Concrete planning
On 25 April 2015 at exactly 11:56, the ground beneath Kathmandu Valley started shaking. Houses built on the soft alluvium of the former lakebed bobbed and swayed like boats in the sea.
Brick and clay monuments and homes collapsed in clouds of dust. Had the duration, intensity and frequency of the earthquake been more severe, reinforced concrete buildings would have also come down.
Because cement houses were spared, the public perception is that reinforced concrete buildings can withstand severe earthquakes.
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While that is partly true, if the shaking had gone on for more than 1 minute, if it was 8 magnitude or more, or if the frequency of the shock waves was different, many of Kathmandu’s concrete structures would have also come down.
Much of the reconstruction after the 2015 earthquake is now complete, although there are still families waiting for money to rebuild. But we still have to be prepared for the next one. And the way to be ready is to retrofit schools and hospitals, ensure open spaces for shelters, and preposition rescue equipment, water and other essentials.
Teams need training in Collapsed Structure Search and Rescue. Compared to older buildings, search and rescue inside the pancaked ruin of a reinforced concrete high-rise is a whole different exercise.
Most of the concrete structures that collapsed in 2015 were illegally built high-rise blocks in Gongabu. Ironically, an eight storey engineering college in Dhapasi was also reduced to rubble. Its building permit was only for three floors.
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Had the earthquake struck on a weekday, hundreds of students and staff would have been inside the college. Tens of thousands of students across central Nepal were saved because the disaster happened on a weekend.
Concrete structure rescue needs specialised robo-worm cameras, snake-eye acoustic, thermal and motion sensors, and human life detector tools like continuous wave Doppler radar and equipment to measure carbon dioxide levels from survivors.
Fortunately, the National Disaster Risk Reduction and Management Authority (NDRRMA) is putting together a wish list of Rs350 million for such specialised equipment, and has already started training search and rescue teams from the Armed Police Force and Nepal Army. Their role will be vital in finding and extricating survivors.
This is not panic mongering. We look back at 2015 in this issue of Nepali Times in order to ensure that state agencies and the public start preparing to be prepared. What happened in Gongabu is a microcosm of what the aftermath of a future mega quake in Nepal will look like.
In January 2015, four months before the earthquake, we reported in this space that earthquakes are not 'natural' disasters, they kill people because of weak buildings. An 8+ magnitude earthquake could occur in western Nepal at any time.
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Concrete is good if quality standards are met, the steel rods are properly installed, and building codes are adhered to. But many pre- and post-2015 structures in Kathmandu do not meet these criteria. Things are far worse in western Nepal. If new reinforced concrete houses are not properly made, you do not even need a 7 magnitude earthquake to bring them down.
In the 2015 earthquake, nearly 4,000 emergency crew from 19 countries arrived in Kathmandu with Concrete Structure Search and Rescue equipment. Much of it was not needed. It was local first responders, Nepal Police and Army that rescued 5,000 survivors with simple shovels and spades. Next time, it may not be so easy.
The 7th anniversary of the 2015 disaster is also a time to turn our attention to western Nepal, and start with retrofitting schools and hospitals, and enforcing building codes. Although 7,000 schools were damaged in 2015, most of those that had been retrofitted survived intact.
We know what to do. We just need to do it before the next one.
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