School of Mechanical Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China; Train and Track Research Institute, State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031, China.
Train and Track Research Institute, State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031, China; School of Mechanical Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China.
Sci Total Environ. 2018 Jun 15;627:1303-1314. doi: 10.1016/j.scitotenv.2018.01.297. Epub 2018 Feb 7.
Noise caused by urban rail transit (URT) has been a hot concerned issue for a long time, and the secondary noise caused by viaduct bridges even make the problem more serious. As well known, structural acoustic radiation (SAR) induced by vibrations of concrete bridges is usually in low frequency. By now, the existing studies mainly focused on the noise above 20Hz, while the infrasonic wave below 20Hz attracts few investigations. However, it is more harmful to human according to relevant medical researches. Focusing on the viaduct bridges in a URT line laid with floating-slab track (FST), the characteristic and mechanism of SAR caused by box girder bridges are investigated in this paper. Primarily, a detailed train-FST-bridge dynamic interaction model is established, which is solved through an advanced mixed explicit-implicit integration method. Then, the SAR of the concerned bridge is analyzed adopting indirect boundary element method, including the infrasonic wave below 20Hz. And finally the mechanism of SAR is investigated based on the theories of structural vibration and acoustic. The conclusions provide theoretical foundation of vibration and noise reduction for viaduct bridges in URT systems.
城市轨道交通（URT）引起的噪声一直是一个长期受到关注的热点问题，而高架桥引起的二次噪声甚至使问题更加严重。众所周知，混凝土桥梁振动引起的结构声辐射（SAR）通常处于低频。到目前为止，现有研究主要集中在 20Hz 以上的噪声，而对 20Hz 以下的次声的研究则很少。然而，根据相关医学研究，次声对人类的危害更大。本文聚焦于采用浮置板轨道（FST）铺设的 URT 线路上的高架桥，研究了箱梁桥引起的 SAR 的特性和机理。首先，建立了详细的列车-FST-桥梁动力相互作用模型，采用先进的混合显式-隐式积分方法求解。然后，采用间接边界元法分析了所关注桥梁的 SAR，包括 20Hz 以下的次声。最后，基于结构振动和声的理论研究了 SAR 的机理。结论为 URT 系统中高架桥的振动和噪声降低提供了理论基础。
