Author(s): Seung Ho Hong; T. W. Sturm
Linked Author(s): Terry Sturm
Keywords: No Keywords
Abstract: A case study of significant bridge scour that caused closing of a bridge and necessitated bridge repair due to damages sustained from a 500-year flood that occurred in Georgia, USA in 1994 is reported. A physical model study with geometric similarity of the bridge embankments, abutments, piers and bridge deck as well as the river bathymetry was conducted in a flume in the hydraulics laboratory at the Georgia Institute of Technology. The embankment and abutment were constructed of erodible materials that were protected by rock riprap according to current design standards in Georgia. Model scaling issues are discussed, and a favorable comparison is made between the measured scour in the laboratory in the vicinity of the left bridge abutment on the floodplain and the measured scour depths in the field. Contraction scour occurred as a result of lateral flow contraction as well as vertical flow contraction due to the submerged orifice flow condition. Simultaneous abutment scour and pier scour were also observed in the vicinity of the abutment. Comparisons are made between current methods of estimating total scour and model observations.
Year: 2009