Truss-Based Monopole Support Structure

Abstract

A monopole support assembly includes at least two truss assemblies secured to an outer surface of a monopole. At least two helical piers or micropiles are secured to the at least two truss assemblies, respectively.

Description

BACKGROUND OF THE INVENTION

The present invention relates to the field of monopole structures, and more particularly to support systems associated with such structures.

Monopole structures may be employed for housing or supporting elements such as antennae and other communications equipment, signage, high voltage transmission wires, or lighting in an elevated position. Such structures often include a long, hollow pole structure connected to an underlying surface such as a concrete pad formed in the ground. Such monopole structures are typically subjected to wind or other types of forces along their length, which may cause the structure to bend or sway. These forces create a moment about the base termination, which in turn stresses the base termination location and can lead to fatigue and eventual failure of the base termination material.

Conventional monopole structures are often rigidly connected to the ground via direct embedment, or via concrete base plates, via concrete encased anchor bolts, or via drilled, concrete filled caissons. Unfortunately, each of these support structures can be expensive and can raise environment concerns.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a isometric view of a portion of a monopole support structure consistent with embodiment described herein;

FIG. 1B is an expanded isometric view of the monopole and support structure of FIG. 1;

FIG. 2 is a side view of an exemplary truss element of FIG. 1A;

FIG. 3 is a top view of the monopole and support structure of FIG. 1B; and

FIG. 4 is an isometric view of an exemplary helical pier usable with the support structure of FIGS. 1A-3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following detailed description refers to the accompanying drawings. The same reference numbers in different drawings may identify the same or similar elements.

Consistent with implementations described herein, a number of truss-based support structures may be used to structurally connect a tubular monopole to a number of helical piers embedded within an environment surface. As described below, each truss-based support structure may be coupled to the monopole via pin or bolt-based assemblies, thereby allowing the support assembly to adapt to variations in installation parameters, such as angle of inclination of the embedded piers. In contrast to existing monopole support systems using concrete base plates, concrete encased anchor bolts, or via drilled, concrete filled caissons, the described system may be employed in environments that are not conducive to the use of concrete or that are not conducive to the impact caused by driving conventional piers or piles. In addition, the described embodiments may be used to remediate or supplement existing monopole support structures with minimal environmental impact.

FIG. 1A is an isometric view of a portion of a support structure 100 for supporting a tubular monopole 105 consistent with an embodiment described herein. Tubular monopole 105 may include a substantially cylindrical or frusto-conical configuration. In some implementations, monopole 105 may be formed of tubular steel or similar material. FIG. 1B is an isometric view of tubular monopole 105 showing an overall length of monopole 105. In some implementations, as shown in FIGS. 1A and 1B, monopole 105 may include a multi-sided configuration, such as a 12-sided (dodecagon) configuration, comprising 12 sides, each having a same width and an angle of approximately 15° relative to each adjacent side.

In addition, as shown in FIG. 1B, monopole 105 may have an extended length relative to its diameter, such length suitable for a given application. For example, a monopole for supporting high voltage power lines may be approximately 117 feet long, while a monopole for supporting a traffic signal may be approximately 20-30 feet long. Embodiments described herein are suitable for monopole 105 having any particular length.

Consistent with implementations described herein, monopole support structure 100 may include a plurality of truss assemblies 110-1 to 110-4 (collectively referred to as “truss assemblies 110” and individually as “truss assembly 110”) depicted in isometric view in FIG. 1A, one of which is shown in side view in FIG. 2. In an exemplary implementation, monopole support structure 100 may include four truss assemblies 110 spaced equidistantly about a perimeter of monopole 105, e.g., at 90° intervals relative to each other. In other implementations, more or fewer truss assemblies 110 may be used. FIG. 2 is a side view of one of truss assemblies 110 and FIG. 3 is a top view of monopole support system 100. Consistent numbering is used throughout, where appropriate.

As shown, each truss assembly 110 may include an angled brace element 112, a horizontal brace element 114, joint elements 116, 118, and 120, mounting brackets 122 and 124, pier bracket 126, and cross members 128 and 130. Truss assemblies 110 are configured for securing to monopole 105 and a number of helical piers 148-1 to 148-4 (collectively referred to as “helical piers 148” and individually as “helical pier 148”). As described in additional detail below, helical piers 148 may include a substantially cylindrical body having a number of helical blade-like elements projecting therefrom. Helical piers 148 are capable of being drilled into a support surface, such as the ground to support a structure attached thereto. In some instances, a number of helical piers 148 may be linked together to allow driving of the piers 148 to significant depths within the Earth, such as depths of 10 to 60 or more feet. Exemplary helical piers 148 for use in the manner described herein may have lengths of 26 feet, shaft diameters of approximately eight inches, and blade diameters of approximately 24 inches. However, other dimensions may be used, depending on the specific application. Though helical piers are shown, it is understood that the system may include a variety of different micropile and pier systems.

