224Soil Reinforcing Mat

224.01 Description. This work consists of furnishing, placing and maintaining a soil

reinforcing mat on seeded or other designated areas in accordance w ith the requirements of the plans and these specifications.

224.02 Materials.

224.02.1 Preformed Permanent Mat. The soil reinforcing mat must be one from the

Department's current APL. The Contractor will be permitted to furnis h and install a multi-width mat with seams securely bonded by welding, stitching or other methods meeting the approval of the Engineer.

224.02.2 Stakes. Unless otherwise specified by the manufacturer of the soil reinforcing

mat, stakes used to secure the mat shall be either:

224.02.3 Acceptance Procedure. Prior to use, the Contractor must furnish the Engineer

three copies of the manufactur er's certification for each ship ment of soil reinforcing mat material stating the number of rolls furnished and that the material in the shipment conforms to the same composition as that originally approved by the Department. When metal pins or wire staples are used, also furnish the Engineer three copies of a certification from the manufacturer or distributor stating the pin and washer size for metal pins or wire size for staples for each shipment. The certifications by the manufacturer or di stributor will be prima facie evidence of the materials meeting the requirements of the specifications.

224.03 Construction Requirements.

224.03.1 General. The area(s) to be covered shall be prepared, fertilized and vegetated

as specified in accordance with the require ments of the contract before the mat is installed. The planted area shall be to finish grade, smooth, and free of stones, clods, or trash. The vegetative mulch material shall be omitted from areas receiving the mat. The mat shall be installed immediately following the planting operations. The installation of the mat material shall be perfo rmed in accordance with the re quirements specified herein and the installation detail sheet in the plans. Terminal slots, both upstream and downstre am, shall be excavated a minimum of twelve inches deep and two feet wide across the fu ll width of each area to be treated before placing the mat. Transverse check slots shall be excavated a minimum of nine inches deep and six inches wide across the full width of the area to be treated at approximat ely 25-foot intervals along the entire length of the area. Outer edge slots shall be excavated four inches deep by six inches wide along the actual perimeter of the mat installation for the full length of the area to be treated. When possible, the mat installation shall begin at the downstream end and unrolled uphill in continuous contact with the soil. When tw o or more widths of mat are required to cover an area, they shall overlap a minimum of three inches. In cases where rolls are to be spliced lengthwise, the ends of the roll s shall overlap three feet minimum with the upgrade strip on top. Temporary staking shall be required to place tension on the mat at crest of check slot for securing mat into slot and for proper alignment during installation. The mat material shall be secured across the full width of the mat with stakes one-foot apart in all terminal, downstream and upstream, and transverse check slots. The stakes shall be placed three feet apart, with the diagonal edge facing upstream when using wood stakes, on outer edge slots, longitudinal overlaps and bonded seams on multi-widths. For longitudinal overlaps, one stake shall serve the overlapped edges of adjoining strips. The center of each strip including each strip between each bond, if multi-width rolls are used, and the center of ditch bottom shall be staked at six-foot intervals with the stakes placed broadside to the stream flow. When the center of a strip or the longitudinal overlap, including a bonded seam, falls within six inches of the center of ditch, the required ditch bottom stakes may be omitted. Where the rolls of mat are spliced lengthwise, the three-