US20100257794A1

US20100257794A1 - Lateral support device

Info

Publication number: US20100257794A1
Application number: US12/758,693
Authority: US
Inventors: N. Daniel W. Stark
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-04-10
Filing date: 2010-04-12
Publication date: 2010-10-14

Abstract

According to one embodiment, a lateral support device for an anchor embedded in the ground includes a central body defining an interior channel sized to receive the embedded anchor. The lateral support device also includes a plurality of fins coupled to and extending outwardly away from the central body. The central body and plurality of fins are embeddable within the ground to position the embedded anchor within the interior channel.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Patent Application No. 61/168,509, filed Apr. 10, 2009, which is incorporated herein by reference.

FIELD

This disclosure relates to embedment anchors, and more particularly, to a lateral support device for embedment anchors.

BACKGROUND

Embedment anchors or piles embedded in the ground are used in any of various applications for providing enhanced vertical and lateral load capability. For example, in some applications, embedment anchors can be used to provide additional load capability to towers that support large structures, such as billboards, wind turbines, fluid containers, communication, power, and other transmission devices, lighting, freeway signs, etc.
In applications that utilize embedment anchors to increase the overall load capability of the structure being anchored by the anchors, it may be desirable to increase the lateral load rating of the anchors. Typically, embedment anchors provide superior vertical or axial load compression resistance properties and moderate lateral load resistance properties. Certain configurations of anchors or piles, e.g., anchors with diameters of twelve inches or smaller, may have a lower resistance to lateral loads relative to the axial loads sustainable by the anchors. This may be especially true when large axial loads are applied to the anchors. In some applications, it may be desirable to increase the lateral load rating of the anchors.
Conventional structures and methods for providing enhanced lateral load capability to embedment anchors have various shortcomings. Accordingly, it would be desirable to provide an apparatus, system, and/or method that provides enhanced lateral load capability to embedment anchors that overcomes one or more of the shortcomings of conventional structures and methods.

