The Environmental Noise Directive 2002/49/EC requires the Member States to determine the
exposure to environmental noise through noise mapping for agglomerations, roads, railways and airports using common methods of assessment. These maps will be made available to the public and will allow adopting action plans to prevent and reduce environmental noise, particularly where exposure levels can induce harmful effects.
The END does not establish how to asses or reduce vibration impact caused by railway
infrastructures. Within this directive, no common method of assessment or evaluation of
people exposure to railway induced vibrations are defined. In this paper, Strategic Vibration Mapping concept for railway infrastructures is developed including discussion about input
data, vibration harshness evaluation, quantification and action planning.
The prediction of vibration impact remains as a complex challenge for designers of new railway infrastructures. Due to the large quantity of parameters involved in the generation, transmission and reception of the vibration waves, it would be necessary to develop a complete study for each potential receiver, which would include: source, soil and building characterization,
infrastructure vibration behaviour modelling and, finally, countermeasures influence prediction.
This process can turn out to be very costly in terms of both time and money. Therefore, it is usually done only for areas very likely to suffer high vibration levels or for high sensitive buildings (hospital, educational).
The CATdBTren project, which has been awarded with R&D funding from the Catalonia
Government, is aimed to develop a new prediction tool for evaluating the vibration impact from new railway infrastructures as well as to develop new types of fastening systems having high vibration isolation properties. That tool is intended to be user-friendly and to produce results with
average accuracy, so it still will be required detailed studies of problematic areas.
In this sense, the software will model the contact forces caused by high-speed, conventional and underground rolling stock. Moreover, it will model the infrastructure’s vibration transmission behaviour, ground vibration propagation, terrain-foundation coupling and building vibration
mechanism. The CATdBTren prediction tool will be also capable of estimating the influence of the rolling stock, rail and wheel roughness, fastening system, substructure, soil vibration propagation properties and building characteristics, all in the final vibration impact.
A model to calculate the vibration impact is presented. Due to the complexity of the phenomena, the model has been divided in different calculation stages, according to the different physical processes of generation, propagation and transmission to the building. The result is obtained after the compilation of different partial results which, however, are related with each other.
Alarcon, G.; Sole, J.; Romeu, J.; Genesca, M. Tecniacustica 2003. 34º Congreso Nacional de Acústica. Encuentro Ibérico de Acústica. EAA Symposium.Expocustica 2003. p. 71-72 Presentació treball a congrés