Reducing railway induced ground-borne vibration by using trenches and buried soft barriers J. Jiang 1 , M. G. R. Toward 1 , A. Dijckmans 2 , D. J. Thompson 1 , G. Degrande 2 , G. Lombaert 2 and J. Ryue 3 1 Institute of Sound and Vibration Research University of Southampton, Southampton, SO17 1BJ, UK 2 KU Leuven, Department of Civil Engineering, Kasteelpark Arenberg 40, 3001 Leuven, Belgium 3 School of Naval Architecture and Ocean Engineering, University of Ulsan, Ulsan, 680-749, Korea Summary To reduce railway induced low frequency vibration, two mitigation measures - open trenches and buried soft wall barriers, have been studied in this paper by using coupled finite element-boundary element models. These models were developed at KU Leuven and ISVR, and have been cross-validated within the EU FP7 project RIVAS (Railway Induced Vibration Abatement Solutions). Variations in the width, depth, location of trench and properties of soft barrier material are considered under various soil conditions. Results show that in all ground conditions, the notional rectangular open trench performs better than the other constructions. The width of an open trench has little influence on its performance, whereas increasing the width of a filled trench reduces the stiffness of the material, improving the performance of the trench. Likewise, fill materials with lower Young’s modulus give higher insertion losses. 1 Introduction Train-induced vibration can be a source of annoyance for line-side residents. For surface railways this vibration often has its highest amplitudes below 30 Hz. Most mitigation methods, such as resilient track systems, are effective at ‘high’ frequencies (typically above around 40 Hz). Open trenches and buried barriers, applied in the transmission path [1], are among the few mitigation methods that have the potential to reduce vibration at lower frequencies. For soil considered as a homogeneous half-space, an open rectangular trench with a depth greater than about one Rayleigh wavelength can lead to a ~12 dB reduction [2], while in-filled trenches are less effective than open trenches.