DAVAO CITY- The Department of Science and Teschnology- Philippine Institute of Volcanology and Seismology (DOST-PHILVOCS) recently launched the Metro Davao Site Response Atlas” aiming to provide information to understand the ground motion and site response during strong earthquakes which can be used to increase seismic resiliency of residential and medium-to-high rise buildings in Metro Davao.
It is a compilation of maps on the Vs30 model, Peak Ground Acceleration, Short Period Microzonation and long period Microzonation of Metro Davao. Through this, Davaoenos will now have a scientific basis in ensuring safety and resilience of building structure as it contains seismic microzoning maps that indicate areas that are critical for residential buildings and medium-to-high rise buildings in the event of an earthquake.
“We wanted to provide hazards on information to the different stakeholders with regards to this information, This really specific to buildings especially for engineers but also this is also good for land use planning which areas are also ground so that liquefaction can be managed well. Ma-idnetify natin yung mga malambot na lugar, mga sira-sira na kalsada na hindi ka maka rescue kaagad kasi wala kang madaanan,” said Dr. Renato U. Solidum Jr., OIC of PHILVOCS and Undersecretary of DOST in an interview.
Soil liquefaction occurs when a saturated or partially saturated soil substantially loses strength and stiffness in response to an applied stress such as shaking during an earthquake or other sudden change in stress condition, in which material that is ordinarily a solid behaves like a liquid.
“Increasing the resiliency of four metro areas would be one of the priority programs and that would be Metro Manila, Metro Cebu, Metro Davao, and Metro Iloilo. But to fulfill those kind of goals, the PHILVOLCS is preparing information for the appropriate measures that can be done to these buildings and infrastructure,” Solidum said during the launching and workshop of Metro Davao Site Response Atlas held on April 10 at The Royal Mandaya Hotel (TRMH).
Solidum emphasized the importance of assessment of hazards especially of the buildings and not just high rise but also residential buildings.
“You can design the building properly in appropriate condition,” he said.
Solidum said Davao Region is susceptible to earthquake hazards due to the fault lines present in the region.
“If we talk about hazards, Davao Region is susceptible as represented already there are many faults within Davao City and towards the southwestern side of the city. Towards the east there are many branches of faults those also are considered as source of earthquake,” he said.
Engineer Eddie C. Fuentes, director of the Philippine Institute of Civil Engineers-Davao Chapter (PICE-Davao) talked about the cost-effectiveness in the building design using the tool of specific response data that the city is providing to the engineers.
“Masaya kami dahil meron ng PHILVOLCS na puwedeng pagkunan ng data lalo na yung building code natin, which requires high rise buildings seismic equipment. Marami na tayong data na pagkukunan lalo na minsan kung yung ginagawa ba ng designer in accordance ba ito sa regulations. Matagal na ito dapat ginawa ng PHILVOCS,” Fuentes said.
Engineer Albert Tamobpong of the Association of Structural Engineers of the Philippines (ASEP) mentioned the conservative values based on the national structural code of the Philippines (NSCP) which ensures the resiliency of the buildings.
“The current basis for our structural design now is conservative because it is based on the NSCP. I will cite example, if the 15t storey building costs P100 million, maybe we can say will boost down to P40 million because of the study and that is very friendly on the part of the owner. We can also assure that our buildings are resilient and could withstand to any earthquakes due to the data provided to us by PHILVOCS. This data would give us guidance for future designs,” he said.
To highlight the importance of regulating buildings designs in preventing loss of lives and damage to properties, DOST-PHILVOCS conducted a workshop on “Specific Earthquake Project Workshop” that was participated by officials and representatives from the Local Government Units of Davao City, Tagum City, Panabo City, Carmen, Sta. Cruz, Digos City, and the Island Garden City of Samal. Representatives from the regional offices of the Department of Science and Technology (DOST), Department of Interior and Local Government (DILG), Department of Public Works and Highways (DPWH), National Economic and Development Authority (NEDA), Housing and Land Use Regulatory Board (HLURB), Mines and Geosciences Bureau (MGB), Office of the Civil Defense (OCD), Philippine Information Agency (PIA), ASEP, PICE, Mindanao Development Authority (MinDA), academe, private sectors, and other stakeholders in Davao Region.
The participants identified ground conditions on site using atlas and estimate natural vibration of buildings to determine the existing structures that are vulnerable to intense ground shaking.
This critical information will serve as guide in earthquake risk, reduction efforts, and comprehensive land use planning and development.
The project also came about after the Metro Manila and Metro Cebu had their own in 2015 and 2018 respectively. The maps maybe used by local administrators in land use planning and strict implementation of seismic design of structures from the effect of short and long period seismic motion.