面向桥面铺装动力响应分析的多尺度桥梁模型

Multi-scale Model for the Bridge Deck-pavement Dynamic Analysis

为了解决传统桥面铺装设计方法不能反映在行车荷载与桥梁振动特性耦合作用条件下的铺装动力响应问题,提出一种面向桥面铺装动力响应分析的多尺度桥梁模型的构建新方法。该方法首先综合考虑桥面铺装和桥梁结构特性对建模的要求,建立整桥有限元仿真模型,然后构建精细化桥面铺装体系局部梁段模型,最后通过动力子结构方法将整桥结构与桥面铺装局部结构衔接,并以某大跨径悬索桥为例进行实例分析。结果表明:由于考虑整桥动力特性和不平度的影响,将使计算结果(不平度等级为A)比静力计算结果大10%～15%,并且随着不平度的增加而非线性增加;采用该模型的构建方法可以避免现行桥面铺装设计中采用静载偏不安全的缺点。

In order to solve the problem of the imprecise stress caused by the conventional deck pavement design which neglects the dynamic coupling of moving vehicle and the bridge, a novel method of multi-scale model for the long-span bridge deck-pavement dynamic analysis was proposed. Firstly, based on the requirements of deck pavement and global bridge structure, the FE model for the whole bridge was set up. Then, the fine model of deck pavement segment was established. Thirdly, the global bridge model and the local pavement system model were integrated according to the dynamic substructure method. Taking a long-span suspension bridge as an example, the results show that, considering bridge dynamic characteristics and surface roughness,the critical dynamic stresses are larger than the static ones by 10%-15%, and moreover, the dynamic stresses develop nonlinearly with the increase of surface roughness. Therefore, it is suggested that the simulation method provided here can be employed to avoid the unsafety caused by the conventional deck pavement design which uses static load scheme.