SW6190504_Outlet RipRap Calculation_7/22/2019

RIP -RAP OUTLET PROTECTION CALCULATIONS

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Calculated Value
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Designed By:
JBG Date: 6/12/2019
Checked By:
BPP Date: 6/12/2019
Company:
Bobbin Design Build. Inc
Project Name:
HOKE COUNTY COOPERATIVE EXTENSION OFFICE BUILDING
Project No.:
18-0236
Site Location (C€tylTown) Raeford
Culvert Id. 1
Total Drainage Area (acres) 0.45
Step 1. Detrrusrne The tailwatet depth (turn cluumel characiensacs belotr rite
pipe outlet for the design capacity of the pipe If rile tailwateT depth is ]cis
than half the outlet pipe diameter it Is classified trimunnin nultvatei condition
If to n peater than half the pipe dianserm it is classified niaxinuun condition
Pipes that outlet onto wide Bat areas with no defined channel are assumed
To base a minimum railwatei condition tuiless reliable flood stage elevatimn
Shoffotherwme
Outlet pipe diameter, Do (in.) 72
Tailwaler depth (in.) 0
Minimum/Maximum tailwater? Min TW (Fig. 8.06a)
Discharge (efs) 3.1
Velocity (tt.ls) 4.9
Step :. Based on the taihtatcr condlitoni detetrmned ut step 1 entet Figure
8 06a of Figure 8 Pbb and determine d, tiprap size and tuutunwit apron length
(Lil The d,. size is the median ttonr size art a well -graded tiprap apron
Step 7. Detetiume apiou urdth at the pipe outlet die apron shape and the
apron %iddi at the outlet cud from the same figrue used in Step 1
Minimum TW
Maximum TW
Figure 6.06a
F4guire 8,
Riprap d50, (ft)
0.25
Minimum apron length, La (ft-}
9
Apron width at pipe outlet (ft.)
18
18
Apron shape
RECTANGLE
Apron width at outlet end (tl.)
15
6
Step 4. Drternunr the m&%inuun store dianieles
dr_
= 1 5 x d,.
Minimum TW
Maximum TW
Max Slone Diameter, dmax (ft.)
0.375
0
Step S. Deleminge the apron durknv.s
Apron thl(kness = I ', , t€,
Minimum TW Maximum TW
Apron Thickne85(ft.) 0.5625 0
Step 6. Fit rile riplap apron to the utr bt imskiag it lrtrl for the lruuunslin
lnsgds Lr front Figtn r 8 06a or I igtue 8 06b Extend the aliion farther
downsoeatn and along charnel banks tuiul slabilin is assured Keel; the
apron as straight as possible and ahgn it tt'tth the flo% of the teceisTng Sticam
%lake am' iirce%swy ahlainienr trends urai rite pipe outlet so that the entraisce
um, the Teceii utp triram It %ualght
somr locatiolil Ills\ trqulre Jigging of the tinlue chwineI doss Sec nun to asSuie
Stabllln'
It lam be siecrssatt ro uscirase the size of ttplap %heir proleogoil of the
channel sine tlopeS is nriesstus' (Appr-rGn 5.0+) Where oterfalls exist at
ptpr outlris tit flott, are rxcessttr a phinge pool should br considrted see
page8669

