20160191_R-2250 - Double 87x63 pipe_20190509

Carpenter, Kristi
From: Lentine, Sarah F
Sent: Thursday, May 09, 2019 4:32 PM
To: Johnson, Jay B; Steffens Thomas A SAW; Ward, Garcy
Cc: Horner, Kenneth V; '[e-mail]'
Subject: FW: [External] R-2250 - Double 87x63 pipe
Attachments: R2250_EC_FINAL_55_050819.pdf, R-2250_96in_extension_hy8.pdf, R-2250
_double_arch_HYBReport.pdf
No
Please see the attached revised plan sheet and hydraulic reports for the pipe we discussed on NC 102 on the Greenville
SW Bypass project on Tuesday.
Thanks,
Sarah F. Lentine, PE
From: Yelverton, Wyatt <[e-mail]>
Sent: Wednesday, May 8, 2019 2:41 PM
To: Lentine, Sarah F <[e-mail]>
Cc: [e-mail]; Rice, James R. <[e-mail]>
Subject: [External] R-2250 - Double 87x63 pipe
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Sarah,
Aaron mentioned a few information requests from agency representatives about the plan for using the two 87"x63"
pipes instead of the originally planned 96" extension.
Regarding the erosion control plan/devices in this area, everything stays the same (see attached). I made minor
adjustments to the silt fence overtop larger headwall on the inlet side. Also, the rock check (sdo #5503) was moved back
slightly. Inlet protection was also added for the new junction box at the end of 87"x63" pipes.
Regarding the calculations for 2-87"x63" pipes versus the single 96" extension, I have attached HY-8 reports for the
updated design as well as original design. In both cases the calculations show plenty of capacity on the pipes. For the
updated design we wanted to provide the same amount of open flow area as we would have been getting with the 96"
pipe. The open area for a 96" pipe is 50.3 sf. Open area for the 2-87"x63" is 64.2 sf (32.1 sf each).
Let me know if any other information is needed.
Thanks,
Wyatt
Wyatt D. Yelverton, PE, CPESC
Hydraulics Project Manager

HDR
555 Fayetteville Street, Suite 900
Raleigh, North Carolina 27601
D 919.232.6623 M 919.389.6681
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