ILOILO City – The P680-million Ungka flyover is, in fact, considered quite cost-effective, according to Engr. Sanny Boy Oropel, the officer-in-charge (OIC) of the Department of Public Works and Highways (DPWH) Region 6.
The superstructure, covering 453.70 linear meters (LM) (referring solely to the four-lane bridges, from abutment to abutment, without including the approaches), costs only P540.28 million. This cost is significantly lower than the supposed P1 million per linear meter estimate, he stressed.
“Our standard bridge estimation calculates at P1 million per linear meter for two lanes. So, if the project length is 450 meters, and we double it because there are four lanes, it should be around P900 million to P1 billion. However, the actual cost turned out to be lower,” explained Oropel.
The OIC director pointed out that the reduced cost is attributed to an error in the flyover’s design by the United Technology Consolidated Partnership (UTCP), the company hired by DPWH central office’s Bureau of Design (BOD) for soil testing and structural design development. Specifically, the piers of the flyover were shallower.
The bored piles of piers 4, 5, and 6, where vertical displacement was observed, currently have a depth of only 28 meters. To prevent further movement, an additional rectification, reaching a depth of 47 meters, is required, as recommended by Engr. Adam Abinales of Abinales Associates Engineers + Consultants.
Oropel mentioned that even with an additional P200 million allocated for rectification, the Ungka flyover remains cost-effective.
Removal of 3 Spans Not Included in Rectification Works
Oropel clarified that the removal and replacement of spans in piers 4, 5, and 6 of the Ungka flyover are not part of the budget of at least P200 million set aside for rectification.
“The removal of the superstructure and its replacement are distinct tasks, not covered by the additional funds we are requesting for rectification,” he clarified.
Oropel also confirmed that the contractor, International Builders Corporation, will manage this work and bear the associated costs.
“The decision to remove the structure on top and replace it was reached through consultations between DPWH and the contractor. This will not result in additional expenses,” he stressed.
A copy of the recommendation from third party consulting firm Abinales Associates Engineers + Consultants is already in the possession of DPWH-6. The more feasible scheme suggested involves providing additional bored piles.
* Pros: Group pile capacity will be significantly increased to meet the required load capacity at the pier base.
* Cons: To install additional bored piles, existing prestressed concrete (PSC) girders on coping beams may need to be removed and replaced, if necessary, due to the use of large equipment for drilling and installation.
In addition to extending the depth of bored piles on piers 4, 5, and 6 by 47 meters, the third-party consulting firm also recommended underpinning the existing piers and abutments, including existing bored piles, with intensive jet grouting./PN
