Spencer Bridge Engineering were initially appointed by the client to review proposed options for construction methods of replacement footway panels, through an early contractor involvement (ECI) process. As part of the review, the project team proposed an alternative method of panel manufacture by suggesting off-site pre-cast units over the clients originally proposed in-situ poured concrete. This was delivered by carrying out accurate surveys of each individual panel, resulting in significant quality improvements to the construction whilst eliminating many of the environmental hazards associated with in-situ poured concrete on site above the Menai Strait.
Following the success of the ECI phase, Spencer Bridge Engineering were awarded the subsequent construction works as the Principal Contractor to replace 73 concrete footway panels on the approach spans of the bridge.
Each footway panel was dimensionally surveyed accurately from both above and below the panel, utilising specialist rope access techniques. Every panel was custom manufactured off-site and inspected before installation to within +/- 2mm tolerance on width, length and squareness.
An A-frame lifting arrangement was adapted which enabled the replacement of the 1.2T panels in one operation, eliminating the requirement to traverse the frame during lifting operations and allow a panel to be replaced with a single day shift.
A lightweight innovative bespoke debris capture system was provided which slides along the length of the approach spans below footpath level, coinciding with panel replacement operations. The system sealed to the bridge along the length and sides of each panel to contain construction materials.
By the end of March 2021, all 37 panels were replaced on the West footpath with 100% success rate, which is a huge credit to the whole project team.
The A-frame lifting arrangement and carefully thought through methodology hugely improved safety and control of the lifting operations.
As a result of the success of the project and excellent collaboration between the whole project team, the project was recognised by winning the Bridges Management Award at the 2021 Bridge Design & Engineering Awards.
The Bridges Awards celebrate the sheer ingenuity, project management and cooperative skills of the people behind the design, construction and maintenance of pedestrian, highway and rail bridges in the UK.
Kerry Evans (Operations Manager of the A55 DBFO on behalf of UK Highways A55 Ltd) collected the prestigious award for the project which involved a collaborative partnership between UK Highways A55, WSP and Spencer Bridge Engineering.
