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Title: Limitations of Traditional Capacity Equations for Long Curb Inlets
Accession Number: 01628128
Record Type: Component
Record URL: Availability: Find a library where document is available Abstract: Recent work with full-scale experiments indicates that there are fundamental problems with standard curb inlet design equations when applied to depressed curb inlets of 10 ft (3 m) or longer. A full-scale laboratory experiment showed that the latter part of a long inlet does not have a simple linear water surface profile at 100% interception, which is assumed for the form of Izzard’s equation that is adopted for many common design approaches [including the Hydraulic Engineering Circular 22 (HEC-22) design equations recommended by FHWA]. For a long inlet, thin flow sheets were observed for a substantial portion of the inlet length, which is consistent with previous observations that have not been incorporated into standard design equations. Experimental results indicate that the HEC-22 design equations significantly overestimate the interception capacity of long, depressed curb inlets for an on-grade gutter. This issue has potential safety implications in that the gutter bypass and spread for a design storm will be larger than expected for such inlets. The present work is preliminary, so an L2 measure previously proposed by Izzard is recommended as a maximum inlet length pending the outcome of further studies.
Monograph Title: Monograph Accession #: 01629806
Report/Paper Numbers: 17-02068
Language: English
Authors: Schalla, Frank EAshraf, MuhammadBarrett, Michael EHodges, Ben RPagination: pp 97–103
Publication Date: 2017
ISBN: 9780309441803
Media Type: Digital/other
Features: Figures
(8)
; Photos; References
(21)
; Tables
(1)
TRT Terms: Identifier Terms: Subject Areas: Design; Highways; Hydraulics and Hydrology
Files: PRP, TRIS, TRB, ATRI
Created Date: Dec 8 2016 10:44AM
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