Free draining seal device and installation method for mechanically stabilized earth wall structures

Abstract

A mechanically stabilized earth (MSE) wall system that permits water drainage through joints while also preventing undesirable migration of backfill through joints, thus dramatically reducing or eliminating undesirable vegetation by incorporation of a free draining seal (FDS) in panel joints, wherein the FDS structure blocks backfill but permits water migration.

Claims

1. A combination concrete barrier and free draining seal system, comprising: a mechanically stabilized earth (MSE) wall including a first precast concrete panel, a second precast concrete panel locate next to said first precast concrete panel, and a joint spacing located between said first precast concrete panel and said second precast concrete panel; and a free draining seal interfitted within said joint spacing thereby allowing water to pass through said joint spacing while inhibiting particulate matter to pass therethrough; wherein said free draining seal comprises a central layer including an elongate compressible core member, and an outer layer completely wrapped about said central layer, said outer layer including a filtration layer, said filtration layer encircling said elongate compressible core member and secured relative thereto; wherein each of said central layer and said outer layer is interfitted within said joint spacing between said first precast concrete panel and said second precast concrete panel of said MSE wall.

2. The combination concrete barrier and free draining seal system of claim 1, further comprising: a filter fabric and an adhesive applied between said filter fabric and said MSE wall such that said filter fabric is secured proximate to said joint spacing.

3. The combination concrete barrier and free draining seal system of claim 2, wherein said joint spacing of said MSE wall is on a face side of said first precast concrete panel and said second precast concrete panel of said MSE wall.

4. The combination concrete barrier and free draining seal system of claim 3, wherein said joint spacing of said MSE wall is on a backfill side of said first precast concrete panel and said second precast concrete panel of said MSE wall.

5. The combination concrete barrier and free draining seal system of claim 1, wherein each of said central layer and said outer layer has a circular cross-section for evenly filtering fluid therethrough while preventing debris from passing therethrough.

6. The combination concrete barrier and free draining seal system of claim 5, wherein said elongate compressible core member is further comprised of open cell foam.

7. The combination concrete barrier and free draining seal system of claim 5, wherein said filtration layer is further comprised of a nonwoven filter fabric.

8. The combination concrete barrier and free draining seal system of claim 7, wherein said nonwoven filter fabric is selected from the group consisting of polyester, polypropylene, and a synthetic polymer blend.

9. The combination concrete barrier and free draining seal system of claim 1, wherein said filtration layer is one of adhesively bonded and heat sealed to said core member.

10. A combination concrete barrier and free draining seal system, comprising: a mechanically stabilized earth (MSE) wall including a first precast concrete panel, a second precast concrete panel locate next to said first precast concrete panel, and a joint spacing intermediately located between said first precast concrete panel and said second precast concrete panel, said joint spacing being curvilinear and spanning across a corresponding major length of each said first precast concrete panel and said second precast concrete panel; and a free draining seal interfitted within said joint spacing thereby allowing water to pass through said joint spacing while inhibiting particulate matter to pass therethrough; a filter fabric and an adhesive applied between said filter fabric and said MSE wall such that said filter fabric is secured exterior of said joint spacing and spaced from said free draining seal; wherein said joint spacing of said MSE wall is on a face side of said first precast concrete panel and said second precast concrete panel of said MSE wall; wherein said joint spacing of said MSE wall is on a backfill side of said first precast concrete panel and said second precast concrete panel of said MSE wall; wherein said free draining seal comprises a central layer including an elongate compressible core member, and an outer layer completely wrapped about said central layer, said outer layer including a filtration layer, said filtration layer encircling said elongate compressible core member and secured relative thereto; wherein each of said central layer and said outer layer is interfitted within said joint spacing between said first precast concrete panel and said second precast concrete panel of said MSE wall.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will be better understood by reading the Detailed Description of the Preferred and Alternate Embodiments with reference to the accompanying drawing figures, in which like reference numerals denote similar structure and refer to like elements throughout, and in which:

(2) FIG. 1 is a cross-sectional view of a preferred embodiment of a free draining seal (FDS) according to the present disclosure;

(3) FIG. 2 is a perspective view of the FDS of FIG. 1;

(4) FIG. 3 is a partial cross-sectional view of a horizontal joint in keeping with the teachings of the present disclosure and further illustrated in a representative position in the wall system of FIG. 7, taken through lines 5-5;

