My WebLink
|
Help
|
About
|
Sign Out
Home
Browse
Search
FLOOD00178
CWCB
>
Floodplain Documents
>
Backfile
>
1-1000
>
FLOOD00178
Metadata
Thumbnails
Annotations
Entry Properties
Last modified
11/23/2009 10:50:38 AM
Creation date
10/4/2006 9:07:49 PM
Metadata
Fields
Template:
Floodplain Documents
County
Statewide
Title
Application of the HEC-2 Bridge Routines - Training Document Number 6
Date
6/1/1974
Prepared For
US
Prepared By
US Army Corps of Engineers
Floodplain - Doc Type
Educational/Technical/Reference Information
There are no annotations on this page.
Document management portal powered by Laserfiche WebLink 9 © 1998-2015
Laserfiche.
All rights reserved.
/
85
PDF
Print
Pages to print
Enter page numbers and/or page ranges separated by commas. For example, 1,3,5-12.
After downloading, print the document using a PDF reader (e.g. Adobe Reader).
Show annotations
View images
View plain text
<br />v2 <br /><l"* = velocity head <br /> <br />HL = head loss <br /> <br />Defining the head (H) on the orifice as the difference between the upstream <br />energy elevation and the downstream water surface elevation (the defini- <br />tion used in HEC-Z) produces: <br /> <br />H = (Yl + Zl + <br /> <br />Z <br /><llVl <br />2g ) - (Yz + Zz) <br /> <br />(Z) <br /> <br />Substituting H from equation 2 into equation 1 produces: <br /> <br />H = <br /> <br />Z <br /><l2VZ <br />Zg + HL <br /> <br />(3) <br /> <br />Head loss (HL) through the bridge can be defined in terms of the bridge <br />velocity head and loss coefficient~. The ,expansion to a point just <br />downstream can be defined by an expansion coefficient K and the change <br />e <br />in velocity head. <br /> <br />VZ <br />HL = Kb ~ + Ke ( <br /> <br />VZ <br />b <br />Zg <br /> <br />Z <br /><lzVz <br />2g <br /> <br />) <br /> <br />(4) <br /> <br />where: <br /> <br />b c subscript designating the bridge <br /> <br />The head loss equation 4 then can be used to define HL in equation 3: <br /> <br />H = <br /> <br />Z <br /><lzV2 <br />2g + Kb ( <br /> <br />l <br />b <br />2g <br /> <br />) + K ( <br />e <br /> <br />~ <br />zg <br /> <br />Z <br /><l2VZ <br />2g <br /> <br />) <br /> <br />( 5) <br /> <br />/ <br /> <br />31 <br />
The URL can be used to link to this page
Your browser does not support the video tag.