110-foot concrete bridge withstands 8.0 earthquake simulation

After a succession of eight separate earthquake simulations, a 110-foot long, 200-ton concrete bridge model at the University of Nevada, Reno withstood a powerful jolting, three times the acceleration of the disastrous 1994 magnitude 6.9 Northridge, Calif. earthquake, and survived in good condition.

"This is very satisfying to see how well the design and components worked," Saiid Saiidi, principal investigator for the project and University of Nevada civil engineering professor said after the final test on this bridge Tuesday afternoon.

"We estimated bridge failure at 8 inches of deflection, which is a lot, but we had 10 inches of deflection in the support columns and the bridge remained standing and usable, even with considerable internal stresses."The bridge model is shaken with bidirectional forces to realistically simulate an earthquake. The researchers mimic the Northridge earthquake using recorded data of the actual earthquake. Computer programs direct the movements of the three large hydraulically-controlled shake tables in the University's world-renowned, large-scale structures laboratory.

"We know the bridge would have survived that quake in good condition and still be usable," Saiidi said.

via 110-foot concrete bridge withstands 8.0 earthquake simulation.