# US 8,465,231 B2 · Graduated silt fence > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,465,231 B2 - Document ID: US8465231B2 - Status: Granted - Kind: B2 - Application number: 12/814,459 - Filed: 2010-06-13 - Published: 2011-12-15 - Granted: 2013-06-18 - Earliest claimed: 2010-06-13 - Applicants: Hunt Lee Christopher - Inventors: Hunt Lee Christopher - Web page: https://patentgrep.com/patent/US8465231B2 ## CPC - E02D 7/20: Placing by pressure or pulling power - E02B 3/04: Structures or apparatus for, or methods of, protecting banks, coasts, or harbours ({E02B1/003 takes precedence;} sealing or joints E02B3/16 ) - E03F 1/00: Methods, systems, or installations for draining-off sewage or storm water - Y10T 442/3179: Woven fabric is characterized by a particular or differential weave other than fabric in which the strand denier or warp/weft pick count is specified - E02D: FOUNDATIONS; EXCAVATIONS; EMBANKMENTS (specially adapted for hydraulic engineering E02B); UNDERGROUND OR UNDERWATER STRUCTURES {(tunnels, tunnelling, mining E21)} - E02B: HYDRAULIC ENGINEERING (ship-lifting E02C; dredging E02F) - E03F: SEWERS; CESSPOOLS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract An geotextile silt fence has an increasing permittivity with increase in height thereby allowing larger storm events to flow through the fence without overtopping. A stiffening device is provided at the top of the silt fence to reduce sagging and improper overtopping. This stiffening device may be a mono-directional extruded geogrid structure that is a higher mil thickness than the geotextile monofilament structure of the silt fence and which is affixed to the geotextile continuously throughout the silt fence length. An overflow preferential pathway may be provided at the top of the silt fence through large voids within the geogrid providing controlled overflow of impounded water which mitigates structural failure of the silt by eliminating the typical overtopping failure mechanism. ## Claims ### Claim 1 A graduated silt fence comprising a woven geotextile fabric that includes a cross-plane permeability coefficient defining a permittivity which is increasing from one width edge and to the opposite width edge of the geotextile fabric, wherein the change in the permittivity is accomplished by a variation in weaving pattern, and wherein the variation in the permittivity throughout the geotextile width remains constant throughout the geotextile length, whereby when installed, the graduated silt fence provides a low permittivity for lower portions of the fence and as height increases, the geotextile fabric contains a greater permittivity created by change in material weave providing the greater permittivity within the textile structure allowing an increase in flow rate through the fence, wherein the variation in weaving pattern includes the use of a plain weave, adjacent a twill weave section, adiacent a satin weave section and further including a support geogrid formed of a mono-directional extruded material that is attached to the top of geotextile fabric and is of a greater material thickness and stiffness than the woven geotextile and is formed as a continuous strand of hollow rectangular structure along the top length of the woven geotextile, and wherein the geogrid is slotted to provide an overflow preferential pathway at the upper portion of the installed silt fence through the geogrid. ### Claim 2 (depends on 1) The graduated silt fence according to claim 1 wherein the geogrid is slotted to provide an overflow preferential pathway at the upper portion of the installed silt fence through the geogrid. ### Claim 3 A graduated silt fence comprising a woven geotextile fabric that includes a cross-plane permeability coefficient defining a permittivity which is increasing from one width edge and to the opposite width edge of the geotextile fabric, wherein the change in the permittivity is accomplished by a variation in change in warp strain deformation resistance of the geotextile fabric, and wherein the variation in the permittivity throughout the geotextile width remains constant throughout the geotextile length, whereby when installed, the graduated silt fence provides a low permittivity for lower portions of the fence and as height increases, the geotextile fabric contains a greater permittivity created by change in warp strain deformation resistance of the geotextile fabric providing the greater permittivity within the textile structure allowing an increase in flow rate through the fence, and further including a support geogrid formed of a mono-directional extruded material that is attached to the top of geotextile fabric and is of a greater material thickness and stiffness than the woven geotextile and is formed as a continuous strand of hollow rectangular structure along the top length of the woven geotextile. ### Claim 4 (depends on 3) The graduated silt fence according to claim 3 wherein the geogrid is slotted to provide an overflow preferential pathway at the upper portion of the installed silt fence through the geogrid. ### Claim 5 A graduated silt fence comprising a woven geotextile fabric that includes a cross-plane permeability coefficient defining a permittivity which is increasing from one width edge and to the opposite width edge of the geotextile fabric, wherein the change in the permittivity is accomplished by a variation in weft material width, and wherein the variation in the permittivity throughout the geotextile width remains constant throughout the geotextile length, whereby when installed, the graduated silt fence provides a low permittivity for lower portions of the fence and as height increases, the geotextile fabric contains a greater permittivity created by variation in weft material width providing the permittivity within the textile structure allowing an increase in flow rate through the fence, and further including a support geogrid formed of a mono-directional extruded material that is attached to the top of geotextile fabric and is of a greater material thickness and stiffness than the woven geotextile and is formed as a continuous strand of hollow rectangular structure along the top length of the woven geotextile. ### Claim 6 (depends on 5) The graduated silt fence according to claim 5 wherein the geogrid is slotted to provide an overflow preferential pathway at the upper portion of the installed silt fence through the geogrid.