US20090266026A1

US20090266026A1 - Method For Repairing A Utility Pole In Place

Info

Publication number: US20090266026A1
Application number: US12/110,926
Authority: US
Inventors: Richard C. Hannay; Richard A. Owen
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-04-28
Filing date: 2008-04-28
Publication date: 2009-10-29

Abstract

A method of repairing a utility pole in place. The method comprises excavating soil from around the utility pole to expose a portion of the pole surface below the ground line, and adhering a plurality of prefabricated sleeve segments to the surface of the utility pole to form a circumferential sleeve. The plurality of sleeve segments are positioned to extend above and below the ground line and have side edges that each overlap an edge of an adjacent sleeve segment. The hole around the pole is then filled, such as with a slurry of soil, water and sodium silicate. This method may be beneficially used on wooden utility poles that have experienced decay, in order to restore strength to the pole.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to repairing wooden utility poles that have experienced decay near the ground line.
2. Description of the Related Art
Wooden utility poles are commonly used to support electrical conductor wires, mount switches and transformers in an electrical power distribution system or other utility systems and other structures supported with wooden piling. Wooden utility poles are normally embedded into the ground to a depth that is equal to 10% of their length plus an additional 2 feet. This embedment “formula” is used in field operations to determine the surface area of the wood pole installed in the soil so that the soil strength surrounding the pole will support the load the pole was designed to carry.
Wooden utility poles are typically treated with a preservative, such as coal tar creosote, to prevent rapid decay or rotting of the wood pole. However, as the soil repeatedly expands and contracts, the preservative is pulled away from the pole and the soil introduces microorganisms into the wood through the “checks” in the wood. The region of the pole immediately above and below the ground line receives sufficient moisture and oxygen to support the growth of the microorganisms. The microorganisms are then able to feed on the untreated interior wood and initiate decay of the pole. Over a period of years, this mechanism continues to decay this region of the pole until it becomes weakened and unable to reliably serve its function.
Structurally impaired poles can be dealt with in several ways. For example, the impaired pole can be replaced with a new pole, but this is very expensive and requires all of the overhead attachments to be removed from the impaired pole and reinstalled on the new pole, preferably without disrupting electrical service. It is also possible to inject a resinous material into the decayed area of the impaired pole. However, this method has not proven to be very successful.
Alternatively, an impaired pole may be “stubbed” to a shorter section of a new pole that is embedded into the ground alongside the impaired pole. In this manner, the base of the impaired pole is banded together with the new pole causing the load to be transferred to the ‘stub pole.’ Similarly, a steel truss may be driven into the ground beside the impaired pole to a depth that is 2 feet further into the soil than the depth of the original pole. The steel truss is then banded to the wood pole at the top of the truss, at the ground line of the truss, and at a point about half way between the top of the truss and the ground line. The steel banding typically has a width of about 1½ inches to 2 inches and a thickness of about 1/16^thinch. This latter method of reinforcing an impaired pole is probably the most prevalent method currently used by the utility industry.
A more reliable method of dealing with an impaired wooden utility pole may be referred to as the “wrapped” procedure. This procedure is described by the present inventors in their U.S. Pat. No. RE 35,322, which patent is incorporated by reference herein. In accordance with the wrapped procedure, the decayed pole is excavated about 3 feet down from the ground line, the pole is cleaned with a wire brush and decayed portions of the pole are repaired with a resin mixture to restore the original circumference and taper of the pole. The resin is coated onto the pole about three feet above an below the ground line and then strips of fiberglass (for example, 16 inches wide and 5.5 feet long) are then placed on the pole and rolled into the resin on the pole. This procedure of applying resin and fiberglass is repeated around the circumference of the pole until there is a layer or “cross-section” of glass and resin that measures approximately ⅝ inches thick. A ⅝ inch thick layer of the resin and fiberglass composite has been determined to sufficiently restore the strength of the pole, because the load on a pole is concentrated around the perimeter (not in the center of the pole) and this thickness of the composite provides the pole with the same strength as the outside 2 inches of a wood pole. Accordingly, this procedure makes the pole as strong as it was when the pole was new. Unfortunately, this method requires excavation of soil around the pole to a depth of 3 feet and over an area large enough for a man to stand within the excavated hole to apply the resin and fiber glass on the pole. This excavation greatly increases the time and effort required to repair the pole, thereby limiting the number of pole repairs that a crew can accomplished in a day. Furthermore, changing ambient temperatures that occur during the day can increase the difficulty of handling the resin, especially if the resin activator is temperature sensitive.

