Photo screengrab from the "How Safe is My House" PDF
How can you be sure that your home is ready for a strong earthquake?
A month ago, the Philippine Institute of Volcanology and Seismology (PHIVOLCS) released a large-scale map pointing to areas directly under the West Valley Fault. It’s been 300 years since the last West Valley Fault earthquake, and, judging from the pattern, a magnitude 7.2 earthquake is bound to happen soon, said PHIVOLCS. Click here to see the list of barangays located directly on top of the West Valley Fault.
As a follow-up, PHIVOLCS in partnership with the Japan International Cooperation Agency (JICA) has launched a 12-point questionnaire to help families assess if their homes will be able to withstand a major earthquake. The self-check checklist is intended for residents of concrete hollow block (CHB) houses that are 1 to 2 stories high. The leaflet also includes the specifics of a stable CHB house, like proper materials and design rules to be followed.
The questionnaire entitled “How Safe is My House” includes questions on the house’s appearance and history: “What is the shape of my house?”, “How old is my house?” and “Has my house been damaged by past earthquakes or other disasters?”.
There are also more complicated and equally important questions: “Are the externals of my house 6-inch (150mm) thick CHB?”, “Are there unsupported walls more than 3 meters wide?” and “What is the gable wall of my house made of?”
There are 3 choices to every question and every choice corresponds to a point. A higher total score means a more structurally stable house.
“The solution is to recognize the problem. Where will this recognition start? It should start with the homeowner,” said PHIVOLCS Director Dr. Renato U. Solidum Jr. He also explained that an earthquake resistant house would not collapse even at a magnitude 9 earthquake.
“Casualties from past earthquakes were caused by the collapse of buildings. And part of those are from damaged to collapsed non-engineered houses,” he added. “What we’re trying to do is to educate everybody, that even if you employ masons and carpenters, they should be following certain standards.”
The questionnaire was derived from field verifications, quake damage surveys, and several experiments and tests. One of which was the full-scale Shaking Table Test of CHB Houses conducted by Filipino and Japanese experts at the National Research Institute for Earth Science and Disaster Prevention. The test involved two houses, one of which followed the Building Code and the other represented typical CBH houses in the Philippines. They found that the latter incurred more damage eventually leading to its collapse during the simulation.
To reach more families, a Tagalog version of the questionnaire is in the works and also a plan for a similar checklist for wooden houses.