Role of UNOPS

Implementing agency responsible for the contracting, auditing, and approval of preliminary studies (topography, geotechnics, hydrology, and EIA), support in the management of public services relocation, execution of constructive designs, construction, and supervision of the work. It conducts the project's social management and strengthens the capabilities of the Executing Unit CONAVI-CABEI.

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General features of the project

The work has a total length of action of 681 meters, which includes:

• Old bridge (285.65 meters long).

• The approach sections on both ends (Tibás to the south and Santo Domingo to the north) measure 80 m and 316 m respectively.

The new section of the bridge will have 3 lanes (currently has 2) with a length of 285 m, and a width of 13.1 m (currently it is 10.9 m) (it does not have a pedestrian path due to capacity limitations, however, the new bridge already includes a pedestrian solution following the law). It has a structure comprising 7 spans, 3 cantilever spans, and 4 spans made of precast beams.

The intervention will allow the work to increase its traffic capacity, comply with the seismic-resistant design standards for bridges (national and international), and increase its useful life, in addition to repairing defects identified to date in structures and accessories.

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Details of the construction process

• The project will take advantage of the temporary access paths built for the recently completed new bridge, which represent savings of up to USD 2 million in the intervention.

• Additional access sections to the old bridge's piers will be constructed.

• The foundations of all the piers (7 in total) will be reinforced, by increasing the section and applying post-tensioning.

• The piers will be reinforced with anchors and an increase in thickness with concrete.

• In the area of the cantilever deck, cracks, and defects will be repaired, and it will be reinforced with carbon fiber throughout the internal section and with reinforcement strips in the internal section, significantly increasing its structural capacity.

• In the areas of the deck with precast beams, the existing beams will be demolished to place new beams with structural capacity according to current regulations.

• All supports will be replaced.

• The intermediate joints on the bridge will be removed, and new, modern joints will be placed at the ends.

• New bastions will be built at the ends of the bridge with foundations made of piles.

• Drainages will be constructed on the bridge to allow proper evacuation of water from the platform.

• Anti-carbonation paint will be applied to the concrete surfaces to increase durability.

• Instrumentation will be placed to monitor the area and new bridge during the rehabilitation activities, similarly to how the old bridge was monitored during the construction of the new bridge.

• Safety barriers to prevent falls will be installed, similar to those placed on the new bridge, which have drastically reduced incidents with people on the site.

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Benefits

The construction of the project will increase the traffic capacity of the section to be intervened, alleviating congestion in the Heredia - San José direction, through which more than 25,000 vehicles pass daily, many of which correspond to the transport of imports and exports to the Caribbean port. The rehabilitation of a highly important road asset that is currently at high risk of seismic vulnerability will be guaranteed, with considerable defects in joints, barriers, concrete elements, and drainage systems.

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Current Status

The review and certification of the design at both national and international levels have been completed, and the Terms of Reference and Technical File have been prepared and approved, which will enable the preparation of the tender documents for the construction of the works.