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Attenuation of ground-borne vibration affecting residents near freight railway lines

Final Report Summary - CARGOVIBES (Attenuation of ground-borne vibration affecting residents near freight railway lines)

Executive Summary:
As pointed out in the White paper for European transport the aim of the European rail operators is to increase the market share of goods traffic from 8% in 2001 to 15% in 2020. The nightly time slots will play an important in this. Railway vibration annoyance and sleep disturbance in residential areas is a potential showstopper for this increase. Therefore, the aim of CargoVibes is to develop and assess measures to ensure acceptable levels of vibration for residents living in the vicinity of freight railway lines in order to facilitate the extension of freight traffic on rail.

Existing evaluation criteria in use are insufficiently based on relevant surveys. There are no uniform assessment methods available and knowledge about mitigation measures is fractured and hardly common.

In this project, the human response at existing evaluation criteria is established. New mitigation measures have been designed and the effect of new and existing mitigation measures have been assessed. Methods, through modeling and laboratory tests, to assess the effectiveness of mitigation measures and to translate these to any situation have been demonstrated.

In operational terms, the project produced the following:

- A guideline on the evaluation of adverse effects, for use of engineering companies doing environmental impact studies and for use of policy makers seeking to balance costs and benefits of rail traffic. The guideline includes exposure-response relationships for annoyance, some general conclusions on the influence on sleep and a table which summarizes the amount of (extremely) annoyed for given criteria in different standards and guidelines.

- Three new mitigation measures targeted at freight traffic, designed, tested and demonstrated, for use by the railway industry:

1) A measure for the rolling stock: a wheel maintenance scheme, as an alteration on existing maintenance schemes, targeting what is found to be the main source of vibration that can be influenced by maintenance: wheel defects.

2) Two measures for ballasted track, based on existing products. One is the application of undersleeper pads (USP’s), especially “wavy” USP’s, for stabilizing the track, that may reduce track deterioration and related vibration. The other is the application of “H-sleepers”, specially designed, heavier sleepers that also reduce track deterioration. Other track based measures, a super-elastic rail support aimed at reducing vibration from switches, and laddertrack, an alternative sleeper system, were investigated, designed and laboratory tested, but are still in the design face.

3) A measure in the propagation path: the coated ground wall. This is a concrete wall, coated with elastomer, with a balance between coating thickness and wall depth.

Project Context and Objectives:
VISION
The European railway network plans to increase its market share of freight transport from 8 % in 2001 to 15 % in 2020. In spite of this increase in rail traffic, the vibration impact on people living in the vicinity of railways should not increase. However, among planners and policy makers there is uncertainty on how railway vibration effects people. Furthermore, engineers are in need of a broader range of cost effective mitigation measures applicable for freight trains on ballasted track.

CHALLENGES
An increase of freight rail transport causes an increase of vibrations in the vicinity of the railway. Existing evaluation criteria for human impact, potentially having a large influence on project costs, are hardly based on relevant surveys. Moreover, no uniform assessment methods for vibration mitigation measures are available, making it difficult for railway planners to compare measures and predict their effectiveness in a new project based on existing applications. Furthermore, the number of mitigation measures that are effective for freight traffic is limited and new measures are needed.
There is a special need for measures that are comparatively simple to implement: measures that target rolling stock maintenance instead of changing rolling stock, measures for use in ballasted track instead of alternative track systems and measures in the propagation path that make use of other, planned, structures.

OBJECTIVES
The project aims to bring progress to three subjects:
1. the evaluation of the effect of train induced whole body vibration (WBV) on residents;
2. the assessment of mitigation measures for vibrations from trains and the possibilities to evaluate such measures in the early stages of railway projects;
3. the range of technical mitigation measures available for tracks with freight trains. The mitigation measures involve mitigation at the source through improved vehicle/track interactions (including track irregularities, maintenance of wheel shape, rolling stock and track design), but also reduction of vibration emission from the infrastructure and transmission in the ground.

