Design for optimal performance of high-speed railway bridges by enhanced monitoring systems (DETAILS) : final report

Steel-concrete composite solutions have been more and more exploited in the new high speed lines of European railway networks. The adoption of new steel concrete composite solutions has been favoured for a number of reasons: the greater possibility and savings given by the high elastic limits reached by thermo-mechanically controlled rolling process; the use of very thick steel plates; the advanced numerical methods and code design approaches; the reduction of maintenance costs by using weathering steels and new paint products; the great increase in transport and assembling capacity that allowed the reduction of 'on site' works; the improvements in welding technologies with the introduction of new methods. Nevertheless these new design solutions, introduced during a period of quick expansion of railway networks, amplified open problems related to dynamic effects and interaction phenomena, fatigue loadings, structural modelling, fatigue life and exercise conditions. The experimental and theoretical analyses performed in the Details project permitted the investigation of some of the uncertainties actually affecting design and management of railway composite bridges, focusing research activities on the investigation of resonance phenomena, train-bridge interaction effects, global and local dynamic loads, fatigue behaviour, modelling techniques, traffic spectra and exercise conditions. To this end, an innovative global approach for the structural assessment was developed and calibrated on suitable case studies, representative of steel-concrete composite solutions currently adopted in European high-speed railway lines. Results permitted the clarification of many of the aforementioned open problems, establishing important guidelines for the correct assessment of composite bridges.