Silt Fences:
Geotextiles which fail to meet the strength requirements for unsupported silt fence but achieve a minimum grab strength of 90 lbf in both the Machine Direction (MD) and the Cross-Machine Direction (XD) can be used as silt fence but an additional support element is required to be installed in the assembly. Supported silt fence shall consist of either 14 gage steel wire with a mesh spacing of 6 in. x 6 in. or prefabricated polymeric mesh. Note 1 in Table 737-01G is being amended to provide the required strength of the additional support element for supported silt fence installations, particularly the strength of the prefabricated polymeric mesh.
Geosynthetic Fibers:
Geosynthetic fibers are expandable polypropylene strands that, when mixed with soils, have shown the ability to somewhat increase its bearing capacity and shear strength. Typical mixtures vary between 0.1 and 0.4% by weight. Specification §737-09 Geosynthetic Fibers is being added to provide the material requirements for geosynthetic fibers
