PERMFILE103728

• Permit No: M2001022
• IBM Index Class Name: Permit File
• Doc Date: 8/5/1996
• Doc Name: IN -STREAM AGGREGATE EXTRACTION AND RECLAMATION GUIDANCE DOCUMENT
• Media Type: D
• Archive: No

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