An inspection of state highway system bridges within a 60-mile radius of the epicenter of Saturday’s 5.8-magnitude earthquake near Pawnee revealed no significant damage. All bridges remain open to traffic and safe for travel.
As part of the Oklahoma Department of Transportation’s policy to inspect state highway bridges in a 30-mile radius following an earthquake of 5.4 to 5.8 magnitudes, 180 state highway bridges were inspected immediately following the Sept. 3 earthquake. This inspection revealed only minor cosmetic damage on two bridges, SH-15 over Red Rock Creek in Noble County and SH-108 over the Cimarron Turnpike in Payne County. These bridges are structurally safe and remain open to traffic.
On Wednesday, ODOT expanded its inspection radius to 60-miles from the epicenter in response to the upgrade in magnitude from 5.6 to 5.8 by the United States Geological Survey. An additional 175 bridges were inspected over a two-day period and no damage was found.
“We are very conservative and deliberate in our approach to bridge inspections following an earthquake because our first priority is the safety of the traveling public,” Mike Patterson, ODOT executive director, said. “With this weekend’s earthquake being the strongest recorded in Oklahoma, we inspected bridges in a greater radius than our policy requires.”
While bridges are designed to withstand a certain amount of vibrations, the department recently went through a rigorous process to develop an earthquake inspection policy and manual beginning with a 5-mile radius on a 4.7 magnitude. As part of this policy, state highway bridges are inspected within a 30-mile radius of an earthquake with a magnitude of 5.4 to 5.8 and within a 60-mile radius of an earthquake with a magnitude of 5.9 to 6.2. Saturday’s 5.8 magnitude is the strongest earthquakes the state has experienced to date.
