Reduce risk, avoid programme delays and make decisions based on evidence – not assumptions.
When managing one of the most critical logistical arteries in the South West, National Highways requires absolute structural certainty. Maintaining the massive M5 Avonmouth estuarine bridge is an immense engineering challenge – asset managers must constantly monitor for concrete degradation, rebar corrosion and bearing fatigue to prevent catastrophic failure.
At Structural Repairs, we know that permanent, effective concrete repair begins with empirical data. To capture this data on the M5 Avonmouth River Crossing, we deployed a groundbreaking approach, combining Visual Bearing Inspections with Ground Penetrating Radar (GPR) using autonomous robotic crawlers.
This advanced methodology delivered comprehensive asset coverage, marking a significant step forward in how we diagnose and engineer remediation strategies for tier-one infrastructure.
The Challenge: Data Acquisition Without Disruption
The M5 Avonmouth River Crossing handles over 70,000 vehicle crossings every single day. Closing lanes to erect scaffolding or deploying heavy access platforms to inspect the piers causes unacceptable disruption to the strategic road network.
However, National Highways required near 100% asset coverage to meet strict SBIM (Structural Building Information Modelling) contract specifications. They needed high-quality data regarding the condition of the bridge support bearings and the integrity of the concrete cover protecting the internal steel reinforcement.
Traditionally, capturing this data required rope access teams suspended high above the tidal estuary – a slow, high-risk methodology. We needed a solution that eliminated working at height while providing the exact diagnostic clarity required to specify future preventative structural maintenance.
The M5 Avonmouth Crossing carries one of the UK’s main transport arteries. By April 2004, by Joe D. – April 2004, by Joe D., CC BY-SA 1.0,
The Solution:
Autonomous Robotic Diagnostics
To meet the strict inspection standards without disrupting traffic or endangering personnel, Structural Repairs deployed an advanced robotic crawler system.
Instead of putting humans on ropes, we sent robots up the piers. These highly agile crawlers were equipped with interchangeable diagnostic payloads, combining high-definition optics for visual inspections with deep-penetrating GPR technology for concrete condition assessments.
The Process: Mapping the Structural Matrix
The robotic crawlers navigated the sheer vertical faces of the bridge structure, targeting the most critical structural nodes:
- Visual Bearing Inspections: Bridge bearings are vital for transferring dynamic loads and allowing the structure to flex. The crawlers used HD cameras to capture detailed video and high-resolution images of each bearing atop the piers, identifying early signs of fatigue or seizure that would require future mechanical replacement.
- Concrete & Rebar Diagnostics: To assess the risk of chloride-induced corrosion, the crawlers deployed advanced GPR payloads. By transmitting radar pulses into the concrete matrix, we accurately located the internal steel reinforcement, measured the depth of the concrete cover and estimated overall concrete thickness.
This dual-pronged approach allowed us to capture the critical engineering data required to specify targeted concrete rehabilitation – all without a single lane closure or traffic delay.
The Result: Engineering-Led Asset Preservation
The deployment of robotic crawlers delivered remarkable outcomes for National Highways, setting a new benchmark for structural diagnostics:
- Zero Working at Height: Dangerous rope access was completely eliminated, dramatically enhancing site safety.
- Zero Traffic Disruption: The entire diagnostic operation was executed from the substructure, leaving the 70,000 daily vehicle crossings entirely unaffected.
- Empirical Repair Data: The robots positioned GPR arrays and cameras extremely close to the inspection points, providing National Highways with the flawless, high-quality data required to pinpoint exactly where future concrete repairs and bearing interventions are needed.
By partnering with an integrated specialist engineering contractor, asset owners can ensure that emerging structural problems are identified and resolved early. We do not just capture data; we use it to engineer the exact interventions required to safely extend the lifespan of critical infrastructure.
Increasing the Longevity of Buildings and Structures
Structural Repairs is a leading global specialist in civil infrastructure preservation. Discover how our Non-Destructive Testing (NDT) and advanced concrete repair methodologies can protect your assets and lower your long-term capital costs.
Structural Repairs team operating robotic crawler for GPR survey on M5 Avonmouth Bridge
