The ministry expects to invest $15 million in the project.
The older span is the one that keeps eroding and exposing its metal structure to traffic. The bridge has been a continual embarrassment for the Óscar Arias Sánchez administration and now for the Laura Chinchilla administration.
Francisco Jiménez Reyes, the minister of Obras Públicas y Transportes, said that two employees are being suspended to face administrative hearings as a result of the bridge dilemma. They are María Ramírez, director of the ministry’s División de Puentes, and Álvaro Ulloa, the engineer who supervised the reconstruction of the bridge.
The problem began in 2009 when the metal covering of an expansion joint became loose. At least three times, the ministry tried to tie down the piece of metal that bounced around every time a vehicle rolled over it. Finally, officials closed the bridge and did a complete overhaul by replacing the metal and concrete bridge deck and the expansion joints. The public and news media quickly named the bridge platina, meaning little plate.
The bridge was closed for weeks after Christmas last year. Within days of reopening the bridge, inspectors noted that the concrete was turning to dust and exposing the rebar underneath. Several times the bridge was closed in the night to put down more concrete.
The ministry never really said what the problem was but unofficial sources say that the bridge flexes too much.
Jiménez put a positive spin on the announcement Wednesday by saying that a new bridge had been planned all along and that the decision to build it now simply speeded up the ministry timetable. The ministry and its Consejo National de Vialidad will seek money for the new bridge from the Banco Centroamericano de Integración Económica in September, Jiménez said.
Officials expect to go to bid before the end of the year. The job is estimated to take 18 months.
The bridge spans the Río Virilla west of San José on the route that leads to Juan Santamaría airport, Alajuela and eventually to Pacific coastal towns.
The ministry also will impanel a committee of experts to oversee the design and construction, it said.
The Laboratorio Nacional de Materiales y Modelos Estructurales of the Universidad de Costa Rica has been involved in assessing the condition of the bridge. Its former director, Jorge Gutiérrez, will serve on the oversight committee.
The ministry is suspending the payment to the contractors who did the latest work on the bridge, it said. The ministry said that there was evidence that the work done after Christmas and into the beginning of this year did not meet specified requirements.
The ministry said that it would seek a specialized firm to plan and execute new strategy for the older bridge so that eventually there will be two bridges of four lanes each over the river. Some 80,000 vehicles a day pass this point.