Shinfield Eastern Relief Road (ERR) forms part of a scheme that will relieve congestion in the village of Shinfield in Berkshire, and also provide access to land for development of new housing and a science park for the University of Reading.
The project brief
Ramboll was appointed by HOCHTIEF UK to provide a full range of design services covering highway, bridge, geotechnical and environmental engineering.
The relief road
The relief road is a 1.8km single carriageway that links the A327 Black Boy Roundabout to the A327 Arborfield and Shinfield Roads. In addition to carriageway, junction and roundabout design, the project involves constructing a new dual three lane bridge over the M4.
The new M4 overbridge is an integral single span portal structure, which has a span of 45.05m measured between the centrelines of the abutments, and a clear span between the reinforced earth faces of 41.9m.
The superstructure comprises of a constant depth weathering steel longitudinal girders acting compositely with a transverse spanning reinforced concrete deck slab. The substructure comprises of a piled foundation, terminating in a capping beam, from which reinforced concrete columns are constructed. The columns are made integral with the deck through the construction of a bankseat abutment that also forms a diaphragm at the ends of the composite deck.
The abutment is a reinforced earth structure isolated from the bridge columns by the installation of precast concrete rings. The reinforced earth structures are constructed from a proprietary system of reinforced concrete panels and metal straps.
Through initial design workshops and value engineering, project savings were made in the layout and size of girders, the extent of pile caps and a reduction in the need for trial pile load testing.
In addition to the above services, Ramboll engaged David Huskisson Associates for Landscaping services and Peter Brett Associates for road safety audits and signals design. Ramboll UK Legal team were also involved in assisting with the wording of designers’ deed of warranty between Highways England, University of Reading, HOCHTIEF and Ramboll.