21-27 April 2017 #855

Search, locate, rescue in collapsed concrete houses

The 2015 earthquake convinced many to use reinforced concrete for reconstruction, but this will make search and rescue more difficult in the next Big One 
Sonia Awale

FUTURE SHOCK: The Morgan College of Engineering in Dhapasi (left) had a permit only for a three-storey structure. It collapsed in the 2015 earthquake (centre) and the site today (right). Hundreds of students and faculty would have been killed had the earthquake not struck on a Saturday. Kathmandu needs to prepare for collapses of poorly-built highrises like these in the next big earthquake.

Two years after the earthquake, it looks like reconstruction is finally taking on momentum. But from remote villages to inner city Kathmandu, most survivors are using reinforced concrete to rebuild damaged and destroyed homes.

The magnitude, intensity and duration of the earthquake on 25 April 2015 were just under the threshold for concrete structure collapse, so most cement buildings in Kathmandu survived. There is therefore a notion that reinforced concrete makes buildings stronger and safer.

“The last quake spread a misconception that concrete structures will withstand the next big earthquake, but substandard cement buildings can be worse death traps,” explains structural engineer Surya Narayan Shrestha at the National Society for Earthquake Technology-Nepal (NSET).  

Nepalis were extremely lucky that the 2015 earthquake hit on a Saturday and it mostly brought down brick, stone and clay houses. But the next time we may not be as fortunate because existing concrete buildings and new ferrocement construction may not be strong enough to withstand the greater shaking. 

The Gorkha Earthquake did not release all the energy accumulated along the Main Himalayan Fault, which means there could be another big earthquake at any time near Kathmandu. Seismologists also predict a mega-quake in western Nepal, where accumulated energy has not been released for 700 years. Both could bring down poorly built concrete structures in Kathmandu. 

To be sure, concrete in itself is not bad. But it needs strict quality control of cement and steel rods, and care in mixing and curing concrete. Many pre- and post-earthquake structures in Kathmandu do not meet these standards.

However, what worries experts even more is that search and rescue in collapsed concrete structures will need a lot more preparation, training and equipment.  

“We didn’t have enough equipment in the last earthquake, we could have saved a lot more lives if we were better equipped,” says Diwakar K C of the Armed Police Force, which has a Disaster Management Training Centre in Kurintar. “We have been training constantly, but need a different kind of expertise for rescue from collapsed concrete structures,” he adds.   Nepal Police Spokesperson Sarbendra Khanal agrees: “We had enough rescuers two years ago, but they lacked proper training and tools. We didn’t have appropriate equipment to dig people out from collapsed highrises.”   In fact, the Nepal Army, APF and Nepal Police do not currently have enough of the necessary equipment for Collapsed Structure Search and Rescue so they can search and locate people trapped in the debris of collapsed concrete floors. They will need pneumatic drills, rotary rescue saws, concrete cutters, chipping hammers,  hydraulic shoring, and life detectors like thermal, CO2 and snake-eyes.  

“A major lesson from 2015 is that we need to train and equip community-level first responders so they can do the surface rescue before the specialised teams arrive,” explains Ganesh Kumar Jimee, an NSET instructor involved in search and rescue in Bungamati and Dharara two years ago.  

In the 2015 earthquake, more than 4,000 international rescuers from 19 countries spent millions of dollars to rescue a dozen or so people, while local communities and security agencies employed simple digging equipment to pull out more than 5,000 people from the rubble.   

Experts say training communities and rescuers to use heavy equipment is the next crucial step in preparing for future disasters. In 2015, excavators and bulldozers were sometimes used to dig into the rubble while survivors were still trapped inside. Locals had no knowledge about moving victims with broken bones and severe trauma.   

Besides the Army and Police, first responders can also be volunteers from local communities, private security guards, the fire brigade, college students and teachers. Rescue paraphernalia, including digging and lifting equipment, lights, stretchers and first aid, need to be pre-positioned in neighbourhoods, water food and tents stockpiled in designated open spaces, and drills should be held regularly to enhance preparedness.

Jimee remembers reaching Dharara on the night of 25 April 2015 only to find there was no heavy equipment to move house-size blocks of fallen masonry to find survivors. He is convinced that communities must be trained in emergency rescue because by the time specialised teams arrive it may be too late. 

He adds: “We have no choice, we must be even better prepared with training and equipment for the next big quake because there will be a lot more concrete structures that will collapse.”   

Read also:


‘Better late than never’, Guest editorial

‘Building back unsafe’, Om Astha Rai

Not out of danger yet, Sonia Awale

Future shock, Editorial

A concrete future, Sonia Awale