All the design work was undertaken by Cheshire Engineering Service, Structures Division with construction by Forkers Civil Engineering Ltd as part of Bellway Homes Kingsley Fields housing development.
Download a plan of the Sir Thomas Fairfax Bridge.
The three span structure features a 16 metre skewed elliptical arch centre span with two 3 metre side spans constructed using pre cast reinforced concrete units, faced with a rustic brick to give the bridge a much older appearance. This has been specifically designed to blend in with its semi-rural location and the existing buildings in the historic market town of Nantwich. The bridge carries the new re-routed A534 into the centre of Nantwich spanning the River Weaver.
The construction process benefited greatly from the use of one piece pre-cast units, foamed lightweight concrete infill and Lenton couplers for all reinforcement interfaces. The waterway was never obstructed and a safer working environment was created because extensive temporary works were not required. Overall deadweight was reduced by 15% and the Lenton couplers further enhanced buildability and safety by removing the need to have reinforcement protruding into the works.
An environmental audit was undertaken and riverbank ledges were included to accommodate otters and other mammals. The pedestrian walkways are also designed to act as overflow channels for the river if exceptional floods should occur. The structure, which is to be adopted by Cheshire County Council, will benefit from the very low whole life costs due to the low maintenance required by arch bridges.
The bridge is named after a famous northern soldier Sir Thomas Fairfax who led the victorious parliamentarian forces at the battle of Nantwich in January 1644. The completed structure has been very well received locally and by the Client.
The 1500 tonne structure is founded on 80 No 750 mm diameter 12.5 to 18.5 metre deep in situ concrete piles supporting 2 No 520 tonne reinforced concrete bases. 17 No pre cast reinforced concrete elliptical arch units were then placed on the bases with 2 brick faced side spandrel units, each weighing 34 tonnes, completing the 16 metre 12 degree skewed central span. The side arches comprise of 13 pre cast arch units on top of in situ sidewalls cast on the bases. They are also finished with 2 brick faced spandrel units. The parapet walls are also pre cast with the wing walls being cast in situ. Throughout the bridge the arch faces, stringcourses and parapet copings are constructed in a 'mock sandstone' finish sandblasted coloured concrete. All the pre cast units were constructed to a very high standard by Macrete in Belfast. The lighting is to a mock Victorian style.
Dave Weir, Principal Engineer (01244 973686 email@example.com)