EVALUATION OF THE EFFECT ON RESIDENTS PROGRESS BEYOND THE STATE OF THE ART
Different regulations or standards apply in the different member states. There is a lack of confidence in some sectors of the industry in the use of the vibration indicators found in current standards and the associated rating values. These difficulties affect policy and standard development in this field and also affect the consistent application of current policy and standards. The project will through meta-analysis and interpretation of existing data, additional field studies and additional data on sleep disturbance provide a best basis for the evaluation of railway vibration and induced noise. On the basis of the available evidence it will produce spectral dose-response relationships for human response to whole-body vibration due to railway noise, and evaluate the most suitable index to be used to express associated levels of vibration. The project will provide the guidance required for the practitioner by defining the best practice methodology, building on the measurement protocol addressing both vibration and social response that has been developed by the University of Salford . The guidance will present an evaluation procedure incorporating results of the work package that can be widely accepted and applied in practice.

ASSESSMENT OF MITIGATION MEASURES PROGRESS BEYOND THE STATE OF THE ART
CargoVibes aims at producing protocols and guidelines for test procedures and modeling tools to assess the performance of mitigation measures related to freight rail trains and vehicles.
Once the key parameter(s) for human exposure to rail freight vibrations has been established, it is used to assess and control mitigation measures. There are three stages where an assessment can be made:
1. in the design and modelling phase (modelling phase);
2. in the laboratory (experimental phase);
3. on a test track or in an operational network (experimental phase).
The aim of CargoVibes is to propose suitable tools for prediction models, already validated for passenger train vibrations, completed and updated with the specifics for freight vibrations. These tools are required for the design of the new mitigation measures and the verification of their performance.
Before expensive construction on site, CargoVibes investigates the possibility of testing the performance of a vibration measure at the track or in the propagation path in a scaled test bench. A test bench is designed and constructed, a parametric study determines the scaling factors to be used, and different types of mitigation measures are installed. Their performance are evaluated by testing and by modelling. This step is important for the verification the good functioning of very costly measures (e.g. soil barriers) before deciding on their use; it also allows the fine-tuning of the initial design of the measure.
After installation on site, proper measurement protocols have to be available to measure and monitor the performance of the installed measures. These protocols will be based on existing measurement protocols for passenger trains, adapted to freight trains. They will include measurement methods, sensor types, measurement conditions, sensor locations, analysis methods and performance evaluation methods. They will deal with the assessment of the complete system and not with the determination of the characteristics of single track or vehicle components, such as improved rail pads or sleepers or different bogie suspension, since these do not provide the global performance of the mitigation measure.
The difficulty in developing performance assessment procedures lies in the physics of vibration generation and transmission: everything is linked and coupled. That makes it difficult to carry out a performance calculation or measurement that really isolates the object of interest, the mitigation measure. It also makes is difficult to translate the calculated or measured effect to different situations (e.g. different soil types).
Guidelines and leaflets are produced with the most common mitigation measures and their performance with indication of the effect of varying conditions (track type, soil type, etc.) on this performance. This will be based on the existing FTA leaflets for passenger train vibrations, which will be adapted to freight vibrations. In conclusion, not only will procedures be established for measuring and calculating the performance of a specific freight vibration mitigation measure but it will also be possible to extrapolate the performance of this measure (eventually with adapted design) to other situations (soils, vehicle speeds, track types, etc.).
Another vital problem is the choice between the available mitigation measures (track side, vehicle side, which type) in the early project study. This choice is economically very important and it will depend on many parameters such as: the area where mitigation measures are required (length and location), the mitigation performance needed, the cost of the investment and the cost of the maintenance, the operational parameters (existing lines where no traffic interruption is possible, new line….). The operators use LCC calculation tools to guide them through this choice of different options. Within CargoVibes all required input data for carrying out such an LCC calculation related to the implementation of different freight vibration mitigation solutions will be established (LLC leaflets). The use of these leaflets will be demonstrated considering different mitigation options for freight vibrations in a real life situation on an end-user freight line.

