Uncovering Hidden Infrastructure – Advanced NDT Structural Analysis at Burrfields Road Railway Bridge
Client: Confidential / Network Rail Infrastructure
Location: Burrfields Road Railway Bridge, Portsmouth
Services Provided: Non-Destructive Testing (NDT), 3D Site Scanning, Concrete Reinforcement Mapping
Company: ACUO Structural Insights Ltd
Executive Summary
When upgrading, repairing, or assessing aging railway infrastructure, structural engineers need precise data on the existing construction. At the Burrfields Road railway bridge in Portsmouth, ACUO Structural Insights was tasked with a critical challenge: determining the exact structural makeup of massive concrete support columns without causing any damage to the active railway infrastructure. By utilizing advanced Non-Destructive Testing (NDT) combined with 3D site scanning, our team successfully mapped the internal reinforcement, providing the client with vital missing data while saving significant time, reducing costs, and preserving structural integrity.
Project Background
The Burrfields Road site features a major railway bridge supported by heavy-duty cylindrical concrete columns. To proceed with structural assessments and future-proofing works, the engineering team required a comprehensive understanding of the columns' internal reinforcement.
From historical data and initial assessments, several specifications of the columns were known:
Dimensions: 5.0m High x 1.5m Diameter
Vertical Reinforcement: 16x 38mm Rebar Bars
Vertical Bar Cover: 60mm – 75mm
Shear Reinforcement (Ligatures) Spacing: Every 150mm
Ligature Cover: 55mm
However, there was one critical piece of missing information: the diameter of the ligature (tie) bars.
The Challenge: The Problem with Traditional Destructive Testing
Knowing the diameter of the shear reinforcement is vital for accurate structural load calculations. Traditionally, obtaining this missing information requires destructive testing—physically breaking out sections of the concrete cover to expose the rebar beneath.
In a sensitive environment like an active railway bridge, destructive testing presents major hurdles:
Structural Damage: Breaking concrete introduces vulnerabilities, requiring costly and time-consuming patching and structural remediation.
Operational Disruption: Operating heavy breakers in a trackside environment requires extended track possessions, leading to railway delays and logistical headaches.
High Costs: The labor required for the breakout, the safety management around the tracks, and the subsequent repair materials drive up project costs significantly.
The client needed an alternative. They needed to see inside the concrete, without breaking a single piece of it.
Our Solution: Advanced Non-Destructive Testing (NDT)
ACUO Structural Insights deployed a rapid-response team to the Portsmouth site, equipped with state-of-the-art NDT technology and 3D spatial scanning equipment.
1. 3D Digital Twin Creation Before inspecting the concrete, we captured the entire underpass using high-resolution 3D scanning technology (Matterport). This provided the client and off-site engineers with an exact digital twin of the environment, allowing for precise spatial planning, clearance measurements, and contextual visualization of the columns in relation to the railway tracks below.
2. Deep-Penetration Concrete Scanning To solve the mystery of the unknown Vertical Bar Diameter, we utilized advanced Ground Penetrating Radar (GPR) and electromagnetic cover meters specifically calibrated for heavily reinforced concrete structures.
We safely scanned the outer surface of the 1.5m diameter columns.
The NDT equipment successfully penetrated the 55mm of concrete cover to map the dense web of steel beneath.
By analyzing the signal responses, we accurately mapped the 150mm spacing of the ligatures and the Vertical Bars and, crucially, determined the precise diameter of the hidden Vertical bars.
The Results & Client Value
Our non-invasive approach yielded exceptional results for the project stakeholders:
100% Data Delivery: We successfully ascertained the unknown Vertical Bar diameter and verified all other existing reinforcement specifications (the 16x 38mm vertical bars and cover depths), giving the structural engineers the exact parameters they needed for their calculations.
Zero Structural Damage: Because no concrete was broken, the structural integrity of the bridge supports remained completely uncompromised. No patching or curing time was required.
Significant Cost & Time Savings: By eliminating destructive breakouts and the subsequent remedial works, the project timeline was shortened by days. Furthermore, the non-invasive nature of our work minimized the need for extended, highly restrictive track closures.
Enhanced Safety: Less time on site and no heavy demolition equipment meant a drastically reduced risk profile for the trackside workers.
Conclusion
The Burrfields Road project is a prime example of how modern engineering challenges require modern solutions. At ACUO Structural Insights, we proved that you don't need a sledgehammer to understand a structure. Through the smart application of Non-Destructive Testing and 3D scanning, we delivered precise, actionable data to our client—saving time, reducing costs, and keeping our vital transport infrastructure intact and operational.
Are you facing structural unknowns on your project? Don’t break the concrete—scan it. [Contact ACUO Structural Insights today] to learn how our advanced NDT services can save your next project time and money.