Sensor-enabled geosynthetic material and method of making and using the same

• US 7,975,556 B2
• Filed: 01/16/2009
• Issued: 07/12/2011
• Est. Priority Date: 01/16/2009
• Status: Active Grant

• Current Assignee: The Board of Regents of the University of Colorado (University of Colorado System)
• Original Assignee: The Board of Regents of the University of Colorado (University of Colorado System)
• Inventors: Hatami, Kianoosh, Grady, Brian
• Primary Examiner(s): Kirkland, III; Freddie
• Application Number:
  US12/354,828
• Publication Number:
  US 20100180691A1
• Time in Patent Office: 907 Days
• Field of Search: 737/60, 737/88, 737/95
• US Class Current: 73/788
• CPC Class Codes: E02D 17/202 with flexible securing means
• CPC Class Codes: G01B 7/18 using change in resistance
• CPC Class Codes: G01L 1/20 by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids of piezo-resistive materials G01L1/18; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress
• CPC Class Codes: G01L 1/205 using distributed sensing elements
• CPC Class Codes: G01M 5/0083 by measuring variation of impedance, e.g. resistance, capacitance, induction
• CPC Class Codes: G01N 2203/0244 Tests performed "in situ" or after "in situ" use
• CPC Class Codes: G01N 2203/0617 Electrical or magnetic indicating, recording or sensing means
• CPC Class Codes: G01N 2203/0664 using witness specimens

Abstract

The present invention is directed to a sensor-enabled geosynthetic material for use in geosynthetic structures, a method of making the sensor-enabled geosynthetic material, and a method of measuring geometric strains of a geosynthetic product made from the sensor-enabled geosynthetic material. The sensor-enabled geosynthetic material includes a polymeric material and an electrically conductive filler. The polymeric material and an electrically conductive filler are combined to provide a sensor-enabled geosynthetic material. The sensor-enabled geosynthetic material having a predetermined concentration of the electrically conductive filler so as to provide the sensor-enabled geosynthetic material with an electrical conductivity and a strain sensitivity within the percolation region or slightly above it.

Claims

1. A method of measuring geometric strains of a geosynthetic structure, comprising the steps of:

providing a geosynthetic structure fabricated from a sensor-enabled geosynthetic material, the geosynthetic structure selected from the group consisting of a geogrid and a geomembrane;

selecting a measuring location of the geosynthetic structure to measure the geometric strain; and

determining the geometric strains of the geosynthetic structure at the measuring location.

2. The method of claim 1 further comprising the step of:

attaching conductive leads to the geosynthetic structure to provide conductivity data; and

manipulating the conductivity data to provide the geometric strains applied to the geosynthetic structure.

3. The method of claim 1 wherein the sensor-enabled geosynthetic material comprises:

a polymeric material; and

an electrically conductive filler combined with the polymeric material to provide the sensor-enabled geosynthetic material, the sensor-enabled geosynthetic material having a predetermined concentration of the electrically conductive filler so as to provide the sensor-enabled geosynthetic material with an electrical conductivity and a strain sensitivity within a percolation region.

4. The method claim 3 wherein the polymeric material is a polyolefin.

5. The method claim 4 wherein the polyolefin is selected from the group consisting of polypropylene, polyethylene, and combinations thereof.

6. The method claim 3 wherein the electrically conductive filler is selected from the group consisting of metal powders, conductive carbon black, carbon fiber, carbon nanotubes, and combinations thereof.

7. The method of claim 3 wherein the predetermined concentration of the electrically conductive filler in the sensor-enabled geosynthetic material is the highest concentration that allows the sensor-enabled geosynthetic material to remain in the percolation region.

8. The method of claim 3 wherein the predetermined concentration of the electrically conductive filler in the sensor-enabled geosynthetic material is in a range of from about 0.01 wt % to about 30 wt %.

9. The method of claim 3 wherein the predetermined concentration of the electrically conductive filler in the sensor-enabled geosynthetic material is within a range of about 5 wt % of the percolation region.

10. The method of claim 1 wherein a plurality of measuring locations of the geosynthetic product are selected to measure their geometric strains.

11. The method of claim 10 wherein the geometric strains of the plurality of measuring locations are measured simultaneously.

12. A geosynthetic structure constructed from a sensor-enabled geosynthetic material, comprising:

a geosynthetic structure constructed from a polymeric material, the geosynthetic structure selected from the group consisting of a geogrid and a geomembrane; and

an electrically conductive filler combined with the polymeric material to provide a sensor-enabled geosynthetic material wherein the entire geosynthetic structure is constructed from the sensor-enabled geosynthetic material, the sensor-enabled geosynthetic material having a predetermined concentration of the electrically conductive filler so as to provide the sensor-enabled geosynthetic material with an electrical conductivity and a strain sensitivity within its percolation region.

13. The sensor-enabled geosynthetic material of claim 12 wherein the polymeric material is a polyolefin.

14. The sensor-enabled geosynthetic material of claim 13 where in the polyolefin is selected from the group consisting of polypropylene, polyethylene, and combinations thereof.

15. The sensor-enabled geosynthetic material of claim 12 wherein the electrically conductive filler is selected from the group consisting of metal powders, conductive carbon black, graphite fiber, carbon nanotubes, and combinations thereof.

16. The sensor-enabled geosynthetic material of claim 12 wherein the predetermined concentration of the electrically conductive filler in the sensor-enabled geosynthetic material is the highest concentration that allows the sensor-enabled geosynthetic material to remain in the percolation region.

17. The sensor-enabled geosynthetic material of claim 12 wherein the predetermined concentration of the electrically conductive filler in the sensor-enabled geosynthetic material is in a range of from about 0.01 wt % to about 30 wt %.

18. The sensor-enabled geosynthetic material of claim 12 wherein the predetermined concentration of the electrically conductive filler in the sensor-enabled geosynthetic material is within a range of about 5 wt % of the percolation region.