Slope Restoration Freeway.pdf

12RC816(A260)

MICHIGAN

DEPARTMENT OF TRANSPORTATION

SPECIAL PROVISION

FOR

SLOPE RESTORATION, FREEWAY

C&T:DMG 1 of 3 C&T:APPR:TWK:DBP:04-25-12

a. Description. This work consists of preparing all areas designated for slope restoration on the plans or as directed by the Engineer and applying topsoil, fertilizer, seed, mulch with mulch anchor, mulch blanket, high velocity mulch blanket and permanent turf reinforcement mat to those areas. Turf establishment must be in accordance with section 816 of the Standard Specifications for Construction and Standard Plan R-100 Series, except as modified herein or otherwise directed by the Engineer.

b. Materials. The materials and application rates specified in sections 816 and 917 of the Standard Specifications for Construction apply unless modified by this special provision or otherwise directed by the Engineer. The following materials must be used on this project:

1. Seeding mixture as called for on the plans

2. Fertilizer, Chemical Nutrient, Class A

3. Topsoil Surface, Furnished or Salvaged, 4 inch

4. Mulch and Mulch Anchoring, Mulch Blanket and High Velocity Mulch Blanket

5. Permanent Turf Reinforcement Mat (TRM) must be 100 percent synthetic and consist of 100 percent ultraviolet (UV) stabilized polyolefin fibers sewn between two layers of black UV stabilized polypropylene netting with polyolefin thread. The TRM must meet the following “minimum average roll value” requirements:

Property Test Method Requirement Mass/Unit Area ASTM D 6566 10 oz/syd Ultraviolet Stability @ 1000 hrs ASTM D 4355 80 percent Tensile Strength (MD) ASTM D 6818 165 lbs/ft

Acceptance. Supply a Test Data Certification for the permanent TRM from one of the following manufacturers:

Recyclex - American Excelsior Co., Arlington, TX (800) 777-7645 P300 - North American Green, Poseyville, IN (800) 772-2040 Landlok 450 - Propex, Inc., Chattanooga, TN (800) 621-1273 PP5-10 - Western Excelsior, Mancos, CO (800) 833-8573

c. Construction. Construction methods must be in accordance to subsection 816.03 of the

Standard Specifications for Construction. Begin this work as soon as possible after final grading of the areas designated for slope restoration but no later than the maximum time frames stated in subsection 208.03 of the Standard Specifications for Construction. It may be necessary, as

C&T:DMG 2 of 3 04-25-12 directed by the Engineer, to place materials by hand.

Shape, compact and assure all areas to be seeded are weed free prior to placing topsoil. Place topsoil to the minimum depth indicated above, to meet proposed finished grade. If the area being restored requires more than the minimum depth of topsoil to meet finished grade, this additional depth must be filled using topsoil or, at the Contractor’s option, embankment. Furnishing and placing this additional material is included in this item of work.

Topsoil must be weed and weed seed free and friable prior to placing seed. Apply seed mixture and fertilizer to prepared soil surface. Seed must be incorporated into top 1/2 inch of topsoil.

Mulch must be applied at a rate of 2 tons per acre. Place Mulch Anchoring over the mulch at a rate specified in subsection 816.03.F of the Standard Specifications for Construction. Mulch Blanket and High Velocity Mulch Blanket must be placed in accordance with subsection 816.03.H of the Standard Specifications for Construction and as shown on Standard Plan R-100 Series.

Areas constructed with the TRM must be installed on prepared (seeded) grades as shown on the plans in strict accordance with the manufacturer’s published installation guidelines. The top edge of the TRM must be anchored in a minimum 6 inch deep trench. Operation of equipment on the slope will not be allowed after placement of the TRM. No credit for splices, overlaps, tucks or wasted material will be made.

If an area washes out after this work has been properly completed and approved by the Engineer, make the required corrections to prevent future washouts and replace the topsoil, fertilizer, seed and mulch. This replacement will be paid for as additional work using the applicable contract items.

If an area washes out for reasons attributable to the Contractor’s activity or failure to take proper precautions, replacement will be at the Contractor’s expense.

The Engineer will inspect the seeded turf to ensure the end product is well established, weed free, in a vigorous growing condition, and contains the species called for in the seeding mixture.

If the seeded turf is not well established at the end of the first growing season, the Contractor is responsible to re-seed until the turf is well established and approved by the Engineer.

Provide weed control, if weeds are determined by the Engineer to cover more than 10 percent of the total area of slope restoration, in accordance with subsection 816.03.J of the Standard Specifications for Construction. Weed control will be at the Contractor’s expense with no additional charges to the project.

d. Measurement and Payment. The completed work, as described, will be measured and paid for at the contract unit price using the following pay item:

Pay Item Pay Unit

Slope Restoration, Type __ ............................................................................. Square Yard

1. Place Slope Restoration, Type A in all areas not described in the other types of slope restoration and measure by area in square yards in place. Slope Restoration, Type A includes all labor, equipment and materials required to install Topsoil Surface, Furnished or Salvaged; Fertilizer, Chemical Nutrient, Class A; Seeding Mixture; and Mulch and Mulch

C&T:DMG 3 of 3 04-25-12

Anchoring which will not be paid for separately but included in the contract unit price for Slope Restoration, Type A.

2. Place Slope Restoration, Type B parallel (6 feet minimum) to the edge of the roadway, in areas that have a 1 on 3 slope and in any ditch with a grade less than 1.5 percent, or as directed by the Engineer. Slope Restoration, Type B will be measured by area in square yards in place. Slope Restoration, Type B includes all labor, equipment and materials required to install Topsoil Surface, Furnished or Salvaged; Fertilizer, Chemical Nutrient, Class A; Seeding Mixture; and Mulch Blanket which will not be paid for separately but included in the contract unit price for Slope Restoration, Type B.

3. Place Slope Restoration, Type C in areas that have a 1 on 2 slope, any ditch with a grade of 1.5 percent to 3 percent or as directed by the Engineer. Slope Restoration, Type C will be measured by area in square yards in place. Slope Restoration, Type C includes all labor, equipment and materials required to install Topsoil, Furnished or Salvaged; Fertilizer, Chemical Nutrient, Class A; Seeding Mixture; and High Velocity Mulch Blanket which will not be paid for separately but included in the contract unit price for Slope Restoration, Type C.

4. Place Slope Restoration, Type D in areas that have a slope steeper than 1 on 2, any ditch with a grade steeper than 3 percent or as directed by the Engineer. Slope Restoration, Type D will be measured by area in square yards in place. Slope Restoration, Type D includes all labor, equipment and materials required to install Topsoil, Furnished or Salvaged;

Fertilizer, Chemical Nutrient, Class A; Seeding Mixture; and TRM which will not be paid for separately but included in the contract unit price for Slope Restoration, Type D.