SUMMARY OF THE INVENTION

One embodiment of the present invention provides a method of repairing a utility pole in place. The method comprises excavating soil from around the utility pole to expose a portion of the pole surface below the ground line, adhering a plurality of prefabricated arcuate sleeve segments to the surface of the utility pole to form a circumferential sleeve, wherein the plurality of sleeve segments extend above and below the ground line and have side edges that each overlap an edge of an adjacent sleeve segment, and filling the hole about the circumferential sleeve. The method optionally further includes banding the plurality of sleeve segments firmly against the surface of the utility pole.
Another embodiment of the method includes mixing the excavated soil with sodium silicate and an activator composition, such as triacetin, to form a slurry composition that will harden, and filling the hole about the circumferential sleeve with the slurry. Preferably, the step of excavating soil includes directing high pressure air into the soil near the pole to form an annular hole having an average width of between 3 and 6 inches.
Yet another embodiment of the method include sleeve segments that are a polymeric material containing a reinforcing material selected from the group consisting of fiberglass, carbon fibers, and combinations thereof. Preferably, the arcuate sleeve segments are sufficiently flexible to match the actual curvature of the surface of the utility pole. Preferred sleeve segments have a thickness from ½ to ¾ inch. The arc length of each sleeve segment is optionally tapered from a bottom end to a top end.
The sleeve segments have an offset lip formed along one edge of the pole contact portion, wherein the offset lip provides tolerance in the angular and perimeter spacing of the sleeve segments without loss of overlapping. An inner surface of the offset lip is preferably adhered to an outer surface of the adjacent sleeve segment.
A further embodiment of the method adheres the sleeve segments to the utility pole using an adhesive that is selected from the group consisting of an isocyanate, acrylic, urea-formaldehyde, epoxy, phenolic, poly-ester, and poly-vinyl. Preferably, the sleeve segments are adhered to the utility pole with a gel formed by mixing an adhesive with fumed silica. One method includes, for example, applying a layer of adhesive to the surface of the utility pole, applying a layer of adhesive to the inner surface of the plurality of sleeve segments, and pressing the plurality of sleeve segments about the utility pole with overlapping side edges. Another specific method includes, for example, excavating the soil to a depth between 3 and 5 feet below the ground line, and adhering the sleeve segments to the utility pole in a position extending between 2 and 4 feet above and below the ground line.
A still further embodiment of the method includes selecting the plurality of arcuate sleeve segments from a predetermined set of segments including from two to four segment sizes, each segment size having a pole contact portion with a different arc length. In one example, the plurality of sleeve segments is three or four sleeve segments. Preferably, none of the sleeve segments extends more than 150 degrees when encircling the utility pole.
Other embodiments, aspects, and advantages of the invention will be apparent from the following description and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic side view of a wooden utility pole installed in the ground.

FIG. 2 is a schematic side view of a wooden utility pole with an excavated hole around the pole.

FIG. 3 is a perspective assembly view of two pre-formed fiberglass sleeve segments.

FIG. 4 is a perspective view of the two fiberglass sleeve segments with a thick adhesive layer applied over the concave inner surface.

FIG. 5 is a top view of the pole and the excavated hole with two sleeve segments disposed into the hole.

FIG. 6 is a top view of the pole with the two sleeve segments positioned against the pole.

FIGS. 7A-7C are schematic diagrams of the sleeve segments profiles.

FIG. 8 is a schematic side view of the pole with the sleeve segments banded tightly around the pole and reinforced at the top.

FIG. 9 is a schematic side view of the pole with the hole filled with a soil and resin composite prepared using a mixing system.

