Project: Railway Vibration Mitigation in Transmission Path (soil)

The passing of rail surface transport (conventional trains, high speed trains and trams) generates vibrations that are heavily affecting and disturbing people inside the nearby buildings. There are existing solutions to mitigate these vibrations : (1) mitigation at the source : isolating the railway track by use of a floating track bed (isolation under the track bed) or by use of (very) resilient rail fastening systems, or (2) mitigation at the receiver: isolating the building (isolators, dampers at the foundation of the building). The above solutions have major drawbacks: they are very expensive, it is almost impossible to install these measures with existing railway tracks and buildings and the modification of the railway tracks interferes with the railway operation._x000D__x000D_The SOILVIBES project aims at developing innovative solutions in the transmission path (soil) between source (railway tracks) and receiver (people in buildings) for mitigating vibration problems, yielding a solution for existing problem situations and yielding far more economical solutions, not interfering with the railway operations, also for newly build railway projects. _x000D_In the SOILVIBES project following solutions for vibration isolation and damping in the transmission path will be developed : (1) semi open trenches (with soft filling material) along the railway, (2) wave impeding structures, in particular specially designed street pavements or walkways between tram tracks and buildings, which increase the speed of the waves and hence could provide unique reduction of the very low frequency vibration amplitudes, (3) absorbing masses on or in the ground acting as tuned vibration absorbers to dissipate energy at the most disturbing frequencies._x000D__x000D_These solutions are not readily available. Attempts have been made in the past by railway operators to use trenches in the soil to isolate vibrations or to put masses on the soil to damp out vibrations. These attempts have not been successful for several reasons:_x000D_(1)lack of correct design rules for these kinds of solutions. In the past simplified calculation models for vibration transfer in the soil have been used (2D models...) and simplified soil configurations have been considered (homogeneous soil idealized as a half space, no soil layering...). This has let to erroneously dimensioned depths and widths of the trenches._x000D_(2)To retain the walls of a trench appropriate filling material has to used. Use of concrete or another rigid filling material (as done in the past) is not ideal for obtaining good vibration isolation._x000D__x000D_(3)To obtain a tuned vibration absorber a resilient material has to be used under or around the masses. In the past the soil has been used as spring/damper system yielding a resonance frequency difficult to tune and to control._x000D__x000D__x000D_The work plan for the SOILVIBES project includes the development and validation of suitable calculation methods for the above described vibration mitigation measures, the development of general design rules, the development of the appropriate resilient materials to be used in the solutions, and the validation of these solutions by on site testing. _x000D__x000D_The SOILVIBES project will be carried out by a consortium consisting of two SME’s: D2S (B) and RBSI(F). D2S is a well known engineering company and solution developer for vibration mitigation along railways. They work worldwide for the railway operators and railway project developers. They have to guarantee the good functioning of the proposed mitigation measures and are fully responsible. A correct design and dimensioning supported by a state-of-the-art calculation study is thus mandatory. D2S has the in house tools and required civil engineering knowledge (with access to latest doctoral thesis works) to carry out the project. RBSI has the appropriate product type (resin bonded recycled rubber granulates) and the appropriate material knowledge to develop resilient products suited for use as filling material in trenches and as resilient material in tuned vibrator applications. The consortium is thus fully complementary and it has the knowledge and tools to bring the research to a good end._x000D__x000D_The SOILVIBES project will result in three innovative systems (to be selected between them in function of the type of transport system and in function of the local conditions and possibilities) for railway vibration mitigation on the worldwide market, supported by validated design methods and by the availability of appropriate resilient materials. These solutions are very price competitive and solve existing problems for which no realistic solution exists today. Both SME’s will benefit directly by increasing their market share and turnover.

Acronym SOILVIBES (Reference Number: 4738)
Duration 01/12/2009 - 01/06/2012
Project Topic This project aims at developing innovative solutions in the transmission path between source (railway tracks) and receiver (buildings) to mitigate vibration and structure borne noise problems.
Project Results
(after finalisation)
The CO achievements are:_x000D_1) The development of a scaled test bench that is able to simulate the wave propagation as well as the soil structure interaction in the soil and its validation._x000D_2) The experimental determination of the performance of vibration mitigation solutions in the propagation path: soil barriers and wave impeding blocks (using the scaled test bench)._x000D_3) The development of a low cost numerical model for the prediction of the considered vibration mitigation solutions. Validation of this model by experimental measurements._x000D_4) Development and design of robust vibration mitigation solutions in the propagation path for train-induced vibrations in the middle to the high frequency range (from 30 to 80 Hz). _x000D_5) Improvement of the performance of conventional concrete soil barriers by adding a layer of resilient material on one or two faces. An insertion loss factor from 6 to 12 dB has been obtained for different distances and in different frequency ranges._x000D_6) Development of design rules for pre-dimensioning of the considered vibration mitigation systems. _x000D_7) Introduction of a new application for the considered specific resilient materials used in combination with the concrete barrier for improving its performance. A specific construction method for the combination of the concrete barrier with a layer of the resilient material is proposed and its application has been examined in a full-scale test. _x000D_8) The results of project will be disseminated in coming conferences and will be published in the specialised journals. In July 2012, results of the Soilvibes project have been presented at the UIC High Speed conference in Philadelphia (USA). Recently, a paper based on the results of the small-scale test bench has been submitted to the conference ICSMGE 2013 that will be held in Paris._x000D_
Network Eurostars
Call Eurostars Cut-Off 2

Project partner

Number Name Role Country
2 D2S International nv Coordinator Belgium
2 RBSI sa Partner France