Saturday, February 09, 2008

Engineers to take in-depth look at three local bridges

(Bridges identified as needing further study after preliminary plan evaluation)

Three local bridges were identified as needing further analysis after bridge engineers completed a study of Missouri’s 232 truss bridges.  Truss bridges use steel beams joined together by steel gusset plates to support the structure.
The three bridges - the westbound Blanchette Bridge on I-70, the westbound Daniel Boone Bridge on Route 40, and the southbound Route 21 bridge over the Meramec River (near the border of St. Louis and Jefferson counties) - will be evaluated further. The preliminary study was to determine if loads had significantly increased since the original construction of the bridge. This further analysis will make sure there were no errors in the original design of the gusset plates. Bridge engineers in Jefferson City will go over the plans for these three bridges, as well as any improvements, to verify the designs.
“So far we’ve found no problems, and I fully expect these studies to confirm that all bridges on Missouri state highways are safe,” said MoDOT Director Pete Rahn.  “Now that we’ve narrowed down the list, we’ll study those bridges further to make absolutely sure there are no problems.”
The westbound Blanchette Bridge was built in 1958, and carries approximately 70,000 vehicles a day. The westbound Daniel Boone bridge was built in 1935 and carries approximately 46,000 vehicles daily. The southbound Route 21 bridge was built in 1940 and carries approximately 21,000 vehicles daily.