Sizewell C – SSSI Bridge Crossings
Suffolk, UK
Project synopsis
Civil, structural and geotechnical detailed design of the SSSI (Site of Special Scientific Interest) Crossings, which enables the construction of Sizewell C project.
Contractor
Atkins Réalis
End client
Sizewell C
Tony Gee is providing civil, structural and geotechnical design of the proposed SSSI Crossings within a multi-disciplinary team to enable the construction of the new Sizewell C (SZC) Nuclear Reactors.
The main scope of work covers the design of the permanent bridge and haul road bridge. The permanent bridge will provide an essential link which will be the long-term primary access to the SZC Power Station during its operation.
The permanent structure is a 15m wide and 30.5m span bridge comprising prestressed pre-cast concrete U-beams acting compositely with an in-situ reinforced concrete deck slab.
The permanent deck provides different functional cross sections;
- one during the construction phase (11m 2-lane carriageway and a 3m footway) in conjunction with the adjacent haul road bridge
- second during the operational phase of Sizewell C (8m 2-lane carriageway and 2no. 3m footways).
The haul road structure, required during construction, has the same span as the permanent structure and the deck is designed to carry a 2-lane 17m wide carriageway and a 5.4m wide dedicated utility corridor for tunnelling and general construction activities. The Haul Road Bridge deck will be removed on completion of the construction of Sizewell C.
Both bridge decks have been designed to carry large abnormal indivisible loads (AIL) to facilitate the construction of the nuclear power station, including the 50m diameter steel Containment Dome Liner which will be carried on SPMTs supported on both decks simultaneously.
The bridge decks are supported on wall-type abutments constructed using modular shells and precast elements to improve the speed of construction.
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