With fall upon us, MoDOT bridge maintenance crews are stepping into high gear to begin their annual bridge inspections. Seven bridge inspectors tackle the task of examining roughly half of MoDOT’s more than 10,000 bridges each year. MoDOT district employees at each location and two special bridge teams help the inspectors so they can complete the inspections by March 1.
“The main duty of the bridge inspector is to ensure that bridges are safe for the traveling public,” said Kenneth Foster, MoDOT supervising bridge inspection engineer.
The bridges are examined for signs of deterioration, section loss, cracked or broken parts, rotten timber, signs of settlement and loose or missing parts and then assigned condition ratings. Each bridge is rated on three elements: the deck, the superstructure (connection between supports) and the substructure (the ground supports). Bridges that receive a rating of three or four must be inspected each year. There are about 1,400 bridges included in this category.
Most bridges require some type of maintenance upon inspection. Common maintenance includes cleaning, sealing cracks, joints or decks, repairing concrete decks, replacing rotten timber, removing drift and slope or channel maintenance.
“Bridge inspections are performed in the fall and winter months because vegetation is down and the cooler weather allows us to dress protectively without getting too hot,” said Foster. “Inspecting in fall and winter also frees the summer months for our underwater inspection program.”
All seven bridge inspectors are SCUBA certified to perform wading and diving operations on parts of bridges submerged in water. This year MoDOT performed 47 wading inspections, 10 depth-sound inspections and 14 SCUBA inspections.
Following the assessments, the bridge inspectors compile several lists, including an “exceptional bridge list,” that describes bridges in extremely poor condition. These lists are designed to provide the districts with information about the condition of their bridges and ideas for future programming needs to ensure bridge safety for motorists.
