‘Metro Manila still not ready for a megaquake’

FOLLOWING the massive earthquake that killed more than 3,000 and injured more than 6,000 in Nepal, a Filipino architect and urban planner suggested that all buildings in Metro Manila should undergo structural audit to determine if they can withstand a very strong earthquake.

In an interview with Radyo Inquirer, architect Jun Palafox said there was a strong need for the country “to address the hazards to architecture and urban planning before they become disasters.”

He explained that in case a 7.2-magnitude megaquake hits the metropolis, an estimated 20 percent of the structures would probably collapse.

Citing a 2004 study of the Japan International Cooperation Agency (Jica), Palafox said an estimated 50,000 people would be killed and that Metro Manila would be divided into four since bridges are expected to collapse and roads would be destroyed.

“Ten-hectare evacuation areas should be identified for metro residents and workers,” the architect added.

He, however, noted that 11 years after the Jica study, there are still no concrete ways to address these hazards in case of a strong earthquake.

Structural audit

“There should already be a structural audit on buildings especially government structures,” Palafox said noting that two percent of all tall buildings and 20 to 30 percent of low-rise buildings will collapse in case of a strong quake.

He added that the bridges and structures that have the tendency to collapse should already be marked and identified.

“There are still structures above the fault line. They should already be identified and transferred to safer areas,” added Palafox, noting that addressing the hazards was 90 percent cheaper than rehabilitation.

Emergency plan

As for old buildings, he explained that these should undergo structural retrofitting to reinforce their strength. Ongoing constructions are advised to have their own earthquake analysis before, during and after construction.

“All should have an emergency preparedness plan,” he added.

In 2011, the Metropolitan Manila Development Authority (MMDA) drew an earthquake response plan in preparation for a magnitude 7 earthquake.

Dubbed Oplan Metro Yakal, the response plan identified four possible evacuation areas in Metro Manila in case of a strong quake. These include the Veteran’s golf course in Quezon City, Villamor golf course in Pasay City, the Wack Wack golf course in Mandaluyong City and the Intramuros golf course in Manila.

It divides the metro into the north, south, east and west sectors for easier disaster response.

MMDA chair Francis Tolentino said the response plan was also based on the 2004 joint study of the agency, the Philippine Institute of Volcanology and Seismology and Jica, which showed the country’s vulnerability to strong tremors.

The West Valley Fault which runs across Marikina, Quezon City, Pasig, Makati and Taguig, has moved four times in the last 1,400 years with a major earthquake occurring every 400 years. The last major earthquake took place in 1658 or 357 years ago.