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The storms killed two people, ripped buildings off foundations, decimated trees and presented a team of University of Nebraska-Lincoln civil engineers with an opportunity to study the ruin wreaked by natural disaster.

“We’re trying to study and analyze complex deformations and be able to detect and quantify damage,� said assistant civil engineering professor Richard Wood.

The engineers spent three days in Pilger within a week of the storm, using lasers and a remote-controlled quadcopter equipped with a camera to document damage. Wood was joined by graduate student Gulipiye Abudukadier and doctoral student Ebrahim Mohammadi.

They had two goals.

The first was to find where engineering falls short, leaving buildings vulnerable to disasters like tornadoes, earthquakes and the more mundane stresses of daily existence. The second was to develop algorithms to predict structures’ weaknesses and how they will behave under stress, and to assess the potential for damage.

“We can’t predict if damage will occur, but we can help quantify and say this area of the structure is most likely to be damaged,� Wood said.

The researchers found unreinforced masonry is particularly vulnerable to tornadoes and that broken windows are the most common damage. Putting a shatter-reducing film on windows can reduce injuries from flying glass, they concluded.

In Pilger, anchor and rivet failure led to grain bins being ripped from their foundations and turned into steel missiles, one of which hit the Wisner-Pilger Middle School and collapsed its southeast corner.

With the information they gathered, the engineers created a three-dimensional image of the middle school they can rotate and examine from different angles. The school was one of six sites they evaluated using a light-detecting and ranging 3D scanner (LiDAR, for short) and the camera-carrying drone.

Using precision technology to examine damage removes guesswork from calculations.

“We want to remove the subjectivity," Wood said. "We want it to be very objective, meaning it is not dependent on whoever is inspecting the facility.�

Next week, Wood plans to travel to Nepal to evaluate damage from a 7.8-magnitude earthquake that killed more than 8,000 people. He'll work with researchers from several other universities.

“We’re going to learn from some modern structures, some historic, culturally relevant temples, and there is some discussion for quantifying landslides, but landslides are always a risk because it is monsoon season,� he said.

Wood and his associates are using Pilger as a case study for rapidly assessing damage and idenfiying shortcomings in the system. They have another case study in El Centro, California, where a 2010 earthquake damaged a two-story reinforced concrete building with masonry walls. As part of the project, additional simulated damage was done with field equipment from UCLA.

“We’re shaking the building,� Wood said.