When the wind blows and the ground shakes

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FROM THE ARCHIVES: In light of the recent earthquakes that rocked the country in April 2019, BusinessWorld is republishing this story on the structural integrity of buildings. Written in the wake of typhoon Yolanda and the earthquake that shook Bohol and Cebu, the story first ran on November 29, 2013. — Ed.

November 29, 2013
WEEKENDER
By Joseph L. Garcia

It looked like no stone, stick, or structure was left unturned in Tacloban in the wake of typhoon Yolanda (international name: Haiyan). Just a month before Yolanda crossed the Visayas, a massive earthquake shook Bohol and Cebu, crumbling houses, heritage churches, even one of the famous Chocolate Hills.

In the wake of the super typhoon and the massive earthquake, how can the Philippines—cities in particular—prepare for another double whammy? “We have to revise, review, and upgrade our building and structural codes,” said Felino Palafox, Jr., Principal Architect, Founder, and managing partner of Palafox Associates, a Manila-based architectural firm cited in the Top 500 Architectural Firms in World Architecture Magazine.

“The super typhoon Yolanda moved [at a rate of] 321 kph. The minimum requirement for wind speed [resistance] in that part of our country is only 250 kph. [Buildings there] were not designed for that type of typhoon,” he said.

Architect Michael de Castro, an Operations Manager and Senior Architect from Palafox Associates, agrees. “The building code is from the ’70s, and it’s antiquated. We need to revise it based on our technology and methods of construction.”

“I have given the president a list of recommendations for Metro Manila and other urban areas,” said Mr. Palafox.

The list, sent to Malacanang in 2010, carries a message that communities have been developed with a lack of urban planning, architecture and engineering considerations, especially in light of the frequent disasters in the country, in addition to the global phenomenon of climate change. The list contains long-term solutions such as flood control measures, reforestation efforts, and pollution abatement measures, as well as immediate action targets such as the relocation of citizens to higher ground, and the creation of disaster prevention bases.

The list from Palafox Associates also includes general recommendations in case of earthquakes, which emphasize the need for structural audits around the country. “All buildings in this country should have a structural audit, especially government buildings. When there are disasters, people tend to run to government buildings [for help],” noted Mr. Palafox.

ALL FALL DOWN
Despite optimism in the structural integrity of new and retrofitted Metro Manila buildings, old buildings that have not been retrofitted and those standing in problem areas stand little chance against, say, a massive earthquake.

“An agency came out with a report that 30 to 40% of the buildings here will collapse in a strong earthquake, and about 2% of tall and high-rise buildings will collapse. You can see we’re not really prepared,” said Mr. De Castro.

The study cited by Mr. de Castro is the Metropolitan Manila Earthquake Impact Reduction Study (MMEIRS), done by the Japan International Cooperation Agency (JICA) in cooperation with the Philippine Institute of Volcanology and Seismology (Phivolcs) and the Metropolitan Manila Development Authority (MMDA) from August 2002 to March 2004.

There are more grim aspects to the study. It says Metro Manila will be separated into four regions by the consequences of a massive earthquake. It predicts that fire damage and collapsing buildings will isolate the Western part of Metro Manila, while the road network of the eastern part of Metro Manila, which lies on the earthquake fault, could possibly break during such a disaster. “In a worst-case scenario, only half of the buildings will be prepared for a disaster,” said Mr. De Castro.

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BLOW THE HOUSE DOWN
Similarly grim scenarios, this time about the effects of typhoons, were presented during a roundtable discussion organized by the United Architects of the Philippines (UAP) last week called “Building Resilient Housing for a Stronger PH.”

The panel of architects from the UAP—Royal Pineda, Managing Partner of BudjiLayug+Royal Pineda Design Architects; Topy Vasquez, Chairman and CEO of T.I Vasquez Architects and Planners; Sonny Rosal, National President of the UAP; and William Coscolluela, Principal Architect of W.V
Coscolluela & Associates—focused on Yolanda’s devastation in Tacloban.

Mr. Vasquez mused on what might have happened if typhoon Yolanda had hit Metro Manila. “Imagine if glass broke off from a high-rise building… its shards will travel at 300 kmph,” he said.

This opened a discussion on the type of materials used in Metro Manila buildings. According to Mr. Pineda, tempered glass, which breaks up into little beads instead of jagged pieces when it shatters, is a smart alternative to the glass used in buildings today.

Some builders and developers have adopted concepts to make buildings more disaster-resistant. Retrofitting—the process by which old buildings are reinforced with new materials to make them stronger—is one adaptation. Some elements of the Metro Manila skyline have been retrofitted with steel, with flyover pillars as an example. “They have huge steel plates in the columns to give added support… so if the cement breaks, the steel plates will hold down the cement,” said Palafox’s Mr. De Castro.

STILL STANDING
Some builders look to the past for inspiration in building disaster-resistant structures. Old churches come to mind, with their thick solid walls standing amidst the onslaughts of natural and man-made disasters.

Of course, some churches, like the heritage sites that crumbled in the Bohol earthquake, have had time take its toll on them. More importantly, churches such as San Agustin in Intramuros, Manila, which remains standing after centuries of onslaughts, have undergone some retrofitting. “You can actually retrofit them with reinforcing bars to make them stronger,” said Mr. Palafox. What may apply to churches may not apply to all buildings, and probably not in urban areas. “Churches have thick walls, and if you will apply the concept [of thick walls] now, then you will waste a lot of space,” noted Mr. De Castro.

Other methods of retrofitting include using protective stickers for glass buildings. Mr. Pineda also discussed the possibility of installing storm shutters for private homes.

Mr. Pineda, during the UAP roundtable discussion, also shared some thoughts about modern architecture looking into the past. “Let’s wake up, and let’s say, let’s be basic, and understand nature again… [We should] understand nature, and create a design that will work with nature,” said Mr. Pineda.

Mr. Rosal and Mr. Vasquez also extolled the virtues of simple designs that can withstand disasters. According to Mr. Rosal, some of the houses left intact in typhoon Yolanda’s devastation had roofs with four sloping corners. This is in contrast to popular designs of high-pitched roofs with eaves and gables and two sloping corners.

Mr. Pineda added that the four sloping corners of the roofs allowed wind to slide and flow freely. Mr. Vasquez said that for a house to be able to withstand typhoon-strength winds, it should have minimal wind resistance and wind drag. Mr. Vasquez also noted the importance of site selection in planning a building project. “If I know that one area is flood-prone, why would I build a difficult house with all these [technologies] and gadgets?”

CORRUPTION AND INACTION
Although the technology and materials to build stronger public infrastructure is accessible in the Philippines, funding has always been a problem.

“Suppose you build a public bridge. Up to 40% of the funds are lost to corruption. You need at least 60-70% of the funds to build it,” said Palafox’s Mr. De Castro. He says that for stakeholders in the projects to cut their losses, materials of lower grade and standard are used to finish the project.

Furthermore, government inaction leads to buildings and homes being built in danger zones.

“There are buildings on earthquake faults, such as the areas of Blue Ridge, Eastwood, and from Marikina down to C5… na supposedly, dapat hindi (which are not supposed to be there)… but our government is not really implementing its rules… developers are just stacking over the faultline,” said Mr. De Castro.

“We have to realize that we have to rethink and redesign on our own, and in ourselves. If we do not, nature herself would do it for us,” said Mr. Edwin Barcia, the Vice-President of Documentation of T.I. Vasquez Architects & Planners Inc., in a closing statement at the roundtable discussion.