Laserfiche WebLink
E- 0 <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 lc wing <br />rate; <br />1.20 gpd/f t2 =0.5 gpd/f t2 = 2_y0 <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 />.&YO x /a ft -2YOft <br />H. Downslope Dike Width <br />1. If landslope is 3% or more, <br />subtract rock layer width <br />from basal width to obtain <br />minimum downslope dike toe wid�fh <br />�ft - %oft -AF Oft Y <br />2. Calculate mound height at edge <br />of rock layer on downslope side; <br />a. Determine depth of clean sand <br />fill at upslope edge of rock <br />layer: /.O feet •/ <br />b. Multiply rock layer width by <br />landslope to determine drop <br />in elevation; / <br />� x % 100 -4.6ft J <br />c. Add drop in elevation to depth <br />c' clean sand at upslope edge <br />of rock layer to get depth of <br />clean sand at downslope edge <br />of rock layer. <br />'0. if + /.Oft = , 6 ft v <br />d. Add depth of clean sand at down - <br />slope edge to depth of rock <br />layer to de.,th of soil backfill <br />to get mound height at downslope <br />edge of rock layer; J <br />4rft +,7Sft +/.LSft =3.0 <br />e. Enter table on page E-18 with <br />landslope and downslope dike <br />ratio. Select dike multiplier <br />of .3. d!6 3 ; / f(IPF <br />11.2.f. Multiply dike multiplier by <br />downslope mound height to gpt <br />downslope dike width; / <br />3.4(6' x,F. 6- _ /.2 ft <br />g. Compare the values of step H.1 <br />and step H.2.f. Select the <br />greater of the two values as <br />the downslope dike width; / <br />/V. 0 feet V/ <br />h. Calculate upslope dike width <br />using upslope mound height <br />and upslope dike multiplier , <br />rn paper E-18; 7 6 ft <br />- ' <br />i. Totalx mound width is the sum <br />of upslope dike width plu:: rock <br />layer width plus downslope dike <br />width; <br />], 6f t+ /D ft +/Y.10f t-,?1,_Cf t <br />3. If landslope is 2.9 percent or <br />less, basal width includes both <br />the upslope and downslope dike <br />widths. <br />a. Calculate downslope dike width <br />using steps H.2.a. through <br />H.2.f; feet- <br />b. Calculate upslope dike width <br />using upslope mound height and <br />dike multiplier from Page E-18; <br />x ft - ft <br />c. Add downslope dike width to <br />upslope dike width to rock <br />layer width to get total mound <br />width; <br />ft + ft + ft - ft <br />d. Compar total mound width to <br />required basal width from step <br />C.4. If total mound width is <br />greater than required basal <br />widtl., use calculated dike <br />/ widths. Tf required basal <br />.// width is greater than total <br />mound width, increase downslope <br />dike width. <br />