Press release: COWI UK projects Mersey Gateway and Garrion gill join Copenhagen Metro as finalists in the Awards' 10th year.
The GE Awards celebrate the very best projects and companies across the geotechnical profession. COWI is delighted that the judging panel, made up of experts from across the industry, have recognised the engineering excellence of not one, not two, but three COWI projects!
COWI UK sees two projects in the list of finalists - Mersey Gateway Project has been shortlisted in the "UK Project with a value of over £15M" category while Garriongill has been shortlisted in "UK Project with a value of £3M - 15M" category. Copenhagen Metro has also been shortlisted in the "International Project of the Year" category.
All three projects are up against stiff competition in their categories, but the project teams are eager to impress the judges in April when they present their projects. They're all looking forward to the Awards ceremony in June, when they hope their project will be named a winner! We'd love to see a COWI hat trick - and will let you know how each of the projects get on!
Mersey Gateway Project
The Mersey Gateway project provides a new six-lane toll bridge over the river Mersey, and delivers a new and improved 9.2km long link road connecting the national motorway network in north Cheshire with Merseyside. The scheme opened to traffic on 14th October 2017 at the culmination of three and a half years of construction work. Completed on time and under budget, the main crossing provides and iconic and landmark structure.
The Mersey Gateway project relieves the congested and ageing Silver Jubilee Bridge with new and improved link roads, connecting the new bridge to the M56 and the main route towards Liverpool and the M62. In addition to helping eliminate congestion across the borough, the new link road will provide reliable connections for the region and forms part of plans to develop and integrate public transport, cycle and pedestrian links across Halton to improve regional transport links. This aims to encourage new and inward investment, and kick start a major 20-year regeneration programme for Halton.
The highlights of the scheme include a 3km long elevated route, including a 1000m long cable stayed bridge, 12 new highway bridges and 7 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.
COWI was the lead designer within a design joint venture comprising AECOM, Fhecor and Eptisa.
COWI was responsible for the design of the cable stayed bridge superstructure, substructure and foundations for the bridge and the main crossing approach viaducts. The permanent works geotechnical elements of the scheme were delivered across the teams led by COWI and AECOM.
Garrion gill is a 40m high steep (25o to 40o), wooded valley in a rural area near Wishaw in Scotland and is designated as a "Site of Special Scientific Interest" (SSSI) as well as a "Special Area of Conservation" (SAC). Immediately north of the valley runs the West Coast Mainline, a main artery for the railway network from London to Glasgow.
In 2013, a 65m long failure along the crest of the valley was identified and found to be some 500mm deep, adjacent to the railway sleeper ends. Following investigation works, drainage works were carried out on the opposite side of the railway and a monitoring regime installed to allow trains to run while further ground investigations and options studies were carried out. Made ground overlying glacial till with ancient mineworkings below (extending below the railway) were identified.
The final solution treated the shallow coal mineworkings with gravity-fed grouting and formed a rockfill buttress (22,000T) to mitigate soil movements, constructed in 5 stages to allow access for the rigs which advanced inclined holes to the workings. High strength bars were inserted into the grouted treatment holes, effectively providing a grid of micropiles on the slope face to improve the short-term stability of the slope, ensuring the safe construction of the works and operational railway.
During the works, an extensive monitoring regime and action plan was followed, due to the instability of the slope. Works were designed and planned to ensure that plant only trafficked where the mineworkings had been treated.
Garrion gill was delivered under Network Rail's RCDP (Renewals Collaborative Delivery Programme) Contract, with COWI taking on the design role, working with QTS Group.
The successful delivery of Garrion gill was dependant on the whole team working together, including the Client (Network Rail RCDP), Main Contractor (QTS), Designer (COWI) and Sub-Contractor (Cementation Skanska).
Copenhagen Metro Project
The Cityringen project comprises the design and construction of a new metro line in the centre of Copenhagen. The 16.6km long circular line is fully underground and connects 17no. metro stations. The tunnels were constructed using 4 EPB TBMs operating in pairs to form the 4.9m internal diameter twin-bore tunnel constructed via four different tunnel drives.
The project includes 5no. shafts housing; 2no. diamond cross-over, 3no. bifurcations (one combined with one of the cross-overs) a ramp structure connecting the tunnels to the at grade depot and 5no. sump pump caverns. The TBMs were launched and serviced from the ramp structure and two of the shafts.
All 17 stations were constructed using the "cut and cover" method. 16 of the 17 stations were constructed adopting a "semi" bottom up-method, whereby the roof slab was constructed first, before excavating to the base level using temporary propping of the retaining structure. The remaining permanent structure was subsequently constructed from the bottom up. One station was constructed completely top-down method.
The 17 stations, 4 shafts and ramp structure were located in existing open spaces within the city to minimise the impact on the historical city centre. This resulted in only two buildings being demolished for the construction of the project. A further listed building was temporarily moved for the construction of a station and moved back to the original location on top of the completed station structure.
COWI led the CAS Design Joint Venture alongside Arup and Systra for Client, Metroselskabet I/S, which is a partnership, owned jointly by the City of Copenhagen, the Danish Government and the City of Frederiksberg.