Author:

Keywords:

Science & Technology, Technology, Engineering, Mechanical, Engineering, GROUND VIBRATION, TRAINS, TRACK

Abstract:

Railway induced vibrations are an important source of annoyance in the built environment, causing malfunctioning of sensitive equipment and nuisance to people. Within the frame of the EU FP7 project RIVAS, mitigation measures on the transmission path between source (railway track) and receiver (surrounding buildings) have been investigated. This paper reports on the numerical and experimental study of stiff wave barriers as efficient vibration reduction measures. Numerical simulations have demonstrated that the wave impeding effect of such barriers depends on the stiffness contrast between the surrounding soil and the barrier, as well as on the barrier's depth. Findings from the numerical studies are verified by means of two field tests. In El Realengo (Spain), a continuous barrier has been created close to an existing railway track using overlapping jet grout columns, while a sheet pile wall has been installed along a track in Furet (Sweden). At both sites, geophysical and geotechnical tests were carried out prior to the installation of the mitigation measures for the determination of the dynamic soil characteristics. Measurements of train passages before and after installation of the barriers are compared to numerical simulations in order to assess the vibration reduction efficiency. In El Realengo, additional measurements have been performed at a reference site adjacent to the test site in order to correct for variations of track, train, and soil characteristics in time. It is shown that both barriers are effective and result in vibration reduction from 8 Hz (El Realengo) and 4 Hz (Furet) on, respectively; the largest reduction is obtained immediately behind the barriers. This ability to solve low frequency vibration problems is a unique feature compared to most other vibration mitigation measures for existing railway lines.