Kier Infrastructure - Mersey Gateway
Project - Mersey Gateway
Sector - Health
Technology - Concrete
Company - Kier Infrastructure
Winner of 2018 Offsite Awards - Infrastructure Project of the Year
Opened in October 2017, Mersey Gateway involved the construction of a new six-lane bridge over the River Mersey, with upgrades to 9km of adjoining road. It took three and a half years to build and it is expected that 20 million vehicles a year will use the new bridge. The Merseylink Civil Contractors joint venture comprised Kier, Samsung C&T and FCC Construcción. A key feature in the delivery of the Mersey Gateway scheme was the approach taken by the team to design and construction, resulting in £250m savings in procurement. Environmental benefits included making 1,423,250 tonnes of contaminated soil made acceptable for re-use.
Mersey Gateway significant offsite elements
Ditton Junction: A two-span bridge with 16 precast beams, each weighing 47 tonnes, and 174 precast concrete piles for the foundation.
Freight Line Bridge: A 99m-long skew bridge spanning a double-track freight line, designed as a precast concrete tunnel, 99.4 metres long and 14.5 metres wide. It comprises 112 base walls and 56 roof units, with the biggest unit weighing 51 tonnes. The precast portal vault units were stitched together on site with in-situ concrete to allow them to deal with uneven loading imposed by the skewed crossing.
Widnes Loops Viaduct: A high-level road crossing comprising 8 precast, pre-stressed 'W' concrete beams, measuring 31 metres and weighing 65 tonnes. These are supported on reinforced concrete abutments and piers founded on precast piles.
Trestle Access Bridge: A 1km long temporary trestle bridge across the river, built as a platform for the main Mersey Gateway Bridge construction work. The pre-assembled steel deck was topped with precast concrete planks.
Mersey Gate Bridge (MGB): The first continuous concrete cable stayed bridge with three pylons in Europe. The six-lane, 1km-long bridge is constructed almost exclusively using concrete technology. The slender mono-pylons are the most visually prominent element of the bridge and comprise preassembled reinforcement cages. Fabricated steel anchor boxes within the top half of the upper pylons provide anchorages for the stays.
Bridgewater Junction: Part of the new 9.2km link road, diverting traffic across MGB to relieve congestion.156 precast beams were placed between 24 bridge piers to create the base of the highway, each 40m long and weighing 106 tonnes.
Lodge Lane Junction: A preassembled structural steel bow-string arch footbridge, spanning 7 lanes of traffic.
Clifton Road Bridge: 6 precast concrete staircase units weighing 32 tonnes each.
M56 Junction 12: A re-modelled junction featuring precast concrete panels used to for the earth-retaining walls.