Flooding of the Iowa River during July and August 1993 caused extensive contraction scour at the State Highway 99 bridge over the Iowa River at Wapello, Iowa. At least 3.3 m of piling under the footing of the second pier from the right (west) abutment were exposed. The scoured streambed did not fill in again after the flood receded, and a bathymetric survey in November 1993 showed that the streambed had been scoured for a distance of about 500 m upstream from the bridge. The bridge was closed to traffic, first because of water over the roadway when a levee failed, and then remained closed because of the exposed piling. The bridge subsequently was reopened to traffic with a weight limit of 13.6 tons.
Additional publication details
Contraction scour at a bridge over the Iowa River
Publ by ASCE
New York, NY, United States
Larger Work Title:
Proceedings - National Conference on Hydraulic Engineering
Proceedings of the 1994 ASCE National Conference on Hydraulic Engineering