ILOILO City – The Department of Public Works and Highways (DPWH) Region 6 is exploring potential modifications to the design of the ongoing Phase 2 repairs of the P680-million Ungka Flyover in Barangay Ungka II, Pavia, Iloilo.
This phase, which focuses on piers 4, 5, and 6 which have significant settlement issues, has been allocated a budget of P200 million.
DPWH-6 director Engr. Sanny Boy Oropel explained that any design changes would depend on the soil conditions following the jet grouting at all 16 piers.
“The modification might involve reducing the diameter of the additional bored piles at piers 4, 5, and 6, which could shorten the duration of the rectification process,” said Oropel.
The need for possible adjustments arose after observations during the jet grouting process, which is aimed at hardening the soil beneath the piers.
Oropel noted that the soil color changed from red to light green during the process, indicating hardening of the soil and the effectiveness of the jet grouting.
Adam Abinales, managing partner of Abinales Associates Engineers + Consultants, recommended adding additional bored piles to these piers to increase the pile group capacity and meet the demand at the pier base.
This involves removing and possibly replacing existing pre-stressed concrete girders if necessary, due to the use of large equipment for drilling and driving the piles.
“Our geotechnical investigations show that the soil is indeed soft, and despite drilling up to 55 meters deep, we have not reached the hard strata or bedrock,” said Abinales.
He advised the DPWH to remove and replace the superstructure on piers 4, 5, and 6 to allow room for the placement of additional bored piles, which are needed to reach depths of at least 40 meters.
The DPWH-6 will finalize decisions on these modifications after completing the jet grouting of all piers, including the critical piers 4, 5, and 6.
“Everything is very fluid, depending on the result of our jet grouting activity, and we are praying for the best to minimize traffic impact,” Oropel added.
He also clarified that there are no plans to change the design of the superstructure or span overhead, ensuring that the same concrete structure seen by the public will be the one delivered after the repairs, expected by August 30.
The DPWH-6 aims to open bidding for the Phase 2 rectification of the Ungka Flyover this week./PN
