Statically Indeterminated Bridges
Product Description
- These bridges feature joints on supports, achieving continuous lengthwise action.
- Innovation in prefabrication techniques in the early 90s.
Main Characteristics
- Connections between beams made of post-tensioned high strength steel bars and subsequently injecting mortar grout in the joint.
- Longer span lengths with smaller depths are covered by a continuous deck.
- Solutions using box girders and U-beams provide the deck with the advantages of closed sections and facilitate the implementation of the joints within them.
Types Of Structures Where It Can Be Used
- Used in straight and curved bridges.
- Thanks to the pier continuity, solutions with single supports per pier can be made when box girders are used.
- They are used in solutions with variable depth (parabolic and straight) and constant depth.
- Used in statically indeterminate solutions in building construction when slabs bear heavy loads.
Main Applications
- They improve the dynamic behaviour of rail bridges.
- In bridges with statically indeterminate solutions for high speed railways, span lengths of up to 40 metres are covered.
- If halved supports or temporary shorings are used for joints between beams, span lengths of up to 80 metres can be reached for road bridge decks.
Advantages
- In decks with heavy loads, very rigid deck solutions are achieved, observing the minimum depth.
- The lack of joints between beams considerably improves the aesthetics of the deck and the comfort when passing over.
- The contribution of the negative moment on the pier makes it possible to transform the beam load to a positive moment in decks with heavy load requirements, allowing for wider span lengths and reduced depths.
- There is less vertical movement, and deflection and dynamic effects are reduced.
Construction Details
- Span lengths between supports ranging from 25 to 45 metres if the joints between beams are on pier, and longer if joints are half-lap.
- Enables a single support solution to be applied on box girder piers.
Projects that have applied them