WYDOT inspects 3 Wyoming bridges
by Wyoming Department of Transportation
August 16, 2007
An inspection Tuesday, August 14, confirmed the safety of the I-25 service road bridge over the South Fork of the Powder River about nine miles south of Kaycee.
The inspection found no problems that had not been previously identified, and no cause for safety concerns. Inspectors will continue to monitor the bridge's condition and maintenance work is already scheduled for next year.
The bridge was the third in Wyoming to be inspected following the U.S. Department of Transportation's request that states look at any bridges with designs similar to the Minneapolis bridge that collapsed on Aug. 1.
The other two Wyoming bridges identified as having similar designs are the US 26-89 bridge over the Snake River at Hoback Junction about nine miles south of Jackson, and the Fremont County Road No. 298 bridge over the Wyoming Canal about 40 miles northwest of Riverton.
Inspections completed last week confirmed the safety of both of those bridges.
"These inspections were a precaution we were happy to take to reassure the public that Wyoming's bridges are safe," said Keith Fulton, assistant state bridge engineer. "The bridge inspection and management program we have been using for many years has allowed us to prioritize rehabilitation and reconstruction projects to make sure our bridges are in safe condition."
Under those programs, each of the 2,774 state- and locally-owned and maintained bridges in Wyoming is inspected at least once every two years. If those inspections identify conditions that require closer monitoring, the inspections are done more frequently.
The bridge inspections measure and record data for the National Bridge Inventory, including dimensions, clearances, alignments, waterway data and structural condition. The structural condition is evaluated by inspecting girders, decks, railings, columns and pilings. The inspectors look for deterioration that could include rusting or cracking of steel components, cracking of concrete, or something as simple as peeling paint.
Of the 1,929 bridges owned and maintained by WYDOT, 1,838 are classified as acceptable, and 91 are classified as structurally deficient or functionally obsolete.
Classification as structurally deficient means there are elements of the bridge that need to be monitored or repaired, but it does not mean the structure is unsafe or likely to collapse. If inspectors find unsafe conditions they restrict access or close the bridge.
The functionally obsolete classification is a measure of how well a bridge serves existing and anticipated traffic volumes and types, considering factors such as the number of travel lanes, the width of travel lanes and shoulders and the amount of vertical and horizontal clearance.
In the photo at right, WYDOT bridge inspectors Paul Cortez and Tom Hammer examine the I-25 service road bridge over the South Fork of the Powder River nine miles south of Kaycee. This bridge was built in 1932, is 307 feet long and is a pin-connected, riveted steel deck truss design.