Betar

Rehabilitation of Dam Bridge over Mondego River

• Location: Coimbra, Portugal
• Solution: Bridges, Asset Management
• Type: Road bridges, Rehabilitation
• Promoter: Infraestruturas de Portugal SA (ex Estradas de Portugal, EPE)
• Client: Infraestruturas de Portugal SA (ex Estradas de Portugal, EPE)
• Scope: Reinforcement and Rehabilitation Design, Inspection, Safety Assessment, Geometric Surveying, Anomaly Mapping, Materials Testing and Geotechnical Study
• Area: 34 000 m2 deck surface
• Project: 2009/ 2010
• Construction: 2011/ 2012
• Contractor: OBRECOL – Obras e Construção S.A.
• Dimension: 3km long
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The Dam Bridge in Coimbra town is located on the Mondego river bed and connects the areas of Bencanta to the beginning of Choupal area.
As part of the Mondego hydric project, where the Aguieira hydroelectric dam was included, this dam was design in 1978 and allowed the creation of a permanent water mirror in front of the city's downtown.

Inaugurated in 1981, this complex structure also included a bridge, built over the dam, and its access viaducts.
In the beginning of the 1990s, the right bank viaduct went through extension works along Fernão de Magalhães Avenue and an access viaduct to Santa Clara.

The infrastructure has a total extension of about 3km.

The deck structural solution is a pre-stressed reinforced concrete slab directly supported on circular piers. The piers top extremity widens forming a paraboloid that supports the slab.

Considering the conservation state of the structure, Estradas de Portugal launched a tender for a rehabilitation and reinforcement project, including the structural assessment accordingly with the updated legislation.

In the study phase, Betar performed several complementary activities and studies in order to support the design project, namely: Inspection, Foundations Inspection, Geological-Geotechnical investigations, dimensional survey, deck leveling survey, materials testing and detailed inspection including defect mapping.

Due to the importance of this bridge within the city's roadway system there was a need to implement a complex road bypass project, executed in several phases during construction.

The main activities were the strengthening or full replacement of piers, the Bencanta abutment foundation strengthening with jet-grouting columns, and the introduction of backstop elements on the branches abutment viaducts for seismic strengthening.