Angled brace element 112 may include one or more structural elements configured to provide a rigid and supportive connection between monopole 105 and pier bracket 126 via joint elements 116 and 118. As described in additional detail below, pier bracket 126 may be coupled to helical pier 148 (one of which is shown schematically in FIG. 4). As shown in FIG. 1A, in one embodiment, angled brace element 112 includes two lengths of angle steel (denoted as elements 112-a and 112-b in FIG. 1A) joined (e.g., welded) to opposing portions of joint elements 116 and 118. The two lengths of angle steel 112-a and 112-b may be joined to each other (e.g., welded) along their lengths for extra support and rigidity. In other embodiments, other types of steel (or other rigid material) may be used, such as hollow structural section (HSS) steel, tubular steel, etc. For example, eight-sided tubular steel may be used for brace elements 112 and 114 and/or cross members 128/130.

A length of angled brace element 112 (shown as “L₁” in FIG. 2) may be determined based on a positioning of helical piers 148 relative to monopole 105, such that a desired angle may be maintained with respect to horizontal. For example, an angle of 45° may be desired for angled brace element 112 with respect to horizontal upon coupling with monopole 105. However, it should be noted that deviations from this angle may be possible due to the adjustable nature of joint mounting brackets 122 and 124, and pier bracket 126, described in detail below.

Horizontal brace element 114 may include additional structural elements to provide a rigid and supportive connection between monopole 105 and pier bracket 126 via joint elements 118 and 120. As shown in FIG. 1A, in one embodiment, horizontal brace element 114 may include two lengths of angle steel (denoted as elements 114-a and 114-b in FIG. 1A) joined (e.g., welded) to opposing portions of joint elements 118 and 120. In other embodiments, other types of steel (or other rigid material) may be used, such as HSS steel, tubular steel, etc. As with horizontal brace element 112, a length of horizontal brace element 114 (shown as “L₂” in FIG. 2) may also be determined based on a positioning of helical piers 148 relative to monopole 105.

As shown in FIG. 2, joint elements 116 and 118 may be secured, such as via welding, to opposing ends of angled brace element 112. In one embodiment, joint elements 116 and 118 may be formed of steel or another rigid material. Joint element 116 may be secured to an upper end of angled brace element 112 and may have a four or five-sided configuration having a mounting aperture 127 formed therethrough. As described in detail below, mounting aperture 127 may align with a corresponding hole 129 in mounting bracket 122 upon assembly of truss assembly 110 to monopole 105.

Although not shown in the Figures, an upper portion of joint element 116 may include an angled or curved configuration, thereby allowing joint element 116 and angled brace element 112 to pivot or move with respect to monopole 105 following assembly.

Mounting bracket 122 may be formed of one or more rigid elements and may be secured to an outside surface of monopole 105. In one embodiment, mounting bracket 122 may include a pair of bracket members 123 and a mounting plate 125. This embodiment may also be referred to as a “doubler”. Bracket members 123 may be secured (e.g., welded, bolted, etc.) to mounting plate 125, such that bracket members 123 extend substantially perpendicularly from mounting plate 125. In addition, bracket members 123 may be spaced parallel from each other by a width substantially similar to a thickness of joint element 116, thereby enabling the end of joint element 116 to be received between bracket members 123. In implementations in which monopole 105 comprises a dodecagon or other multi-faceted or multi-sided configuration, mounting plate 123 may include an angled or beveled surface, thereby allowing mounting plate to conform to an outer configuration of monopole 105. By providing a doubler configuration for supporting angled brace element 112, through plates extending through monopole 105 may be unnecessary, thereby increasing the ease of assembly and reducing both the cost and complexity of monopole support system 100.

As shown in FIG. 2, during assembly of truss assembly 110, the exposed end of joint element 116 may be inserted between bracket members 123, and aperture 127 in joint element 116 may be aligned with hole 129 in bracket members 123. A bolt or pin 134, as shown in FIG. 1A, may be received through aperture 127 and hole 129 and may be secured via nut 135, as shown in FIG. 3. By providing a bolt on assembly for truss assembly 110, field installation is made possible without requiring welding, thereby increasing the speed and efficiency with which the installation may be made.

