Bridge Collapse

CROSS, the Confidential Reporting of Structural Safety organisation have issued a warning about the safety of bridges following the collapse of an historic bridge.

An historic bridge collapsed minutes after workers fled to safety. They had been reinforcing the flood weakened foundations of the bridge when a crack was seen. Two of the three spans of the brick arch bridge fell. It had been closed to traffic for repairs to scoured foundations. It had been reported that prior to the collapse there had been no signs of any structural damage, and no indication it would give way. Investigations are being carried out into the cause of the collapse. Suggestions have been made that horizontal props should have been installed as soon as the scour was identified.
CROSS advises that by far the most common cause of bridge failure worldwide is scour. The age of the bridge is significant because older bridges are more likely to have foundations of inadequate depth. The fact that it was a masonry arch may not have contributed to the cause of failure. In general river bridges need adequately maintained river training works, and regular reassessments of the future magnitudes of hydraulic flows, and the adequacy of the training works to contain them. When repairing damaged structures need to pay special attention to the process of how it is done. In many case preliminary works may be required to prevent further damage and or make the structure safe so that the repair work can start. Further information can be obtained at www.scoss.org.uk.
The photographs are illustrations of bridges that Thomas Consulting have inspected in the past.
.