EAST LINK TOLL BRIDGE AT RINGSEND - DUBLIN
This five span reinforced concrete bridge structure and linking approach road was constructed over the River Liffey in Dublin Port. The central span is of the bascule opening type, bridging a 31 metre navigational channel over part of the river.
The abutments and control pier are founded on 305mm x 305mm H-piles whilst the intermediate river piers are founded on 800mm dia. tubular piles which are encased in concrete.
Construction of the control pier and the south abutment necessitated the provision of a coffer¬dam. The control pier cofferdam was approximately 27m x 16m in plan using 17m long Larsen 4/20 sheet piles. Formation level was approximately 10m below H.W. and the bracing system comprised of a steel frame at low water and a concrete plug at formation level.
The north abutment cofferdam was similar utilising lighter sheet piling over a plan area of 18m x 16m.
Both cofferdams were designed in-¬house.
The bridge is a combination of concrete and steel. Precast and prefabrication were major features of the design both for simplicity of construction and early completion
The fixed spans utilised precast concrete decking and the opening span used high yield steel with an orthotropic deck system.
The total project comprised: Construction of roundabouts on the north and south to link into the existing street network, a 60 metre approach embankment, a 150 metre bridge with four 26 metre fixed spans and a 31 metre opening span, a 6-lane Toll Plaza with an operations building and a 1.5 kilometre southern approach road.
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