DETAILED DESCRIPTION

One embodiment of the invention provides a method of repairing a utility pole in place. The method comprises excavating soil from around the utility pole to expose a portion of the pole surface below the ground line, adhering a plurality of prefabricated sleeve segments to the surface of the utility pole to form a circumferential sleeve, wherein the plurality of sleeve segments extend above and below the ground line and have side edges that each overlap an edge of an adjacent sleeve segment, and then filling the annular hole. This method may be beneficially used to reinforce wooden utility poles that have experienced decay primarily in a region extending above and below the ground line, such as from about 8 inches above the ground line to about 9 inches below the ground line. The method may be used to restore strength to a region of a wooden utility pole that has decayed or been worn away.
Another embodiment of the invention provides a prefabricated composite sleeve segment. The composite sleeve segment is preferably made with a resin that is reinforced with fiberglass material and is preferably formed into a curvature to fit about the perimeter of a pole having a known diameter and taper. The curvature and arc length of the sleeve segments can be modified to accommodate various utility pole diameters. Sleeve segments may be made with a specific arc length so that a given number of the segments, such as three segments, will extend exactly around a utility pole of a given diameter, such as a twelve inch diameter utility pole. Similar sets of sleeve segments may then be made for utility poles having other diameters. Alternatively, sleeve segments may be made in a fixed number of the different sizes, wherein the number of segments and the combination of segment sizes are selected to extend around a utility pole of almost any diameter. A suitably sized overlapping lip, such as a lip of 3 to 5 inches, provides the ability of the selected segments to fit a range of diameters and tapers while still overlapping. Each sleeve segment has a lip on a vertical edge that overlaps a mating vertical edge on an adjacent sleeve segment. Two or more sleeve segments are overlapped in this manner to extend around the circumference of the pole to form a cylindrical sleeve. Most preferably the sleeve is prepared with exactly three or four sleeve segments that each extend over an arc no greater than 150 degrees about the utility pole to accommodate an overlap.
In yet another embodiment of the invention, the lip on each sleeve segment extends a sufficient distance to provide angular or circumferential positioning or spacing of the segments without loss of overlapping. For example, a sleeve segment will preferably be positioned so that the lip will overlap between 2 and 4 inches of an adjacent sleeve segment. Accordingly, the actual diameter of the sleeve formed by a given set of sleeve segments may be varied somewhat during installation to accommodate natural variations in the diameter and taper of each pole.
Since the greatest source of stress on the pole may be caused by tension in the power line pulling on the upper portion of the pole, it is preferable to avoid positioning a joint (formed by two overlapping segments) where the pole may experience the most stress. Accordingly, the joints are preferably not positioned in angular alignment (relative to a central axis of the pole) with the power line. Rather, the sleeve segments are preferably positioned against the pole so that a vertical joint between two adjacent segments is formed in at an angular position on the pole that is generally perpendicular, or at least angularly offset, to the direction(s) of the power line.
In an additional embodiment, at least one band is secured around the sleeve to hold the sleeve segments in place around the pole. Tightening of the band may also serve to push adhesive into openings in the pole and into the joints and contact points between sleeve segments to improve the bonding strength. Most preferably, a first band is applied near the top of the sleeve, a second band is applied in the middle of the sleeve, and a third band is applied near the bottom of the sleeve. The bands not only compress the sleeve and hold the sleeve in place while the adhesive cures, but the bands may also add to the hoop strength of the sleeve. Furthermore, a band applied near the top of the sleeve reinforces the upper portion of the casing to oppose expansion of the pole caused by changes in the moisture content near the top of the sleeve where moisture that wicks up the pole evaporates out of the wood. Exemplary bands may be made from steel, nylon, or polypropylene.
In a specific embodiment, a steel band is cut to a length about 1.2 times the outer circumference of the sleeve segments that fit around the pole. The ends of the band are then bent to a 90 degree angle perpendicular to strap or band. These bent ends or “ears” may includes a predrilled hole or be punched to allow a bolt and nut to be inserted and tightened to secure the band. The band may be tightened near the bottom of the sleeve using remote tightening system. A preferred band installed at the bottom of the casing is approximately ⅛^thinch thick by 2 inches wide, whereas the bands applied at the ground line and at the top of the sleeve may be standard, commercial, galvanized bands that are 2 inches wide by 1/16^thinch thick and are currently available with crimping devices to secure the ends of the band.
