DPWH-6 says defective design caused flyover to sink

By Joseph Bernard A. Marzan

The Department of Public Works and Highways (DPWH)-Western Visayas’ regional director on Tuesday admitted outright that the design of the ₱680 million Ungka Flyover was defective, a problem he blamed on the firm contracted by the department to draw the structure’s design.

DPWH-WV officer-in-charge Engr. Sanny Boy Oropel presented the flyover’s situation in a press conference hosted by the regional office.

Oropel pointed to two factors as bases for his pronouncement, including the shallow depth of the bored piles at Piers 4, 5, and 6, as well as the undervalued cost of the flyover’s construction.

Minimal displacement had been observed in Piers 4 and 5, while there was a more significant displacement in Pier 6, according to Oropel.

“When we look at the actual [flyover], we can see that there was sagging. The ramp is a bit imperfect because it sagged along Pier 6. So, there is [displacement along] Spans 4 to 5, 5 to 6, and 6 to 7,” he explained.

TOO CHEAP?

As to the alleged undervaluing of the flyover’s cost, this was based on the department’s usual spending on two-lane bridge construction projects, which was valued at ₱1 million per linear meter.

The Ungka Flyover, a four-lane flyover, is 743.30 linear meters long, including its approaches at its two namesake barangays in Iloilo City and neighboring Pavia town.

“The total amount released was only at ₱540.28 million, considering that this is a four-lane flyover. This is a very minimal budget for this kind of flyover. The budget for a conventional bridge will always come up to almost ₱1 million per linear meter. The Ungka Flyover is only ₱540 million for 4 lanes,” Oropel said.

Who is to blame? The director pinned the blame on United Technologies Consolidated Partnership, which was contracted by the DPWH’s Bureau of Design for the detailed engineering design (DED) for the flyover.

“The big discrepancy in the budget is because the design of the UTCP is defective. Nonetheless, the UTCP is the one at fault here. We (DPWH-WV) had nothing to do with the implementation, we had nothing to do with the supervision, because we are only religiously implementing the plans that were [done] by the UTCP,” he said.

“Since this was commissioned by the DPWH to present and decide on whatever [DED] that [the UTCP] can provide, we just deemed that as submitted because they were the consultant, and we did not doubt their product. It was only at the later part of project implementation, that when we halted [access to the flyover] to traffic, we saw the displacement. Had there been no displacement, we wouldn’t have seen it,” he added.

Oropel said that DPWH Secretary Manuel Bonoan’s decision to procure the services of a third-party firm to conduct a geotechnical investigation into the displacement was done after the latter personally confirmed the detected design defects.

CORRECTIONS

Oropel said that they would be preparing the DED of the rectification works, which would include the installation of four additional bored piles around Piers 4, 5, and 6, with the deepest at 47 meters.

A footing or shoe will also be added at the base of the three piers which manifested the deepest displacement or sinking at more than 1 foot each.

The additional bored piles and footing will serve as wedges (kalso) that will stabilize the foundations and prevent them from further sinking.

As to the 13 other piers, DPWH-6 intends to apply intense jet grouting and installation of two more abutments to stabilize the soil layer beneath the structure.

Jet grouting entails the injection of concrete material beneath the piers to stabilize the soil underneath and prevent further displacement.

But Oropel was mum on how much would be spent on the rectification works due to continued detailed estimates.

Structural engineer Adam Abinales, head of the firm that the DPWH contracted for the probe, said in May 2023 that civil works alone for rectification, are valued at around ₱250 million.

Bonoan also told the House of Representatives during a hearing on its 2024 budget that the works on the flyover may cost around ₱200 million, but Oropel clarified that this is just an estimate that might increase or decrease.