@article{ref1,
title="July 1993 flood damage to US-71 bridge over Brushy Creek, Carroll County, Iowa: case study",
journal="Transportation research record",
year="1995",
author="Monk, W.Curtis",
volume="1483",
number="",
pages="38-46",
abstract="The flood of 1993 inundated much of the upper Mississippi River Basin, resulting in significant damage at numerous sites in Iowa. A record flood on Brushy Creek resulted in failure of the US-71 bridge 14.5 km south of Carroll, Iowa. Development of a computer flow model at the site and analysis of scour for the failed bridge and its replacement are included. On the basis of data from plans, topographic maps, and a United States Geological Survey (USGS) crest stage gage at the site, the computer model was developed using WSPRO (a USGS/FHWA computer program for Water Surface Profile Computations). To construct the computer model, cross sections were developed, and Manning's roughness coefficients &quot;n&quot; were assigned, such that known stage elevations were produced for a given flow. The model was then used to estimate flood flows during the event. Scour was estimated using the WSPRO data, soil boring data, and procedures from HEC-18, &quot;Evaluating Scour at Bridges&quot;. Long-term aggradation or degradation, contraction scour, and local pier scour were all evaluated. The case study allowed verification of HEC-18 procedures and formulas based on an actual flood event versus a laboratory flume study. The scour analysis predicted scour below the pile tips at the piers, and the bridge failed when the piers were undermined--good evidence of the validity of HEC-18 scour calculations. The computer program WSPRO and the scour procedures from HEC-18 as analysis tools that can be used to assess stream flows, scour potential, and design adequacy are presented.  Record URL:  http://onlinepubs.trb.org/Onlinepubs/trr/1995/1483/1483-005.pdf<p /><p>Language: en</p>",
language="en",
issn="0361-1981",
doi="",
url="http://dx.doi.org/"
}