Joint element 118 may be secured to a lower end of angled brace element 112 and may include a joint portion 136 and a flange portion 138. As shown, joint portion 136 may be further configured to secure to a first end 140 of horizontal brace element 114 in addition to the lower end of angled brace element 112. More specifically, horizontal brace element 114 and angled brace element 112 may be fixed to joint element 118 in a desired relative angle, such as a 45° angle. In addition, as shown in FIG. 1A, flange portion 138 may extend substantially perpendicularly from a lower end of joint portion 136 and may form a base for receiving pier bracket 126. In one embodiment, a width of flange portion 138 may be slightly larger than an outside diameter or maximum outer dimension of pier bracket 126. Pier bracket 126 may be fixed to flange portion 138 via welding, for example. In other embodiments, pier bracket 126 may be co-formed with joint element 118 (e.g., via casting, molding, etc.).

As described briefly above, joint element 120 may be secured to a second end 142 of horizontal brace element 114. Joint element 120 may include a four or five-sided configuration having a mounting aperture 144 formed therethrough, as shown in FIG. 2. As described in detail below, mounting aperture 144 may align with a corresponding hole 145 in mounting bracket 124 upon assembly of truss assembly 110 to monopole 105.

Mounting bracket 124 may be formed substantially similar to mounting bracket 122 and may be formed from one or more rigid elements secured to an outside surface of monopole 105. For example, mounting bracket 124 may include bracket members 123 and mounting plate 125. As shown in FIG. 1A, mounting bracket 124 may be vertically aligned with mounting bracket 122.

During assembly of truss assembly 110, the exposed end of joint element 120 may be inserted between bracket members 123, and aperture 144 in joint element 120 may be aligned with hole 145 in bracket members 123. Bolt 134 is received within aperture 144 and hole 145 and may be secured via nut 135.

Cross members 128 and 130 may be formed of a rigid material and may have lengths dictated by a desired geometry of truss assembly 110. For example, cross member 128 may have a length (shown as “L₃” in FIG. 2) configured to provide a vertical (e.g., 90° relative to horizontal brace element 114) interconnect between an intermediate portion of angled brace element 112 and an intermediate portion of horizontal brace element 114. Similarly, cross member 130 may have a length (shown as “L₄” in FIG. 2) configured to provide an angled (e.g., approx. 45° relative to horizontal brace element 114) interconnect between the intermediate portion of angled brace element 112 and an end of horizontal brace element 114. In other implementations, alternative geometry may be used, including additional cross members, different angles, etc. In some embodiments, as shown in FIG. 1A, one or more of cross members 128 and 130 may be formed of more than one member (e.g., two, paired members, etc.).

Cross members 128 and 130 may be secured to angled and horizontal brace elements 112 and 114 via welding. In one embodiment, when brace elements 112 and 114 comprise pairs of structural elements (e.g., elements 112-a/112-b or 114-a/114-b), one of cross members 128 and 130 may be welded between each member in the pair and the other of cross members 128 and 130 may be welded outside of each member in the pair. For example, as shown in FIG. 1A, one end of cross member 128 may be welded between the elements 112-a and 112-b of angled brace element 112 and the other end of cross member 128 may be welded between the elements 114-a and 114-b of horizontal brace element 114. In this embodiment, the two members of cross member 130 may be welded to the outside of angled brace element 112 and horizontal brace element 114.

As described briefly above, joint member 118 may be configured to support pier bracket 126. As shown in FIG. 1A, pier bracket 126 may comprise a substantially tubular member having an inside diameter substantially similar to an outside diameter of an exposed end 146 of helical pier 148. Pier bracket 126 may include holes 149 for aligning with holes in an end of helical pier 148, as described below.

FIG. 4 is an isometric view of one of helical piers 148. As shown, helical pier 148 includes a shaft portion 150 and a number of auger or blade portions 152. An operating end 154 of shaft portion 150 may include a pointed end for enabling pier 148 to more easily penetrate the Earth during installation. A retaining end 156 of shaft portion 150 may include retaining apertures 155. Following insertion of helical pier 148 into the Earth to a desired or predetermined depth, retaining end 156 may project from the Earth by a set amount. As shown in FIGS. 1A and 1B, helical piers 148 may be inserted into the Earth at locations radially aligned with mounting brackets 122 and 124. Pier bracket 126 may be aligned with retaining end 156 and retaining apertures 155 may be aligned with holes 149 in pier bracket 126. In some instances, it may be necessary to rotate helical pier 148 to bring apertures 155 into alignment with holes 149. A pin 158 may be received through apertures 155 and holes 149 to secure pier bracket 126 to helical pier 148. In other embodiments, pin 158 may be secured via other mechanisms, such as snap rings, nuts, clips, etc.

