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<br />*i~~,; "?';~:, !O..'?~.:~,>:~~:.;:','j? y "~ . .,..-~~...::..
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<br />,'~~" .,f~ ";. '::.;'H:? '~:1::~g::~5i. . : .-', .. :.'~,'~ ...}.,.,....~....~:......~,':..~.''\j,..''.~.~~.'...,:.:.:.'.,,'.,..~t..'..":t'_"'-""~"':"';_:'>-"".'::~'....~,,:.-._;.'.:.it...:.~..'ft....:,::...,..~;.~._,";:.'.~......;:...,:1.".. ... ,,,;,~,,:' " ,'i - ':.'.,~.\\;.:':<;~.:.~-.',;~'." .ii,t..:' ....
<br />.;.~.\?i,..;~ ....~.'..'..'!":';:."'..,,.ETL 1110-2-120 .'.!.~.':~i~i..t':':".~.; t.... . . ."".~" ,. .'}1'::.,....-'
<br />~@;;',~~'*.3.-.14 May 1971 ",,,";. ~:,,~. . .. . . ;;: ., .;'>:"')~,. ~/.
<br />'.'f;tl!;7;~'~~~;'f.;~':~~'~~-':~-"':''''~;~~- :"ih~,t.~~di.:;-<:? .<,~~:#'f.J;~~t;,<;-, -."~? ":~'. 4<..<.~ ~"t>>~;..~._- . ~;,~,~t~~ _ -:.' <j: "v~,~.;"." ...,. . ~~~f) .
<br />.~:.:(~~J!;t::,:>From EM UIO~2-1601, Plate 30, the DSO size of the trial riprap ~~'i.{
<br />~~;.i~b'?';';;/-'i; uterial 'ranges from 0.88 to l.0 ft. Priction coefficients for use' :~ '.. ~;:"')>.
<br />}~f~'F:i., >;~/iin the water surface' computations should be determined for the range. ... i:':,':::'
<br />....~..'f..~;;...}j..}.y):"'; of expected ~esign depths by the procedures described in ,.EM 1l10-2~ ~'~5!"'."~."it.;~. ..~~.;....:-;.,.
<br />....~'~,'...~.... 'l:.'~..1601, Append1x. IV.; Inclosure S. i1~ustrates. t~e computat1onal procedu;:e.<~~:.~, .'
<br />,,' for the determ1nat1on of the fnctlon coeff1c1ent based on boundary ..< ..;: . ,\..;\f~;.".
<br />;'l{:i':N~:d . ~~~::~~o~~: :a~~d f~n d~~~hdet~n::~g f;~~~i:e c::i:~c~:~::c:nd ~:c~. ': ' :j;:t.
<br />
<br /><:""i. ,',","'conservative estimates of other losses, result in a depth of 10 ft . ;~"" '.
<br />~!?~ ""'~/l~..for the deSign discharge of 7,SOO cfs, the corresponding average . :ff~:' .
<br />~N;~~~~.t:',;~'l!Velocity in the ch~el secti~n is 10 fps. As.the c~annel bed is .' :...."~...
<br />~V..:~:~;i'J1.",.' ,smoother than the nprapped Sldes, the average veloclty in that part
<br />:k,,*;:~,i.,;':;;'~t,,of the channel section vertically above the bed, which will be .t,..
<br />~~~~i:\::;'~.~great~r than t~e. average velocity in th.e' entire :section/ should ~e ~~.,
<br />Jr4'y~~;:,~,!r'.used 1n detenDln1ng the ~ocal. boundary shear. at . the toe of t~e npraJ:' '. ':r;;
<br />. :.,.'~t..,.~~-'.,.:., "~evetment. The computat7ons 1n Inclosure S 1ndJ.cate that. thlS VelOC1ty,."
<br />i;1r' ':'!I-:,< !.,15 11.S fps.prom equatlon (32) and Plate 32 _fo~ the max1~ DSll st~ne .'
<br />.' ~"t<<'~r ,:; size equal to 1.0 ft and applying the 1. S non~~iform flow f~cto.r, ~.
<br />;:f1,;J;'\i;{1t~the local boundary shear at the toe, of ,~he. riprap, ;reveulen.t .1S COli
<br />. ""'~puted as follows' ,,"'~ ,o~~"'..~.. ,\'-'~,..:, ;.~l'."'. ,.. " "\ ,,~.
