Abstract: As the vehicle bumping at bridge expansion joint has become a serious problem affecting bridge structure, in this paper a simply supported bridge with steel box girders was presented for case study. Based on vehicle-bridge coupling vibration theory the vibration characteristics of bridge considering the effect of expansion joint was investigated through numerical calculation. In order to simulate the influence of expansion joint the roughness of road surface at expansion joint was adjusted. Wavelet transformation (WT) is adopted to obtain the dynamic characteristics in time- and frequency- domain. The effectiveness of vibration control method for this kind of vibration was studied. The results show that: the acceleration re-sponse is amplified due to the existing of expansion joint; the response is dominated by high frequency; this kind of vibration can be effectively reduced by filling the girder end with concrete.

摘要： 车辆在经过桥梁伸缩缝时的跳车问题已成为影响桥梁健康的重要病害之一。以简支钢箱梁桥为对象，在车桥耦合振动计算理论的基础上，通过修改伸缩缝处的路面条件来模拟伸缩缝的影响，并通过小波变换研究车辆经过伸缩缝时的时频域振动特性，并针对此类振动的桥梁减振效果进行分析。计算表明：由于伸缩缝的存在，明显加大了车辆对结构的冲击效应，且作用的响应以高频为主；伸缩缝处的特性、车速与车重对车辆经过伸缩缝产生的冲击响应都有显著的影响；梁端填筑混凝土法能有效的降低此类振动产生的冲击效应。

关键词: 振动与波, 伸缩缝, 车桥耦合振动, 小波变换, 桥梁减振