基于修正Burgers模型的钢桥面铺装车辙有限元分析

Finite element analysis of steel bridge deck pavement rut based on modified Burgers model

为了准确预估钢桥面沥青铺装层的车辙深度,以南京四桥钢桥面铺装层为研究对象,采用了修正Burgers模型建立沥青混合料的本构关系,以单轴蠕变的试验数据拟合模型参数,并通过了ABAQUS有限元软件模拟车辙形成的过程。研究表明,对于浇注式沥青混凝土+高弹改性沥青铺装结构,车辙主要发生在浇注式沥青混凝土层,该层车辙深度占总车辙深度的63%。车辙随铺装层厚度增加而迅速增大,随轴载加大而增大,随荷位的变化尤其是横向荷位变化而有一定改变。车辙病害总体上随着环境温度升高而增大,但两者呈现突变的非线性关系。研究结果对同种类型沥青钢桥面的抗车辙设计、车辙预估、寿命预测具有一定的指导意义。

In order to accurately predict the rutting depth of steel bridge deck asphalt pavement and analyze the influence of paving layer thickness, environment temperature and loads on rutting occurrence in asphalt paving layer, the steel bridge deck pavement layer of the Fourth Nanjing Yangtze River Bridge is taken as a research object. The modified Burgers model is adopted to establish the constitutive relation of asphalt mixture and the uniaxial creep test data is used to fit model parameters. The rut formation process in the double-layered pavement system applied widely in the long-span sus- pension and cable-stayed bridge paving is simulated using ABAQUS finite element software. The pavement system includs the high elastic modified asphalt concrete as its upper layer and the Gussasphalt as its bottom layer and the calculation results are validated by road tracking tests. The results indicate that, for Gussasphalt＋high elastic lnodified asphalt concrete structure, the rutting mainly occurs in the Gussasphalt concrete layer, reaching 63% of the total rut depth. The rutting increases rapidly with the increase in thickness of pavement layer. It also increases along with the increase in axial load. And it increases along with the change in load position, especially the transverse load change. Generally the rutting increases as the temperature rises with mutational and nonlinear. This study is of great importance to the design of antirutting, rutting depth prediction and life prediction for the same type of steel bridge deck pavement.