重载铁路桥梁曲线段振动和噪声特性试验研究OA

To investigate the amplitude-frequency characteristics of noise and vibration of heavy-haul trains when passing through curved bridge sections,as well as their propagation attenuation laws,and reveal the relationship between the train load and the structural response,field experimental research were conducted on the curved bridge sections of heavy-haul railways.Taking the curved bridge section of a typical heavy-haul railway as the research object,a multi-measurement-point synchronous acquisition system was deployed to record sleeper vibration acceleration and wayside noise signals when empty and loaded trains passed through.Time-domain and frequency-domain analyses were performed to study the quantitative relationship between vibration amplitude and noise level,and the attenuation law of noise along the propagation path was analyzed.The results show that the sleeper vibration under loaded train conditions is significantly stronger than that under empty train conditions,and the dominant frequency is higher.When the empty train passed,the maximum time-domain acceleration of the sleeper at the mid-span of the beam ranged from 11.05-27.77 m·s-2,and the maximum frequency-domain ranged from 1.92-3.04 m·s-2.The vibration acceleration at the track center and near the rail edge remained below 10 m·s-2 and was barely affected by sleeper vibration changes.When the loaded train passed,the maximum time-domain acceleration of the sleeper at the mid-span of the beam ranged from 37.80-61.93 m·s-2 and the maximum frequency-domain ranged from 4.16-10.40 m·s-2.The vibration acceleration near the rail edge was below 20 m·s-2,while the acceleration of the track-center fluctuated strongly.The wayside noise level of the loaded train was about 10 dB(A)higher than that of the empty train,with a lower dominant frequency.A linear relationship was observed between total sleeper vibration acceleration and noise level.The noise sound pressure level gradually decreased with the increasing distance from the noise source.The load of heavy-haul trains significantly affects the vibration and noise characteristics of curved bridge sections.Under loaded conditions,both the vibration amplitude and noise level increase significantly,showing a linear correlation.Noise propagation conforms to the line-source attenuation law.