Investigation of post-flood-damage bridges: RMS perspective

In the last few years, severe weather changes are experienced in all parts of Australia. One of the severe weather changes is seen in the form of flooding, causing damage not only to the roads but bridges. Flooding along high velocity flow across the bridges can produce considerable damage to the bridge structures and this is typically worse for multi spans bridges. The force can intensify if logs and other debris pile against the bridge, creating a dam effect. Also the flood can cause erosion or scouring in the surrounding foundation material which can endanger the bridge stability and approaching roads. Modern bridges are made to withstand the type of flooding that might only occur once every 2000 years but to withstand unpredicted levels of flooding is a big challenge for existing bridges. The Bridge Engineering Section of Roads and Maritimes Service assessed the flood affected bridges to ensure that they are structurally safe and suitable for routine traffic after inundation. The assessment is generally comprised of thorough visual inspection of super structure, sub structures and foundations followed by limited structural analysis where required. The experience gained from recent post flood assessment can assist assets managers in developing risk mitigating strategies for flood prone bridges.