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Designed By: JSG Date: 611212019
Checked By: BPP Date: 6/12/2019
Company: Bob" Design Blind, Inc
Project Name: HOKE COUNTY COOPERATIVE EXTENSION OFFICE BUILDING
Project No.: 18-0236 _
Site Location (CityfTown) Raetwd
Culvert Id. 2
Total Drainage Area (acres) 025
Step 1, l3ete1n11n tile- tallwatel depth front cluniilel chwacterlsrics brlmx the
pipe. outlet tot the drszgil eapaciry of the pipe If the tatlw-atei depth is less
than half the outlet pipe diameter it is classified nuninwai talhcatez colyditioll
If it Is greater than half ibe pipe diameter it is classified trumi vtuit condition
Pipes that outlet onto wade flat areas alth no defined charnel are amunied
to have a nluunnirn milwatet condition tultess reliable Rood stake elrl'atlotl%
sholl oche wi-r
Outlet pipe diameter, Do (in.) 72
Taitwater depth (in.) 0
Minimum/Maximum tailwater? Min TW (Fig. 8.069)
Discharge (cis) 1.7
Velocity (ft.ls) 4.2
Step 2- Based on the taihaatrr conditions drietnuned at step I enter Figwr
8 06a or figure 8 t?6b and deterllline d,, rlplap size and tnmunwn apron length
(L,) The d,. tin " die utedlan stone size in a welt -]traded nprap apron
Step t, Deienniue apron stidth at the pipe outlet the apron shape- and the
apron st"idol at die oisitri end from the saint figlur used ui Step
Minimum TW Maximum TW
Fiala 8,063 Figure 8.06b
Riprap d5o, (ft.) 0.2
Minimum apron length, La (ft.) B
Apron width at pipe outlet (ft.) 18 18
Apron shape RECTANGLE
Apron width at outlet end (ft.) 12 6
Step 4. Delenlune die ulwUliuuu stone diameter
d—= 15xd„
Minimum TW Maximum TW
Max Stone Diameter, dmax (ft.) 0.3 0
Step S- Dereriinue die allion duckilrss
Aptoi It11 Aness = 1 5 x et_,
Minimum TW Maximum TW
Apron Thickness(ft) 0.45 0
Slep 6. Fit the tlp,ap allicnn to the strr bs nudking at ksel fol the iluutnitml
lengd) LI from Figtue 606a or Frgtue 806b Extend ehr Apt oil farther
domi%tiema and along chrunlel banks tutu] srabilin is assturd Keep the
apron as stlalght ai possible and align it with the floe of the Ieceriiiig stiealn
`'take Rr1\' LICCeW111allglIHIC111 tlelidl hell tilt 17111e 01111e1 so ttult the eIAMICC
Into rile leccl\'1119 srreanl 1s %lialgill
Saint Ioca11011, IILA% Iectt"Ic 1113ing of the futile cls.,innel CIO%% seclioll Ioas4itic
scatsllim
h Ina 'N be uecrssan a to ulcrest the size of npiap ulrrlr protection of the
channel side Slopes Is uecessar) (.ippr+rr'n S.0) %%licit olrrfatls exist at
pipe outlets of Hosts ate rxcrlsnr a phmgr luol should be considered see
page 9 D6 S

User Input Data
Calculated Value
Reference Data
Designed By:
,IBA Date: 611=019
Checked By:
BPP Date: 6/12/2019
Company:
Bobbrtt Design Build. Inc
Project Name:
HOKE COUNTY COOPERATIVE EXTENSION OFFICE BUILDING
Project No.:
48-0236
Site Location (CitylTown) I Raeford
Culvert Id. 3
Total Drainage Area (acres) 0.3
Slop 1. Determine the tail atei depth front chatutel chitraclerishcs below The
pipe outlet for the design capaclts' of The pipe If the tatlnatel depth Is less
than half the outlet pipe drametn. it is classified nutunuat taltttater cola tiorh
If it is gzeater than half the pipe diaruerer it is classified utaxumuuu condition
Pipes that outlet onto uide flat micas wilt no defined channel ate assumed
to have a nu mnitun taihsater condition wiless reliable Hood stage elrtattons
shoss otherwi e
Outlet pipe diameter, Do (in) 72
Tailwater depth (in.) 0
MinimumlMaximum tailwater? Min TW (Fig. 8-06s)
Discharge (cfs) 2.05
Velocity (US) 4.2
Step 2. Baud on the taduatri conditions deurnnned rn step I enter Figure
8 062 of Figute 8 06b and deteltnrne d., tipiap size and itninunutri apron length
(L) The d,_ size is the mrdun stone we in a well -graded nptap apron
Step 11. Detetunue apfoe w idth at the pipe outlet the apron shape and the
apron width at the owlet end 5001 the sarne figure used ul Step '
Minimum TW Maximum TW
Fiowe 8.06a Fla,uM 8 D
Riprap d5o. (ft.) 0.2
Minimum apron length, La (ft) 6
Apron width at pipe outlet (ft.) 18 18
Apron shape RECTANGLE
Apron width at outlet end (ft.) 12 6
Step 4 Drrrruuu< di< rtraxrnuuu stout dtatuetn
dam„15xd„
Minimum TW Maximum TW
Max Stone Diameter, dmax (ft.) 0.3 0
Step 5. Detenuune the &pion duckrless
Apron Ihlckness = 1 5 x d_
Minimum TW Maximum TW
Apron Thickness(fl.) 0.45 0
Step 6. Fit the upna)) apron It- the site bs ulakrng n le%el fol ncc rrullinuun
length L front Flgitre 8 06a or FiPtue 8 061) Extend the apiou farther
dounstiealn and along charnel biuiks ulml smbhhn is a45lued Deep the
apiou m straight as possible and align it a rib the flon of due tecris lug stream
Make arlp rlec<ssan allgruilrut bends near the prpr Mllt<t so Out the rutiance
n110 rile IecelV'lllg %tlrallh i, %Ilalylli
Sonic locations user} lequnr huuhg of the rrtue chalwel cross ,ectholl to asssur
stablllrs
It teat be n"essej to urctease the size of nprap "bete piolecnon of die
charnel side slopes is necessan i.ippirtin S.05) Where oe-erfalts exist at
pipe outlets of Holt s are excess ne a phuuge l.nnl should Lee considered srr
pace8068

