Established in 1968, the Structural Awards are the world’s leading awards for structural engineering excellence.
Rose Fitzgerald Kennedy bridge
| STRUCTURAL DESIGNER|
Arup and Carlos Fernandez Casado S.L.
| CLIENT NAME|
Transport Infrastructure Ireland
| CLIENT NAME|
Transport Infrastructure Ireland
| ROAD SAFETY AUDITOR|
Wexford and Kilkenny, Ireland
| THIRD PARTY CHECKER|
Eptisa and Siegrist y Moreno Engineering Ltd.
BAM Civil Ltd. & Dragados Ireland Ltd
Flynn Furney Environmental Consultants
|CONCEPT DESIGN AND AESTHETICS|
Mott MacDonald and Ron Yee
Carlos Fernández Casado S.L. are proud to receive this award and we want to thanks The Institution of Structural Enginners for it and we want to congratulate ARUP and our own team for the excellent work they have done and how important awards they are getting. In addition, the Bridge has been awarded this year with the IABSE Outstanding Structure Award of 2021.
Judge’s comment:The 887m long, nine-span, three-tower extradosed concrete bridge rises 36m over the water to provide navigational clearance for access to the Port of New Ross. The structure is impressive in scale and slenderness. It holds multiple records, including the longest bridge in Ireland, the longest concrete extradosed spans in the world and, during construction, the longest balanced cantilever for concrete deck extradosed bridges in the world.
To reduce materials required, high strength concrete was used, and precast panels were introduced on the cantilevers to minimise the cross-section weight. A long service life is ensured through careful detailing and specification of materials with provision for structural health monitoring systems and maintenance.
State of the art structural analysis tools, such as explicit time dependent creep curves and step-by-step non-linear iterative analysis, were used during the complex construction. The result is a highly optimised structural design and statement piece of engineering.
Miguel Ángel Astiz, Scientific Director of CFC and the CFC Manager for the New Ross bridge highlights the enormous satisfaction that the award brings to the entire team, for which a slender and beautiful resistant structure is one of the main objectives in all their designs.
The Rose Fitzgerald Kennedy Bridge over the Barrow River is located near the city of Dunganstown, the ancestral farm of former United States President John F. Kennedy and is named after Kennedy’s mother, Rose Fitzgerald Kennedy, whose ancestors came to this area.
This three-tower extradosed bridge has two main spans of 230m each, the longest post-tensioned all concrete extradosed spans in the world. While there are longer spans in extradosed bridges, they all take advantage of a lighter steel composite section in the central part of the main span. The structure is part of the N25 New Ross Bypass project, which strengthens regional connectivity as well as local connections between the communities of Wexford, Kilkenny and Waterford in the south east of Ireland. At the location of the crossing, the River Barrow is 300m wide and is surrounded by a landscape of gently rolling hills.
This modern, 21st century landmark has been designed to be sympathetic and complementary to its surroundings and environment, enhancing the quality of life in New Ross town which was previously subjected to frequent traffic congestion. The structure was conceived during the planning stage as a three-tower extradosed bridge with a central tower higher than the lateral towers. Proportioned to the golden ratio in height and span distribution, with a truly shallow (less than 15 degrees) cable arrangement in a harp configuration, the bridge represents a formidable structural design and construction challenge.
Three towers following an asymmetrical configuration give the bridge a unique profile, with a shallow single central plane cable system in a pure extradosed structural system. The Rose Fitzgerald Kennedy Bridge has two main spans of 230m each which are the longest post- tensioned all concrete extradosed spans in the world to date. Despite the main span lengths, the towers are only 27m and 16m in height, while a deck slenderness of L/65 at the central section and L/35 and L/27 over the lateral and central towers was achieved. The structure comprises a single central plane of cables supporting a dual carriageway, leading to a 21.9m deck width.
The deck is slender, with a 3.5m deep section (span/65) at midspan, 8.5m over the central tower (span/27) and 6.5m over the side towers (span/35). The tower height limits, with the central tower rising 27.0m above the deck level and the lateral towers 16.2m, result in all cables following the conventional extradosed harp arrangement with minimal spacing in the pylon (1m) and a shallow angle with the deck, which varies from 9 to 11 degrees due to the longitudinal slope of the deck.