In a still further embodiment, the composite sleeve segments are manufactured by molding. For example, a steel mold may be used to fabricate and lay up fiber glass to form a sleeve segment. Each sleeve segment should have a thickness that will provide the strength that the pole requires near the ground line. The sleeve segments are preferably from ½ to ¾ inch thick and most preferably about ⅝ inch thick. A plurality of sleeve segments can be made and adhered to a utility pole to collectively form a sleeve. An optional gel coat is sprayed on the mold before the fiberglass is applied so that the gel coat becomes bonded to the fiberglass and provides color and UV protection to the sleeve segment. For the most common wooden utility poles, a sleeve segment will have a length from 6 to 8 feet and will accommodate pole diameters from 8 to 15 inches in diameter or greater. Other lengths and diameters may be prepared for use with any specific pole shapes and dimensions. The sleeve segments are preferably installed with about 50% of the sleeve length extending above the ground line to allow the structural load to be transferred from the utility pole to the sleeve.
In another embodiment, the sleeve segments are a composite material including fiberglass or carbon fiber that has various strand orientations. Preferably, the fiberglass has a triaxial orientation that most closely duplicates the strength of wood fiber in the pole to be repaired.
A viscous adhesive is disposed between each sleeve segment and the pole to secure the segment to the pole and is preferably also disposed between the edges of each of the segments to secure each segment to each adjacent segment so that the segments form an integral sleeve. Although the adhesive may be applied directly to the pole, such as with a small paint roller, the adhesive is preferably applied to an inside surface of each sleeve segment before positioning the segment against the side of the pole. Optionally, a thin protective barrier film could cover the material until it is ready to be used at a job site. Furthermore, the adhesive may be applied to both the pole and the sleeve segments before positioning the sleeve segments against the side of the pole.
The adhesive should be viscous so that most of the adhesive applied to a sleeve segment remains on the segment as it is positioned vertically in the hole and placed against the pole. A preferred adhesive is an isocyanate pre-polymer, but many different adhesives may work as long as it forms a suitable bond to the sleeve segment and the wooden pole (containing preservatives). Suitable adhesives include, without limitation, acrylic, urea-formaldehyde, epoxies, phenolics, poly-esters, and poly-vinyls. Optionally, the adhesive may be mixed with fumed silica to make a gel that does not run when the sleeve segment is installed vertically.
In accordance with preferred embodiments of the invention, it is not necessary for the annular hole excavated around the utility pole to have a width that is sufficient to accommodate a person. Rather, the adhesive laden sleeve has sufficient physical integrity that it can be extended into the annular hole and placed in position against the pole by handling upper and middle portions of the sleeve. Accordingly, the width of the annular hole only needs to provide a small clearance more than the thickness of the sleeve and the adhesive. For example, an annular hole having a width of four inches would accommodate the installation of a one inch thick sleeve segment with a one inch thick layer of adhesive with a clearance of two inches. It should be recognized that the hole should be generally annular, but need not be precisely annular. In fact, the hole is partially defined by the surface of the utility pole, which is tapered. Accordingly, if the soil boundary of the hole is substantially vertical, then the hole will generally taper with depth.
In yet another embodiment of the invention, the annular hole is excavated using a high pressure excavator, such as a VACMASTER air vacuum excavation system (a trademark of Vacmasters of Arvada, Colo.). This machine uses high pressure air to break up the soil and then a larger vacuum hose removes the spoils which are then stored in a tank that has been placed next to the pole that is being repaired. An air vacuum excavation system is ideal to remove soil from around the pole to a 3 foot depth with a very small annular width, such as 2 to 4 inches. The annular width of the hole may be bigger, but it is not deemed necessary. The soil is vacuumed into a pile or container near the pole for later use in refilling the hole. However, other conventional methods for forming the hole may be used.
Decayed wood on the sides of the pole above or below the ground line should be removed, such as by abrading or scraping the pole down to a layer of wood that still has structural integrity. For example, removal of the decayed wood may be performed with a wire brush, such as a wire brush attachment mounted to the distal end of an air vacuum excavation system so that soil excavation and decay removal can be performed by a single tool more-or-less simultaneously. If a significant amount of decay is removed from the pole, the holes or cavities left in the pole are preferably filled with a viscous resin to maintain the natural pole shape and taper.
In a further embodiment, some or all of the soil removed from around the pole is mixed with water and a hardening agent, such as sodium silicate, to form a slurry. For example, the soil may be vacuumed directly into a mixing tank where water and a hardening agent can be added. After the sleeve segments have been installed around the pole, the slurry is conveniently poured into the annular hole that remains around the pole and sleeve. The hardening agent will cause the slurry to cure (set up), resulting in an increase in the load strength of the soil, thus further increasing the effective pole diameter. For example, a slurry formed with sodium silicate will cure in about 1 hour with a compressive strength of 500 to 700 psi. Optionally, the slurry may be formed with soil, sodium silicate, a setting agent, water and a surfactant. An exemplary setting agent is triacetin. Depending upon the exact size of the hole, about 2 gallons of the slurry is sufficient. A recommended slurry is formed with approximately 2½ cubic feet of soil mixed with 2 gallons of a solution including about 88% water [by volume], about 10% sodium silicate, about 1% triacetin, and about 1% surfactant. The solution may optionally further include a biocide or fungicide, such as various forms of copper salts, to eliminate microorganism contamination near the pole.