MITIGATION MEASURES: PROGRESS BEYOND THE STATE OF THE ART
To provide efficient mitigation possibilities, CargoVibes develops three new mitigation measures for freight traffic, determining the key effects and parameters and setting up design rules for application in any given situation. A ‘situation’ is a combination of the characteristics of the soil and the characteristics of the freight train vibration.
The three are chosen based on their promising effect in the lower frequency range and on the possibility of application as retrofit measure. The measures are viable and offer possibilities to mitigate at the source, on the trackbed or in the soil (vibration propagation path) in function of what is considered the most viable way depending on operational conditions and existing vehicle and infrastructure conditions.
1. Adequate wheel and rail profiles:
For conventional rail traffic and urban rail traffic, the relationship between roughness and soil vibrations is known (e.g. SPURT project). Large vibration mitigation can be obtained by maintaining adequate roughness levels by turning, grinding and / or milling the rail and the wheel.
For freight traffic, this relationship is different due to the absence of a secondary vehicle suspension. The objective consists of the determination of the relationship between wheel and rail roughness, wheel geometry and rail alignment, and vibration intensity for freight traffic on ballasted track with the aim of defining an adequate max. wheel and rail surface quality function of the acceptable vibration intensity.
2. Stable ballasted track:
Extended sleepers, such as ladder track with it longitudinal sleepers, and a product like HDS from SSL in Austria, have the benefit of a lower need for track maintenance. This implies that a better track geometry is maintained. It is noted that such systems indeed significantly reduce the dynamic load on the ballast and the subgrade. As track geometry, or bad condition thereof, is an important source of railway vibration, and freight trains with their high axle loads have an important influence on it, as well as generate vibration through it, the idea is to reduce vibration by implementing more stable ballasted track systems. Furthermore, they would, in principal, be easy to implement in normal ballasted track, making it a very economical retrofit option. The aim of CargoVibes is to establish the effect is of more stable sleepers and improve on them by adding elastomer solutions such as Under Sleeper Pads (UPS’s) and more resilient rail supports.
3. Coated ground walls
The coating of soil barriers with a thick elastic layer. Today, soil barriers are considered as an interesting measure in reducing vibration induced noise levels inside buildings located next to tracks. Their workings rely on the impedance jump that is created between the relatively stiff soil and the soft elastic layer.
As for freight traffic the focus is on vibration disturbance rather than secondary noise, the existing soil barrier technology will need adaptation in order to function efficiently. In the city of Arnhem, the Dutch railway operator already has commissioned the implementation of a soil barrier to reduce vibration of passenger trains. This “pilot” shows that positive effects at 10 Hz and lower are possible and will be used as the basis of further investigations that are needed to make it applicable for freight trains in various circumstances. Aspects to be investigated and put into design rules are, among others:
 the desired thickness and material characteristics of the elastic layer;
 the desired depth of the soil barrier, also in relation to the layering of the soil and the water table;
 the influence of the horizontal angle and the vertical angle of the soil barrier with the track.

Figure 1 (attached): Overview of activities in CargoVibes at the source level, the track infrastructure level and the in the propagation path.

Project Results:
see attached document: 266248_S&T_result_foregrounds.pdf

Potential Impact:
POTENTIAL IMPACT

CargoVibes will produce a guideline on how to assess the adverse effects of freight train vibrations on residents that is aimed to be acceptable for both railway operators and for residents. It is unclear whether with current standards and guidelines resources to protect residents from railway vibration are allocated optimal. Therefore, CargoVibes produces a guidance that is based on new and existing surveys and on new and existing research into health effects, all this focused on night-time freight traffic. The document is intended to provide an extension to the currently available body of guidance in light of the current state of the art. The CargoVibes extension set will be brought into use by policy makers, railway operators and planners. With it, they will evaluate current policies on environmental impact assessments, current operations and plans and decide whether mitigation measures are needed. It will lead to less adverse effects, as it takes a broader spectrum of effects into account, and to more efficient allocation of resources.

