When a bridge is subjected to scouring, erosion caused by fast-flowing water, its foundations can become undermined. It is vital that regular bridge scour assessments are carried out to protect not only the integrity of the bridge infrastructure but also the safety of those who use it.
A bridge scour assessment evaluates the extent to which the bridge has been scoured and whether it remains safe for use. These assessments, which primarily involve close inspection through diving, require specialist expertise and skill. Divers measure the riverbed profile and inspect the footings, abutments, and piers to determine and record the condition of these structural elements. Where elements are found to be in poor condition, remedial measures are identified. Repairs may range from minor repointing to the installation of fabric formwork grout systems.
While there are established requirements for highway structures, there is currently no formal guidance or regulation for privately owned structures.
Bridge assessments are fundamental to safeguarding infrastructure and ensuring public safety. While technologies such as remotely operated vehicles (ROVs) exist, combining these with visual inspections is often preferred due to the higher level of detail achieved. Assessment begins by measuring the riverbed profile and identifying any voids. Following this, a professional report should be compiled to present the findings and recommend necessary actions.
Depending on the bridge’s location, the UK highways document CS 469 provides guidance on what a scour assessment should include. The document categorises the depth of assessment into Level 1 and Level 2, with the latter a more comprehensive assessment for structures considered at greater risk of scour damage.
Strict guidelines must be followed by contractors undertaking bridge scour assessments. The Design Manual for Roads and Bridges includes the document CS 450 Inspection of Highway Structures, which sets out the regulatory framework and mandates assessment standards. The frequency of inspections is determined by the overseeing authority’s risk assessment, with additional inspections often required following significant storm events where damage is likely.
Assessing bridges for scour is essential to public safety and maintaining resilient infrastructure. Without routine monitoring and maintenance, structures may deteriorate, potentially leading to catastrophic failures.
Given the increasing impact of climate change, the need for consistent bridge scour assessments has never been greater. Failure to act may result in scour-induced collapse, with devastating consequences. However, if risks are identified early, appropriate mitigation measures can be implemented, extending the lifespan of the structure. Regular assessments also support cost control, as unplanned bridge closures and major repairs can be both expensive and highly disruptive to transport networks.
Offering expert advice from our marine engineering team, AWA has the diving capability to assess your bridge and the design expertise to propose effective solutions for any required remedial works. With engineers who possess specialist knowledge, we can efficiently develop a tailored plan to support and strengthen your bridge infrastructure.
AWA Consulting Engineers is a structural, civil, and marine engineering consultancy established in 1987, with a hard-won but deserved reputation for delivering excellence in our profession.
Our philosophy is simple: we put people first. This has resulted in a high number of repeat clients and an impressive track record of successful award-winning projects. We are proud to be professional, and approachable; we believe this makes us the ideal partner for your project.
AWA has technical teams in our offices located in Romsey, Hampshire and Bath, Somerset. We deliver services to clients typically across the South, South East and South West.
Our team includes both chartered structural engineers and chartered civil engineers committed to continuous professional development ensuring you benefit from up to date industry expertise, whatever your project entails.
To find out more about how AWA Consulting Engineers can help with your project, get in touch today. Email mail@awaengineers.com and one of the team will be in touch. Alternatively, call 01794 524447 to speak to a member of our team.
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