A field investigation into the effect of under sleeper pads on the reduction of railway-induced ground-borne vibrations

Abstract

Train-induced vibrations have adverse effects on the structure of a track and its surroundings. It is thus necessary to study and control this issue through efficient measures. Special polyurethane pads that are placed under sleepers have been recently suggested as a solution to this problem. The use of these pads reduces vibrations at their source. These pads, called under sleeper pads (USPs), have numerous advantages and have found wide application in the railway industry. However, very few studies have been conducted on USPs; thus, this paper presents a field study that documents their effects on reducing vibration levels. Fifty stiff and 100 soft pads were prepared with the required technical and mechanical specifications. They were then installed onto concrete sleepers during the production process. These sleepers were installed at km-253 of the Mashhad–Tehran track. Train pass-by vibrations of passenger and freight trains were recorded using geophones placed at 0, 3, 7, 11, 15 and 19 m distances from each track axis (one track with and one without USPs). The results of the tests show that the maximum root-mean-square velocity was reduced by about 60%. Frequency analysis of the results demonstrates that the vibration reduction effect of the USPs appears above 40 Hz. The best efficiency levels of the USPs were observed in the range 40–80 Hz and the maximum USP efficiency occurred at the frequency of 50 Hz. At this specific frequency, the maximum vibration velocity level was decreased by more than 6.7 dB for all the considered distances (0, 3, 7, 11, 15 and 19 m).

Installation of under sleeper pads on ballasted railway tracks: An economic analysis of their potential implementation

“…The buildings within 300 metres of the track were assumed to be affected by air-borne noise whereas the buildings within 80 metres of the track would be affected by ground-borne noise 37 . Moreover, the use of USPs could lead to a reduction of ground-borne noise 38 of up to 15 dB 39 , but would slightly increase air-borne noise 40 . For those buildings within 80 metres the effect may be reduction in groundborne noise whereas for those houses between 80 and 300 metres the increase in air-borne noise would be the dominant impact.…”

Development of train ride comfort prediction model for railway slab track system

“…Train ride comfort (TRC) is one of the most important vibration indicator of railway vehicle performance. It is influenced by properties of train's suspension systems, vehicle speed and railway track conditions including rail irregularities and track condition (Connolly et al 2015, Kim et al 2003, Kouroussis et al 2014, Zakeri et al 2016).…”

Numerical investigation on train-induced environmental vibration in floating ladder tracks

“…Waves generated by the dynamic interaction between the train and the track (Zakeri et al, 2016b;Solonenko et al, 2017) propagate from surrounding soils to adjacent buildings, resulting in structural vibrations. Although there are several methods to mitigate train-induced vibrations (Esmaeili et al, 2014;Zakeri et al, 2016a;Mosayebi et al, 2017), in order to reduce vibration effects to an acceptable level, a floating slab track can be used in railway systems. A review of the available literature illustrates that there are several numerical, analytical and experimental studies on the dynamic behavior of floating ladder tracks.…”