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A Comparison of the One-dimensional Bridge Hydraulic Routines from HEC-RAS, HEC-2 and WSPRO
A Model Study of Bridge Hydraulics
Author: A. David Parr
Publisher:
Published: 2007
Total Pages: 72
ISBN-13:
DOWNLOAD EBOOK →Most analyses of bridge hydraulics for flood flows are performed using the Army Corps of Engineers HEC-RAS (Hydrologic Engineering Centers River Analysis System) computer program. This study was carried out to compare results of HEC-RAS bridge modeling with experiments performed in a laboratory flume. The study was intended to add some insight into the effect of bridge hydraulic features such as ineffective flow regions, weir overflow and flow through skewed bridges. This insight should be useful for bridge engineers in HEC-RAS bridge modeling endeavors. A laboratory flume was constructed specifically for this project. The flume cross section has a main channel region and relatively wide left and right overbank regions. Different bridge scenarios were modeled. Froude number similarity was used to "scale up" model parameters and create prototype HEC-RAS hydraulic models simulating laboratory model conditions. Water surface profiles were compared for corresponding HEC-RAS and laboratory results.
Flow Transitions in Bridge Backwater Analysis
A Model Study of Bridge Hydraulics, Edition 2
Author:
Publisher:
Published: 2010
Total Pages: 124
ISBN-13:
DOWNLOAD EBOOK →Most flood studies in the United States use the Army Corps of Engineers Hydrologic Engineering Center's River Analysis System (HEC-RAS) computer program. This report is the second edition. The first edition of the report considered the laboratory model to be distorted with 1:100 horizontal scale and 1:20 vertical scale. The second edition considers both distorted and undistorted interpretations of the laboratory models. Moreover, more advanced HEC-RAS modeling techniques are used to better match the HEC-RAS and the laboratory results. The advanced HEC-RAS models were based on review comments and model revisions by Mr. Gary W. Brunner, Senior Technical Hydraulic Engineer, Hydrologic Engineering Center (HEC).
Guide to Bridge Hydraulics
Author: Transportation Association of Canada
Publisher: Thomas Telford
Published: 2004
Total Pages: 206
ISBN-13: 9780727732620
DOWNLOAD EBOOK →Basic hydraulic considerations - Channel types and behaviour relation to bridges - Basic hydraulic requirements - Hydraulic design procedures Hydrologic estimates - Statistical frequency analysis - Runoff modeling - Empirical methods - High water levels and stage-discharge relations - Extreme floods and risk Scour protection and channel control - Scour protection around bridge foundations - Erosion protection of banks and slopes - Design of rock riprap - Cannel control works Hydraulic aspects of construction, inspection and maintenance - Construction - Inspection - Maintenance Special problems - Tidal crossings - Inland basic crossings - Waves and waves protection - Physical modeling of bridge problems - Alluvial fans - Debris flow and torrents
Determination of Ineffective Flow Areas in Bridge Modeling Using HEC-RAS by Locating Ineffective Flow Stations
Author: Venkata Subbarao Bayareddy
Publisher:
Published: 2016
Total Pages: 58
ISBN-13:
DOWNLOAD EBOOK →The Hydrologic Engineering Center's River Analysis System (HEC-RAS) uses a simulation model to delineate floodplains, but it may also be used to size bridges and culverts. HEC-RAS has an option for defining ineffective flow stations at bridges and culverts. An ineffective flow area is a portion of a river or stream's cross section where there is no water flowing downstream due to the presence of a bridge or a similar structure, i.e. no conveyance. Current practice is for modelers and engineers to provide an estimate of the location of ineffective flow stations. The purpose of the research effort detailed in this document is to develop an iterative approach capable of quickly and accurately locating ineffective flow stations at bridges. The ultimate goal of the proposed research effort will be to include the methodology in future releases of the HEC-RAS model.
Assessment of HY-8 and HEC-RAS Bridge Models for Large-Span Water-Encapsulating Structures
Author: Dennis Lyn
Publisher:
Published: 2019-02
Total Pages:
ISBN-13: 9781622605064
DOWNLOAD EBOOK →Current INDOT policy requires that culvert-like structures with spans greater than 20 ft be treated for purposes of hydraulic analysis as a bridge, and hence mandates the use of software such as HEC-RAS for predicting the headwater, rather than the culvert-specific software, HY-8. In this context, culvert-like structures are assumed to have a standard inlet geometry (e.g., such as those already modeled in HY-8) and a constant barrel geometry. The present study examines the technical basis of this policy, and whether the policy could be revised to allow the application of simpler culvert-hydraulics analysis and HY-8 to culvert-like structures with spans greater than 20 ft. Laboratory experiments were performed with model box culverts of span 1.5 ft and two streamwise lengths, 2.1 ft and 8 ft, and performance curves describing the variation of headwater with discharge were obtained. The effects of bed roughness, the presence or absence of a cover (if present, the rise was 0.5 ft), and a range of tailwater levels, were investigated. The laboratory observations were compared with predictions by HY-8 and HEC-RAS models, and the model performance assessed. In general, HY-8 predictions were found to be as good as, and in some cases superior to, the HEC-RAS predictions, for both long and short culvert-like structures. This was attributed to the empirical information in HY-8 being more tailored to the specific standardized geometry of culvert-like structures, and the automatic inclusion of roughness effects, whereas HEC-RAS, at least when used with default coefficients and settings, relied on generic coefficients and neglected roughness effects. It was therefore recommended that a change in INDOT policy allowing large-span culvert-like structures to be analyzed using conventional culvert hydraulics would be technically justified for problems where the structure could be considered in isolation and accurate input data are available.
Bridge Hydraulics
Author: Dr Les Hamill
Publisher: CRC Press
Published: 1998-12-03
Total Pages: 384
ISBN-13: 148227163X
DOWNLOAD EBOOK →The design of bridges across rivers and streams is a major component of many civil engineering projects. The size of waterways must be kept reasonably small for reasons of economy and yet be large enough to allow floods to pass. Bridge Hydraulics is the first book to consider both arched and rectangular waterway openings in detail and to describe a
HEC-RAS 2.2 for Backwater and Scour Analysis
Author: A. David Parr
Publisher:
Published: 2000
Total Pages: 188
ISBN-13:
DOWNLOAD EBOOK →The Kansas Department of Transportation (KDOT) and most bridge consultants in Kansas have been using the DOS-WSPRO program and the KDOT scour spreadsheets to perform bridge hydraulics and scour analysis for the past several years. Unfortunately, DOS-WSPRO is a DOS program that is no longer supported and there is no metric version. Consequently, the newer Windows-based hydraulics program HEC-RAS (Hydrologic Engineering Center River Analysis System) developed by the U.S. Army Corps of Engineers appears to be a logical choice to succeed DOS-WSPRO as the basic flow model in KDOT's bridge design and scour analysis program. HEC-RAS has gained considerable popularity in the engineering community and offers many options not previously available to hydraulic modelers. It also has a scour module and has an option, the WSPRO bridge analysis routine (henceforth called HR-WSPRO). This study compared the HEC-RAS program with the DOS-WSPRO program and examined the HEC-RAS program with regard to scour analysis. The possibility of using the existing KDOT scour spreadsheets with output from the HR-WSPRO bridge routine was also considered. Finally, a literature review was performed to determine if any updates in the scour methods and new approaches to special conditions, such as the effect of debris or pressure flow affecting pier scour, were available.
