After Sabah tremblor, expert says earthquake-resistant buildings needed in high risk zones

On Friday, an earthquake of magnitude 5.9 hit Sabah near Mount Kinabalu in the Ranau district and caused the deaths of 16 climbers. ― File pic
On Friday, an earthquake of magnitude 5.9 hit Sabah near Mount Kinabalu in the Ranau district and caused the deaths of 16 climbers. ― File pic

KUALA LUMPUR, June 10 ― The deadly Sabah earthquake last week has exposed a need for buildings that will withstand potential damage in areas prone to seismic activity, said one seismology expert.

Universiti Teknologi Malaysia’s Prof Dr Azlan Adnan said that while there is no need to avoid buildings in areas with high risk of earthquakes, he explained Malaysians should “build buildings with seismic/earthquake resistant design”.

The risk posed by earthquakes would depend on the buildings, infrastructures and population density of a city, he explained, adding that there is a “very high” possibility of collapse if buildings that are not properly designed.

“Therefore, in Sabah, Kota Kinabalu will be the highest risk city in Sabah. In peninsular (Malaysia), Putrajaya, Kuala Lumpur and Penang will be the top highest risk cities,” the research head of UTM’s Engineering Seismology and Earthquake Engineering Research told Malay Mail Online when contacted.

Azlan also said Sabah has the most active fault lines, naming the state’s coastal areas Semporna, Lahad Datu as well as highland areas Ranau and Kundasang as those most likely to experience tremors.

Azlan said Malaysia currently has no design provision for buildings to withstand earthquakes, adding that the country should adopt design codes with specific requirements for earthquakes.

“We should follow the design practice elsewhere such as in the US which uses International Building Code (IBC) or European countries which use Eurocode,” he told Malay Mail Online.

For example, steel structures that are preferable in earthquake-resistant designs and conform to the European Code building standard ― otherwise known as Eurocode 8 ― can be used, Azlan said.

“For very important structures such as hospitals, schools, emergency centres, police and fire departments, technology such as base isolators are recommended,” he added, referring to a technique that prevents or minimises a building from suffering damage during earthquakes.

For older buildings that were not built with earthquake-resistant designs, Azlan said these could be retrofitted with “base isolators and dampers”.

While the construction methods and technology are readily available, Azlan said the biggest obstacle was cost and a reluctance to incur these in order to incorporate quake-resistance into building design.

Universiti Malaysia Sabah’s Prof Dr Felix Tongkul said five states in the country has active fault lines ― Sabah, Sarawak, Selangor, Pahang and Negri Sembilan ― with Sabah having the most.

“The towns of Kundasang, Ranau, Lahad Datu and Kunak has the highest risk of earthquake,” the geologist told Malay Mail Online when contacted, referring to towns along Sabah’s coastal area and highlands.

Felix similarly said Malaysians need not avoid building in these high-risk areas, but should be “extra careful” when doing so.

Felix acknowledged a risk of buildings collapsing, particularly if they are not built according to approved standards and are heavy like those constructed using concrete, but insisted that “the risk is low”.

Malaysia’s buildings are generally not built to specifically handle earthquakes as there are no “significant” or “strong” earthquakes here, unlike in regional neighbours Japan, Philippines or Indonesia, he said.

“However, most buildings are built strong enough to handle moderate earthquakes. There is no urgency and real necessity to make the buildings stronger as they are now. They are good enough, if built according to specification,” he added, pointing out that the expected highest magnitude of an earthquake hitting Malaysia would be around 6.0.

“I think the existing buildings in Malaysia is strong enough,” he said, confirming that earthquakes beyond the 5.0 magnitude are “quite rare” in Sabah, with most falling below that magnitude.

In the moment magnitude scale used to measure earthquakes, those with magnitude of 5.0 to 5.9 are categorised as moderate, while 6.0 to 6.9 are considered strong, 7.0 to 7.9 are major, those above 8.0 are great.

“What is urgently required is to ensure that buildings in high risk areas are properly built, sited correctly, avoiding unstable areas, such as steep slopes. It would also be useful to use lighter materials, instead of concrete,” he said, suggesting materials such as composite materials (plastic), timber, aluminum frame and steel frame.

Old buildings should be left as they are and reinforced only if necessary, Felix said.

“There is no real obstacle to improve construction standards and methods if we want to. The technology is already available. The challenge is to minimise using substandard materials and methods and doing away with ‘shortcuts’ and ‘corruption’,” he said, agreeing that higher construction costs could also be an obstacle.

On Friday, an earthquake of magnitude 5.9 ― said to be the strongest in Malaysia in close to four decades ― hit Sabah near Mount Kinabalu in the Ranau district and caused the deaths of 16 climbers.

The earthquake was reported to have caused damages to buildings in Ranau ― including its hospital, police headquarters and mosque. School buildings were also reported to have been damaged, but no further casualties were reported aside from that of the climbers.