箱梁桥顶板对钢弹簧浮置板声辐射的影响

Effect of the Top Plate of the Box Girder Bridge on the Acoustic Radiation of the Steel Spring Floating Slab Track

桥上铺设钢弹簧浮置板减振轨道虽然可以减弱桥梁结构的振动,但因自身振动有所增大,其振动噪声有可能反而加剧。此外我国轨道交通中主要采用混凝土桥,由于混凝土桥具有很大的刚性,导致桥上轨道结构的声辐射并非在自由声场中传播,进而影响轨道结构的声辐射。因此通过建立列车-钢弹簧浮置板减振轨道-箱梁桥耦合动力学模型和浮置板声学边界元模型,在计算桥上长钢弹簧浮置板振动声辐射特性的基础上,进一步考虑箱梁桥顶板的反射作用,对这一声学边界条件作用下的浮置板结构声辐射问题进行探究,相关研究则更加符合客观实际情况。研究结果表明混凝土桥对浮置板自身的声辐射有很大的影响;在研究轨道结构的声辐射问题时,有必要详细考虑混凝土桥对其声辐射的影响,这样才能更加准确地分析轨道结构的振动声辐射特性。

The steel spring floating slab track(SSFST)can reduce the bridge’s vibration when it is laid on the bridge,but the track own vibration increases instead.The radiation noise of the SSFST may be intensified due to the vibration enhancement.In addition,the rail transit bridges in China are mainly reinforced-concrete bridges which have very large rigidity.Therefore,the radiation noise of the SSFST does not propagate in the free sound field which affects the acoustic radiation of the track structure.In this paper,the train and the SSFST-box girder bridge coupling dynamic model and the acoustic boundary element model of floating slab were established.Based on the calculation of the vibration and acoustic radiation characteristics of the floating slab for the long SSFST on the bridge,and considering the top plate reflection effect of the box girder bridge,the acoustic radiation of floating slab structure was researched under this acoustic boundary condition.And the related research accorded with the objective practical situation.The results show that the concrete bridge has a great influence on the acoustic radiation of the floating slab.In order to more accurately analyze the vibration acoustic radiation characteristics of the track structure,the influence of the concrete bridge on the acoustic radiation of the track structure needs to be considered.