<br />~, :;.. . ~ . .,_..., ".,," ~-I'I........,,>, _, :io:IO"", . .. ~~. .,
<br />""'i';'(':B;;';~='{~;~:[~~~/D-5"0"-:':~ :iO/l'-:'7"';O'~~d"~..'~~~o~oi35~'~~'~~ 'q( ~":~'{:, "',
<br />. -. ~~:r-' . ~;'~..:.f~ .i"'f. - ---...~ .J~~',.,I. ,,(\.'4~~~'-"';";~'~"-';: ~". .....~ ~
<br />if'~ ~r, ',. 'i. ~.'1f:';~<..;.;<. ." . _' ',~ '," 2 .~y"'{" ~... :~,~.(;t-.'t l 4 t~ ..~... "~;~h ,-
<br />:.;.. . ~';~~l. f':;7{~;"~'I:~' ,",; ~.5 x 0.0135 x (ll:.~t~t(~~~;,.~~~~, per ~q. ft . '~if6IJ:
<br />~~~r~. ;: -'''-'H1The de~ign ~hear, using. the miniDIUID DSO stone sue.. 0.88 ft, for;~i':t"J~'
<br />:::~t"'; :. ,';::,;, the ,~r.1.aI._.:.1prap. gr.ada~1on,_ as dete~~ned from l}a~es 3S and 36, 1,S.;..:~ ~ ,; '.
<br />"'ft~~~.f.', 'Jii.~'t"..t';;;t;f"_'~ 'r~. ~ ~,"'~' ' . .~... .'-C_; 'r! .....~.'J . ." -~'--.;:...~ .. '
<br />1i),: UJf;i,"~.'."'" " ."'V,'T . 3.60 Ibs for sq ft and ~ '.' 0.82 '{;'!" ~.;", " ',' .;;,
<br />?rlf.t.;OI~"f':: ~r.~'~' ;::, :.\' _ .~-~, '$: - ".." ~~>, ,~,..iit,.,~~':l. ~~~~;-:~"~f' y~:.;':
<br />". ". ,.....,~ :'.T'.' 0.82 x 3.60 . '2.95lbs per sq ft ,:",,,~.v, ':.",'.
<br />:~~~~~~~<<if~At~1i.-~J*ll~..I__Jll ,-,~~~~... .\. :;:-y~"""tL'.'.1f;V~t_h; .. '..'
<br />.t,J':''[''As the design shear ,exceeds the local,boundary"shear by a'S1gnificant
<br />;'.<f.;f~amount, . the ~SSibil.. ity o. f us. ing a},s..-.,'~.inch. riprap .1ayer.th~ckne~~jM,~./. .
<br />,:~,t!shOUld be checked. In'lLCco!CianceW1t.~.paragraphs 14h and 1 of ~"""'-<<'
<br />~"'::;~~'EM 1110-2-1601, the}S-inC:h layert~~~kness ~uld require the fol1~wing:
<br />.....,. .t:'. riprap gradation' """~"~ ".".... .,..~ '.' . .". ,,.. ..,
<br />;.';;'i~''-''';~;(,...~"",~::iY.:'$lii~,;.:;-tm'~~~r;';'" .:~t:'~lK~' ..i.t'~::Th.~ "..
<br />, "'" ,,'.,'" .".. J., ';.: ,,,,,"PERCENT LIGHTER """'LIMITS OF STONE'
<br />iV;:r :;"J-.~~'# ~..-,~""'" . _'ft.~J . '-',t<' .p"'-'~
<br />",>., ',,'.,", .. ...<'>". .. ., BY WEIGHT (55D) ..' "WEIGHT-LBS '.'ro'"
<br />r ,~-J'~_~:,-4~:.lo_'':';'''''';'- _(~!' "t-, :. ''''~,_ '.. _'_.. _ _ ,', . _~. , . .,..:r....;. '.t.
<br />~..Nl.,'t.'.,... ~~.~,';;..,.1..-.~.. 5;;,;; '~..,.\:~..~~~.;...7..~;;:1 .:;" .:....;>:. :'-'l~"__'-':;"
<br />,,-i""~?"-_~ {,~.'1,...- .~, ~ "~':-': -..-...,.,~. ,~_:~,.~,J_~ of'' .... .~,~'"... - ,>',. -~'.!
<br />;ii' '~li!l." ;.. ,,"',. 100"""'" 170"~' 70 ...~,~ .'
<br />~~!;.~~,.0.~~~<t~.~. !i~il ;~~~~i'~~".
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<br />. ,)~( Por this ~adatio~, the min~mum Dsostone she is 0.74 ft and the .,)~,".
<br />.' ':.}'. correspond1ng deSlgn shear 1S 0.82 x',3.0 = 2.46 Ibs per sq ft. '. As .this'
<br />"", . ': . value is less than the local boundary shear determined for the first ".~'..
<br />. ''!'!J.,- .' trial riprap gradation and the su11er size stone in the lS-inch layer:'~
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<br />~_ _ ,--' _-. ',.v.. (f"..'~" . . 6 '. ~::;.~,.t ",,:;,' '~-j" -..' ...~-;,
<br />,""; .:.", ,;Ii '. ';:iillt\i.i:: .~."''&.. ..i!iiIiiI,: 'W:;" ':;~"~" "~'';<.',,*''.'' /'
<br />~., :<;'t--"~'- ~. -'~.~~.; ."' ~~j:';"; . :':'''dii.~"_.--r,''''.',~,~~_.:,,,,---
<br />.;<}. ,"i~).:.' ~~~~"l ..~ t.[.........,;~, . ,w,~_ --~:'-''j~~~1 ..~ .... ~'t~~,-~:"""
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