CIRIA to update scour manual

If the depth of the scour becomes significant, the stability of the foundations may be endangered, with a risk of damage or failure of the structure.

The CIRIA guide Manual on scour at bridges and other hydraulic structures (C551) was conceived, researched and written over 10 years ago. The guidance in the publication readily became a reference standard for transportation and related infrastructure owners and operators together with government departments and local authorities.

CIRIA says the key driver for the use of a common reference standard on scour was and remains the ‘in common’ nature of engineered assets located in a river or estuarine environment where the impact and mitigation of scour effects is an instrumental part of responsible asset management. This consideration overrides the differences between certain asset types and the legal, commercial and safety regimes which dictate their operational surety.

So, what has changed? Simply, scour is not a new phenomenon, but the increasing frequency and intensity of extreme weather events (at least in part as a consequence of climate change) over the past ten years has acted as a salient reminder as to the vulnerability of aged infrastructure assets and that the design basis for more newly constructed works may not be as robust as intended. In addition, the understanding of scour has improved in recent years.

The project intends to update the 2002 CIRIA manual and will incorporate advances made in the understanding and application of the science, engineering and hydraulics of scour at bridge sites, hydraulic structures and pipeline crossings. The specific objectives are:

· to provide up to date, practical and detailed technical guidance for hydraulic engineers, bridge engineers and bridge owners/maintainers to enable the effective management of river and estuarine based assets

· to provide this guidance in the context of prevailing and projected climatic conditions

· to provide informative case histories on scour protection measures and the damage that can result from adverse impacts.

CIRIA is currently seeking support and involvement from industry. For more information about the project or to get involved, contact Philip Charles at CIRIA.