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DocuSign Envelope ID: E39A7F34-1956-4F98-91AB-121A6B293FOE <br /> B <br /> Sample Problem Short-term esi n = bare soil channel stability <br /> 6.17b con't. <br /> • _ _Use Qpeak- Q2-year-45 CfS <br /> • From Figure 6.17b: Limiting shear=4.5 Ib/ft2 <br /> • For mat on bare soil, n = 0.03 <br /> Determine depth of flow via trail-and-error using Manning's Equation: <br /> For trapezoidal channels: (bd + zd2) <br /> (bd + zd2) 2/3 = Qn <br /> (bd + zd2) <br /> b + 2d (z2 + 1)1/2 1.49S112 <br /> From trial-and-error, d = 1.0ft <br /> Check shear stress T=YDS <br /> _ (62.4) (1.0) (0.05) <br /> = 3.12 1 b/ft2 <br /> 3.12 < 4.5 Ib/ft2, therefore acceptable <br /> Construction <br /> Specifications ven if properly designed, if not properly installed, Ps will probably <br /> not function as desired. Proper i nstal I ati on is imperative. ven if properly <br /> i nstal I ed, if not properly timed and nourished, vegetation will probably not <br /> grow as desi red. Proper seed/vegetation selection i s al so imperative. <br /> rade the surface of i nstal I ati on areas so that the ground is smooth and loose. <br /> hen seedi ng pri or to i nstal I ati on, fol I ow the steps for seed bed preparati on, <br /> soi I amendments, and seedi ng i n S rfa e Stabili ation, 6.1. All gullies,rills, <br /> and any other disturbed areas must be fine graded prior to installation. Spread <br /> seed before P i nstal I ati on.( : emove al I I arge roc s,di rt cl ods, <br /> stumps,roots,grass cl umps,trash,and other obstructionsfrom the soi I surface <br /> to ad ow for di rect contact between the soi I surface and the P.) <br /> Termi nod anchor trenches are requi red at P ends and i ntermi ttent trenches <br /> must be constructed across channels at 25-foot intervals. Terminal anchor <br /> trenches should be a minimum of 12 inches in depth and 6 inches in width, <br /> while intermittent trenches need be only 6 inches deep and 6 inches wide. <br /> Installation for Slopes—Place the RECP 2-3 feet over the top of the slope <br /> and into an excavated end trench measuring approximately 12 inches deep <br /> by 6 inches wide. Pin the RECP at I foot intervals along the bottom of the <br /> trench, backfill, and compact. Unroll the RECP down (or along) the slope <br /> maintaining direct contact between the soil and the RECP. Overlap adjacent <br /> rol I s a mi ni mum of 3 i nches. R n the P to the ground using staples or <br /> pins in a 3 foot center-to-center pattern. Less frequent stapling/pinning is <br /> acceptable on moderate slopes. <br /> 6.17. Rev.6/06 <br />