Higher loads, faster trains and busier timetables should soon make it possible to double the number of passengers using the European rail network, and even triple the level of goods transported. At the same time, the safety of existing railway bridges, some of which are over fifty years old, must be guaranteed. To investigate the scale of the problem, the EU has recently started the «Sustainable Bridges» research project. The aim of the project is to develop methods to better utilize the capacity of the existing infrastructure, and to formulate more efficient maintenance practices.

A large number of bridges in the European rail network are old and in poor shape, a fact which represents a major problem for rail system operators. However, improved monitoring and maintenance makes it possible to avoid expensive renovation work, with the knock-on effects of reduced service levels. Newer rail bridges designed for lighter loads generally have significant unused reserve capacity, and here also costly strengthening work can be avoided thanks to newer, more accurate measurement and analysis techniques. The estimated value of the bridges in the European rail network is €50 billion, and the findings of the project indicate that total savings of several billion euros may be possible.

Empa and EPFL lead working groups in the EU project

Project participants include rail operators, private engineering firms, research organizations and universities. Heading the working group dealing with the electronic monitoring is Dr. Glauco Feltrin of the Empa, the materials research and technology institute of the Swiss Federal Institutes of Technology group. He is coordinating the work being done in eight countries to improve sensing techniques, data transmission and computer-aided bridge structure diagnostics. Automated monitoring systems are being developed and tested which must be capable of continuously supplying data while being subjected to the very high electromagnetic fields found in the proximity of railway lines. The data will provide vital information on the serviceability, lifetime and safety of both existing and newly built bridges.

Prof. Eugen Brühwiler, Head of the Maintenance, Construction and Safety of Structures Laboratory at the Federal Institute of Technology Lausanne will, with the help of his team of researchers, concentrate on the effects of fatigue on the safety of steel-reinforced concrete bridges. New results and test methods will allow them to decide how best to exploit the existing reserve capacity, so avoiding inessential reinforcing work.

Other key areas which the project will cover include the creation of an inventory of railway bridges as an aid to planning the European transnational rail system, the optimization of monitoring methods, the development of improved renovation and reinforcing measures, together with the thorough testing of the methods and systems being developed. The results obtained will be disseminated to end users by means of courses and conferences. A guideline document containing a summarized version of the findings will enable rail system operators to take appropriate and optimized measures to maintain a specific bridge to the appropriate level, depending on the state of the structure and the requirements placed on it.

Still too little funding promised

The four-year project, which began on December 1st 2003, is financed via the 6th Framework Programme of the European Commission and (in the case of the Swiss partners, Empa and EPFL) by the Swiss Federal Office for Education and Science. While the EU partners will share funding of €6.9 million, the size of the contribution to the Swiss partners from the federal authorities is not yet known. Because the federal funding level across the board for Swiss partners participating in EU projects is inadequate, the current situation is that only the first 28 months of the project are completely financed.

Contact person for further information:

Dr. Glauco Feltrin, Empa Structural Engineering Laboratory, Tel. +41 44 823 44 50, glauco.feltrin@empa.ch

Prof. Eugen Brühwiler, EPFL Maintenance, Construction and Safety of Structures Laboratory
Tel. +41 21 693 28 82, eugen.bruehwiler@epfl.ch

Editor:

Martina Peter, Empa Communication/Marketing Dept., Tel. +41 44 823 49 87, martina.peter@empa.ch