Relation of the infrasound characteristics and the continuous steel bridge vibration modes generated by the vibration of moving heavy trucks

Abstract

As heavy trucks pass over highway bridges, bridge vibration occurs and generates infrasound. General trucks in Japan with rear leaf suspension have whole body vibration (suspension spring vibration) frequencies of about 3 Hz. Also, the frequencies of the wheel vibration (tire spring vibration) are about 10-20 Hz. The continuous steel highway bridges with middle span length have vibration modes with the same phase in each span at the frequencies of about 3 Hz and also have those with the secondary mode shape at the frequencies of about 10-20 Hz. Truck vibrations and bridge vibrations are closely related. In this work, vibration tests are conducted using a heavy test truck for two cases of infrasound complaints in order to investigate the relation between the continuous steel bridge vibration modes generated by the vibration of moving heavy trucks and its infrasound characteristics. As a result of the examination, two types of bridge vibration modes are caused by the vibrations of a moving heavy truck. Moreover, the bending vibration modes with the same phase in each span have the most powerful infrasound pressure, since each span vibrates with the same phase. Two countermeasures, including viscoelastic damper at the end of the girders and extended deck method, are proposed to reduce the amplitude of bridge vibration and its infrasound.

3A25 Vibro-acoustic behaviour of a non-uniform beam traversed by a moving point load(The 12th International Conference on Motion and Vibration Control)

“…Hdwever, the analysis done in the paper assurnes significance since the sound generated in ihis frequency range belongs to the category ofinfrasound occurring in the frequency range of O-20 Hz. Vibration of bridges due to the passage oftrains is one ofthe sources ofthis low frequency infrasound, People living near the bridge can feel the infrasound which causes mental and physical discomfort (Saiji et al,, 2012). Also, the yibration ofbuildings due to the propagation efthese Iow frequency waves through the ground has beerr a serious problern faced by the residerits living nearby.…”

Investigation of Infrasound Radiated from Highway Bridge Owing to Moving Truck

“…Similarly, the mid spans (P1 -P2) of both the eastbound and the westbound bridges share the same band level at a frequency of 12.5 Hz. A comparison of the 1/3 octave band frequencies with the reference values for complaints about rattling sounds and complaints of mental and physical discomfort by the Japanese Ministry of Environment [6] is shown in the same figures. Although this rattling sound curve is only defined beginning from 5 Hz, the levels measured in Houses A and B appear to be larger than the rattling sound curve defined by the Japanese Ministry of Environment for frequencies of 2.5 -4.0 Hz.…”

“…In general, the dynamic response of a bridge is influenced by the running speed [1], vehicle load [2], and suspension system [3] of the truck; truck's lane position on the bridge [1]; road surface roughness [4]; and bridge dynamics by the matching of the bridge's and the truck's natural frequencies [5]. In particular, the infrasound radiated from the bridge is related to the frequencies of the bridge vibration, truck suspension spring vibration, and tire spring vibration [6].…”

“…Conventional trucks with a rear leaf suspension [6,7] have frequencies of about 3.0 Hz; furthermore, their tire spring vibration frequencies are 10 -20 Hz. When the frequency of the truck's vibration (suspension spring vibration or tire spring vibration) and that of the bridge's vibration are similar, there is likely to be a rise in complaints from nearby residents about rattling soundsowing to the truck's suspension spring vibration, which has a frequency of about 3.0 Hz-and/or mental and physical discomfort-owing to the truck's tire spring vibration, which has a frequency of 10 -20 Hz [6].…”

Proposition of Estimation Method for Repairing the Roughness in Expansion Joints of Expressway Bridges

“…When a truck crosses a bridge with long wavelength road roughness, bridges with 30-40m spans vibrated significantly by resonating with the leaf suspension spring vibration [2][3] caused by long wavelength road roughness. On the other hand, when a truck passes over a bridge's expansion joint with a short wavelength road roughness, the tire spring vibration [4] of the truck is significantly generated by the road roughness. Moreover, damage to the bridge deck and environmental vibration problems, such as infrasound [5][6] and ground vibration [7], occurred as a result of the impact force [8] of the tire spring vibration.…”