Abstract

The damage early warning of bridges is a mandatory issue if we want to guarantee the safety of transport lines."br" In principle, bridges should show a non-linear damaged phase which has enough remaining capacity to avoid"br" brittle collapse, while permitting the identification of the decrease in stiffness, and therefore the warning about"br" the efficiency of the structure (Farrar & Warden 2006)."br" It is however to point out that the change detection of the bridge dynamic properties is a very complicated task,"br" due to the variable environmental and loading conditions, and the small entity of change that by far severe"br" damages produce (Magalhães et Al., .2012)."br" In the paper the preliminary results of a two year long European project, granted by the Infravation Call, are"br" presented. In this period, a consistent number of bridges all around the world have been monitored, and some"br" specimen bridges thoroughly investigated in laboratory (see for instance the project description at the site"br" http://www.infravation.net/projects/SHAPE)."br" The performed investigation has shown that the continuous monitoring of bridges can be transformed in a sort of"br" bridge behaviour intrinsic model which fixes the range of normal operation of the bridge itself. By this way,"br" outliers can be identified, but a very important issue is the evaluation of the extent of the change that can start the"br" warning activity."br" Among the possible strategies, it is shown that algorithms that evaluate the derivative of the change can be"br" effective in pointing out the onset of a permanent damage (Nikowski & Jain, 2009).

Abstract

The FP7 Theseus research project (2009–2013) aims to develop and assess innovative technologies and methodologies for coastal protection against erosion, flooding and environmental damages. While protection structures may help to reduce the level of hazard and the expected degree of loss, some danger of technical failures or human errors will always remain. For extreme events, the implementation of non-structural measures as early warning systems and disaster management practices is required to ensure the protection of population. During Theseus, a methodology for helping the local authorities to prepare an action plan in case of coastal flooding was developed and tested on the estuary of Gironde in France. The methodology builds over the return of experience from past events and tries to clearly identify all the stages of an evacuation and the thinking process that can lead to a robust evacuation plan. It relies on a conceptual framework – SADT – which helps to understand how data should be processed from its collection to its use in the plan. The risk scenarios were calculated for current and future conditions of the XXIst century, taking into account the effects of climate change. The methodology is supported by the OSIRIS software, prototyped during the FP5 eponymous project and later distributed by CETMEF and the French basin authorities of Loire and Meuse. The methodology for the preparation of evacuation plans was applied on a pilot city of Theseus, Bordeaux on the estuary of Gironde (France), and the software used to calculate evacuation times was tried out on Cesenatico near the Adriatic coast (Italy). This comparison verified the replicability of methodological guidelines in two different European contexts. The cultural and organizational differences and the different number of people involved underlined strong questions to be addressed when applying them. In order to assess the efficiency of an evacuation strategy and to compute the number of people successfully evacuated over time, a macroscopic model (not representing each individual vehicle but only flows of vehicles in congestion points) for the simulation of traffic congestion was used, based on the work of the University of Twente, Rijkswaterstaat and INFRAM. This model will be integrated in the Theseus decision support system for helping coastal managers to select their strategy for risk mitigation.