Retrofitting to make PH buildings resilient to earthquakes

The Department of Public Works and Highways (DPWH) is see­king a $309.5-million loan from the World Bank to retrofit public health and school buildings in Metro Manila and make them more resilient to earthquakes.

World Bank documents showed the Washington-based multilateral lender’s board is expected to tackle the DPWH-led Philippines Seismic Risk Reduction and Resilience Project on March 18 next year.

This investment project financing from the World Bank will cover the entire cost of the DPWH project, which is aimed at enhan­cing the safety and seismic resilience of selected public buildings in Metro Manila as well as the agency’s capacity to prepare for and respond to emergencies.

In particular, the project will improve public facilities’ multihazard resilience by retrofitting about 425 priority buildings, including schools and health centers, especially amid the COVID-19 pandemic.

The World Bank said the structural upgrades would be “in accordance with the most up-to-date seismic [and wind loading] provisions of the National Structural Code of the Philippines (NSCP)” as of 2015.

“As performance-based design is not currently specified under the NSCP, compliance with the seismic provisions implicitly targets allowing building occupants to safely evacuate the building, thereby significantly reducing fatalities and severe casualties (but not guaranteeing that the building will be usable immediately after an event),” the World Bank said.

According to the World Bank, compliance with the seismic provisions was expected to substantially reduce but not entirely eliminate the expected damage “in the event of the design earthquake, which is within the range of Intensity 8 (associated with ‘The Big One’ scenario) on the Modified Mercalli Intensity scale.”

“The major benefits of retrofitting therefore include (but are not limited to) reduction in building damage and potential casualties. An ancillary benefit of the scaled-up retrofitting activities under this subcomponent is the provision of higher-skilled, labor-intensive jobs in the short to medium term, thereby building more broad-based capacity for retrofitting in the national construction industry,” the World Bank added.

The World Bank noted that Metro Manila was highly exposed to earthquake hazards, combined with the vulnerability of buildings and infrastructure, leading to very high risk of loss of life, direct damage and economic losses—for instance, The Big One scenario of a 7.2- magnitude earthquake along the West Valley Fault could result in about 48,000 fatalities and $48 billion in economic losses. —Ben O. de Vera