From MDOT Policy Manual
- 919.01 Geotextile Requirements. Geotextiles used on AdministrationShall mean any one of the Administrations within the Maryland Department of Transportation, as listed in GP 1.02. projects shall participate in the National Transportation Product Evaluation Program (NTPEP) and conform to the Contract DocumentsThe written agreement executed between an Administration and the successful bidder, covering the performance of the work and furnishing of labor, equipment and materials, by which the Contractor is bound to perform the work and furnish the labor, equipment and materials, and by which the Administration is obligated to compensate him therefore at the mutually established and accepted rate or price. The Contract Documents shall include the Invitation for Bids, Notice to Contractors, Instructions to Bidders, Proposal, Contract Forms and Bonds, General Provisions, Specifications, Supplemental Specifications, all Special Provisions, all Technical Provisions, all Plans and Notices to Proceed, also any written Change Orders and Supplemental Agreements that are required to complete the construction of the work in an acceptable manner, including authorized extension thereof and MSMT 732. Geotextiles shall be manufactured from fibers consisting of long chain synthetic polymers, composed of a minimum 95 percent by weight of polyolefins or polyesters, and formed into a stable network so the filaments or yarns retain their dimensional stability relative to each other, including selvages. Geotextiles used on AdministrationShall mean any one of the Administrations within the Maryland Department of Transportation, as listed in GP 1.02. projects shall conform to the following:
TYPE OF GEOTEXTILE GRAB STRENGTH
PERMITTIVITY sec-1 APPARENT OPENING SIZE, MAX
TRAPEZOID TEAR STRENGTH***
D 4632 D 6241 D4491 D 4751 D 4533 SD TYPE
NONWOVEN 160 310 0.50 0.43 55 WOVEN, MONOFILAMENT 250 495 0.50 0.43 90 TYPE
NONWOVEN 160 310 0.20 0.25 55 WOVEN, MONOFILAMENT 250 495 0.20 0.25 90 PE TYPE
NONWOVEN 200 430 0.70 0.43 80 WOVEN, MONOFILAMENT 250 620 0.70 0.43 90 TYPE
NONWOVEN 200 310 0.20 0.25 55 WOVEN, MONOFILAMENT 250 495 0.20 0.25 90 TYPE
NONWOVEN 200 220 0.10 0.22 40 WOVEN, MONOFILAMENT 250 370 0.10 0.22 70 SE NONWOVEN 160 310 0.20 0.30 80 WOVEN 250 495 0.20 0.30 90 ST WOVEN 300* 600 0.05 0.15** 110 F WOVEN 200 450 0.05 0.60 75 E NONWOVEN 200 450 1.1 0.21 80 WOVEN, MONOFILAMENT 370 900 0.28 0.21 100
- Note 1: All property values in the above table are based on minimum average roll values in the weakest principal direction except for apparent opening size.
- Note 2: The ultraviolet stability shall be 50 percent after 500 hrs of exposure for all classes, except Class F, which shall be 70 percent (D 4355).
- *15 percent elongation for silt fence and monofilament woven geotextile in Machine Direction
- **This is a MINIMUM apparent opening size, not a maximum.
- ***Machine Direction
- Contact the Office of Materials Technology’s Soils and Aggregate Technology Division for approval of geotextiles used for reinforcement applications.
- 919.02 Seam and Overlap D 4884. Geotextiles joined by sewing shall conform to the following:
- (a) Either “J” or “Butterfly” type seams joined with a lock stitch.
- (b) Tensile strength requirements when tested across the seam.
- (c) Thread used for seaming shall be of equal or greater durability than the geotextile itself.
- 919.03 Securing Pins or Staples. Minimum 10 in. length and designed to securely hold the geotextile in place during construction.