SUMMARY

The subject matter of the present application has been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently devices and systems. Accordingly, the subject matter of the present application has been developed to provide a lateral support device and associated systems and methods that overcomes at least some shortcomings of the prior art.
According to one embodiment, a lateral support device for an anchor embedded in the ground includes a central body defining an interior channel sized to receive the embedded anchor. The lateral support device also includes a plurality of fins coupled to and extending outwardly away from the central body. The central body and plurality of fins are embeddable within the ground to position the embedded anchor within the interior channel.
In certain implementations, when the central body and plurality of fins are embedded in the ground to position the embedded anchor within the interior channel, lateral loads on the embedded anchor are transferred to the central body, from the central body to the plurality of fins, and from the plurality of fins to the ground. In some implementations, the central body has an elongate tubular shape and each of the plurality of fins extends along an entire length of the central body. Each fin can be substantially parallel to the length of the central body. In certain implementations, each fin includes a leading edge angled relative to the length of the central body.
According to some implementations, the plurality of fins are positioned about an outer periphery of the central body equidistantly apart from each other. Each of the plurality of fins can extend substantially transversely away from the central body.
In another embodiment, an anchoring system includes an anchor embeddable into the ground and a lateral support sleeve that has an anchor receptacle. The lateral support sleeve is embeddable into the ground about the anchor such that the anchor is positioned within the anchor receptacle. The lateral support sleeve has a plurality of fins.
In some implementations of the system, the plurality of fins each extends substantially parallel to the anchor when the anchor and lateral support sleeve are embedded into the ground. In certain implementations, the cross-sectional size and shape of the anchor receptacle is substantially the same as a cross-sectional size and shape of the anchor such that when the anchor is positioned within the anchor receptacle the anchor is in substantial contact with the anchor receptacle. In certain other implementations, at least one of a cross-sectional size and shape of the anchor receptacle is different than at least one of a cross-sectional size and shape of the anchor such that a gap is definable between the anchor and the anchor receptacle when the anchor is positioned within the anchor receptacle. The system can include a plurality of anchors embeddable into the ground and a plurality of lateral support sleeves each being embeddable into the ground about a respective one of the plurality of anchors.
According to yet another embodiment, a method for installing an anchoring system includes removably coupling an installation tool to an anchor embedded in the ground. The method also includes movably coupling a lateral support device to the installation tool and while movably coupled to the installation tool, driving the lateral support device into the ground about the embedded anchor. Further, the method includes removing the installation tool from the anchor after driving the lateral support device about the embedded anchor.
In some implementations of the method, the lateral support device includes an anchor receptacle and a plurality of fins extending away from the anchor receptacle. In such implementations, movably coupling the lateral support device to the installation tool can include inserting the installation tool into the anchor receptacle.
According to some implementations, driving the lateral support device into the ground about the embedded anchor includes inserting the embedded anchor into the anchor receptacle. The method can further include positioning a grout-like material between the embedded anchor and the anchor receptacle. Alternatively, the method can include press-fitting the embedded anchor into the anchor receptacle.
In certain implementations of the method, when removably coupled to the embedded anchor, the installation tool is aligned with and extends substantially parallel to the embedded anchor. In yet some implementations of the method, driving the lateral support device includes moving the lateral support device along the installation tool where the installation tool maintains the lateral support device in alignment with the embedded anchor as the lateral support device moves along the installation tool.
In another embodiment, a tower foundation system includes a base and a plurality of anchors coupleable to the base and embeddable into the ground to secure the base to the ground. The tower foundation system also includes a plurality of lateral support sleeves each securable to a respective one of the plurality of anchors. Each lateral support sleeve is embeddable into the ground about the respective anchor. Also, each lateral support sleeve comprises a plurality of fins.
In yet another embodiment, a method for installing a tower foundation includes embedding an anchor in the ground, securing an installation tool to the anchor, and positioning a lateral support device over the installation tool. The lateral support device includes a plurality of fins. The method also includes driving the lateral support device along the installation tool and into the ground about the anchor. Further, after driving the lateral support device, the method includes removing the installation tool from the anchor. The method additionally includes securing a foundation base to the anchor.
Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the subject matter of the present disclosure should be or are in any single embodiment. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present disclosure. Thus, discussion of the features and advantages, and similar language, throughout this specification may, but do not necessarily, refer to the same embodiment.
Furthermore, the described features, advantages, and characteristics of the subject matter of the present disclosure may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the subject matter may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments. These features and advantages are more fully apparent from the above description and appended claims, or may be learned by the practice of the subject matter as set forth above.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the advantages of the subject matter may be more readily understood, a more particular description of the subject matter briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the subject matter and are not therefore to be considered to be limiting of its scope, the subject matter will be described and explained with additional specificity and detail through the use of the drawings, in which:

FIG. 1 is a top plan view of a tower foundation base according to one representative embodiment;

FIG. 2 is a cross-sectional side elevation view of the tower foundation base of FIG. 1 taken along the line 2-2 of FIG. 1 but shown with caps and anchors coupled to the base;

FIG. 3 is an exploded side view of the tower foundation shown in FIG. 2;

FIG. 4 is a top plan view of a tower foundation according to another representative embodiment;

FIG. 5 is a cross-sectional side elevation view of the tower foundation of FIG. 4 taken along the line 5-5 of FIG. 4;

FIG. 6 is a side elevation view of a lateral support device according to one representative embodiment;

FIG. 7 is a top plan view of the lateral support device of FIG. 6;

FIG. 8 is an exploded side elevation view of the lateral support device of FIG. 6 along with an installation tool and an embedded anchor according to one embodiment;

FIG. 9 is a side elevation view of the lateral support device of FIG. 6 being installed about the embedded anchor using the installation tool and a driving mechanism according to one embodiment; and

FIG. 10 is a side elevation view of the lateral support device of FIG. 6 installed about the embedded anchor.

