Nepal earthquake: Engineering lessons from a disaster


  • Science & Technology
  • Wednesday, 24 Jun 2015

Binod Tiwari, a geo-technical engineer from Cal State Fullerton, examines a building damaged by the April 25 earthquake in Nepal. Photo: Los Angeles Times/TNS/Molly Hennessy-Fiske

Lessons from a disaster: Binod Tiwari, a geo-technical engineer from Cal State Fullerton, examines a building damaged by the April 25 earthquake in Nepal. Photo: Los Angeles Times/TNS/Molly Hennessy-Fiske


Binod Tiwari leaps out of an SUV onto the busy Araniko Highway and stops in front of a foot-wide crack in the pavement.

As trucks and motorcycles whiz by, Tiwari, wearing a fluorescent yellow vest over his Cal State Fullerton shirt, raises his camera to snap photographs of the crack. A bridge nearby shows similar fractures, and Tiwari walks alongside it to check some nearby homes that tip perilously forward.

“Definitely has lateral spreading,” he mutters as he snaps photos. At times, he props a yellow ruler or his cellphone next to the cracks to measure them.

Tiwari, a civil engineer at the Fullerton university, has come to Nepal to help lead the Geotechnical Extreme Events Reconnaissance team, which assesses the damage after mega-earthquakes such as the magnitude-7.8 one that ripped through Nepal in April.

They want to find out what happened to the rock and soil during the quake, and which buildings and infrastructure responded well – or didn’t.

The best way to learn how to build safer structures, Tiwari says, is to head to the disaster zones where they have failed. “Natural disasters come without telling us,” he says. “Science has to chase that disaster.”

The team has brought along a host of different experts. Tiwari studies soil liquefaction, a phenomenon that sometimes occurs during earthquakes that causes the soil to move like a fluid instead of a solid, tipping buildings as if pulling the rug out from under them.

The scientist made a similar research trip after the 2011 earthquake and tsunami in Japan. But here, the physical damage cuts a far wider swath across the country – and for the Nepalese-born researcher, it hits closer to home.

Motorcyclists whiz by as Binod Tiwari and colleagues try to photograph buildings damaged by the April 25 earthquake in Nepal. Tiwari, a Cal State Fullerton geotechnical engineer, co-led the Geotechnical Extreme Event Reconnaissance team to learn more about which structures failed and why. (Molly Hennessy-Fiske/Los Angeles Times/TNS)
Motorcyclists whiz by as Binod Tiwari and colleagues try to photograph buildings damaged by the April 25 earthquake in Nepal. Tiwari, a Cal State Fullerton geotechnical engineer, co-led the Geotechnical Extreme Event Reconnaissance team to learn more about which structures failed and why. Photo: Los Angeles Times/TNS/Molly Hennessy-Fiske

Tiwari was born in Gorkha district in a mud-mortar house, the kind of building that proved deadly during the quake. When he was a teen, his family moved to Kathmandu, the capital, where he would look through his window at the sky-scratching Himalayas.

“All around you see snowcapped mountains. So, that makes your life a little different,” he says. “If you feel a little sad, you just look to the mountains.”

Beautiful as they are, the soaring peaks are caused by the same for-ces that make Nepal such a dangerous earthquake zone.

As members of the geotechnical team travel across the city and visit villages, they see children and elderly Nepalese sleeping in the open, huddling under tarps near flattened and crumbling houses.

It’s “devastating,” Tiwari says. “You want to cry.”

It’s cool on this gray spring day; the overcast sky threatens to rain, a foreshadowing of the season to come.

“You should follow the cracks through the buildings, it’s spectacular,” says Scott Kieffer, Tiwari’s co-leader on the team, a California native now based at Graz University of Technology in Austria, who has already scoped out the area.

“I just want to go there,” Tiwari replies, pointing across the bridge. On the other side, he traces the cracks down an alley, over a construction site, into a mechanic’s garage, snack shop and finally a man’s backyard.

Tiwari’s ability to connect with Nepalese people on the ground and in government is essential to the team’s mission.

Earlier in the day, he chatted in Nepali with Tulasi Prasad Sitaula, the secretary of physical infrastructure and transport. Now, as he tracks the damage into the rubble-filled yards of damaged homes, Tiwari asks residents for details on what happened during the quake.

“We’ve got to have somebody who has connections there. We’re lost without that,” Kieffer says. “Thank goodness for Binod.”

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Hit the ground running

Being able to hit the ground running is key, because the scientists are working in a shrinking time window: After the humanitarian rescue operation, but before the geophysical evidence that they need to find is erased by the monsoon rains that sweep through the region during the summer.

Nepalese people are known for being quick hikers, and Tiwari has the rest trailing him.

“In my heart, I am still Nepali,” he calls over his shoulder.

Tiwari and the team, which is supported by the US National Science Foundation, are examining every bit of infrastructure they come across – bridges, roads, houses and hydropower projects.

But they’re also looking at how different types of soil reacted, in part to identify slopes in this mountainous country that have a high risk of landslide.

Finding those structural weaknesses in the terrain now will allow them to better predict which slopes are most likely to give way when the monsoon comes – and make sure that residents are out of harm’s way.

Soil also plays a role in whether a building survives an earthquake – its composition, the grain size, how densely packed it is and how much water it’s holding.

Later in the day, in an area called Gongabu, Tiwari climbs under a metal gate to examine a three-story brick-and-concrete school that has sunk, its side sheared off so that a classroom gapes open next to the basketball hoop.

The principal’s son joins Tiwari and his team as they stand next to a mural depicting Charles Darwin, Marie Curie and Galileo. He explains that school officials had built the structure to withstand an 8.0 quake.

“But they didn’t check the soil profile,” Tiwari says, shaking his head. “If you don’t check the soil, how do you build a foundation?”

NEXT PAGE: Read about the team's nightmare ride through quake-affected roads.

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