A 7.8-magnitude earthquake hit Nepal on April 25, killing thousands of people and causing widespread devastation to buildings and infrastructure.
The next day, Oregon State University researchers Ben Mason and Deepak Rayamajhi got calls asking them to travel to the country to study the earthquake’s damage.
“As an earthquake engineer, this is like getting called up to the big leagues,” said Mason, who did similar research after the 2010 earthquake in Japan.
For Rayamajhi, who was doing postdoctoral research at OSU at the time, being called to study the earthquake’s effects had particular significance: He is a native of Nepal.
“It’s my responsibility to help,” he said of his feelings about going to study the aftermath of the earthquake.
The pair are geotechnical earthquake engineers, and their research has particular relevance for Oregon:
“We know an earthquake is going to happen in Oregon, and Nepal is particularly relevant because they have the same type of plate boundary as we do,” said Mason, an assistant professor who has been with the Civil and Construction Engineering Department at OSU since 2010.
Rayamajhi, who will be starting a job with CH2M Hill in Corvallis later this month, was in Nepal doing research from May 28 to June 27; Mason was there May 25 to June 3 and again June 15 to June 27.
Mason and Rayamajhi study an effect that occurs during earthquakes known as liquefaction, a process in which shaking soil can become a viscous liquid, affecting anything built on the soil. On slopes, liquefied soil flows downhill, causing landslides.
The researchers, along with colleagues from the California Institute of Technology and the U.S. Geological Survey, examined and documented collapsed and tilting buildings and used an auger to drill into areas where they knew liquefaction had occurred so they could understand the structure of soils that liquefied.
They also occasionally dug trenches to look at soil composition with an excavator, and used a seismometer to gather data about microtremors in areas that had liquefied.
Mason said they were looking for anomalies — areas that had liquefied that did not fit existing models for liquefaction. The anomalies they plan to investigate further.
“We’re trying to bring the lessons there back home,” said Mason.
Understanding what types of soil liquefy in an earthquake could be useful in determining where and how to build structures, or how to upgrade existing structures to make them more likely to survive an earthquake.
Mason and Rayamajhi said in Nepal, soils are not studied before buildings are constructed. As a result, they saw high-rise buildings that collapsed or ended up leaning because the ground beneath them liquefied.
“I describe these trips as emotionally and physically exhausting,” said Mason.
Rayamajhi, who earned a doctorate in geotechnical engineering in 2014, said he was proud of the resilience he saw in his native country.
“The government was not well-prepared, but at the end it worked out OK because the people helped each other,” he said.
Mason and Rayamajhi said they traveled to villages the earthquake had made inaccessible except by helicopter, and in some places saw people who were still living in damaged buildings because they had no other choice.
“I was touched,” Rayamajhi said of seeing people in these circumstances. “They said ‘we don’t want your help, we want to help ourselves.’”
Mason said he thinks that in some ways the Nepalese are handling the earthquake better than Oregonians might, in part because they are accustomed to making do without infrastructure, but also because their culture has such a strong community orientation.
However, he said, Oregon has an opportunity to prepare its infrastructure to better withstand a quake.
Meanwhile, they also have a long-term goal of building the capacity so that scientists and engineers in Nepal can do soil testing themselves, so that buildings there can be constructed to avoid liquefaction damage.
Mason said they are looking into trying to get funding from the United States Agency for International Development to get equipment for Nepalese universities and government agencies to do the soil testing.
Mason said he is excited to return to Nepal for further research and that it is an amazing place.
“We have a lot of lessons to learn from the Nepalese,” he said.