Adverse Affects of Flood Flow at Skewed Railroad Crossings

This poster presents a case study documenting the hydraulic issues relating to skewed bridge crossings. Although Hydraulic Engineering Circular Number 20 (HEC-20) discusses these adverse affects, the illustrations and discussions of the issues relating to skewed bridges are brief. This is not a failing of HEC-20 but an acknowledgement that, given the extensive scope of the subject matter contained in HEC-20, this document can only provide a very broad treatment of the methods and process for evaluating and designing bridges in a variable morphological environment. This study presents the hydrologic investigation of a flood event from historic, eye witness, and post flood investigation. Analysis of this data clearly indicates that due to embankment skew, the water levels on the approach embankment were as much as 1.5 m (5 ft) higher than at the bridge opening. The consequences of this are graphically illustrated by photos taken during the flood, and analysis of post-flood hydrographic survey data.