DETAILED DESCRIPTION

Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
Additionally, instances in this specification where one element is “coupled” to another element can include direct and indirect coupling. Direct coupling can be defined as one element coupled to and in some contact with another element. Indirect coupling can be defined as coupling between two elements not in direct contact with each other, but having one or more additional elements between the coupled elements. Further, as used herein, securing one element to another element can include direct securing and indirect securing. Additionally, as used herein, “adjacent” does not necessarily denote contact. For example, one element can be adjacent another element without being in contact with that element.
Furthermore, the details, including the features, structures, or characteristics, of the subject matter described herein may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize, however, that the subject matter may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the disclosed subject matter.
Described herein are various embodiments of a lateral support device and methods for an embedment anchor or pile. As mentioned above, embedment anchors can be used in myriad applications. Correspondingly, the lateral support device described herein can be used in myriad applications for providing lateral support to an embedment anchor. For exemplary purposes only, the lateral support device of the present application is described hereinafter as being associated with one specific application, i.e., a tower foundation. Although the lateral support device is described in the context of a tower foundation, it can be used in any other application in which embedment anchors are used without departing from the essence of the invention. The description of the lateral support device proceeds with reference to several embodiments of a tower foundation. Following the description of the tower foundation, embodiments of the lateral support device of the present application will be described in more detail.
Referring to FIG. 1, a tower foundation 10 according to one representative embodiment is shown. The tower foundation 10 includes a plurality of arms 20 that are secured to and radially extend away from a central support column 30.
The central support column 30 includes a generally tubular shaped member extending from a first lower end 38 to a second upper end 39 (see FIG. 2). The tubular shaped member of the central support column 30 defines an outer surface 32 and an inner surface 34. Preferably, the central support column 30 is made of a substantially rigid and durable material, such as steel.
The central support column 30 can have any of various lengths and cross-sectional shapes. For example, in some implementations, the central support column 30 can extend the entire length of the tower from the foundation 10 to the supported structure. More specifically, the central support column 30 can be a continuous, one-piece length of pipe secured to the foundation 10 at lower end portion and the supported structure at an opposite upper end portion. Alternatively, as shown in FIG. 2, the central support column 30 can comprise a section of the overall support column of the tower. For example, the central support column 30 can be a base section of the overall support column with one or more sections attached or spliced to the base section to complete the overall support column. In some instances, for ease in transportation, the central support column 30 can be a base section of the overall support column, and transported separate from the remaining section or sections of the overall support column. Likewise, in some instances, for ease in installation, as will be described in more detail below, the central support column 30 can be a base section and the foundation 10 can first be secured to the ground, with the remaining section or sections of the overall support column attached to the base section later.
Each of the arms 20 extends lengthwise from a first inner end 24 to a second outer end 26. The arms 20 can have any of various lengths. In certain instances, the length of the arms 20 depends at least partially on the above-ground height, weight, and size of the supported structure. In some exemplary implementations, the length of the arms 20 is between about 1 and about 10 feet. The first inner and second outer ends 24, 26 each extend substantially parallel to a height of the arms 20. The first inner end 24 is secured to an outer surface 32 of the support column 30 and the outer end 26 is coupled to a housing 62 of an anchor attachment system 60. As shown in FIG. 2, in some implementations, the arms 20 are secured to the central support column 30 at a location intermediate the first lower end 38 and second upper end 39. In other words, the support column 30 can extend above and below the support arms. However, in other implementations, the arms 20 can be secured to the central support column 30 at any of various locations on the support column. For example, the arms 20 can be secured to the central support column 30 such that their upper edges are proximate, e.g., substantially flush with, the second upper end 39 of the support column, or their lower edges are proximate, e.g., substantially flush with, the first lower end 38 of the support column.
