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HomeMy WebLinkAbout1902824240001-09062014SPECIFICATIONS FOR SOIL AMENDEMENT BY SOIL RIPPING SOIL AMENDMENT BY SOIL RIPPING TO RELIEVE COMPACTION: a)Ripping (Subsoiling) should be performed using a solid—shank ripper and to a depth of 18 inches as measured from the top of topsoil. b)The goal of soil ripping or subsoiling is to fracture compacted soil without adversely disturbing plant life, topsoil, and surface residue. Soil compaction occurs most frequently with soils having a high clay content. Fracturing compactedsoil promotes root penetration by reducing soil density and strength, improving moisture infiltration and retention, and increasing air spaces in the soil. Compacted layers typically develop 12 to 22 inches below the surface when heavy equipment is used. c)Subsoilers (rippers) can break up the compacted layer without destroying soil aggregate structure, surface vegetation, or mixing soil layers (Kees, 2008). How effectively compacted layers are fractured depends on the soil's moisture, structure, texture, type, composition, porosity, density, and clay content. Success depends on the type of equipment selected, its configuration, and the speed with which it is pulled through the ground. No one piece of equipment or configuration works best for all situations and soil conditions, making it difficult to define exact specifications for subsoiling equipment and operation. d)Subsoilers are available with a wide variety of shank designs. Shank design affects subsoiler performance, shank strength, surface and residue disturbance, effectiveness in fracturing soil, and the horsepower required to pull the subsoiler. According to Kees (2008), "Parabolic shanks require the least amount of horsepower to pull. In some forest applications, parabolic shanks may lift too many stumps and rocks, disturb surface materials, or expose excess subsoil. Swept shanks tend to push materials into the soil and sever them. e)Ripping, subsoiling, or scarification of the subsoil should be performed where subsoil iics become compacted by equipment operation, dried out and crusted, or where necessary to obliterate erosion rills. f) Subsoiling should not be performed within the drip line of any existing trees, over underground utility installations within 30 inches of the surface, where trenching/drainage lines are installed, where compaction is by design. g)Subsoiling is only effective when performed on dry soils. if soils are saturated, the Contractor shall delay operations until the soil will not hold a ball when squeezed. Only one pass shall be performed on erodible slopes greater than 1 vertical to 3 horizontal. When only one pass is used, work should be at right angles to the direction of surface drainage, whenever practical. CONSTRUCTION SEQUENCE: o)Subsoil ripping, or scarification of the subsoil will be required wherever the subsoil has been compacted by equipment operation' or has become dried out and crusted, and where necessary to obliterate erosion rills. Sub—soiling shall be completed in areas as indicated on the plan where plant establishment or grass turf is planned. b)Install perimeter, and/or down gradient, erosion control BMP's prior to any upslope land disturbance. c)Rough grading of the project should be complete and measured implemented to protect the soil ripping area from experiencing further compaction by heavy equipment. d)Existing topsoil shall be stripped from the area of soil ripping work. Topsoil shall be stockpiled and temporary erosion control measures shall be implemented as required for the stockpile. e)The subsoil shall be in a relatively dry, friable condition to a depth of 18 inches below final topsoil grade. f) Ripping channels shall be created by a commercially available, multi—shanked, parallelogram implement (solid—shank ripper or equivalent equipment). The equipmentshall be capable of exerting a penetration force necessary for the site. The grid channels shall be spaced a minimum of 12 inches to a maximum of 36 inches apart. The channel depth shall be a minimum of 18 inches. g)Sub—soiling shall be completed such that ripping channels result in a two—directional grid. h)Topsoil shall be re—spread over the soil ripping subsoil area at a minimum 6" depth. i) Final grade of the soil ripping area shall be achieved by use of light equipment with tracks or turf type tires. Equipment with high pressure narrow tires or large lugs will cause excessive compaction. j) Permanent ground cover turf shall be established by sod or seed with established growth before perimeter erosion control BMP's are removed. Erosion control BMP's are to be removed once final stabilization is achieved. GRAPHIC FROM MPCA MINNESOTA STORM WATER MANUAL CLIENT: CITY HOMES DESIGN + BUILD, LLC 4220 Crocker Ave Edina, MN 55416 952-920-8250 �- o 0 0 CD m m m W z a. '+ t p q J Q Wct FILE N0. 00509 O w Z 0 cC �O T_ co W fr. w r -p O L w R o % 00 d' U zt c: t} (4 .� y Q:(�m L X I N O� v C p '(5 k C 1 N t`^+ � t w U� 3 I W N 3 Ct. C:� q t co0 0 3 _ I C cl w CL C3 Ej J (j I r ++ O O m V 4 C' O Q 3 o Q W AZ -o o 4 S 1 Cl- �- o 0 0 o m O m W ©' p q U Q FILE N0. 00509 212 Storm Water and Erosion Control Plan H - 0 2,8 -a�. 94. 0 o I 4 6 [ D fiwuZ S -E—)