Adopt guidelines for earthquake resistant buildings
Published on: Saturday, October 14, 2017
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It was devastating yet not too surprising to learn of the two powerful earthquakes that struck Mexico in only two weeks last month.
The first occurred on 8th September with a magnitude of 8.1 and the second on 19th of a 7.1-magnitude.
After the first quake, the worst-hit states of Tabasco, Oaxaca and Chiapas were left in rubbles; more than a million faced power cuts and many families were displaced from their homes. But the death tolls from both quakes – at 65 and 370 respectively according to latest statistics – were much lower than the 1985 earthquake that was said to have taken the lives of almost 10,000 people.
Since the massively deadly earthquake that happened 32 years ago, the Mexican authorities have tightened building codes and intensify earthquake drills.
Mexico may not be as distant as we perceive. Both Malaysia and Mexico sit on the Pacific Ring of Fire, a horseshoe-shaped string of at least 450 active and dormant volcanoes dominating the Pacific Ocean and bounding a number of sea plates including the Philippine’s. As many as 90 per cent of earthquakes have been reported to strike within this Ring.
Earthquake hazards are considered low in Malaysia, except for Sabah where the level is deemed to be moderate.
Sabah is relatively prone to seismic (earthquake related) activities. It is situated on the south-eastern Eurasian Plate, bordered by the Philippine Plate and the Pacific Plate.
It has experienced low to moderate seismic activities due to the interaction of these main tectonic plates and several active fault lines. Between 1900 and 2016, 182 earthquakes with moment magnitude ranging from 2.9 to 6.0 have been recorded.
The 2015 Ranau earthquake that registered 6.0 on the Richter scale and killed 18 was the highest ever recorded in the country and a strong warning bell for Sabah to implement seismic design for its structures as soon as possible.
Mosti through the Department of Standards Malaysia or Standards Malaysia, has been developing a Malaysian Standards (MS) on earthquake. We published the draft of “MS EN 1998-1 Eurocode 8: Design of structures for earthquake resistance – Part 1: General Rules, Seismic Actions and Rules for Building” in 2015.
Since then several consultation forums were held with stakeholders and the public for feedbacks.
Last November Mosti co-organised a roundtable meeting with the Sabah local government for comments on the MS. The discussion revolved around the values of Peak Ground Acceleration (PGA), a crucial guide in building earthquake-resistant structures. PGA is the maximum ground acceleration that occurs during an earthquake at a specific site.
The debate was whether the PGA values published in the MS should be region-specific in the Peninsular, Sabah and Sarawak as opposed to just one PGA value. Setting a minimum PGA value that applies to all regions might be able to provide a certain degree of safety to all but might also incur unnecessary costs to structures that are built in non-seismically active areas.
Since then, experts have reconvened and finally agreed that the PGA values should be site-specific.
To come up with these PGA values a seismic hazard map for Malaysia was drawn up by local experts, headed by Prof. Azlan Adnan of Universiti Teknologi Malaysia and Prof. Felix Tongkul of Universiti Malaysia Sabah.
These maps, endorsed by Jabatan Mineral dan Geosains Malaysia in September, indicate region-specific PGA values drawn as contours and thus serve as a safety guide for construction activities.
There has been excellent progress in developing this MS. Last Monday the Sabah Ministry of Local Government and Housing signed a Memorandum of Understanding (MoU) with Standards Malaysia for the preparation of guidelines and development of MS for earthquake-resistant building design code.
A standard is only as good as being implemented. The development of this MS is only the beginning of our mitigation measures.
I strongly urge relevant agencies and local governments to enforce this MS for the safety and well-being of the people. We will continue to promote and explain this MS to various stakeholders and review it from time to time based on the most current seismic activities in the country.
However, experts have lamented that there is a lack of seismic, geological and geodetic data that have impeded efforts to gather comprehensive information on earthquakes.
Since the 2015 Ranau tragedy, the Malaysian Meteorology Department, also under Mosti’s purview, has added several seismic stations across Sabah to improve the detection of earthquakes. Geology experts recommended that the next steps would be to upgrade and increase earthquake engineering laboratories, seismic data centres and to invest in advanced remote-sensing technologies that could monitor minute ground movements.
Apart from equipment we also lack expertise in the earthquake-related fields. In the development of this MS for example, is a collective effort of multidisciplinary scientists such as geologists, engineering geologists, seismologists, earthquake engineers and structural engineers. There is an urgent need for data analysts for advanced research and even data scientists, who are able to interpret the data and turn them into something useful.
Closer to home, we have much to learn in disaster risk reduction and management from our neighbour the Philippines, which is part of the Pacific Ring of Fire and has been experiencing earthquakes far more often.
Besides the enforcement of building and construction regulations, we are not quite ready for an earthquake, psychologically and mentally.
Finally, it is important to note that building codes such as this MS can only help increase a structure’s resistance to earthquake and does not completely guarantee our safety. Thus we need to educate ourselves about earthquake mitigation measures and attend earthquake drills if they take place near you.
It is rather interesting to know that despite the advancement mankind claim to have in science and technology, till to date it is still impossible to accurately and effectively predict when an earthquake would strike.
Some quake victims have even related deadly earthquake incidents to the destruction of Sodom and Gomorrah.
Mankind would be humbled again in such tragedies and be reminded that science and technology do have their limitations.
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