CLOSER LOOK | At least three foundations of the P680-million Ungka flyover have sunk just three months after it was opened to the public. The Department of Public Works and Highways will conduct a soil reinvestigation to determine what caused the problem. (Photo courtesy of AJ PALCULLO / Panay News)
ILOILO CITY, Iloilo, Philippines — The Department of Public Works and Highways (DPWH) is set to conduct a soil reinvestigation to determine what caused the “vertical displacement” or sinking of a newly built P680-million flyover here.
Councilor Ely Estante, in an interview on Tuesday, said members of the Regional Development Council (RDC) headed by the National Economic and Development Authority (Neda) in Western Visayas, recently inspected the Ungka flyover which straddles Pavia town and Iloilo City.
The RDC, he said, found out that the flyover’s foundation was placed on a large bored pile (also called replacement pile) during construction. Estante said the RDC believed that the four-lane flyover’s vertical displacement in three of its foundations might have been caused by ground shaking since it sits near a fault line.
They also discovered that the layers, where the foundations were placed, were thin and that there’s a presence of soft soil layers underneath.
Estante said the RDC recommended reviewing the commitment of the DPWH and the contractor, International Builders Corp., to address the vertical displacement of the structure.
The RDC also issued a resolution urging the DPWH to expedite its recruitment of a third-party firm which will conduct an investigation to find out what caused the flyover to sink.
“The problem here is that since it’s a government process, there must be a bidding process. The panel urged that it be done instead through a negotiated contract considering that it is an emergency,” Estante said.
“The [DPWH] will provide a specific timeline and technical scope of the [third-party] study, which will include audit of the design and implementation, geotechnical investigation and traffic management, among others. It was also included in the investigation of the Aganan flyover [in Pavia],” he added.
Closure
Estante said the DPWH must be able to establish its third-party partner, as well as the timeline soon to prevent further damage to the flyover and risk to the public.
“If this cannot be started, there may be a tendency that [the flyover] would continue to [either] sink, settle, or displace, and would cause more damage. It would be risky to those who would pass by there. Vehicles parking underneath the flyover should also be taken out because it is a hazardous area, and other piers may submerge,” he said.
Estante said the city council would no longer push for further actions as it had been investigating and passing resolutions since the flyover’s issues sprung up.
The 453.7-meter Ungka flyover was partially opened to the public on June 30 this year.
Three months later, on Sept. 6, the structure was fully opened to commuters. But on Sept. 18, the DPWH closed the flyover after motorists complained about the “wavy feel” while driving over it, and amid reports and images of puddles at the top of the flyover during rainy days.
Iloilo City Mayor Jerry Treñas earlier sent a letter to Public Works Secretary Manuel Bonoan to ask what was delaying the repair of the flyover which was constructed in January 2020.
The flyover was funded through the efforts of former Sen. Franklin Drilon.