宁波轨道交通高架线路现场振动测试与分析

Vibration Test and Analysis in the Ningbo Urban Rail Transit Viaduct

通过对宁波轨道交通1号线一期工程高架线路进行现场振动测试,分析普通整体道床、梯形轨枕、减振垫道床3种不同轨道结构的振动传递规律和频谱特性,评价梯形轨枕和减振垫道床的减振效果。结果表明,对于桥面振动,跨中桥面明显大于梁端桥面;地面振动随水平距离的增大而衰减,衰减频段主要在20 Hz以上;梯形轨枕和减振垫道床对桥面、地面振动都有一定的减振效果,对梁端桥面的减振效果最明显;两种减振轨道对地面振动的减振效果相近。

A field vibration test was performed in the viaduct of the Ningbo Line 1 first phase. According to the test data, the vibration transfer law and frequency spectrum characteristics of three different tracks, which are general monolithic roadbed track, ladder sleeper track, and damping pad roadbed track, were analyzed. The damping effect of the ladder sleeper track and damping pad roadbed track were also evaluated. The test result shows that the vibration of the mid-span bridge deck is obviously larger than that of the beam-end bridge deck. The ground vibration attenuates with increasing horizontal distance. The attenuation spectrum is mainly greater than 20 Hz. Good damping effects for both the ladder sleeper track and damping pad roadbed track were observed for vibration of the bridge deck and ground and are especially remarkable at the beam-end bridge deck. Close damping effects were observed for these two damping tracks for ground vibration.