动载作用下钢桥面双层SMA铺装层有限元分析

Finite Element Analysis for Steel Bridge Deck Pavement of the Double-layer SMA under Dynamic Loadings

基于罗埠大桥钢桥面铺装层早期病害的维修方案,采用有限元软件建立三维模型,研究不同沥青铺装层与钢桥面层间接触状态下、不同沥青铺装层结构设计参数下的铺装层结构设计指标变化规律。结果表明:沥青铺装层沿深度方向的平均剪应力分布规律为:磨耗层>缓冲层>保护层;SMA层厚度及缓冲层厚度的增加可有效改善沥青层受拉、受剪和层间受剪状况;缓冲层模量的增加有利于降低沥青层拉应变,但不利于层间剪应力和沥青层剪应力指标。提出双层SMA钢桥面铺装层结构设计建议,罗埠大桥铺装方案中SMA层厚度为6.0 cm,沥青胶砂层厚度为2.5cm。

Based on repair program of early disease of the paving layer of Lobu Bridge steel bridge deck,a three-dimensional finite element model is established by using finite element software.The change rule of structural design indexes of the pavement layer is studied under the state of different asphalt pavement layer and steel bridge deck interlayer contact state and different asphalt pavement layer structural design parameters.The results show that:asphalt paving layer along the depth direction of the average shear stress distribution law:wear layer>buffer layer>protective layer;SMA layer thickness and buffer layer thickness increase can effectively improve the asphalt layer tensile,shear and interlayer shear condition.The increase of buffer layer modulus is helpful to reduce the tensile strain of asphalt layer,but not conducive to the indicators of interlayer shear stress and asphalt layer shear stress.The structural design of double-layer SMA steel bridge deck pavement layer is proposed,that is,in the Lopu Bridge paving scheme,the thickness of the SMAlayer is 6.0 cm and the thickness of the asphalt mortar layer is 2.5 cm.