CargoVibes will produce a guideline on how to assess and measure the effects of mitigation measures. The guideline will explicitly take into account the situation dependency of the measure effect, making it possible to translate assessment results in one situation to a different one. This way, mitigation performance data sheets can be build, filled with assessment results and the way those can be translated to any given situation. The guideline will be brought into use by railway planners and railway industry.

The project will also treat scaled laboratory tests. These kinds of tests are of great use for new types of mitigation measures that have been developed based on models and for which direct implantation would involve too much risk. The scaled laboratory tests will be used by developers and suppliers of mitigation solutions.

CargoVibes will also develop some new mitigation measures, enabling more traffic and/or less adverse effects:

Criteria for the maintenance of wheel sets:
With these criteria, it becomes possible to use the current and future on-board and track-based monitoring equipment in place to pick up on wagons and locomotives that have characteristics that result in excessive vibrations. The evaluation can be used by railway operators and infra managers for setting a cap on the contribution of freight trains to the overall generation of ground-borne vibration. Railway operators and infra managers want to use the project results to set ground borne vibration related maintenance limits for wheel defects.

Stable sleeper systems and highly elastic rail fixations for ballasted track:
This type of solutions in the super structure can be employed to reduce the geometrical stability degradation of the track. The geometrical track characteristics have a large influence on the emitted ground borne vibrations. Instead of using standard concrete and wooden sleepers, ladder track or similar track structures (larger sleepers, reduced sleeper spacing etc.) with or without under sleeper pads or high elastic rail fixation can be used to reduce maintenance and provide vibration reduction. Infra managers can choose to apply these solutions in new and existing hot spots with the benefit that they combine well with the adjacent regular ballasted track.

Coated ground walls:
For situations where track based solutions are not feasible, measures in the propagation path are wanted. Ground walls make it possible to better an existing situation with a minimum of disturbance of the railway. Models will be developed for an appropriate design of soil barriers. These design models for barriers, coated if needed, will make it possible for railway engineers to readily decide if it is an option for their project.

DISSEMINATION

The dissemination of the project's knowledge involves all the tasks for communicating foreground information beyond the consortium. All the partners, the focus being on the RTD performers, coordinate the publication of articles in international scientific journals, the organization of workshops and the set-up of web-based activities (i.e. web portal development) aiming at disseminating the knowledge and technology to be produced in the project. Dissemination activities are subject to the knowledge protection provisions to be agreed by all partners. Targets groups to be addressed for the communication of project's innovation include the international scientific community, industrials forums at national and European level, educational boards, the internal organization hierarchy and business partners of the participants, under and post graduate students.

Indicative activities include:
- Activities for the effective and sustainable dissemination of knowledge among and beyond the members of the consortium (beyond the life time of the project);
- Coordination of knowledge management and other innovation related activities;
- Activities promoting the exploitation of the results;
- Activities to provide for the adequate and effective protection of knowledge created in the project; having due regard to the legitimate interests of the contractors concerned;
- Reporting about these activities.
Strategy
The dissemination strategy aims to identify:
- the objectives;
- the target groups and their respective interests;
- the tools for disseminating the CARGOVIBES results.
Objectives
- To set up a dissemination platform to facilitate wide-spread information transfer among and beyond the members of the consortium (and beyond the life of the project);
- To ensure that the project outputs reach targeted decision makers who will implement them;
- To guarantee the delivery of high-quality results and sound technologies;
- To facilitate the implementation of CargoVibes results in applicable codes and standards through specific contacts with National standardization and certification associations.

Target group and their respective interests
The purpose of this task is to disseminate the project's results to the freight rail operators, infrastructure managers and the industrial and scientific community, including European and International organisations such as UIC and UNIFE and interested ISO working groups. The target group also includes the EC departments involved with Environmental Impact Studies: legislative and technical departments, EC and national Health Departments, national and regional Environmental Departments.

