Contractor helped beat bridge deadline
A LEADING bridge and engineering services specialist helped complete the Mersey Gateway Project ahead of time and below budget.
Mabey was contracted by Merseylink to provide temporary supports for four out of the eight landside sections, which create the approach to the bridge, the largest being the Astmoor and Bridgewater viaduct.
The engineering firm’s role was critical in supporting the bridge loads from the pre-cast concrete beams and cast in situ cast diaphragms onto the permanent concrete piers, using its temporary propping system to transfer the weight. This included developing a unique test rig for every pier arrangement to guarantee it was structurally safe for the heaviest applied loads.
With its team, equipment and technology based just a few miles away in Garswood, Mabey had almost every element of its propping solutions in place at its peak, including the Superprop, Mat125, Mass50, Mass25, System 160, hydraulics, instrumentation equipment, together with other specialist equipment with 65 people working on site at its busiest time.
The company implemented monitoring throughout the construction phase, which helped facilitate the transfer of the bridge loads from the temporary propping system onto the permanent works and ensure even distribution.
The process was monitored by Linear Variable Differential Transformers, a sophisticated piece of technology that monitors ● movement and load.
It allowed Mabey to de-jack the loads with full control and in a synchronised manner.
Mabey UK Hire chief executive Gordon MacDonald said: “Our proactive approach to providing the right resource, labour, engineering and facilities is what has enabled this project to be carried out more quickly, safely and efficiently.
“Working with Merseylink, we quickly identified and overcame design and test loading challenges to keep the project on track.
“As our biggest UK Hire project to date, the opening of the bridge marks an iconic and proud moment in Mabey’s history.”
Nearly 90,000 cubic metres of concrete, the equivalent of 36 Olympic-sized swimming pools, was used to build the bridge, the North Approach Viaduct, and the South Approach Viaduct.
Together they measure almost 2.5km long, and the bridge’s tallest pylon rises 125m above the river.
The bridge opened to the public after three-and-a-half-years of construction.
The six lane toll bridge has been built to relieve traffic and congestion at the existing Silver Jubilee Bridge.
Until this point, more than 80,000 vehicles were using the Silver Jubilee every weekday; 10 times the number it was originally designed to accommodate.
The improved transport link will also enable further regeneration of the Halton area, with easier, quicker access for building and improvement works.
Merseylink’s senior operations manager Jim Rice said: “The Mersey Gateway Project signifies a major step forward in the regeneration of the North West.
“Mabey’s role in this project helped us overcome a number of challenges, such as determining access arrangements and the specific method we would use to install the pre-cast concrete beams and avoid over-stressing the temporary propping system.”