QCOSTARICA — Failure to heed to recommendations by the Laboratorio Nacional de Materiales y Modelos Estructurales (Lanamme) of the University of Costa Rica (UCR), is mostly likely the reason for the failure of the pedestriation bridge over the Circunvalacion in the area of the parque La Paz, that today is in its third day of complete closure of that section of the ring road.
Experts at the Lanamme filed a report in 2022 of the poor condition of the bridge that was built some 35 years ago, that is the Consejo Nacional de Vialidad (Conavi) – the National Road Council – knew since May 2022 but did nothing about it.
Initially, the Ministerio de Obras Públicas y Transportes (MOPT) – Ministry of Public Works and Transportation, parent arm of the Conavi – attributed the situation to a heavy vehicle that had hit the structure Monday night.
The bridge was closed Monday night. However, officials were quick to point out the bridge’s cable failure was due to corrosion and not the impact of the truck.
“The cable failed due to corrosion, causing the bridge to lose its structural capacity and the bridge will be removed and the cables cut,” confirmed Mauricio Batalla, executive director of the National Road Council (Conavi).
Batalla explained that the bridge has to be completeley to avoid putting users (pedestrians and vehicular traffic below) at risk.
In a statement to legislators last year, paraphrasin Batalla: all bridges can fall as long as they do not fall on anyone … everytime the phone rings I cringe that there hasn’t been a fatallity!
“The bridge will be removed and the cables cut,” Batalla said in a statement on Tuesday.
The MECO company (whose owner is under investigation in the Conavi corruption case), road conservation contracts for this site, is being tasked with the removal of the structure.
The site is completely closed off to vehicular traffic and will remain so until the bridge is removed, which is expected to be done before next Monday (January 8), when traffic in the greater metropolitan area returns to normal.
The Conavi knew
The report by the Lanamme (EIC-Lanamme-INF-0634-2022), published on May 19, 2022, warned of an alarming state of components such as the concrete slab and the main cables, the cables that party snapped on Monday.
“There are fractures in the cable protection ducts and visible surface corrosion of cables that can affect the structural integrity of the bridge,” the Lanamme cited in that report.
On that occasion, an alarming state of the cable stays was also noted, with corrosion with loss of section in the bar-clamp connection of a stay on the east cable of the bridge, which could compromise the structural integrity of the superstructure.
Julián Trejos, Lanamme engineer and coordinator of the laboratory’s Bridges Unit, explained this Tuesday, January 2, that the report that warned about the deterioration was sent in May 2022 to Conavi.
“A series of interventions were determined that should have been carried out in order to safeguard the lives of users and the integrity of the bridge. In addition to the report prepared by Conavi, they prepared a budget indicating the cost of the intervention. Finally, the Ombudsman’s Office, in August 2023, asked the executive director of Conavi (Batalla) for a list of the activities that had been carried out on the bridge in order to safeguard the lives of users,” Trejos cited.
In May 2022, Lanamme recommended that the MOPT, Conavi and the Costa Rican Sports Institute (Icoder) – the agency that manages the park divided by the Circunvalacion and connected by way of the pedestraion bridge – take actions to prevent the advancement of the observed deficiencies.
“The recommendations are divided into actions to be carried out in the short and medium term, for each element evaluated in this report,” the document indicated.
Among the recommendations made almost two years ago:
- Remove obstructions in the expansion joints of the bridge and, subsequently, seal the expansion joints.
- As a temporary measure, seal the cracks in the board in order to prevent rust and corrosion in the reinforcing steel of the concrete slab.
- Carry out a detailed inspection to determine the general condition of the main cables and the protection duct of superstructure No. 2, in order to define the necessary care measures for the conservation or improvement program.
- Perform a detailed inspection to determine the severity and extent of corrosion of the reinforcing steel in the beams and columns of towers #1 and #2.
- Protect the connections of the tie rods of the No. 2 superstructure that show corrosion or damage to the corrosion protection system, applying an appropriate paint system. If necessary, the original thickness of the anchors and jaws of the tie rods that show corrosion with loss of section must be restored.
Detour
Traveling from west to east, traffic is being diverted at the Rotonda de Paso Ancho (Guacamaya); from east to west, traffic is being diverted at the Rotonda de la Y Griega. To avoid being caught in the nightmare congestion, which is light this week, is best to avoid the area entirely and plan out a new route.