FIG. 1 is a schematic side view of a wooden utility pole 10 installed in the ground 12. The utility pole 10 has a lower end 14 disposed in the ground 12 below the groundline 20 and an upper end 16 that supports an electrical transmission line 18, transformer, telephone line or other component. The utility pole 10 is a common wooden utility pole that tapers from the lower end 14 to the upper end 16. The installation procedures and standards for wooden utility poles are well-known in the art.
FIG. 2 is a schematic side view of the wooden utility pole 10 with an excavated hole 22 around the pole 10. The generally annular hole 22 extends around the exposed surface of the pole and has a width “W”. A high pressure air excavation system 24 is preferably used to remove the soil from the area immediately surrounding the pole. A hose or nozzle 26 directs high pressure air over a small area to dislodge the soil and remove it through a second hose. By carefully controlling the position of the hose or nozzle, a generally annular hole 22 may be excavated. The hole 22 is not expected to have a smooth soil wall and the surface of the pole 10 will be tapered, but the hole is still generally annular. The soil removed to form the hole 22 may be deposited in a pile or in a container.
FIG. 3 is a perspective assembly view of two pre-formed fiberglass sleeve segments 30. Each sleeve segment 30 has an arcuate, pole contacting portion 32 that fits around a utility pole. One edge of the arcuate sleeve segment 30 has a lip 34 that is offset from the pole contacting portion 32 in order to overlap with an adjacent sleeve segment 30. In particular, when the sleeve segments 30 are brought together to form a sleeve around a utility pole, the inner surface of the lip 34 receives the outer surface 36 of the adjacent sleeve segment. Although two sleeve segments are shown, any plurality and size of sleeve segments may be used to form a sleeve that completely encircles the utility pole.
FIG. 4 is a perspective view of the two fiberglass sleeve segments 30 with a thick adhesive layer 38 applied over the concave inner surface of the pole contacting portion 32 as well as the inner surface of the lip 34. The adhesive is preferably sufficiently viscous so that it does not run and will stay in place while the sleeve segments are vertically oriented for positioning about a utility pole.
FIG. 5 is a top view of the pole 10 and two sleeve segments 30 disposed into the generally annular hole 22. Each sleeve segment 30 has an inner surface with adhesive layer 38 facing the surface of the pole 10. The pole 10 is shown as having received an optional adhesive layer 40. It should be noted that the sleeve segments 30 extend below the groundline 20 and into the generally annular hole 22 of width “W”.
FIG. 6 is a top view of the pole 10 with the two sleeve segments 30 positioned about the surface of the pole 10 and the lips 34 receiving and overlapping an edge of the adjacent sleeve segment. A liberal application of the adhesive is intended to fill cracks and crevices in the surface of the pole, fill spaces between the sleeve segments and the pole, and fill the gaps between adjacent sleeve segments. However, it is expected that irregularities in the surface of the pole will cause the sleeve segments to contact the pole in some areas or points and not in others.
FIGS. 7A-7C are schematic diagrams of two sleeve segments 50, 60 having different arc lengths and radii. In FIG. 7A, a first sleeve segment 50 has a radius “R₁”, for example 5 inches, and an arc length “L₁”, for example 10 inches. Furthermore, this segment 50 has one edge with a lip 52 that is offset by a distance of “A₁”, for example about ⅝ inch (to receive a ⅝ inch thick edge of an adjacent sleeve segment), and has a length of “L₃”, for example 4 inches. Therefore, a sleeve may be formed about a utility pole having a 10 inch diameter using three sleeve segments 50 having a 10-inch arc length. Since three such segments will leave three gaps of about ½ inch between the segments, the 4 inch lips will provide an overlap of about 3½ inches each. Still, the degree of overlap may be reduced toward the lower end of the sleeve due to the taper of the utility pole. It should be recognized that even though these two segment sizes 50, 60 are described as having a nominal radius, these segments are preferably sufficiently flexible to conform along its arc length to nominal pole diameters that are within about four inches of the nominal segment diameter.
FIG. 7B shows a second sleeve segment 60 has a radius “R₂”, for example 7.5 inches, and an arc length “L₂”, for example 15 inches. Furthermore, this segment 60 has one edge with a lip 62 that is offset by a distance of “A₂”, for example about ⅝ inch (to receive a ⅝ inch thick edge of an adjacent sleeve segment), and has a length of “L₄”, for example 4 inches. Therefore, a sleeve may be formed about a utility pole having a 16 inch diameter using three sleeve segments 60 having a 15-inch arc length. Since three such segments will leave three gaps of about 1¾ inch between the segments, the 4 inch lips will provide an overlap of about 2¼ inches each.
FIG. 7C is a schematic of a utility pole 54 having a 12 inches diameter. The sleeve is formed from two segments 50 having a 10 inches arc length and one segment 60 having a 15 inch arc length. The lips 52, 62 are each about 4 inches in length so that there is about 1 inch gaps between the pole contacting portions of the adjacent sleeve segments and an overlap of about 3 inches at each joint. Table 1, below, describes how the two sleeve segment sizes 50, 60 may be used in various combinations in order to form a sleeve for any of four different pole diameters. Of course, other sleeve segment sizes and combinations may be used to form sleeves for utility poles having the same or different diameters.

