超限运输车辆通过T梁桥的合理横向位置分析

对超限运输车辆通过多梁式简支T梁桥时的合理横向位置进行了分析.以我国公路桥梁中常见的中小跨径T梁桥为例,通过有限元分析提取了车辆在不同横向位置加载时梁底跨中截面处的最大弯曲应力,并对计算结果进行了对比,从优化结构受力的角度确定了超限运输车辆过桥时的最佳横向行驶位置.分析了桥梁跨径、主梁根数、主梁连接方式等因素对超限运输车辆过桥时的合理横向位置的影响.结果表明:超限运输车辆的横向加载位置对多主梁桥的结构响应有较大的影响;当主梁根数为奇数时,车辆的最佳横向行驶位置位于中心梁与其相邻梁的中间位置处;当主梁根数为偶数时,超限运输车辆的最佳横向行驶位置与桥面中心线重合;主梁之间的连接方式对车辆荷载作用下桥梁的结构响应影响显著.

Analysis on Optimal Transverse Position for Overweight Trucks to cross T-beam Bridges

This paper aims to investigate the optimal transverse position for overweight trucks to cross the simply-supported multi-girder bridges. Finite element analysis is performed for a group of prefabricated concrete T-beam bridges commonly used in China under the action of overweight trucks with varying transverse positions. The maximum bending stresses at the mid-span of the girders are extracted from finite element analysis and compared with each other. The optimal transverse position is determined from the point of optimizing the structural response. The effects of a few important parameters, including the length of bridge spans, number of girders and type of girder connections on the optimal transverse truck position are investigated. It is found that the transverse loading position of overweight trucks has a significant impact on the responses of multi-girder bridges. For the T-beam bridges with odd number of girders, the optimal transverse position for overweight trucks is in the middle between the center girder and the adjacent girder; for the T-beam bridges with even number of girders, the optimal transverse truck position is the centerline of the bridge. The influence of the girder connection condition on the bridge responses is significant.