The stakeholders include:
- Representatives from national railways;
- Standards organizations;
- Professional associations from industry (UITP), operators (UIC) and infra managers;
- Health organizations;
- Public representatives (POLIS and others);
- National and EU policy makers and planners;
- Consultants;
- Researchers.
The stakeholders are all invited to the end seminar on March 12 & 13, 2014, hosted by TNO in Delft (NL).

Tools for dissemination
1. Establishing and maintaining a project related web site (APT) which will be available for at least 5 more years after the end of the project: the website is up and running since the end of June 2011;
2. Preparing 'marketing material': logo, regularly press releases, newsletters, posters, flyers and other:
3. Writing of technical papers for publication in technical and scientific journals and/or for presentation at conferences;
4. Presence at technical conferences with dissemination of project results through personal contacts and by making available technical papers and marketing material to conference participants (eventually as exhibitor);
5. Organization of workshops related to the individual WP's;
6. Organization of a final dissemination conference at the end of the project (TNO);
7. Providing a contact point informing freight operators and infrastructure managers (stakeholders) about the project and the partners activities in the context of the project mainly on the EU level in Brussels: the EUB (End User Board) convenes every three months;
8. Participation in relevant meetings and events in order to present the project and its progress and results mainly on the EU level in Brussels;
9. Making contacts with SMEs and industry representatives, through organizations such as UNIFE, for the presentation and possible exploitation of the project results i.e. by exploitation of CORDIS database, support in technology transfer (CDM);
10. Monitoring IPR issues, IPR protection and management (TNO);
11. Distribution of catalogue of mitigation measures (D2.6 APT, M24). This catalogue will be produced in hardcopy for distribution to all stakeholders and it will also be available on the web at no cost.
12. Distribution of LCC input data sheets with the investment, maintenance and operational cost of all the available mitigation measures for use in LCC studies (D2.7 APT, M24). This LCC input data information will be made available on the web at no cost and its information will be regularly updated.
13. Development of a training tool (D6.1 ISQ, M36) guiding the selection of the optimal mitigation tool out of the available mitigation measures in function the freight line to be mitigated against vibration impact. Benchmark examples will be used for illustration. The use of the mitigation performance data sheets and of the LCC input data sheets will be demonstrated. This tool will be based on a e-learning system platform which will allow a friendly understanding particularly by the end-users of the mitigation measures, vibration abatement procedures and related assessment criteria.
14. Standardization and normalization (D6.3 APT, M36): Important project results will be directly brought to the level of ISO 14837 WG and CEN TC 256. Both TNO and APT will request membership of these bodies through their national organizations. They will present their findings at the regular meetings of the respective working groups and APT will support this with a report on proposed standards. This might result in feedback from the standardization bodies.

Logo & Templates
A logo was designed by TNO, which was used by APT in both the website and the project templates for deliverables and presentations. From the website, the partners of the consortium have a direct link to the ftp-server, which they access using their personal login and password. On this ftp-server, all documents related to the project, such as the signed contract, consortium agreement, logo, templates, technical notes, and deliverables are made available. EUB members have also access to the ftp-server, but restricted to the EUB folder only.

EXPLOITATION OF RESULTS
To ensure the exploitation of the project's results and developed technologies by the industries (suppliers) and freight railway operators (end users), the exploitation activities include working out of exploitation strategy, further activities promoting the exploitation of the results.

The work on exploitation involved a comprehensive cost-benefit-, life cycle cost and market analyses for CargoVibes results, including a thorough analysis of the general impact of CargoVibes. The partners ensure the use of the results from this research project for their daily activities. It is expected that project's output will be capable of both industrial (end users) and commercial application in short to medium term. Thus, appropriate actions were undertaken to assure an efficient use of the project results.

The industrial partners have immediately started the marketing of the developed tools, components and solutions inside their business units and defined the necessary steps to enable the usage of the proposed mitigation solutions through demonstrative representative cost-benefit and life cycle cost studies developed in collaboration with the railway operator partners.


List of Websites:
www.cargovibes.eu