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Appendts D ~ PoteNia! Hydro/oRtc Structures to Minimize Impacts and Alining Melhads <br />Table D-1 <br />_ Classification and Gradation of Ordinary Rip-rap <br />% Smaller Than Given Intermediate Rock <br />Rip-rap Designation Size by Weight Dimension (inches) <br /> <br />Dso* <br />(inches) <br />Type M 70-100 21 <br /> 50-70 18 <br /> 35-50 12 12 <br /> 2-10 4 <br />Type H 100 30 <br /> 50-70 24 <br /> 35-50 18 18 <br /> Z-10 6 <br />Type VH 100 42 <br />,,, 50-70 33 <br /> 35-50 24 24 <br /> 2-10 9 <br />* Dso =Mean particle size <br />into the installation, with the fmal objective being a vegetated channel. When a mulching <br />geotextile is used, seed is placed on the bank prior to placement of the fabric. Zoned bank <br />protection can be provided when the banks are rip-rapped up to the average water level, and <br />grasses and woody species are planted above the rock armoring along the banks using a mulching <br />geotextile. <br />Geotextile fabrics used below rip-rap should prevent movement and piping of fine particles while <br />allowing liquid to flow into the rip-rap. Finer filter blankets aze required for clay-sized particles; <br />looser, larger opening sizes may be used with coarse-grained particles. The installation should <br />be perpendicular to the direction of flow, with sheets shingled in the direction of flow. Anchor <br />at the top of the bank at least 1-foot above the high water line. <br />Contact with a manufacturer's representative to obtain specifics on the appropriate fabric for the <br />situation should be conducted. Be prepared to specify the side slopes and bottom slopes of the <br />channel, the type of soil, whether there aze elevated sodium concentrations or other conditions that <br />make the soil highly dispersive, how plastic the soil is, the percentage of gravel and the grading <br />of the gravels. The representative will determine the equivalent opening size (EOS) of the woven <br />- fabric based on the soil type and the average diameter of the i•ip-rap. <br />tt.ssnn~~ra ~. isve ~ D-4 <br />