Facilitating fine-tuning of Manchester motorway bridge bearings

Barton Bridge, Manchester

Project Overview

Location	Barton Bridge, Manchester
Sector	Highways
Products	Monitoring Propping & Jacking

When differential settlement was detected between the piers to a busy motorway bridge in Manchester, we were called upon to assist with adjustments to the bridge bearings, involving levels of precision rarely seen, as well as continuous monitoring of the micro-millimetre increments to the jacking procedure.

The challenge

Movement beyond design tolerances

Monitoring revealed that differential movement at Barton High Level Bridge had reached, and in some cases exceeded, design limits. This placed the structure among National Highways’ highest-risk assets, triggering the need for intervention.

Precision jacking and realignment

A jacking scheme was required to lift the bridge deck, reintroduce tolerances and realign bearings using additional shims. The works demanded precise control and monitoring, with movements measured in fractions of a millimetre.

Early contractor involvement

Working under the National Highways framework, we supported Balvac through early contractor involvement. This included advising alongside Amey on monitoring equipment and temporary works requirements during pre-contract planning.

Our solution

The real-time monitoring consisted of 14 linear displacement transducers which were used to ensure that the bridge was kept within tolerance throughout the works. A total of 85 No strain gauges were installed on each side of the structure to measure the stresses created during the jacking works. 13 No Strain gauges were installed on top of the concrete bridge deck; these were installed through holes which were cored in the tarmac to allow access to the concrete. Underneath the deck, 40 No Tri-Axial gauges were used to monitor the stresses in the main steel beams. Arrays of 10 were installed on both the internal and external faces of the beams. A further 32 No linear strain gauges were used to monitor the stresses in the cross bracing between the outer and inner longitudinal beams.

View Applications

Both the ambient and steel temperatures were recorded in order to correlate the movements due to thermal effect. All data was transmitted back to Insite, our web portal for round the clock visibility while alert thresholds were set to automatically notify of any breaches in movement levels to ensure that the bridge remained within safe working limits. One of the challenges with the project was that the motorway had to remain live throughout the works. In order to lift the bridge, bespoke high-pressure jacks were required because of the limited space available while, due to regular expansion and contraction of the deck, bespoke temporary bearings were designed and installed to allow for the normal articulation of the structure.

Get in touch

“Mabey Hire played an important role in the effective planning and delivery of these works. They used their experience to help plan around key project risks, and the level of support during the work was extremely professional, and well-aligned to our target of achieving technical excellence through a ‘right first time’ approach.”

Andrew Higson

Contract Manager at Balvac