GB2324825A

GB2324825A - Pole support and reinforcement

Info

Publication number: GB2324825A
Application number: GB9707784A
Authority: GB
Inventors: Thomas Peter Hartley Newbery; John Edward Hodnett
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-04-17
Filing date: 1997-04-17
Publication date: 1998-11-04
Anticipated expiration: 2017-04-17
Also published as: GB9707784D0; GB2324825B

Abstract

A support for reinforcing a pole (20) comprises a number of reinforcement members (10,12) which are securable to one another by fastening means (18) to define a sleeve to encircle a pole (20). The support is intended to be driven into the ground at the base of the pole (20). A void between the pole (20) and the reinforcement members (10,12) may then be filled with a stress transmitting material eg concrete, mortar or sand. The method may be performed while the pole (20) is in situ, and without interrupting its function. The support may comprise an upper part and a lower part, and may be galvanised to offer corrosion protection.

Description

POLE SUPPORT AND REINFORCEMENT This invention relates to the reinforcement and support of poles which, for example, are used in supporting electricity supply conductors or telephone wires and cables.

It is known to suspend electricity supply conductors and telephone wires and cables from wooden poles which are sunk into the ground to a depth of up to 2 metres. A number of such poles become rotten at around ground level while the rest of the pole remains sound.

Replacement of such poles is a costly and time consuming exercise, and it may be preferred to reinforce the existing poles rather than remove the poles and replace them with new poles.

An object of this invention is to provide an assembly which reinforces poles simply and conveniently at around ground level. A further object is to provide a method of installing this assembly whilst maintaining the function of the pole without interruption.

According to the present invention there is provided a method of reinforcing and supporting a pole comprising the steps of assembling a plurality of reinforcing members such that the assembly of reinforcing members defines a tubular assembly encircling the pole, driving or sinking the tubular assembly into the ground around the base of the pole, and providing a stress transmitting material in the void between the pole and the tubular assembly to transmit stress therebetween.

It will be appreciated that the method can be carried out whilst the pole is in situ and is performing its intended function.

The reinforcing members are conveniently of L-, U- or W-shaped cross section, but members of other cross-sectional shapes could be used.

The reinforcement assembly may be in one section, or may be composed of a lower part arranged to be driven or placed substantially completely into the ground, and an upper part to be subsequently secured to the lower part. Once the upper part has been secured to the lower part, the driving operation may be continued, if desired, and subsequently the stress transmitting material is located in the void between the pole and the tubular assembly. Such an arrangement may be of particular use where the pole is provided with attachments at relatively low level restricting the length of reinforcement member which can be located adjacent the pole.

It will be appreciated that the invention is also suitable for use in reinforcing new/sound poles where additional strength is required at ground level, and in supporting poles which are of insufficient height, either by design or as a result of damage.

Although many poles are wooden, the invention is equally applicable to pole of other materials, such as steel or concrete which may corrode or deteriorate or require strengthening for any other reason.

Corrosion resistance for the reinforcing members may be provided by galvanising or applying protection to the reinforcing member before or after inserting them.

In addition to the method, the invention relates to a tubular reinforcement assembly comprising a plurality of reinforcement members, the members being securable to one another to define the tubular assembly which is arranged to encircle a pole, in use.

It will be appreciated that the tubular assembly of the present invention is advantageous in that it is simple to assemble and use on site, the method being advantageous in that it does not require the excavation of a hole around the pole which is time consuming and disturbs the earth around the pole. The tubular assembly comprises parts which are relatively compact and do not present storage or transportation difficulties, and can be simply sized to provide strength in excess of the design requirements used for poles.

The invention will further be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 illustrates part of an L-shaped reinforcement member in accordance with an embodiment of the invention; Figure 2 is a diagrammatic sectional view of a reinforcement assembly including the reinforcement member of Figure 1, in use; Figure 3 is a diagrammatic view of the assembly of Figure 2, in use; Figures 4 and 5 are diagrammatic plan and sectional views illustrating part of a method of reinforcing a pole; Figure 6 is a view illustrating an alternative method; Figures 7 and 8 are views of alternative reinforcement assemblies using members of W- and U-shaped cross-sections, respectively; and Figures 9 and 10 are views of reinforcement assemblies using two part reinforcement members of U- and L-shaped cross-section, respectively.

Figures 1 to 3 of the accompanying drawings illustrate a pole reinforcement assembly which comprises a pair of identical reinforcement members 10, 12. Each of the first and second reinforcement members 10, 12 comprises a steel member of L-shaped cross section. Each of the reinforcement members 10, 12 includes an outer edge which is bent to define a flange 14 which as illustrated in Figure 1 is provided with a series of apertures 16. As shown in Figure 2, the orientation of the flanges 14 is such that the first and second reinforcement members 10, 12 can be positioned adjacent one another, and in this position each of the flanges 14 lies substantially parallel to the un-flanged edge of the other reinforcement member, the apertures 16 aligning with corresponding apertures provided in the un-flanged edges.

