DPWH mulls another technique to stabilize sinking Iloilo flyover

Aganan Flyover in Pavia, Iloilo

ILOILO CITY, Philippines — The Department of Public Works and Highways (DPWH) is considering applying another method to stabilize the soil under the unfinished P802-million flyover in Barangay Aganan, Pavia town, Iloilo.

Sanny Boy Oropel, DPWH Western Visayas regional director, said they might recommend a jet grouting method for the 436.90-meter Aganan flyover if geotechnical study would confirm stability problems similar to those of the controversial Ungka flyover in Iloilo.

The P680-million Ungka flyover, a separate project with its own set of challenges, was opened to the public in June 2022 but was closed in September of the same year after it started sinking. While the Ungka flyover has been partially opened since late last year, the Aganan flyover is yet to be finished.

READ: Before Iloilo flyover work resumes, DPWH-6 wants 3rd-party probe

According to Oropel, jet grouting is a ground improvement technique that involves injecting high-pressure jets of grout into the soil to create columns of solidified material.

This method enhances the soil’s load-bearing capacity, reduces permeability, and mitigates hazards associated with unstable ground.

Additional funding

“We need a [third-party]consultant to really determine the status of the Aganan [flyover]. A consultant will help referee and provide an unbiased perspective,” Oropel said.

Work on the Aganan flyover was halted in December 2022 due to concerns about soil stability.

The DPWH-Western Visayas have requested its central office for additional funding of between P10 million and P15 million for a third-party investigation into the Aganan flyover’s structural issues.

The regional office had previously conducted confirmatory and seismic testing of the flyover area’s soil which revealed that the necessary depth to reach stable soil was actually 43.50 meters, deeper than the 28.50 m provided in the architectural design by the United Technologies Consolidated Partnership, the firm contracted by the DPWH Bureau of Design for the Aganan flyover.

Oropel said the use of jet grouting is currently underway at the Ungka flyover, which has suffered vertical displacement due to the soft soil it stands on.

He said similar measures might be necessary for the Aganan flyover if the geotechnical study reveals comparable soil conditions.

Aware of the issues with the Ungka flyover, Oropel expected that the Aganan flyover might face similar challenges due to their proximity and alignment.