In some implementations, each arm 20 can be a relatively thin plate with a length and height that each is substantially greater than its width. The arms 20 are made of a substantially rigid and durable material, such as, for example, steel. Moreover, the arms 20 can be secured to the central support column 30 and coupled to the housing 62 by any of various coupling methods known in the art, such as, for example, welding, bracketing, bolting and/or fastening. Although the tower foundation 10 includes eight arms 20 equidistantly spaced about the circumference of the support column 30, in other implementations, the tower foundation can include more or less than eight arms and can be an equal distance from each other or variably distanced from each other about the support column.
In the illustrated embodiment of FIG. 1, the housing 62 is a generally tubular member extending in a generally vertical direction, i.e., substantially parallel to a central axis 36 of the central column 30 (see FIG. 2), between bottom and top ends 64, 66, respectively. However, in other embodiments, the housing 62 can be angled with respect to the central axis 36 of the column 30. The housing 62 defines a conduit or space 63 having at least a minimum cross-sectional dimension within the housing. For example, the tubular member of the housing 62 can be substantially cylindrical shaped with a conduit having at least a minimum diameter. Alternatively, the tubular member of the housing 62 can be shaped according to various shapes, such as a substantially rectangular or square shape in cross-section with a conduit having at least a minimum width, length and/or diagonal dimension.
The tower foundation 10 can also include a foundation stiffener 40 that couples the arms 20 and housings 62 together. The stiffener 40 includes two vertically spaced-apart stiffener plates 40 a, 40 b secured to the top and bottom edges of the arms 20, the outer surfaces of the housings 62 and the outer surface 32 of the support column 30. Accordingly, in some implementations, the distance between the stiffener plates 40 a, 40 b is approximately equal to the height of the arms. Although the stiffener plates 40 a, 40 b are shown secured to the top and bottom edges of the arms 20, in some embodiments, the stiffener plates 40 a, 40 b can be secured to the sides of the arms and the distance between the plates can be less than the height of the arms Like the arms 20, the plates 40 a, 40 b can be relatively thin plates made of a substantially rigid and durable material, such as steel.
Referring to FIG. 2, the anchor attachment system 60 further includes bottom and top caps 68, 70, respectively. Generally, the bottom and top caps 68, 70 are securable to the bottom and top ends 64, 66 of respective housings 62 to effectively enclose or seal the conduit 63. The bottom cap 68 includes a sealing portion 72 and an anchor attachment portion 74. The sealing portion 72 includes a plate having a surface area greater than the cross-sectional area of the conduit 63. The anchor attachment portion 74 includes a tubular member with an inner diameter greater than an outer diameter of the anchor 50 (at an upper attachment end portion 56 of the anchor) and a plurality of apertures 76 (see FIG. 3). The apertures 76 are alignable with apertures 54 formed in the anchor 50.
Similar to the bottom cap 68, the top cap 70 includes a sealing portion 78 with a plate having a surface area greater than the cross-sectional area of the conduit 63. The top cap 70 also includes an anchor attachment portion 80 made of a tubular member with an outer diameter less than an inner diameter of the anchor 50 (at the upper attachment end portion 56 of the anchor) and a plurality of apertures 82 (see FIG. 3). Unlike the tubular member of the anchor attachment portion 74, the tubular member of the anchor attachment portion 80 is extendable from the upper end 66 of the housing 62, through the conduit 63, and through the lower end 64 of the housing. More generally, the anchor attachment portion 80 is longer than the anchor attachment portion 74. The plurality of apertures 82 are position proximate a lower end of the anchor attachment portion 80 and are alignable with the apertures 76 of the anchor attachment portion 74 and the apertures 54 of the anchor 50.
In the illustrated embodiment, the bottom and top caps 68, 70 each include a plurality of flanges 90 secured to and extending between the sealing portions 72, 78 and the anchor attachment portions 74, 80, respectively.
The anchor 50 includes an elongate rod-like element extending from the attachment end portion 56 accessible above the ground 52 to an embedment end portion 58 embeddable in the ground. The anchor 50 can be any of various anchors, piers, or piles known in the art having any of various working tensile and compressive load ratings. For example, depending on soil characteristics, the anchors 50 can have a working tensile and compressive load rating between about 50,000 pounds and about 100,000 pounds, and a lateral load rating of approximately 15,000 pounds. For example, in some implementations, the anchors 50 can include embedment end portions 58 that have helical screws (as shown), helical fins, spin fin, and/or other embedding elements. The type of embedment end portion 58 can be based at least partially on the geology at the installation site. For example, helical screws may provide better embedment within soil and geological formations of a particular type than helical fins, while helical fins provide better embedment within soil and geological formations of a different type than helical screws.
