A GOVERNMENT structural engineer revealed several structures that have survived the July 16, 1990 earthquake remain vulnerable to strong quakes.
City Building and Architecture Office Structural Engineer Januario Borillo said at least 20 buildings mostly residential structures have yet to comply with the city's order to reinforce and retrofit the structures to withstand strong earthquakes like the recent tremor that hit Bohol province last Tuesday.
Borillo stressed while new buildings mushrooming in the city are compliant with the National Building Code of the Philippines, several structures in the city outskirts remain without action on their structures which is why the city government have ordered the demolition of more than 50 buildings in the past two decades that were severely damaged during the earthquake.
According to Borillo, what delayed the compliance of these buildings are decades-old litigation and ownership battles which has resulted to confusion among property owners on whose responsibility it is to rehabilitate these structures.
He said to make buildings earthquake resistant, wooden structures, for example have to strengthen its foundations with steel frames while concrete structures should have mechanisms to withstand strong tremors by constructing additional foundations and support mechanisms.
Since the 1990 earthquake, he said many buildings have been rehabilitated, demolished and reinforced to withstand the intensity 7 earthquakes.
The city government has also been enforcing strict requirement for developers to conduct soil testing before they could construct buildings that are more than three-stories high.
However, despite compliance with the National Building Code of the Philippines, he said structures are not fully earthquake resistant and may sustain minor damages especially if very strong earthquakes occur like the 2011 Japan earthquake.
Mayor Mauricio Domogan, meanwhile, said the city has been conducting regular earthquake drills in schools especially every July 16 as the local government continues to commemorate the 1990 earthquake.
The city government remains mindful of minor faults that crisscross the city according to the Mines and Geosciences Bureau which are the Loakan, Mirador, San Vicente and Burnham faults.
These minor faults according to Phivolcs could easily be affected by any nearby earthquake generator fault such as the San Manuel, Tuba and Digdig fault which resulted to the 1990 Luzon earthquake, according to Phivolcs.
Domogan said the existence of faults around the city is the reason why they have updated the City Land Use Plan to include geo-hazard maps provided by the MGB so that proper zoning of residential and commercial buildings will be imposed.
In terms of preparedness, Domogan said the city government has been seriously preparing setting aside its Disaster Risk Reduction and Management funds for purchase of equipment like additional fire trucks and ambulances and rescue equipment to be used by responders.
However, he said no matter how prepared local governments are, there will always be lapses that could occur.
In building constructions, he said, while structural designs are compliant of the National Building Code of the Philippines, poor implementation of these designs and low quality of materials used becomes the cause of the collapse of buildings.
The mayor further said private owners of these structures whether residential or commercial, should also move into making their buildings safe and secure during strong quakes.
He reminded residents that preparedness is the only key to prevent the loss of lives as the more than 1,600 killed in 1990 which is reason enough for everyone to prepare and be alert in times of calamities.