Australia has suffered loss of life and extreme damage to infrastructure from natural hazards and as our communities grow, so does the potential for greater losses in these areas. Floods have the greatest damage potential of all natural disasters worldwide and effect the greatest number of people. The aim of this project is to investigate the vulnerability of the U-slab bridges during flood as they are one of the vulnerable structures during flood. By this research it is expected to derive the damage cure, which can determine the limitation and damage boundaries, so it would be possible to predict the behaviour of U-slab bridges and optimise them. The research questions are:

• What are the failure modes of a U-slab bridge structure exposed to flood?
• What are the typical loads to be considered in analyses the effect of flood on bridges?
• How can we create a numerical model to analyse the effect of flood loading on U-Slab bridges?
• How can we derive vulnerability models for bridge under flood loading?
• How can we enhance resilience of bridges to flood loading?

This study focus on the effect of flood loading on U-slab bridges as oldest and the most vulnerable bridge structure, identified by VicRoads. It aims at investigation of  the best approach for numerical modelling and general vulnerability modelling of U-slab bridges which can be used by the end user to evaluate the effect of flood loading on structure. Besides, for hardening of the structure to achieve a required level of resilience, the outcome of this research can develop a framework to identify the most vulnerable bridges to attend strengthening work. In general, it would be useful for prediction of the damage level and presenting the framework of strengthening of U-slab bridges

This project will establish a damage curve and index for U-Slab bridges under different exposure scenarios, an estimation of the design loads to be considered to ensure a given level of resilience, a 3D numerical model for U-Slab bridges to evaluate the effect of flood loading, a vulnerability map for all U-slab bridges in Victoria, and a generic methodology for assessing the vulnerability of bridges.