References

Rail roughness levels

Evaluation of rail roughness levels with respect to acoustical grinding and polishing of the rails.

Aims at the reduction of railway induced vibrations by addressing the vibration generation at the vehicle level, the track level and in the transmission path.

D2S International was the coordinator of this European research project, the objective of which was to optimise special trackwork, especially in urban transports. This project is co-funded by the European Commission.

Dynamic behaviour of aging ballast

This study involved the measurement of the tunnel wall vibrations in different sections of the Paris Metro with ballast of different ages and with all the other parameters (a.o. rolling material) identical or similar. The dynamic characteristics of the different tunnel sections were also measured. It also required the creation of mathematical models to describe the dynamic behaviour of the ballast in the tunnel environment. This study resulted in conclusions on how the dynamic stiffness of ballast changes with time and how this affects the vibration isolation behaviour of the ballast.

Vibration maps of the metro

Structure borne vibration maps for the metro of Paris. These analyses were based on the results of extensive noise and vibration measurements in the environment and in buildings. This study shows that there is a good correlation between the calculations and the measurements.

Noise maps

Complete airborne noise maps were computed based on SRM I for the public transport systems in Brussels (tram, metro, train, bus).

High-speed line

The purpose of this project was to study the vibration and acoustical performances of different slab track systems for a high-speed train compared to a standard ballasted track. The vibration study was performed by means of Finite Element calculations of the tracks under a harmonic loading. The acoustical study has been carried out with D2S International in-house developed rolling noise calculation software: WR Noise.

Development of new component designs and maintenance processes aimed at improving the integrity of urban rail transport infrastructure through the deployment of intelligent design and sensor technologies integrated in cost effective products and targeted non-intrusive monitoring processes.

D2S International was the coordinator of this European research project, the objective of which was to acquire a deep understanding of rail corrugation phenomena, especially in urban transports. This project is co-funded by the European Commission.

Dynamic behaviour of wooden and concrete sleepers

This study involved the measurement of airborne noise and soil vibrations on RER line A in two different sections (one with wooden sleepers, one with concrete sleepers). The dynamic characteristics of the track and of the soil were measured. The rail displacements, sleeper displacements and soil pressure during train passage were measured. Mathematical models were tuned to these measurement results. This study resulted in conclusions on how different wooden and concrete sleepers are in terms of noise emission and vibration isolation.

The aim of the project QCITY is to develop an integrated technology infrastructure for the efficient control of road and rail ambient noise by considering the attenuation of noise creation at source at both vehicle/infrastructure levels. The activity will support European noise policy to eliminate harmful effects of noise exposure and decrease levels of transport noise creation, especially in urban areas, deriving solutions that will ensure compliance with the constraints of legislative limits. A major objective is to provide municipalities with tools to establish noise maps and actions plans (Directive 2002/49/EC) and to provide them with a broad range of validated technical solutions for the specific hot-spot problems they encounter in their specific city. This project is co-funded by the European Commission.