Global monitoring concepts for bridges

Life extension and replacement strategies are crucial issues in an efficient highway infrastructure management system. Due to normative and budgetary constraints, knowledge of the integrity of in-service structures on a continuous time basis has to be an ultimate objective of owners as well as maintenance authorities. A key component of any infrastructure management system is a set of surveillance techniques to assess the conditions of existing structures. Recent progress in the development of sensing technologies and material/structure damage characterisation combined with current data processing techniques have resulted in a significant interest in diagnostic tools to monitor structural integrity and to detect structural diseases. The comparison of measured and calculated behaviour in order to tune and calibrate mechanical and numerical model assumptions is an essential part of any system analysis. Once a model has achieved a certain level of completeness and validity, analytical prediction provides a quantitative knowledge of structural performance and safety assessment.