20110728 Ver 1_More Info Received_92010829

Strickland, Bev
From: Witherspoon, Lauren
Sent: Monday, August 29, 2011 9:21 AM
To: Strickland, Bev
Subject: FW: Bragg Street additional information_Project #2011-0728
Attachments: Riprap outlet protection.pdf
For the file
Thanks,
Lauren
From: Becky Ward [mailto:bwardC&wce-corp.com]
Sent: Wednesday, August 24, 2011 12:05 PM
To: Witherspoon, Lauren
Cc: 'Thomas-Ambat, Sheila'
Subject: Bragg Street additional information
Lauren:
I have attached the riprap outlet protection calculation for the Bragg project as requested. I believe I satisfactorily clarified
the statement on page 7 of the text when we talked this morning. Please let me know if you require any additional
information to complete your review.
Sincerely,
Becky L. Ward, P.E.
Ward Consulting Engineers, P. C.
8368 Six Forks Road, Suite 104
Raleigh, NC 27615-5083
Ph: 919-870-0526
email: [e-mail]
DESIGN OF RIPRAP OUTLET PROTECTION WORKSHEET
Project Bragg Street Date 30-Nov-10
Project No. Designer J. Eakins
Outlet 1D FES Al
Outlet flowrate 23.2 cfs
Pipe diameter 24 inches
Number of pipes 1
Pipe separation 0 feet
Outlet pipe slope I percent
Pipe diameter (ft)
Zone from graph above = 2
Outlet pipe diameter 24 in. Length = 12.0 ft.
Outlet flowrate 23.2 cfs Width = 6.0 ft.
Outlet velocity 7.4 ft/sec Stone diameter = 6 in.
Material = Class B Thickness = 22 in.
Zone Material Diameter Thickness Length Width
1 Class A 3 9 4 x D(o) 3 x D(o)
2 Class B 6 22 6 x D(o) 3 x D(o)
3 Class I 13 22 f x D(o) 3 x D(o)
4 Class I 13 22 8 x D(o) 3 x D(o)
5 Class II 23 27 10 x D(o) 3 x D_(o)
6 Class H 23 27 10 z D(o) 3 x D(o)
7 Special study required
1. Calculations based on NY DOT method - Pages 8.06.05 through 8.06.06 in NC Erosion Control Manual
2. Outlet velocity based on full-flow velocity
2010-11-30 - Design of g;prap Outlet ProtectioN.As
11/30/2010