Mersey Gateway’s award for Outstanding Structure
THE Mersey Gateway Bridge has been given an award. The crossing between Runcorn and Widnes has been given the IABSE Outstanding Structure Award for 2019.
It was described by the judges as ‘ an elegantly integrated solution for a multispan concrete cable stay bridge in which form follows function’.
The IABSE Outstanding Structure Award recognises the most remarkable, innovative, creative, or otherwise stimulating structures.
Sustainability and respect of the environment is also an important factor.
COWI’s Paul Sanders, also project director for the design joint venture, said: “Everyone involved with the design and construction the Mersey Gateway Bridge over the past six years knows that this is an incredibly special structure.
“But to have this officially recognised with such a prestigious award from IABSE, especially given the fierce competition from around the globe, is incredible.
“I’m extremely proud of the role our team played in designing and delivering this outstanding project.”
The unique three-pylon cable-stayed bridge has pylons up to 125m high and is 2.250km long with a 1km long cable supported section.
The main bridge deck is constructed from re-stressed and
● reinforced concrete suspended from the pylons via high strength steel cable stays.
The decks of the approach viaducts were constructed using two 1,700 tonne, 157m long self-propelled launching gantries (movable scaffolding systems) enabling rapid and safe construction of a complete 70m long span in a single pour.
On the cable-stayed bridge, six smaller gantries (form travellers) were used to cast the deck in 6m long segments in a typical cycle of just five days.
The design for the bridge was selected from a wide range of options to maximise benefits for users and the local community while minimising the environmental impact on the estuary and its surrounding environment.
The scheme was officially opened by Her Majesty The Queen and the Duchess Of Sussex in June 2018, at the culmination of three-and-a-half years of construction work.
The six-lane toll bridge over the Mersey is part of a bigger project delivering a new and improved 9.2km long link road connecting the national motorway network in north Cheshire with Merseyside.
Designed for rapid construction and minimal maintenance, the highlights of the scheme include a 3km long elevated route, including a 1,000m long cable stayed bridge, 12 new highway bridges and seven new or upgraded junctions along the route through Runcorn and Widnes.
The main crossing over the Mersey required a range of foundation solutions incorporating shallow and deep foundations, while the approach highways dealt with a number of significant challenges arising from ground conditions and historic land use.
Currently up to 76,000 vehicles cross the bridge per day, and average vehicle speeds of 58mph demonstrate improvements in journey time, with savings across the route typically in the order of 20 minutes or more.