By providing pin or bolt-type securing of truss assemblies 110 to both monopole 105 and helical pier 148, field assembly may be more easily managed. For example, it is not necessary for installers to weld items together in the field. Rather, pre-constructed truss assemblies 110 may be brought into the field and secured to monopole 105 and helical piers 148 using easily portable tools.

In some embodiments, as shown in FIGS. 1A and 1B, an additional helical pier 148-5 may be mounted beneath a center of monopole 105. For example, a pier bracket (not shown) similar to pier bracket 126 may be welded or otherwise secured to a center of the bottom of monopole 105. During installation, helical pier 148-5 may be driven into a location corresponding to the center of monopole 105. The helical pier 148-5 may be aligned with the center pier bracket and secured in a manner similar to that described above with respect to piers 148-1 to 148-4.

In still other implementations, additional helical piers may be installed and secured to truss assemblies 110. For example, one or more additional pier brackets may be secured to a bottom surface of horizontal brace element 114. Additional helical piers may be driven corresponding to the locations of each additional pier bracket. The additional piers may be able to support longer monopoles having longer lengths or monopoles positioned in potentially less stable environments. As previously mentioned, though helical piers are shown in the embodiments, it is understood that the system may include a variety of different micropile and pier systems.

By providing a truss-based, helical pier monopole support system 100, embodiments described herein may provide an efficient and environmentally sensitive alternative to existing monopole support systems. More particularly, helical piers may be driven into the ground surrounding a monopole with minimal environment impact. The above-described truss assemblies may be secured to both the helical piers and the monopole to provide an effective support system with minimal impact and cost.

The foregoing description of exemplary implementations provides illustration and description, but is not intended to be exhaustive or to limit the embodiments described herein to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of the embodiments.

Although the invention has been described in detail above, it is expressly understood that it will be apparent to persons skilled in the relevant art that the invention may be modified without departing from the spirit of the invention. Various changes of form, design, or arrangement may be made to the invention without departing from the spirit and scope of the invention. Therefore, the above-mentioned description is to be considered exemplary, rather than limiting, and the true scope of the invention is that defined in the following claims.

No element, act, or instruction used in the description of the present application should be construed as critical or essential to the invention unless explicitly described as such. Also, as used herein, the article “a” is intended to include one or more items. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise.

Claims

1. A monopole support assembly, comprising: at least two truss assemblies secured to an outer surface of a monopole; andat least two helical piers or micropiles secured to the at least two truss assemblies, respectively.

2. The monopole support assembly of claim 1, wherein each of the at least two truss assemblies, comprises: an angled brace element;a horizontal brace element;at least one cross member coupled to the angled brace element and the horizontal brace element;wherein a first end of the angled brace element is coupled to the outer surface of the monopole and a second end of the angled brace element is coupled to a first end of the horizontal brace element; andwherein the second end of the horizontal brace element is coupled to the outer surface of the monopole.

3. The monopole support assembly of claim 2, wherein the angled brace element further comprises a first pair of aligned support elements; and wherein the horizontal brace element further comprises a second pair of aligned support elements.

4. The monopole support assembly of claim 3, wherein the first and second pairs of aligned support elements further comprise: pairs of angle steel support elements;pairs of hollow structural section (HSS) steel elements; orpairs of tubular steel elements.

5. The monopole support assembly of claim 3, wherein each of the at least two truss assemblies further comprise: a first joint element for coupling the first pair of aligned support elements at respective first ends;a second joint element for coupling the first pair of aligned support elements at respective second ends and coupling the second pair of aligned support elements at respective first ends; anda third joint element for coupling the second pair of aligned support elements at respective second ends.

6. The monopole support assembly of claim 5, wherein the first joint element is secured between the first pair of aligned support elements; wherein the second joint element is secured between the first pair of aligned support elements and further secured between the second pair of aligned support elements; andwherein the third joint element is secured between the second pair of aligned support elements.

