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<br />Determine trajectory of jet off deflector lip: <br />Define coordinate basis for analysis of jet (Point 3): <br /> <br />x = 0 at 5ta. 9+44 <br /> <br />SLFES o 944.ft <br /> <br />tit <br /> <br />y = 0 at 60.93 ftel (0/5 lip invert) <br /> <br />Calculate jet trajectory (ref: U.S. Bureau of Reclamation. <br />p.387): <br /> <br />K '.0.9 <br /> <br />1987. Design of small dams. <br /> <br />(loss coefficient: K = 1.0 for <br />theoretical jet) <br /> <br />y 0 dpp <br /> <br />x oO.ft <br /> <br />(iterative solution) <br /> <br />x2 <br />y - x.tan(8} - . _: . 2, (Eq. 19) <br />K. 4.ldoSL ' hVOSL).cos(8) J <br /> <br />Find the intercept between the plunge pool bottom and the trajectory <br />of the jet of water leaving the flip bucket {Point 4}. Trajectory <br />calculations tabulated on following page. <br /> <br />x c 20.56.ft <br /> <br />SLpp 0 SLFES - x <br /> <br />SL = 923.44-ft <br />pp <br /> <br />. <br /> <br />Trajectory impinges on plunge pool bottom 20.56 ft from flip <br />bucket (Sta. 9+23.44). <br /> <br />Determine channel slope below jet impingement {slope between bottom of plunge pool and where <br />structure ties into downstream channel}: <br /> <br />SLoSc c 896.0.ft <br /> <br />EOSe 058.78.ftel <br /> <br />SOS 0 <br /> <br />SL - SLos : <br />pp c <br />E - E <br />: pp oSc, <br /> <br />SOS = 3.07 <br /> <br />OK, slope is 3.07:1. Slope must be flatter than 3:1. <br /> <br />Determine channel slope above jet impingement (slope between bottom of plunge pool and lip of <br />flared end section): <br /> <br />SUS <br /> <br />_ i SLpp - SLFES' <br />jEpp- EFES' <br /> <br />SUS = 1.95 <br /> <br />OK, slope is 1.95:1. Slope must be steeper than 3:1. <br /> <br />Determine plunge pool freeboard. Use freeboard of 0.2 times scour depth. . Therefore, total plunge <br />pool depth including freeboard is 1.2 times scour depth. <br /> <br /> dfree c 1.2.d d = 16.35.ft <br /> pp free <br />. Ertee :: Epp t. dfree Efree = 66.19.fte! <br /> <br />Riprap must extend up to 66.19 ft elevation. <br /> <br />J~o <br />