New buildings to be more quake-resistant under new guidelines

S'pore puts in place new building codes with seismic clause

Singapore has adopted a new set of building codes that include guidelines on making new buildings more resistant to earthquakes.

The Eurocodes - which replace the British Standards which Singapore has been using for decades - were formally adopted by the Building and Construction Authority (BCA) this month.

The industry has two years to comply with the new codes, that were developed over 30 years and are used by 27 European countries.

The BCA said the Eurocode clauses are "structured to stimulate innovation and are less prescriptive than the British Standards".

They include a seismic clause called EN1998 Eurocode 8, which sets out design and construction guidelines on making structures more earthquake resistant.

Professor Pan Tso-Chien, former dean of Nanyang Technological University's School of Engineering and director of the Institute of Catastrophe Risk Management, said the new codes should be sufficient in mitigating the effects of major quakes in nearby Sumatra.

"We cannot have buildings that are completely resistant to earthquakes... the cost will just be too high," he said.

"What we can have are buildings that can resist shaking for a long enough period of time for occupants to vacate. You build resilience, with failure in mind."

Prof Pan has just completed a study commissioned by the BCA in 2008 to ascertain Singapore's risk exposure to powerful earthquakes in the region.

His conclusion is that the likelihood of a quake powerful enough and near enough to damage buildings in Singapore is low.

The closest one, recorded in 1943, was 400km away in south-western Sumatra and measured 7.6 on the Richter scale.

More powerful ones tend to be farther away, like the 8.4-magnitude quake recorded north of Sumatra in 2007, which was 700km away from Singapore.

The catastrophic 2004 quake that triggered a deadly tsunami occurred 900km away.

"It's not whether something is dangerous or not dangerous. It's all probabilistic," Prof Pan said.

"We now know a lot more (about earthquakes in the region) than before. Having learnt what we learnt, we want to make the minimum (building standards) safer."

Prof Pan added that even though existing buildings here were not built to withstand tremors specifically, they are built to withstand winds, which exert similar forces on structures.

Commissioner of Building Control Ong See Ho said: "We now have a set of building codes that is constantly reviewed at an international platform. For Singaporeans, we'll live, work, play and learn in a safer built environment."

Mr Chong Kee Sen, vice-president of the Institution of Engineers, Singapore, said the new codes could even result in "potential cost savings of 5 to 10 per cent" because they are more efficient.

"The industry's challenge is to train our engineers to familiarise themselves with the new codes as well as new software," he said.

"This is a cost element. Anything that is new, we have to approach more carefully. It's a new learning curve."

christan@sph.com.sg