User Input Data
Calculated Value
Reference Data
Designed By:
JDG Date: 611212019
Checked By:
BPP Date: 6/1212019
Company:
Bobbin Design Build. rrx
Project Name:
HOKE COUNTY COOPERATIVE EXTENSION OFFICE BUILDING
Project No.:
18-0236
Site Location (City/Town) Raeford
Culvert Id. 4
Total Drainage Area (acres) NA (no flow for 10-yr storm)
Sirp 1. Detrnnuhe the is lwalev depth from charuhrl charactenwcs below the
pipe outlet fat the design capacin of the pipe It the taihrater depth is less
than half the outlet pipe dhame-ter. it is classified nutunhunt tahlwatei condition
If it is greater than half the pipe dhartterer it is classified maxmiwn condition
Pipes that owlet onto wide flat wets with no defined channel are asstuned
to have a ntuunntm railwater condition unless Fellable flood stage elevations
shou otherw3w
Outlet pipe diameter, Dp (in) 15
Tailwater depth (in) 0
Minimum/Maximum tailwater7 Min TW (Fig. 8.06a)
Discharge (cfs) 0
Velocity (Wls) 0
Step !. Based on die lailuaici conditions dererttunrd in step I eritn Figure
li 06a of Fgwr B 06b and determine dw iiprap size athd iutniiutnu apron length
(L,) The d,, size n the median stone size in a well -graded nprap apron
Step 3. Deicroune apron width at the pipe outlet the apron shape. and the
apton width at the outlet rthd 6oin the sahue firae usrd tit Step i
Minimum TW Maximum TW
Figurea.Diia r}yLr _UQ0 h
Riprap dam,, (ft) 0.2
Minimum apron length, La (ft-} 8
Apron width at pipe outlet (ft.) 3.75 3.75
Apron shape RECTANGLE
Apron width at outlet end (ft.) 9.25 1.25
Step i D e1ehuutie the nntxirnnrn stone dianteler
d,, = I S x d..
Minimum TW Maximum TW
Max Stone Diameter, dmax (ft.) 0.3 0
5rep S_ Drtefihuue the apron tlucl:ness
Apron thickness = 1 5 x d. ,
Minimum TW Maximum TW
Apron Thickness(ft.) 0.45 0
Step 6. Fit the npiap apron to the sire bs Inalwhg it level for ncC usuuutun
length Li from Figuue R 06a or Figu it S 06b Extend the apron fanliet
dots'rnuemn and along channel batiks Mid uabhlm n assured }weep the
aptan as straight is possible and align it ssith the flow of the imen'uig suctull
Vtake tut' necesstup aligisnew bends meal the ptix outlet so that the entrance
men the recent utg stream is sliarelht
15033re locations ma}' requite lunutg of the etuu a citvuhcl a oss lectlorl to a"M r
stabihn
is bray be necrssmA to increase the size of iipiap ultete protection of the
chahntel side slopes is nece%sars(Appmeirt S.05) 11Trere osYrfalls exist at
pipe ourlris or Hosts air excessnr a phmge pc ,l snood tv considned sre
page 9 06 8

User Input Data
Calculated Value
Reference Data
Designed By:
JBG Date: 6/12/2019
Checked By:
EIPP Date: 6/1212019
Company:
Sobb81 Design Build, Inc
Project Name:
HOKE COUNTY COOPERATIVE EXTENSION OFFICE BUILDING
Project No.:
18-0236
Site Location (Cityrrown) Raeford
Culvert Id. 5
Total Drainage Area (acres) 0.18
Step I. Determine the tath%airs depth &ont chn,wel chalacterlstice below the
pipe outlet for the design capAern of the pipe If the twfwatet depth is less
dull half the outlet pipe dlamrter. it is classified nuninnial tailwalei condition
If it is gieatei than half the pipe d3motin. it is classified alasutitun condition
Pipes that owlet outo tssde flat areas nyth no defined channel arc asixinted
to have a rritiutraun lailwatet condition unless Fellable flood stagy rtera11011%
shoo ollirm- se
Outlet pipe diameter, D. (in.) 8
Tailwater depth (in.) 0
Minimum/Maximum lailwater? Min TW (Fig. 8.06a)
Discharge (cis) 1.27
Velocity (ft Is) 1.2
Step Based on the ailnater conditions deterrllmed In itep I entei Fiewe
8 06a of Figitse 8 06b. and detertrlrric d,g riprap size and aiintmiuu apron length
(Q the d_ size is the median stone size in a well -graded riprap apron
Step S. Determine apron iciddi at the pipe outlet the apron shape and the
apt on a With 21 the nutlet end froin the same filnire tisrd in Step
Minimum TW Maximum TW
Figura 8.068 i'gllr'C $.t)fb
Riprap dam, (ft.) 02
Minimum apron length. La (ft.) 6
Apron width at pipe outlet (ft) 2 2
Apron shape RECTANGLE
Apron width at outlet end (ft.) 6.666666667 0.666666667
Step 4. DCtflnalle lilt IIIAM2114L11 S101re d)aillelfl
d_, 15xd„
Minimum TW Maximum TW
Max Stone Diameter, dmax (ft-) 0.3 0
Step 5. Dricrauur the alnon dliclutcss
Apron Ihtekness r 1 5 x cL,.
Minimum TW Maximum TW
Apron Thickness(ft) 0,45 0
Step 6. Fat the irptap apron to thr site bi timkwp it lctel foi the Ilmlliminu
lriagdl L. frotu Figtue 8 0&1 or Figlue 8 06b Extend the apron farlhrf
downsneanl and along charnel batiks twill stabaltri- is asstiled Keep the
apron as straight as possible and align at n tilt the fiou of the recto urg stieain
Stare am>' neceswu) aligilinetrl brtids ncai the pipe Lntilet so that the enuaiicr
Into Ihr recnl Ing stream is Sti Algili
Some locations alai iectianC 11tIn IpZ of the rime Chatulel C30%% sec ILVI1 IU aislaf
stabilln
It Ilia}% n be ecessan to increase the size of riptap utiu heie ptolecoof the
chaiutel side slopes is oecessan' (.lppe,rdn S.0.4) %LIiere osrrfAlh mast at
pipe outlers or flotss are rrcrssilr a piwiFe pool shoadd be romsidried Set
page 9 06 9