Referring to FIG. 2, the length of the anchors 50 can be predetermined such that the embedment end portion 58 is embedded within a geological formation a predetermined distance D below the ground, which, as shown, can correspond to the lower end 38 of the support column 30. Accordingly, based at least partially on the geology of the installation site, the length of the anchor 50 and the type of embedment end portion 58 can be selected such that the embedment end portion 58 embeds in a suitable formation at a suitable depth D for achieving a desirable resistance to overturning forces acting on the tower. In some embodiments, the tower foundation 10 is capable of resisting overturning forces up to about 20,000,000 ft-lb. In more specific implementations, the tower foundation 10 resists overturning forces up to between about 5,000,000 ft-lb and 7,000,000 ft-lb.
Generally, the embedment end portion 58 of the anchor 50 can be embedded at a greater depth D if more resistance to overturning forces is desired. Alternatively, or in addition, the embedment end portion 58 type that provides the strongest embedment with the type of formation at the desired depth D can be selected for achieving a greater resistance to overturning forces. In some instances, the embedment end portions 58 of the anchors 50 can be substantially below the support column 30, e.g., the depth D below the ground and support column can be between about 20 feet and about 30 feet. If necessary, the desired depth D can be any of various other lengths below 20 feet or above 30 feet. Further, in some instances, the outer diameter of the support column 30 can be between about 1 foot and about 10 feet. Accordingly, in some representative implementations, the ratio of the depth D and the outer diameter of the support column 30 is between about 2 and about 30.
Referring to FIG. 3, one representative method of installing the tower foundation 10, e.g., secured it to the ground 52, is shown. The tower foundation 10 can be installed above or at least partially below ground level. In an above-ground installation (see FIGS. 2 and 3), the arms 20 and central support column 30 are positioned above the surface of the ground 52. When installing the tower foundation 10 in this manner, an excavation pit need not be dug in the ground prior to installing the foundation. However, in a below-ground installation where the arms 20 and central support column 30 are completely or partially below ground level, a shallow excavation pit should be formed in the ground prior to installing the tower foundation 10 (see, e.g., FIG. 5).
In most below-ground installation implementations, the depth of the excavation pit is not significantly more than the distance between a lower end 38 of the central support column 30 and a top of the top cap 70. For example, if concealment of the tower foundation 10 is desired, the depth of the exaction pit can be just greater than the distance between the lower end 38 of the central support column 30 and a top of the top cap 70 such that ground components, such as dirt, soil, rocks, etc., or a solidifying agent, such as concrete, grout, etc., can placed on top or over of the foundation to conceal it. However, in some implementations, the depth of the excavation pit can have any of various depths as desired by the user. As used herein, shallow excavation pit can include excavation pits having a depth that is between about 5% and 25% of the depth D of the anchors. In certain implementations, the shallow excavation pit can be between about 3 and about 6 feet. Because the excavation pit is shallow, less debris is removed, shoring is not required, and de-watering is effectively eliminated as shallow pits are not deep enough to reach most water table levels. Therefore, the installation step of removing water with a water-pump truck required by most conventional tower foundations in not required for the installation of the tower foundation 10.
Anchors 50 suitable for the installation site are embedded within the ground such that the attachment end portions 56 of the anchors are above the ground 52 (or at least above the bottom surface of the excavation pit if an excavation pit is desired) and the embedment end portions 58 are secured to desired geological formations proximate the desired depth D. In some implementations, the anchors 50 are torqued, e.g., rotated or screwed, into the ground 52 by a torque motor or similar device until the embedment end portions 58 reach the desired depth D. In other implementations, narrow, upright cylindrical holes are dug into the ground and the anchors 50 are inserted into the holes. A solidifying, shrink-resistant material, such as concrete, mortar, or grout, can then be poured into the holes around the anchors 50 to at least partially secure the anchors to the ground.
