3886.1SCOPE
For the purpose of the Work specified in 3886, “Silt Fence,” the Department defines MARV as two standard deviations below the mean value of the rolls tested. Provide Silt fence to retain sediment. Provide machine sliced (MS) Silt fence consisting of a woven geotextile fabric installed by machine and supported by steel posts. Provide hand installed (HI) Silt fence consisting of a woven geotextile fabric installed by hand and supported by steel posts. Provide super duty (SD) Silt fence consisting of concrete or water filled jersey barriers with fabric wrapped around the front face of the barrier. The Contractor may provide woven or non-woven geotextile fabric or poly/poly-reinforced sheeting. Provide pre-assembled (PA) Silt fence consisting of a woven geotextile fabric supported by wood posts pre-attached to the fabric. Provide turbidity barrier (TB) Silt fence consisting of a low permeable fabric barrier, installed in water and supported by steel cable and steel posts.
3886.2REQUIREMENTS
Provide geotextiles for MS and HI Silt fences from the APL. A Fabric Provide fabric meeting the following requirements and characteristics:
during outdoor exposure
Table 3886.2-1 Silt Fence Requirements Silt Fence Type Minimum Width, inches Grab Tensile (machine direction), pounds * Apparent Opening Size ǁ Puncture Strength † UV Stability, 500 hour, percent ‡ MAX Permittivity # Maximum Flow Rates, GPM/square foot MS, HI woven geotextile § 36 130 No. 30 Sieve — 70 1.0 s−1 130 PA woven geotextile 36 100 No. 30 Sieve — 70 0.1 s−1 5 SD woven or nonwoven geotextile ** 36 100 — — 70 — — TB polyester or polyvinyl Fabric 60 200 — 90 pounds 70 0 0 Values in the table are Minimum Average Roll Values (MARV). * ASTM D4632, Standard Test Method for Grab Breaking Load and Elongation of Geotextiles. ǁ ASTM D4751, Standard Test Methods for Determining Apparent Opening Size of a Geotextile, Maximum average roll value. † ASTM D4833, Standard Test Method for Index Puncture Resistance of Geomembranes and Related Products. ‡ ASTM D4355, Standard Test Method for Deterioration of Geotextiles by Exposure to Light, Moisture, and Heat in a Xenon Arc-Type Apparatus. # ASTM D4491, Standard Test Methods for Water Permeability of Geotextiles by Permittivity. § Provide MS, HI woven geotextile with monofilament in both directions. Do not make substitutions. ** Meeting 3733, “Geosynthetic Materials,” Types 3, 4, 5, or 7, or poly/poly-reinforced sheeting meeting 3888, “Poly Sheeting” of variable width.
For TB fabric, width is finished width with a 4 inch overlap heat sealed hem pocket at the top. B Fasteners Provide fasteners with a tensile strength of at least 50 pounds. Use plastic ties to fasten geotextile to posts on MS, HI, and TB applications. Use wire ties or plastic ties to fasten geotextile to anchor points on SD applications. C Supports Provide steel posts for MS, HI, and TB Silt fence types per 3403, “Hot-Rolled Steel Fence Posts,” and the following: Table 3886.2-2 Steel Silt Fence Post Requirements Characteristic Requirement Type T-post Weight 0.95 pound/foot Length ≥ 5.0 feet Embedment ≥ 24 inches Post spacing <6.0 feet
Provide wood posts for PA Silt fence type meeting the following requirements: Table 3886.2-3 Wooden Silt Fence Post Requirements Characteristic Requirement Type Hardwood Size ≥ 2 inches by 2 inches Length ≥ 4.0 feet Embedment ≥ 18 inches Post Spacing < 5.0 feet D Portable Precast Concrete Jersey Barriers For SD, use portable precast concrete barriers per 2533, “Concrete Median Barriers,” for main support and strength. If placing the barrier adjacent to traffic, provide a barrier with a shape meeting the requirements of the Standard Plates design designation shown on the Plans. The Contractor may use barriers meeting obsolete Standard Plate designs in non-traffic areas. E Portable Water Filled Jersey Barriers For SD, provide main support strength of at least 1,200 pounds when filled with water. Provide a plastic, water-filled barrier. If placing the barrier adjacent to traffic, provide a barrier with a shape meeting the requirements of the Standard Plates design designation shown on the Plans. F Steel Cable Provide a top line for TB made of a 5/16 inch galvanized steel cable with a breaking strength of at least 9,800 pounds. Incorporate into the 4 inch hem pocket at top of fabric.
3886.3SAMPLING AND TESTING
Provide the following to the Engineer with each shipment of geotextile:
maximum average roll values for the geotextile
Silt Fence in other states
Get an email when 3886 changes
Minnesota revises spec sections through supplementals and new editions. We check this one every week and email you the day it changes. Free, no account.