AS I write this article, I am watching the news on the 7.8 magnitude earthquake that shook General Santos and the surrounding cities and towns in Sarangani, Davao and South Cotabato. The strongest earthquake that hit the Philippines was the Moro Gulf quake with the magnitude of 8, which caused the destructive tsunami that killed more than 4,000 people. This recent earthquake is almost as strong as that one. Hence, we can presume that there will be substantial damage to buildings and infrastructure that was never experienced by the region since the Moro Gulf earthquake. As for this writing, we are unaware of the exact number of casualties and extent of damage, but reports are coming of more casualties and extensive damage. Aftershocks continue to hit the region.
Unlike floods and typhoons, earthquakes cause far more extensive and expensive damage to infrastructures that will take years to restore. The search and rescue operations to save those who were pinned and buried alive in the concrete debris of the aftermath of the tremor will take days and the clearing of debris will take months if not a year. The visible damage to commercial establishments of General Santos City such as the KCC Mall and the SM mall would take a year at least to repair and reinforce.
Clearly, the Philippines, being in the Pacific Ring of Fire, is not a stranger to earthquakes. In fact, it is a country indisputably right in the path of the world’s most active fault lines and string of volcanoes. It is expected therefore that Philippine planners and public works officials have adopted measures and technologies to address the challenges and dangers of an earthquake.
As city planners and developers, what are the measures that we could adopt to make a city or town more quake-resilient. Designing a city to be earthquake-resilient involves a mix of engineering, urban planning, and policy.
When Super Typhoon Yolanda battered the Philippines in 2013 with gustiness that has never been experienced before, former Public Works secretary Babes Singson immediately got down to work in updating and upgrading the Philippine Building Code. This latest revision of the building code upgraded the structurally standard designs of roofs to be able to withstand the gustiness of one of the strongest super typhoons the country has ever experienced.
In Meralco, we hardened our infrastructure to survive the natural and man-made calamities that threaten our infrastructures.
However, the recent collapse of a nine-story building in Pampanga did not point towards lack of publicly available design guidelines. It rather pointed clearly to the lack of integrity in doing the work. Thus, the structural integrity of our buildings does not depend solely on the design of the buildings but more importantly, on the character and integrity of the engineers and the workers involved in the construction.
The role of city or town engineers in earthquake-resistant construction standards is critical in ensuring the safety of people. Enforcement of easements and design standards must be complied strictly.
Further, it is important for everyone’s safety that a seismic zoning and land use planning be implemented. This includes that no one should build near fault lines and on soft soils that are prone to liquefaction and in areas that are landslide prone. To do this, UP has mapped the geohazards of the country and these maps could be great reference.
From the get-go, we must build where it is safer — not when it is more convenient and aesthetically alluring but dangerous.
It is imperative also to strengthen existing vulnerable structures (schools, hospitals, bridges) which will include base isolation, adding steel braces and shear walls.
We must, likewise, have design systems that do not fail all at once. This refers to the need for redundancy, which can mean having multiple routes for roads and bridges, backup power grids and water systems and flexible pipelines that do not break. Having this ensures the city still functions after a quake. A backup infrastructure for all utilities and government operations must be set up.
We cannot overemphasize the necessity of having open areas such parks where people can be evacuated and gathered safely and clear accessible evacuation routes. It is about time that cities and towns reclaim areas to be designated as parks and open spaces.
Smart city technologies such as early earthquake warning systems, automatic shutdown systems of critical utilities and infrastructures can save lives. Again, proper zoning ensuring controlled density and better and safer urban layout can avoid overcrowding in high-risk zones. It also distributes population and services across the city.
In the end, a well-planned city needs vigilant and prepared citizens. Hence, regular earthquake drills, public awareness programs and strict inspection and enforcement of building design standards must be done.
We pray for the safety of all our fellow Filipinos in Mindanao who are affected by this natural calamity.
