ILOILO – Undersecretary Roberto R. Bernardo of the Department of Public Works and Highways (DPWH) confirmed that the P802-million Aganan flyover in Barangay Aganan, Pavia town will also undergo geotechnical investigation.
Bernardo said the investigation would determine if the soil underneath the structure is soft, which could consequently cause displacement, such as in the case of the defective P680-million Ungka flyover in the town’s Barangay Ungka II.
“To evaluate din, the same process… baka sa geotechnical [investigation] ay mayroong paglambot ng lupa na hindi natin inaasahan so with need to reinforce likewise,” he said.
Bernardo said DPWH is taking this measure so as not to compromise the safety of motorists and riding public.
“Napaka-importante sapagkat ‘yon ang basihan ng lahat ng mga design, ‘yong geotechnical,” he added.
The undersecretary estimates that around P10 to P15 million is needed for the Aganan flyover’s geotechnical investigation.
There is no chosen consultant for the investigation yet, according to Bernardo, because it will be done through bidding.
DPWH may start preparing the budget next week so that the bidding process can start immediately, he added.
“Ginagawa po namin ang lahat, hindi lamang sa mga taga-Iloilo kundi sa karatig bayan. Asahan po ninyo na gagawin namin lahat at pabilisin eto,” said Bernardo.
Geotechnical investigation, according to trenchlesspedia.com, implies the use of different methods to determine the physical properties of soil and rock below the surface of the earth at a proposed installation site. It helps engineers make decisions regarding the type of tools that will be required to dig through the site most economically. It also assesses the potential environmental impact that a project may have on a particular area.
Geotechnical investigation is an essential step in any trenchless operation because knowledge of subsurface conditions is key to a successful project.
To recall, the DPWH-6 recommended to its central office the use of steel girders instead of concrete for the Aganan flyover.
DPWH-6 assistant director Jose Al Fruto said steel girders will specifically be used for the 50-meter-span intersection part of the flyover.
“The premise is that ang Ungka and Aganan (flyovers) isa lang ang nagplano or nag-design, so gina-upod na lang ang paglantaw kag pag-assess,” Fruto said.
The Ungka flyover, which was closed in September last year two weeks after it opened to traffic, suffers from vertical displacement.
“But we are not saying nga may issue or may deficiency man (in the Aganan flyover),” clarified Fruto.
Both flyovers were planned by DPWH’s Bureau of Design.
Fruto said steel girders are easy to fabricate, and their use would hasten the Aganan flyover’s completion.
“This is an alternative or option just in case…kay looking at it, bug-at gani ang 26 meters (referring to span being supported by problematic piers 4, 5 and 6 of the Ungka flyover), how much more ang 50 meters span. Steel is lighter than concrete, sobra-sobra,” said Fruto.
The concrete girders that are already in place won’t be dismantled, said Fruto.
The Aganan flyover construction started in July 2020 and is supposed to be completed this year./PN