TABLE 1

An Example of Two Sleeve Segment Sizes
Combining To Repair Any of Four Different Pole Diameters

Pole Diameter	Circumference	Sleeve Segment Selection

10 inches	31.4 inches	3 × 10 inch segment
12 inches	37.7 inches	2 × 10 inches segment, and
		1 × 15 inch segment
14 inches	43 inches	4 × 10 inches segment
16 inches	50.2 inches	3 × 15 inches segments

FIG. 8 is a schematic side view of the pole 10 with a sleeve 70 made of two sleeve segments 50, 60 (and a third sleeve segment 50—not shown) banded tightly around the pole and reinforced with three bands 64, 66, 68 near the top, middle and bottom of the sleeve segments, respectively. Preferably, the bands are tightened to press the sleeve segments 50, 60 against the pole 10 and force the adhesive 38, 40 to spread into cracks, crevices and gaps. The tightened bands are then secured with bolts or crimp-couplings. Most preferably, the bands are steel bands. The assembly of the sleeve 70 is complete and the adhesive is allowed to cure.
FIG. 9 is a schematic side view of the pole 10 with the hole 22 having been filled with a soil (from soil 28) and resin composite 72 prepared using a mixing system 74. The mixing system 74 has an opening to receive soil, water, sodium silicate, a setting agent, and a surfactant. A motor may be used to rotate the mixing chamber and form a slurry. Once the sleeve 70 is completed and the slurry has been thoroughly mixed, the slurry may be poured into the annular holes 22 and allowed to set up as the composite 72. It should be recognized that there are many types of mixing systems that may be utilized to form the slurry.
In a further embodiment, a specific method of restoring a wooden utility pole is set out as follows:

Pole Restoration Steps

- 1. Excavate an annular hole around the pole to a depth of 3 feet to 4 feet deep depending upon pole size and an annular width of about 2 inches. For example, use an air vacuum excavation system to dislodge the soil and vacuum the soil into a mixing system or drum.
- 2. Clean or brush the pole to remove decayed wood.
- 3. Inspect the pole's ground conductor integrity and repair the conductor if necessary.
- 4. Prepare a slurry by mixing soil removed from the annular hole with water and silicate in the mixing system or drum.
- 5. Add a preservative to the pole. For example, bore a ⅞ inch hole at a 45 to 30 degree downward angle into the pole and insert pole preservative, such as a boron rod or other known wood preservative and plug the hole with a wooden plug.
- 6. Apply a layer of adhesive over the surface of the pole to be repaired (i.e., the area that will receive the sleeve segments).
- 7. Apply a layer of adhesive to the inside (concave) surface of the sleeve segments to be used.
- 8. Position each of the sleeve segments around the pole with the adhesive facing the pole and temporarily hold the sleeve segments in place with a bungee cord
- 9. Tighten steel bands around the sleeve segments at positions near the top, middle and bottom of the sleeve.
- 10. Pour the slurry of mixed soil and silicate into the annular hole and allow it to solidify.

