAQUS有限元软件中,实现了非线性材料在ABAQUS有限元软件中的数值分析计算。再次,建立了基于材料非线性的沥青路面结构响应的有限元分析模型,以纵向应力、路表竖向变形、基层层底拉应力和路基表面垂直应变作为路面结构响应指标,分别研究了碎石底基层非线性、土基非线性和双层材料非线性对路面结构响应的影响。研究结果表明,相对材料线弹性特性,碎石底基层非线性在重载下强度增大,能够加强路面结构；在考虑双层材料非线性时,各路面结构响应指标均为最不利情况,尤其是路基表面垂直应变指标。并且随着载荷的增大,非线性条件下各路面结构响应指标呈现非线性的增长,相对于线性条件明显增加,表明重载对路面结构响应有较大的影响。最后,基于不同类型的碎石底基层和土基非线性,比较了单轴、双轴和三轴载荷下路面的结构响应。结果表明,多轴情况下的路表竖向变形和路基表面垂直应变均大于单轴情况,而层底拉应力却小于单轴条件下,说明多轴载荷对路面的抗车辙性能影响较大,而对路面的抗疲劳性能影响较小。材料方面,上基强弱对各个指标均有较大的影响,设计中宜采用回弹模量较高的强土基；碎石级配对路表竖向变形影响较小,对基层层底拉应力和路基表面垂直应变影响较大,设计中碎石底基层采用间断级配较好,不宜采用连续级配。
[Abstract]:In order to meet the logistics transportation needs, solve the contradiction between transportation economy and overloading of vehicles, vehicle multi axle heavy haul transportation has become the inevitable trend of traffic development. At the same time, requirements of multi axis heavy load vehicles on the pavement structure and material also presents new challenges, especially in the subgrade and pavement materials, exhibit nonlinear characteristics the larger the material in the subgrade and pavement under heavy load. In addition, with the increase of flexible pavement in recent years, the engineering practice shows that the nonlinear characteristics of pavement design and research of road surface structure of materials can not be ignored. Based on the above situation, this paper adopts field survey and data analysis of vehicle, subgrade material properties of pavement research and numerical simulation methods. Analysis of gravel subbase and subgrade pavement structure of nonlinear response at the same time, based on the material nonlinear on the multi axis under heavy load The response of pavement structure. The investigation and Analysis on the development of freight cars in our country and current situation in this paper. Research and analysis shows that heavy trucks in China achieved rapid growth in the past ten years, in the current city expressway and highway, multi axis heavy vehicles can be accounted for half of the total number of trucks, along with the development of logistics transportation. Multi axle heavy truck will be the future development trend of truck in China. In order to analysis based on subgrade pavement structure and material nonlinear multi axis under heavy load response, we studied the following aspects. First of all, in the subgrade and pavement material nonlinear gravel subbase and subgrade materials were considered, and the the nonlinear stress dependence model was studied. This paper chooses the commonly used at home and abroad pavement stress dependent model, through the analysis of existing test data fitting gravel resilient modulus, obtained Three different graded gravel constitutive model parameters for subgrade materials, investigation on flexible pavement assessment of the US Federal Highway Administration Illinois and based on the actual situation in our country, according to the constitutive relation of bilinear stress dependent model of the soil, analyzed four different from strong to weak subgrade materials, selection the constitutive model parameters of different subgrade. Secondly, based on the finite element principle, respectively according to the constitutive model of gravel material and subgrade materials, selection of tangent stiffness method for the preparation of the corresponding material subroutine through the UMAT Interface subroutine into ABAQUS finite element software, the numerical analysis of nonlinear materials in ABAQUS the finite element software. Thirdly, established the finite element response of asphalt pavement structure material nonlinear analysis model based on the longitudinal stress, surface vertical deformation, base bottom tensile stress and The vertical strain response of pavement subgrade surface as the index, the gravel subbase of nonlinear, nonlinear and double nonlinear effect of subgrade material on pavement structure response. The results show that the relative material elastic properties, gravel subbase nonlinear under heavy load intensity increases, can strengthen the pavement structure; considering the double nonlinear material, the the pavement structure response index is the most unfavorable situation, especially the subgrade surface vertical strain index. And with the increase of the load, the response index shows a nonlinear growth of the pavement structure under nonlinear conditions, compared with the linear condition increased significantly, that heavy load has a great influence on pavement structure response. Finally, different types of gravel subbase and subgrade based on the nonlinear, compared the single axis response of pavement structure and three biaxial axial loads. The results show that the multi axle case The road surface and the vertical deformation of subgrade surface vertical strain were greater than the single axis, while the bottom layer tensile stress is less than the uniaxial conditions that influence multiaxial loading on anti rutting performance of pavement, and has little effect on fatigue performance of asphalt pavement. Based on the strength of materials, impact on every large in the design of appropriate indexes, strong rebound modulus of subgrade adopted high; gravel gradation of road surface vertical deformation has little effect on base, bottom layer tensile stress and vertical strain of subgrade surface has great influence, in the design of gravel subbase using discontinuous gradation is better, should not be used in continuous gradation.

【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U416.217

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