Many bridges in the St. Louis area are incapable of withstanding the impact of a major earthquake, according to a recent study by University of Missouri-Rolla student Robert Riess, a senior in civil engineering from The Woodlands, Texas.
Working with officials from the Missouri Department of Transportation, data from the Federal Highway Administration, and his advisor, Dr. Ronaldo Luna, UMR associate professor of civil engineering, Riess conducted a yearlong study on bridges in the St. Louis area to determine which bridges were vulnerable to seismic activity based on seven general characteristics.
"We picked various bridges based on their soil classification, length, year built, and other characteristics to determine which ones might be vulnerable in an earthquake," says Riess. With more than 2,500 bridges in the St. Louis area, Riess’ research focused only on shorter bridges spanning 200-500 feet. He studied 16 bridges that do not follow current seismic requirements.
"The performance of the highway system in a major metropolitan city in mid-America is of great importance and significance to the economic and social welfare of this region," Riess says. "The highway system should be earthquake resistant. However, the infrastructure on which this highway network is built on is, in many locations, past its design life. Many of the bridges built in the 1940s through the 1970s did not incorporate seismic design considerations."
The St. Louis area is vulnerable, says Riess, because it is close to the New Madrid seismic zone in Missouri’s Bootheel region. The zone is known for the New Madrid earthquakes of 1811-1812, one of which registered 8.0 on the Richter Scale and rang church bells in Boston.
"Based on the history and the location of the New Madrid seismic zone, St. Louis could receive ground motion from an earthquake that would result in serious consequences to the structures in St. Louis and more importantly, the safety of the citizens," Riess says.
The destruction from an event similar to the 1811-1812 New Madrid quakes would be catastrophic for St. Louis, Riess says.
"The New Madrid seismic zone has the capability of producing earthquakes with fatal consequences. The consequences during the 1811 earthquake would not be considered a fatal consequence because there were not many settlers in the area, but imagine the magnitude of destruction capable if an earthquake occurred today and the distance the shock waves would travel in the Midwest area."
Riess conducted the research under Luna’s guidance through UMR’s Opportunities for Undergraduate Research Experience program, which gives students opportunities to conduct hands-on academic research with UMR faculty. Reiss’ paper and presentation on the topic won first place in UMR’s Undergraduate Research Symposium last year, and Reiss received the $1,000 first-place award.
In June, Riess will begin using his civil engineering expertise as a facilities engineer at ChevronTexaco Overseas Petroleum in Houston, Texas. His work will focus on a project in Angola, Africa.