By Engr. Arthur Lazaro
Undeniably, the Philippines should be more wary, stricter, and innovative in structural design compared to its Asian neighbors, and even to the Western counterparts. Our country is at the front line of climate and geologic change and it has become normal for us to feel the changing temperament of nature.
The Philippines sits at the edge of the Pacific and expects an average of 20 typhoons a year, not counting the monsoons that bring heavy downpour. It was not long ago when Metro Manila was literally drowned by Ondoy (2009) and Habagat (2012). Located within the Pacific Ring of Fire, our country expects a higher chance of feeling earthquake and tectonic movement compared to the other parts of the world. In the 1990 Luzon Earthquake, a magnitude 7.8 earthquake significantly damaged thousands of homes and collapsed a handful of buildings. An estimated number of 1,621 people perished. Recently, Bohol and Cebu (2013) were struck by a 7.2 magnitude earthquake, and it is said that Metro Manila is waiting for her turn as well.
That is why Filipino architects and engineers actually play a significant role in innovating structural design and integrity throughout the world, as the Philippines is the most devastated by climate and geologic change. Filipinos should set the bar high for responsive structural design throughout the world.
Recommendations
Because of the average magnitude 7.0 earthquake that the Philippines experiences, there should be a thorough review of the National Structural Code of the Philippines (NCSP) regarding the conformity of the design to withstand the severity of a magnitude 8.0 earthquake or higher. For the safety of the citizens, routine inspection and structural audit for all buildings and houses should be done, particularly the old ones. Aged structures should be subject to structural review and, if necessary, recommended for retrofit. If it is a must, condemn and demolish buildings that are unsafe and found unfit to survive big earthquakes.
As part of the review, there should be a district or community identification of fault lines and strictly implemented geologic reviews and studies of soil liquefaction and footing settlement so that citizens and engineers can aptly design and adjust structural designs for specific vicinities and areas. All earth fill should be properly compacted and the field density tests should be properly documented for reference. Also, proper concrete sampling should be done on site as it is crucial in monitoring the quality of concrete used and to prevent casualties caused by substandard materials.
There are already new technologies available in earthquake engineering that should be used and practiced such as: the integration of isolators and dampers that lessen transmitted energy of the earthquake towards the structure.
Hydrologic studies and identification of flood location should also be done in order to develop community disaster preparedness plans and adaptive designs. To better anticipate the possible impact of weather and climate, the capability of PAG-ASA in probing and monitoring weather conditions and disturbances should be enhanced. Also, the NSCP guideline provisions for wind pressure should be upgraded beyond 300 kph. It is forecasted, because of climate change, stronger typhoons may come and become a normal occurrence.
Government bureaucracy
The government should amend and change its red tape policy in securing building permits. While it was designed to be for the strict implementation of guidelines for building structures and for the safety of the citizens, it has become a root of bribery and corruption. There are many instances that certain officials and government engineers do not thoroughly review structural calculations and seismic analysis to fast track particular projects, and often it is reportedly done through bribery.
The government should also be strict in compelling contractors to follow technical specifications provided by the structural engineer. They should also be criminalized for using cheap and substandard materials, short-cutting labor procedures, and other acts that question the integrity of the structure causing its deterioration.
Repairs and warnings
For the part of the residents, they should inspect their homes for any cracks that can be found on slab, beams, and columns. If there are, it must be sealed off by using high-grade structural epoxy, and if possible, ask a structural engineer to check the severity of the cracks to the total structure of the house.
To address the damage caused by strong typhoons, provide additional metal fasteners on roofing to counteract the effects of strong winds. Also, it is advisable to use higher gauge of roofing material to strengthen its capacity.
In summary, the citizens should only utilize qualified and accredited contractors that are well equipped with experienced manpower and proper tools. The safety of the persons residing in the building is a must, and the government must make sure that contractors adhere to the safety standards. More so in the situation of the Philippines, climate change is knocking on her doorstep.
[Note: Arthur Lazaro is the Senior Project Engineer for most of the landmark projects of Palafox Associates. He oversees the vertical engineering component of each project, including structural, mechanical, electrical, plumbing and sanitary engineering services, fire protection, safety and building management. Art graduated with a degree in Civil Engineering from the Mapua Institute of Technology and is a member of the Philippine Institute of Civil Engineers.]