The flanges may be located inside the other reinforcement member or outside (as illustrated). The apertures 16 are dimensioned to receive rivets 18 for securing the first and second reinforcement members 10, 12 to one another. Although rivets 18 are illustrated in Figure 2, it will be appreciated that the reinforcement members 10, 12 could be secured to one another using an alternative technique, for example by means of bolts or alternatively by welding the first and second reinforcement members 10, 12 to one another.

As shown in Figures 2 and 3, when the first and second reinforcement members 10, 12 are correctly secured to one another, the reinforcement members 10, 12 define a tubular assembly of substantially square crosssection which encircles a pole 20 to be reinforced. As shown in Figure 3, in order for the reinforcement to occur, the assembly of the first and second reinforcement members 10, 12 is driven or where necessary inserted by other means into the ground, thus the assembly of the first and second reinforcement members 10, 12 is self-supporting. In this position, concrete or another stress transmitting material, for example mortar, kiln dried sand or steel springs is provided in the void defined between the assembly of the reinforcement members 10, 12 and the pole 20.

For a wooden pole of approximately 25cm diameter, the first and second reinforcement members 10, 12 are constructed of 4mm thick steel sheet, each side of the L-shaped section being of width slightly greater than the diameter of the pole, and the length of the first and second reinforcement members 10, 12 is approximately 2.5m, depending upon the extent of the pole it is desired to reinforce. As shown in Figure 3, approximately half of the length of the assembly of reinforcement members 10, 12 is driven or inserted into the ground. It will be appreciated that these dimensions can be modified to enable the invention to be used with poles of other dimensions or materials. Also, these dimensions may be modified depending upon the magnitude of the bending moment which the apparatus must be capable of supporting.

Figures 4 and 5 illustrate steps of a method for reinforcing a wooden pole using the reinforcement assembly illustrated in Figures 1 to 3. In the method, a lightweight driving arrangement is located adjacent an existing wooden pole, the lightweight driving arrangement comprising a fibreglass lattice derrick 22 which at its upper end includes a pair of substantially parallel arms 24. The arms 24 are located on opposite sides of the pole 20. A two-part weight arrangement 26 is assembled around the pole 20, the weight arrangement 26 being connected to ropes 28 which pass around pulleys carried by the outer ends of the arms 24. The ropes 28 pass downwardly through the derrick 22 to a winch 30 carried by the derrick 22, the winch conveniently being an electrically driven winch. Once in this position, a pair of guy ropes 32 are tightened to lift the driving arrangement to the position illustrated in Figures 4 and 5 in which the weight arrangement 26 is lifted slightly from the ground.

Once in this position, the winch 30 is used to raise the weight arrangement 26.

With the weight arrangement 26 in a raised position, the first and second reinforcement members 10, 12 are positioned adjacent the pole 20 so that the flange 14 and apertures 16 of each member are aligned with the un-flanged edge and apertures of the member so that the reinforcement members 10, 12 encircle the pole 20. In this position, the first and second reinforcement members 10, 12 are secured to one another using rivets 18. Once the first and second reinforcement members 10, 12 are secured to one another, the assembly is driven downwardly using the driving arrangement in the usual manner until the assembly occupies the position illustrated in Figure 3. Once in this position, mortar or another stress transmitting material is placed into the space between the assembly of the first and second reinforcement members 10, 12 and the pole 20 until this spaced is filled or there is sufficient material to transmit the stress.

The driving arrangement is then removed by separating the two parts of the weight arrangement 26 from one another so that they no longer encircle the pole 20, and subsequently removing the remainder of the driving arrangement from the site.

It will be appreciated that once the stress transmitting material has been inserted, stresses applied to the pole 20, for example due to high winds, are transmitted from the parts of the pole adjacent to the upper ends of the reinforcement members, through the stress transmitting material, to the steel reinforcing members 10, 12 which are driven into the ground and are thus firmly supported. Some stress is also transmitted from the lower end of the reinforcement members to the adjacent part of the pole.

The tubular assembly of the reinforcement members 10, 12 gives the assembly sufficiently great strength to withstand the stresses applied thereto. It will be appreciated, therefore, that the stresses transmitted onto the relatively weak parts of the pole 20, i.e. the parts of the pole at around ground level, are significantly reduced or, in the case of failure of the pole, totally replaced. The application of stresses to the pole 20 are therefore less likely to result in the pole 20 breaking than in a pole which is not reinforced.