(5) FIG. 4 is a partial cross-sectional view of a vertical joint in keeping with the teachings of the present disclosure and further illustrated in a representative position in the wall system of FIG. 7, taken through lines 6-6;

(6) FIG. 5 is a partial cross-sectional view of a horizontal joint in keeping with the teachings of the present disclosure and further illustrated in the wall system of FIG. 7, taken through lines 5-5;

(7) FIG. 6 is a partial cross-sectional view of a vertical joint in keeping with the teachings of the present disclosure and further illustrated in the wall system of FIG. 7, taken through lines 6-6;

(8) FIG. 7 is a partial diagrammatical front view of an improved mechanically stabilized earth wall system in keeping with the teachings of the present invention;

(9) FIG. 8 is a cross-sectional view of a prior art MSE wall system, showing undesirable vegetation, and further illustrated in the prior art wall system of FIG. 10, taken through lines 8-8;

(10) FIG. 9 is a partial cross-sectional view of a vertical joint of a prior art MSE wall system, showing undesirable vegetation, and further illustrated in the prior art wall system of FIG. 10, taken through lines 9-9; and

(11) FIG. 10 is a front face view of a prior art MSE wall system, showing undesirable vegetation.

DETAILED DESCRIPTION OF THE PREFERRED AND ALTERNATE EMBODIMENT(S)

(12) The present device will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the present device are shown. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, the embodiments herein presented are provided so that this disclosure will be thorough and complete, and will convey the scope of the invention to those skilled in the art. In describing the preferred and alternate embodiments of the present device, as illustrated in the figures and/or described herein, specific terminology is employed for the sake of clarity. The device, however, is not intended to be limited to the specific terminology so selected, and it is to be understood that each specific element includes all technical equivalents that operate in a similar manner to accomplish similar functions.

(13) As previously discussed, and referring initially to FIGS. 8-10, mechanically stabilized earth (MSE) walls are typically constructed with joints having a % inch joint spacing between opposing precast concrete panels. The joints are typically covered with a strip of filter fabric F (+/−18″) glued to a back fill side of the panel with adhesive G during construction, as illustrated with reference to FIGS. 8 and 9. The filter fabric allows water to pass through the joints and seeks to inhibit the passage of backfill through the filter fabric. Free draining seal (FDS) 10 of the present disclosure is an improvement over the disadvantageous failures of placement and of function of such known filter fabric application, and of installation requirements related thereto.

(14) One exemplary embodiment of the present device includes free draining seal (FDS) 10, as illustrated with reference to FIGS. 1 and 2, wherein FDS 10 may replace or supplement the filter fabric F illustrated and described, by way of example. FDS 10 is preferably defined by elongate member 12, wherein a plurality of layers 14 preferably form elongate member 12. According to the preferred embodiment, central layer 16 of FDS 10 is compressible core 18 and outer layer 20 is filtration medium 22.

(15) Materials of construction for the presently described FDS 10 are preferably selected for characteristics such as compressibility, porosity, durable weatherability, or the like, wherein exposure to earthen components and environmental elements is expected to be endured, generally without compromise of functionality. For example, and without limitation, compressible core 18 of central layer 16 is preferably open cell foam, with a generally dense structure and functional porosity. Outer layer 20 is preferably polyethylene or polypropylene formed as a nonwoven fabric. Of course, any other natural or manmade material may be utilized, either alone or in combination with other material(s), as long as the preferred characteristics are considered, recognizing however that an FDS constructed with inferior materials, such as minimally compressible or minimally porous core material, but according to that structure as described herein, is intended to be within the scope of the present disclosure, even though realized functionality would be diminished.

(16) According to the preferred embodiment, outer layer 20 may be extruded, needle punched, or otherwise formed. Although polyester and/or polypropylene are preferred, it should be recognized that it is the free draining nature of the material for outer layer 20 that is important. Nonwoven geotextile filter fabrics are particularly effective. Geotextiles may, for example, be selected from such source options as Carthage Mills, ADS, BP Amoco, Contech, Linq, Mirafi, Si, TNS, and/or Webtec, and may include, for example, monofilament filtration fabrics, woven slit film and high performance fabrics, and/or nonwoven fabrics.