User Input Data
Calculated Value
Reference Data
Designed By: rBG Date: 6/12/2019
Checked By: BPP Date: 611212019
Company: Bobbin Design Build, Inc
Project Dame: HOKE COUNTY COOPERATIVE EXTENSION OFFICE BUILDING
Project No.: _ 18-0236 _
Site Location (City/Town) Raeford
Culverl Id. Roof Drain
Total Drainage Area (acres) 0.03
Step 1. Determwe the tailualet depth from chuulel characteristics below rile
pipe autlrl for the design capacity of the pipe If the taihvat t depth Is less
rha,r half the outlet pipe diametes. it is classtffed rem sunizu taitwilier condition
If at is g,"ret than half the pipe diameter it is clasu5ed n,axuinnn condition
pipes that owlef olllo utde flat ideas with uo defuwd chatuxl are ai' u ied
to have a iniuuntim fallu'aTef condirton tutless reliable flood stage etevatiom
%ho" othermi%cr
Outlet pipe diameter, Do (in.) 6
Tailwater depth (in.) 0
Minimum/Maximum laitwater? Min TW (Fig. 8.06a)
Discharge (cfs) 0.2
Velocity (ft.ls) 1.8
Wep 2. Baud on the taduaret conditions detennuied III step 1 elite, Figtut
6 06a or Figtue B 06b and detcrniwe d,,, flpfap size alld ulrnlllltrin apron levirth
(L.) The d,- size "the mrdun stone size nit a well -graded nprap apron
slap;. Deitrnunr aprou width ar rite ptpr outiri the apron shape and the
apron nidib at die outlet eud ftom the saint figure used kit Seep '
Minimum TW Maximum TW
Ftaure 9.06a EQure 8-06b
Riprap d", (ft) 0.2
Minimum apron length, Le (ft) 6
Apron width at pipe outlet (ft } 1.5 1.5
Apron shape RECTANGLE
Apron width at outlet end (ft.) 6.5 0.5
Step 4 Detenitine die tniwnuun stone d,aniele,
d„, = 1 5 x d,.,
Minimum TW Maximum TW
Max Stone Diameter. dmax (ft } 0.3 0
Step S. Deieruune Ihr apron durkiless
Apioii thickness = 1 5 x d
Minimum TW Maximum TW
Apron ThickneWft.) 0.45 0
Step 6- Fit the npirap ape" its ihr site b% making it Icl ci for like uuanillull
Irngth L f,rnn Viplie 806a o, rigtur 606b Extnid the aluon farther
doLiTl%t,eafit and along chiumel Wuika wiui stabihn is nsStued Keep the
"oil as straight as possibir and align it ss tth the flow of the recenuig streatn
Make am Itecessary alig,nnrul braids neai the pgle ontiet so that the nwance
alto the remit'Alit stlfaln IN sltaiPlit
Some locations urns lequale hilaig of the nnlle chalulel cross section to asssne
stabihn
It Ina) be urcrssan to tucteasr the size of nprap %%bete protection of the
chalul%el side slopes is necess.7r) (Aypmrn S.0.+1 Where otfrfallS exist a,
pipe Ptltirts of flolls are excesslle a pinrkge ponl shottht br fpnsldmrrt see
page 8 06 9