Hidden defects in bridges. Guidance for detection and maintenance

The UK and Ireland’s bridges play a critical role in support of their countries’ economies and societies. As evidenced by the rarity of bridge failure, they are generally well managed and fulfil their operational requirements. This guide collates a group of case studies demonstrating that hidden defects do exist in critical bridge components. In some cases they have threatened safety to the travelling public, and in extreme cases they have resulted in the collapse of bridges without warning. If the risk posed by hidden defects is not managed appropriately then the likelihood of encountering such failures will increase. This guide provides methods to identify, investigate and manage many known hidden defects. It fills important gaps in knowledge and is complementary to existing bridge inspection guidance.