(17) One example is a nonwoven geotextile multipurpose fabric of polypropylene staple fibers, needle punched and heat set. For such a fabric, exemplary physical or dimensional properties, for example, are mass per unit area of 3 to 16 oz/yd2 and/or thickness of 40-165 mils. Exemplary hydraulics/filtration features are, for example, apparent opening size of 70-100 US Standard Sieve size, with no open area, permittivity of 2.0 to 0.70, permeability of 0.22-0.27 em/sec, and a flow rate of 150-50 gpm/ft2. UV resistance, a preferably feature of outer layer 20, maybe about 70% and mechanical properties, for example, may have grab tensile strength of 80-380 lbs, wide width tensile of 30-150 lbs/in, puncture of 50-240 lbs, and trapezoidal tear of 30-150 20 lbs. Of course, these properties are exemplary only, and should not be considered to limit available options for materials for formation of outer layer 20 of FDS 10.

(18) Additionally, the preferred nonwoven fabric may be utilized in any selected thickness.

(19) Accordingly, it is important to note that the representative FDS 10 of FIGS. 1 and 2 is an exemplary depiction only, and should not be viewed as a limitation or necessary dimensional relationship of outer layer 20 and central layer 16. According to the preferred relative contribution of plurality of layers 14, central layer 16 is preferably a more principle component, with outer layer 20 preferably defining an essentially thin outer covering secured around an essentially thick central compressible core 18. Alternately, outer layer 20 may be comprised of a plurality of wrappings rather than a single wrapped layer, or outer layer 20 may be formed from a generally thick nonwoven filter fabric, such that even a single wrapped layer about central layer 16 is dimensionally significant.

(20) Compressible core 18, also referred to as backer rod 24, may be provided in anyone of a variety of different diameters. The preferred diameter for compressible core 18 is preferably selected according to the targeted installation site, and the characteristics of the joint(s) to be “sealed” by FDS 10. Color of FDS 10, backer rod 24 and filtration medium 22 may also be selected according to the targeted installation site, wherein light colors may be more beneficially concealed proximate a light MSE structure and/or dark colors may be more camouflaged proximate a dark MSE structure.

(21) Irrespective of color similarity or dissimilarity, outer layer 20 of FDS 10 is preferably securely attached to central layer 16. In the preferred embodiment, filtration medium 22 extends around the preferably cylindrical outer surface of backer rod 24 to define seam 26, wherein seam 26 is preferably adhesively bound. Alternately, seam 26 may be heat sealed, or otherwise securely positioned in place. In another alternate embodiment, filtration medium 22 could be extruded, in tubular form, such that no seam would be necessary along the length of FDS 10.

(22) Other configurations and/or manners of forming FDS 10 may be employed, even wherein backer rod 24 and filtration medium 22 could be integrally formed as layers of a structurally holistic device.

(23) In new construction, FDS 10 may replace both the filter fabric F and the construction adhesive G on the backfill side of the panel. As illustrated with reference to FIGS. 3-4, the FDS is inserted into the panel joints allowing water to pass through the joints but preventing the backfill from migrating through the joints with the water. With continued reference to FIGS. 5 and 6, the FDS may also be installed on the face side of the panels due to fill dirt that may make its way into the joint during construction.

(24) As above addressed, as representatively depicted in FIGS. 8-10, and as is well known in the art, typical MSE walls have undesirable vegetation V growing through the joints of panels (possibly due to poor installation of the filter fabric) from backfill that is inadvertently placed in the panel joints during construction, or from vegetation growing from the finish grade up through the joints. FDS 10 of the present disclosure may be inserted in the joints (+/−½″) to seal the joint from vegetation V growing through the front joints, but will allow water to pass through the joints. By way of example, and with reference to FIG. 7, FDS 10 would be inserted after the existing vegetation has been removed, and desirably does not require an adhesive to keep it in place during installation because of the nature of compressible core 18.

(25) Having thus described exemplary embodiments of the present invention, it should be noted by those skilled in the art that the within disclosures are exemplary only, and that various other alternatives, adaptations, and modifications may be made within the scope of the present invention. Many modifications and other embodiments of the device will come to the mind of one skilled in the art having the benefit of the teachings presented in the present description and the associated drawings. Accordingly, the present invention is not limited to the specific embodiments illustrated herein, but is limited only by the following claims.