Rather than use the arrangement illustrated in Figures 4 and 5 to drive the assembly of reinforcement members into the ground, the driving arrangement of Figure 6 may be used. The arrangement of Figure 6 comprises a pair of driving mechanisms, only one of which is shown.

Each mechanism comprises an upper plate 34 which includes a downwardly extending lip 36. A lower plate 38 is carried by the upper plate 34. The upper plate 34 carries a pneumatic ram 40, which in turn carries weights 42. In the rest position, the weights 42 are supported by the lower plate 38. In use, the upper plate 34 is hooked onto the upper end of one of the reinforcement members. Pressurised air or hydraulic pressure is supplied to the ram 40 to lift the weights 42. Subsequently, the pneumatic or hydraulic pressure is reversed and the weights 40 are allowed to fall under gravity. When the weights contact the lower plate 38, the momentum of the weights causes the reinforcement assembly to be driven into the ground. It will be understood that as one of the mechanisms is used to drive the first reinforcement member 10, the other mechanism is used, simultaneously, to drive the second member 12.

It will be appreciated that many configurations of this arrangement are possible with the ram being horizontal or inverted and lifting the weight(s) via a single or double acting pulley arrangement. Similarly, the weight(s) may be situated above the upper plate 34, the weight(s) contacting the upper plate, in use, the drive the reinforcement assembly.

Figure 7 illustrates a modification in which the L-shaped reinforcement members are replaced by members of W-shaped cross-section. Similarly, Figure 8 illustrates a modification using reinforcement members of Ushaped cross-section. It will be appreciated, however, that reinforcement members of other shapes are possible, and fall within the scope of the present invention.

In a modification to the illustrated arrangement, each of the first and second reinforcement members may be of two part form with the top and bottom parts fitting together as illustrated in Figure 9 (using reinforcement members of U-shaped cross-section) and Figure 10 (using members of L-shaped cross-section). In use, a first, lower part 10a, 12a of each of the first and second reinforcement members 10, 12 is positioned so that the assembly thereof encircles a pole to be reinforced.

These parts are secured to one another in the manner described hereinbefore and are subsequently driven or otherwise inserted substantially completely into the ground. When the lower parts 10a, 12a are in position, the upper partslOh, 12b of the first and second reinforcement members 10, 12 are secured to the lower parts 10a, 12a thereof, for example using rivets or by welding, and to one another in the manner described hereinbefore. Finally, a stress transmitting material is provided between the pole and the assembly of the two-part reinforcement members.

If desired, as shown in Figure 10, the positioning of the upper parts may be such that the flanges thereof lie on the opposite diagonal to those of the lower parts. Alternatively, the flanges of the upper parts may lie on the same diagonal as those of the lower parts.

Claims

1. A method of reinforcing and supporting a pole comprising the steps of assembling a plurality of reinforcing members such that the assembly of reinforcing members defines a tubular assembly encircling the pole, driving or sinking the tubular assembly into the ground around the base of the pole, and providing a stress transmitting material in the void between the pole and the tubular assembly to transmit stress therebetween.

2. A method as claimed in Claim 1, wherein the tubular assembly is of substantially square cross-sectional shape.

3. A method as claimed in Claim 1, wherein the tubular assembly is of substantially circular cross-sectional shape.

4. A method as claimed in any one of the preceding claims, wherein the reinforcement assembly includes a lower part arranged to be driven or placed substantially completely into the ground, and an upper part to be subsequently secured to the lower part.

5. A method as claimed in any one of the preceding claims, wherein the reinforcing members are treated to reduce corrosion thereof.

6. A method as claimed in Claim 5, wherein the reinforcing members are galvanised.

7. A tubular reinforcement assembly comprising a plurality of reinforcement members, the members being securable to one another to define the tubular assembly which is arranged to encircle a pole, in use.

8. An assembly as claimed in Claim 7, wherein the tubular assembly is of substantially square cross-sectional shape.

9. An assembly as claimed in Claim 7, wherein the tubular assembly is of substantially circular cross-sectional shape.

10. An assembly as claimed in any one of Claims 7 to 9, wherein the reinforcement assembly includes a lower part arranged to be driven or placed substantially completely into the ground, and an upper part to be subsequently secured to the lower part.

11. An assembly as claimed in any one of Claims 7 to 10, wherein the reinforcement members are galvanised.

12. A method of reinforcing and supporting a pole substantially as hereinbefore described with reference to the accompanying drawings.

13. A reinforcement assembly substantially as hereinbefore described with reference to the accompanying drawings.