7. The monopole support assembly of claim 5, wherein the second joint element comprises a joint portion and a flange portion; and wherein the flange portion is secured to the helical pier or micropile.

8. The monopole support assembly of claim 5, further comprising: at least one pier bracket secured to at least one of the second joint elements or the horizontal brace element; andwherein the at least one pier bracket is configured to receive an exposed end of a corresponding number of helical piers or micropiles following insertion of the helical piers or micropiles into the ground.

9. The monopole support assembly of claim 8, wherein the at least one pier bracket comprises a hole formed therethrough; wherein each of the corresponding number of helical piers or micropiles comprise a mounting aperture formed therethrough; andwherein each of the corresponding number of helical piers or micropiles are secured to the at least one pier bracket via a bolt or pin inserted through the mounting aperture and the hole.

10. The monopole support assembly of claim 5, wherein the angled brace element and the horizontal brace element are secured to the second joint element in a predetermined geometrical configuration.

11. The monopole support assembly of claim 10, wherein the predetermined geometrical configuration comprises a 45° angle.

12. The monopole support assembly of claim 5, wherein each of the at least two truss assemblies, further comprises: a first mounting bracket for securing the first joint element to the monopole;a second mounting bracket for securing the third joint element to the monopole;wherein the first and second mounting brackets comprise a mounting plate and at least two bracket members projecting from the mounting plate; andwherein the first joint element and third joint element are secured between the at least two bracket members.

13. The monopole support assembly of claim 12, wherein the first and third joint elements comprise a mounting aperture extending therethrough; wherein the first and second mounting brackets include a hole therethrough corresponding to the mounting aperture; andwherein the first and third joint elements are secured to the first and second mounting brackets, respectively, via a bolt or pin inserted through the mounting aperture and the hole.

14. The monopole support assembly of claim 12, wherein the mounting plate is welded to the outer surface of the monopole.

15. A monopole structure, comprising: a monopole having an outer surface;at least two truss assemblies secured to the outer surface;at least two helical piers or micropiles inserted into the ground and secured to the at least two truss assemblies; andwherein the at least two truss assemblies comprise: an angled brace element having a first end and a second end;a horizontal brace element having a first end and a second end;at least one cross member having a first end and a second end;wherein the first end of the angled brace element is secured to a first position on the outer surface of the monopole;wherein the second end of the horizontal brace element is secured to a second position on the outer surface of the monopole;wherein the second end of the angled brace element is secured to the first end of the horizontal brace element; andwherein the first end of the at least one cross member is secured to the angled brace element and the second end of the at least one cross member is secured to the horizontal brace element.

16. The monopole structure of claim 15, wherein each of the at least two truss assemblies are secured to the outer surface of the monopole via at least two mounting brackets; wherein each of the at least two mounting brackets comprises a mounting plate and at least two bracket members projecting from the mounting plate; andwherein each of the at least two truss assemblies are secured between the at least two bracket members via a bolt or pin.

17. The monopole structure of claim 15 further comprising: at least four truss assemblies spaced equidistantly about the outer surface of the monopole; andat least four helical piers or micropiles inserted into the ground and secured to the at least four truss assemblies.

18. A method for remediating a monopole structure having a monopole, comprising: inserting at least two helical piers or micropiles into a support surface of the monopole;securing at least four mounting brackets on an outer surface of the monopole;securing at least truss two truss assemblies to the at least four mounting brackets;securing the at least truss two truss assemblies to the at least two helical piers or micropiles; andwherein each of the at least two truss assemblies comprise: an angled brace element having a first end and a second end;a horizontal brace element having a first end and a second end;at least one cross member having a first end and a second end;wherein the first end of the angled brace element is secured to one of the at least four mounting brackets;wherein the second end of the horizontal brace element is secured to one of the at least four mounting brackets;wherein the second end of the angled brace element is secured to the first end of the horizontal brace element; andwherein the first end of the at least one cross member is secured to the angled brace element and the second end of the at least one cross member is secured to the horizontal brace element.

19. The method of claim 18, further comprising: bolting the first end of the angled brace element to one of the at least four mounting brackets;bolting the second end of the horizontal brace element to one of the at least four mounting brackets; andusing a pin connection to secure the at least two truss assemblies to the at least two helical piers or micropiles.

20. The method of claim 18, wherein the at least two helical piers or micropiles comprise at least four helical piers or micropiles; wherein the at least four mounting brackets comprise at least eight mounting brackets; andwherein the at least two truss assemblies comprise at least four truss assemblies.