Following the first earthquake in Nepal, a team from Search and Rescue Assistance in Disasters (SARAID) was deployed to help rescue people trapped in collapsed buildings. ICE members Josh Macabuag, and Mark Scorer were structural engineers on the team. Macabuag, tells us about his experience.
What was your role?
As an urban search and rescue engineer I advise on whether a building is safe to enter, and if so, devise the safest way to enter or breach the structure.
How would you describe the situation in Nepal regarding buildings?
Many collapsed buildings had disintegrated into solid mounds of rubble with no survivable voids. Partially collapsed buildings were also incredibly unstable.
How did you cope given this was your first deployment?
Being in or around these structures was nerve-wracking but it is what we train for. You are also very aware of the locals watching you, hoping for loved ones to be found, so you focus on the job at hand.
As an engineer, what went through your mind when assessing buildings?
I was thinking about stability and load paths, which parts of the structure cannot be disturbed, and which walls could be breached without compromising the structure’s stability.
I was also thinking about how the building can be stabilised before entry. During the rescue I was watching for movement or changes to the structure.
Why do you think damage was so bad?
Nepal has a lot of adobe (mud-brick), unreinforced masonry and poorly-constructed reinforced concrete frames. Adobe and unreinforced masonry are heavy and brittle, and so vulnerable to sudden collapse under earthquake loading.
Buildings are also often built by homeowners with no design input from engineers.
This risks dangerous defects including excessive height, inadequate foundations and the removal of stabilising walls.
Do you think this contributed to the casualty numbers?
Yes, the structures - especially the masonry adobe buildings - disintegrated upon collapse and so left no voids in which people could survive.
This must have made your job challenging
Yes, there is frustration at not being able to reach victims faster and a feeling of helplessness due to the low chances of survival.
What structural issues does Nepal face now?
It must address existing vulnerable buildings - most surviving buildings are of similarly weak construction and are vulnerable to future earthquakes. Nepal must also “build back safer”.
In a more developed country, regulation of building design requirements and controls during construction could be used.
In Nepal, because most buildings are non-engineered, a “bottom-up” approach is required. This means training communities and builders in basic techniques to safeguard buildings.
Were there any positive experiences?
People were very grateful that we were there to help, and it was good to provide closure that no one is trapped alive within the buildings we searched.
Were you able to use your engineering skills elsewhere?
I stayed on when the search and rescue phase ended to assess buildings like hospitals and schools. I felt proud to use my engineering skills here, and assure some people that their buildings could be used.