The term “utility pole” as used herein refers to the general type of pole used in common utility distribution systems. However, it is well-known to use these same type of poles in non-utility structures, such as elevated decks or beach houses. Those having ordinary skill in the art will recognize that the present invention has utility for the repair of other structures where wooden poles have one end embedded in the ground.
The terms “comprising,” “including,” and “having,” as used in the claims and specification herein, shall be considered as indicating an open group that may include other elements not specified. The terms “a,” “an,” and the singular forms of words shall be taken to include the plural form of the same words, such that the terms mean that one or more of something is provided. The term “one” or “single” may be used to indicate that one and only one of something is intended. Similarly, other specific integer values, such as “two,” may be used when a specific number of things is intended. The terms “preferably,” “preferred,” “prefer,” “optionally,” “may,” and similar terms are used to indicate that an item, condition or step being referred to is an optional (not required) feature of the invention.
While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.

Claims

1. A method of repairing a utility pole in place, comprising:

excavating soil from around the utility pole to expose a circumferential portion of the pole surface below the ground line;

adhering a plurality of prefabricated arcuate sleeve segments to the surface of the utility pole to form a circumferential sleeve, wherein the plurality of sleeve segments extend above and below the ground line and have side edges that each overlap an edge of an adjacent sleeve segment; and

filling the hole about the circumferential sleeve.

2. The method of claim 1, further comprising:

banding the plurality of sleeve segments firmly against the surface of the utility pole.

3. The method of claim 1, further comprising:

mixing the excavated soil with sodium silicate and an activator composition to form a slurry composition that will harden; and

filling the hole about the circumferential sleeve with the slurry.

4. The method of claim 3, wherein the activator is triacetin.

5. The method of claim 1, wherein the step of excavating soil includes directing high pressure air into the soil near the pole to form an annular hole having an average width of between 3 and 6 inches.

6. The method of claim 1, wherein the sleeve segments are a polymeric material containing a reinforcing material selected from the group consisting of fiberglass, carbon fibers, and combinations thereof.

7. The method of claim 1, further comprising:

applying a layer of adhesive to the surface of the utility pole;

applying a layer of adhesive to the inner surface of the plurality of sleeve segments; and

pressing the plurality of sleeve segments about the utility pole with overlapping side edges.

8. The method of claim 1, further comprising:

flexing the arcuate sleeve segments to match the actual curvature of the surface of the utility pole.

9. The method of claim 1, wherein the sleeve segments have an offset lip formed along one edge of the pole contact portion, wherein the offset lip provides tolerance in the angular and perimeter spacing of the sleeve segments without loss of overlapping.

10. The method of claim 9, further comprising:

adhering an inner surface of the offset lip to an outer surface of the adjacent sleeve segment.

11. The method of claim 10, further comprising:

selecting the plurality of arcuate sleeve segments from a predetermined set of segments including from two to four segment sizes, each segment size having a pole contact portion with a different arc length.

12. The method of claim 1, wherein the plurality of sleeve segments is three or four sleeve segments.

13. The method of claim 12, wherein none of the sleeve segments extends more than 150 degrees about the utility pole.

14. The method of claim 1, wherein the arc length of each sleeve segment is tapered from a bottom end to a top end.

15. The method of claim 1, wherein the sleeve segments having a thickness from ½ to ¾ inch.

16. The method of claim 1, wherein the adhesive is selected from the group consisting of an isocyanate, acrylic, urea-formaldehyde, epoxy, phenolic, poly-ester, and poly-vinyl.

17. The method of claim 1, further comprising:

adhering the sleeve segments to the utility pole with a gel formed by mixing an adhesive with fumed silica.

18. The method of claim 1, further comprising:

excavating the soil to a depth between 3 and 5 feet below the ground line; and

adhering the sleeve segments to the utility pole in a position extending between 2 and 4 feet above and below the ground line.

19. The method of claim 1, wherein the step of excavating soil forms a minimal annulus around the exposed portion of the pole.