Future strong

Can Sri Lankan buildings withstand an earthquake? :
NBRO comes up with a building code to ensure they can:

by Manjula Fernando

The devastating earthquake in Nepal has opened a Pandora’s Box of concerns for Sri Lanka about disaster preparedness and the country’s ability to cope with natural disasters.

In the aftermath of the devastating April eartquake in Nepal Photo: National Geographic

Galle ravaged by the 2004 tsunami waves Photo: Sydney Morning Herald

From the widespread devastation caused by the 2004 Box Day tsunami to every wreck and ruin wrought by earthslips, floods and gale force winds, Sri Lanka has had its fair share of natural disasters. But the graphic chronicling of death and destruction in Nepal is a reminder that things could get heart-wrenchingly worse in a matter of seconds.

The detritus of what were once historical buildings in Kathmandu is a stark reminder that neither history nor awe inspiring statures can withstand the force of high magnitude tremor, unless they are disaster proofed. Yet, Sri Lanka is in the midst of a construction boom and there is no sign of any building codes to ensure that the structures that are coming up are resilient to natural disasters. This reality is more evidenced in the city of Colombo, which is seeing a surge of construction from high-rise apartments both for luxury living and to accommodate the low income city dwellers, to sophisticated road networks.

The Nepal earthquake is an eye opener, hammering home the point that Sri Lanka should fast track the ongoing efforts at disaster mitigation and streamline the construction sector to ensure at least minimum standards are followed. This sentiment is enunciated in no uncertain terms by the Director of the Human Settlements Planning and Training Division of the National Building Research Organisation (NBRO), Kishan Sugathapala, who acknowledges that a mechanism to re-evaluate the existing high rise buildings is indeed the need of the hour.

“Heightened risk or no risk for Sri Lanka, the constructions should be monitored and streamlined to maintain consistency and safety. The World Trade Centre was built two decades ago. It is time their disaster resilience is put to the test,” he says, cautioning that if necessary their disaster resilience should be re-evaluated to determine whether improvements are needed to withstand new risks.

Guideline

According to Sugathapala, the NBRO is in the process of introducing a manual on hazard resilient housing construction, providing general guidelines for any construction as well as specific guidelines for constructions in disaster prone locations.

The manual, he says, is not being formulated as a response to the Nepali quake, but has been a work in progress since 2012.

The building code will initially be a voluntary exercise, but the NBRO is planning to make it a law under the Urban Development Authority (UDA) and the Geological Survey and Mines Bureau (GSMB) in due course.

The manual, created following three years of research work by an eleven-member panel of expert geologists, geophysicists and engineers, is to be published within the next two months and cover a range of natural disaster from earthquakes to landslides, high winds and floods.

The building code provides for resistance up to a magnitude 6 earthquake, since the risk factor for Sri Lanka is considered between 2 to 3 points on the Richter scale.

Such an effort, the NBRO believes would help elevate Sri Lanka's preparedness to earthquakes and other natural disaster to new heights.

According to Sugathapala, initially, constructions that come under medium rise category as well as private houses, which account for 80% of the constructions in the country, will be bound by the code. “We will move on to high rise buildings, which are built by international contractors, further along the way," he explains, adding, “We have to put them under the microscope as well, but unlike others, these constructions are monitored at certain points."

Biggest deterrent

Sugathapala acknowledges the biggest deterrent to implementing the building guidelines will be the cost factor.

"It is a deterrent, but we are planning it in such a way to keep costs as low as possible," he says, explaining that abiding by the general guidelines would incur a 10 - 15 % cost increase, while constructions in disaster risk areas would incur a 30% cost increase.

Only 12% - 15% of constructions are done by professional bodies in Sri Lanka.

The others are built without professional involvement. "The specific conditions for disaster prone sites will take at least two years to be fully implemented," he says, adding that the GSMB will be the monitoring body for the guidelines.

The NBRO is also in the process of profiling the disaster risk areas, with the aim of finalising a risk map covering the entire country by the end of this year.

SL: Increased vulnerability

In the aftermath of the April 25 Nepal earthquake, serious concerns have been raised about Sri Lanka’s vulnerability. And expert views don’t help allay those concerns one way or the other. “We can not say Sri Lanka is located in an earthquake prone area or it is in a safe area with certainty”, says reputed Geologist and former Head of Peradeniya University’s Geology Department, Emeritus Professor at the National Institute of Education at Maharagama, Kapila Dahanayake.

“It is true Sri Lanka is not located on a tectonic plate boundary where earthquakes are a frequent phenomena but the intra-plate earthquakes are a possibility, as we have witnessed already,” he says, explaining that it is the geologists perspective that earthquakes can occur anywhere, anytime and no living technology can predict an earthquake before it strikes. “Not even countries like Japan have been successful in inventing such technology although it is plagued by catastrophic earthquakes round the year,” he points out.

However, Prof. Dahanayake rejects the notion that the Nepal earthquake is an indication of increased vulnerability for Sri Lanka. “The Himalayan region is the centre of seismic activity. It has long been predicted that the Himalayan region would experience a strong earthquake anytime soon. It experienced a similar intensity earthquake some 80 years ago and the geologists have been predicting a sinister cycle,” he says, pointing out that though India has reasons to be concerned by the Himalayan region earthquakes, it is very unlikely that Sri Lanka would be affected as a result.

Prof. Dahanayake’s sentiments are echoed by Nilmini Thaldena, Geophysicist at Geological Survey and Mines Bureau’s Geology Division, who says there are no geological aspects to pinpoint Sri Lanka facing a major earthquake. She also rules out the theory that the breaking up of the Indo-Australian Plate along a fault zone running east-west about 400 kilometres south of Sri Lanka, could put the country in a more vulnerable state. “In term of geological years, they are looking at thousands of years before Sri Lanka can be in greater risk,” she points out.

She says the human tragedy and the devastation in Nepal was extreme because the country was short of preparedness to face such a calamity, and that the damage from a similar occurrence in Sri Lanka may not be as big as the Nepal experience.

Tokyo, Thaldena says, has also been issued a warning of the likelihood of an 8.0 or stronger magnitude earthquake striking the city at any given time. “It is only a matter of time before Tokyo experiences such a devastating phenomena. But the deaths and the physical devastation have been predicted to be much less,” she say and explains that some of the collapsed structures in Nepal were built of brick and clay and were not solid enough to withstand a strong earthquake.

Although Sri Lanka lacks a national building code, she however believes, the building structures in comparison are of a better standard.