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1:-20 <br />MOUND DESIGN PROCEDURE (Continued) <br />(For Flows up to 1200 gpd) <br />G.3. Calculate basal width ratio <br />by dividing rock layer <br />loading rate of 1.20 gpd/ft2 <br />by allowable soil loading <br />rate; <br />1.20 gpd/ft2 ; 0.9dgpd/ft2 <br />Check this value on page E-16. <br />4. Multiply basal width ratio by <br />rock layer width to get <br />required basal width; <br />Z.0 x LO ft = 20 ft <br />H. Downslope Dike Width <br />11.2.f. Multiply dike multiplier by <br />downslope mound height to get <br />downslope dike width; <br />3.ti/ x -7.`/ _ //.6ft <br />g. Compare the values of stela :{ l <br />and step 11. 2. f . Select the <br />greater of the two values as <br />the downslope dike width; <br />//. 6 f e e t <br />1. If landslope is 3% or more, i <br />subtract rock layer width <br />from basal width to obtain <br />minimum downslope dike toe width <br />20 ft - /O ft = eft <br />Calculate upslcpe dike width <br />using; upslope mound height <br />and upslope dike multiplier <br />f_rot� page E_-18; 0 ft <br />'total mound width is the sure <br />of upslope dike width plus rock <br />layer width plus downslope dike <br />width; <br />BQft + /0 ft +//6ft=?9.6ft <br />2. Calculate mound height at edge <br />3. If <br />landslope is 2.9 percent or <br />of <br />rock layer on downslope side; <br />less, <br />basal width includes both <br />a. <br />Determine depth of clean sand <br />the <br />upslope and do•..nslope dike <br />fill at upslope edge of rock <br />widths. <br />b. <br />layer: _ / feet <br />`?ultiply rock layer width by <br />a. <br />Calculate downslope dike width <br />landslope to determine drop <br />using stets H.2.a. hruus;h <br />in elevation; <br />H.2.f; feet <br />/D x Y `/, = 100 =O.`i f t <br />b. <br />Calculate upslope dike width <br />c. <br />Add drop in elevation Co depth <br />using upslope mound height and <br />dike multiplier frog. Page E-18; <br />of clean sand at upslope edge <br />ft - ft <br />of rock layer to get depth of <br />clean sand at downslope edge <br />c. <br />Add downslope dike width to <br />of rock layer. <br />upslope dike width to rock <br />d, Y f t + / f t = /. Y ft <br />layer width to get total mound <br />d. <br />Add depth of clean sand at down- <br />width; <br />slope edge to depth of rock <br />—ft + ,ft + _ft = _ft <br />layer to depth of soil backfill <br />d. <br />Compare total mound width to <br />to get mound height at do -%%slope <br />required basal width from step <br />edge of rock layer; <br />G.4. If total mound width is <br />/, / f t +49,7Sf t + /, 2S'f t = 3. Y f t <br />grr_a ter than required basal <br />e. <br />Enter table on page E-18 with <br />width, use calculated dike <br />landslope and downslope dike <br />widths. If required basal <br />ratio. Select dike multiplier <br />width is greater than total <br />of <br />mound width, increase downslope <br />dike width. <br />