The base 12 of the tower foundation 10 can be used as a template for facilitating proper placement of the anchors 50 relative to the outer ends 26 of the arms 20. The base 12 can be positioned in the location at which the tower is to be installed. Each anchor 50 is then continuously inserted through a housing 62 of respective anchor attachment systems 60 until properly embedded into the ground 52. In this manner, the housings 62 act as a guide for proper placement and orientation of the anchors 50. Once the anchors 50 are properly embedded into the ground 52, the base 12 can be removed.
The attachment end portions 56 of the anchors 50 are then inserted into the anchor attachment portion 74 of respective lower caps 68 by lowering the lower caps over the anchor attachment portion. The base is then lowered over the lower caps 68 such that each lower cap is aligned with a respective housing 62. The top caps 70 are then inserted into and through respective housings 62, and within the attachment portions 56 of the corresponding anchors 50. The bottom and top caps 68, 70 can be rotated until the apertures 76, 82 are aligned with each other, and aligned with the apertures 54 of the corresponding anchor 50. Once aligned, fasteners (not shown) can be extended through the apertures 76 of the anchor attachment portion 74, the apertures 54 of the anchor 50, and the apertures 82 of the anchor attachment portion 80 and tightened to secure the bottom and top caps 68, 70 to the anchors 50, and the anchors and caps to the base 12.
The length of the anchor attachment portion 80 of the top caps 70 and placement of the apertures 76, 82 are such that when the bottom and top caps 68, 70 are secured to each other, the sealing portions 72, 78 of the bottom and top caps contact the bottom and top ends 64, 66 of respective housings 62 to effectively seal the bottom and top ends of the housings. In some implementations, just prior to securing the top cap 70 to the bottom cap 68, a solidifying, shrink-resistant material, such as grout, can be poured into the space 63 between the housing and the anchor attachment portion 80. In some implementations, at least one of the sealing portions 72, 78 can include a coverable hole through which the solidifying material can be injected into the space 63 after the bottom and top caps 68, 70 are secured to the anchors 50 and housings 62. The effective seal achieved by the sealing portions 72, 78 acts to contain the solidifying material within the space 63 of the housings 62. As the material hardens, it acts to improve the connection between the housing 62, caps 68, 70 and anchors 50. Further, the solidifying material can act to resist rotation of the anchors 50 after they are properly embedded within the ground 52. As used herein, the seals created by the caps are not limited to hermetical seals, but can include partial seals, such as seals sufficient to prevent larger materials from entering the housing but may allow smaller materials to enter the housing.
The anchor attachment system 60 is designed to accommodate tilting or angling of the anchors 50. As the anchors 50 are embedded within the ground 52, they may have a tendency to angle inward or outward relative to vertical due to the installation site geology or the installation technique. In some implementations, the anchors 50 are desirably embedded within the ground in a vertical orientation, e.g., parallel to the support column central axis 36 (see FIG. 2), but may inadvertently tilt during installation. Alternatively, in certain implementations, the anchors may be desirably embedded within the ground at an angle relative to vertical. Whether the anchors 50 are advertently or inadvertently embedded within the ground at an angle, the anchor attachment system 60 allows for such angling.
Because of the coupling between the bottom and top caps 68, 70 and the respective anchors 50, any angling of the anchors causes a corresponding angling of the anchor attachment portions 74, 80. Therefore, to accommodate angling of the anchors 50, the anchor attachment system 60 should also accommodate angling of the anchor attachment portions 74, 80. To accommodate tilting of the anchors 50 and anchor attachment portions 74, 80, the inner diameter of the housing 62 is significantly larger than the outer diameter of the anchor attachment portion 80 of the top cap 70. Accordingly, there sufficient room within the space 63 of the housing 62 for the anchor attachment portion 80 to be angled with respect to a central axis (not shown) of the housing 62 and remain within the space. To facilitate a seal between the sealing portions 72, 78 and the bottom and top ends 64, 66 of a respective housing 62 when an anchor is angled with respect to the housing, the sealing portions 72, 78 can include lips 79 extending about a periphery of the sealing portions to capture solidifying material poured into the housing 62, thus maintaining a proper bearing at the seals.
Although the bottom cap 68 is shown below the housing 62 and the top cap 70 is shown above the housing, in some implementations, the bottom and top caps can be reversed if desired. As shown, the top cap 70 includes a second of set apertures 83 positioned proximate an end of the top cap opposite the end of the top cap at which the apertures 82 are approximately located. The top caps 70 can be coupled to the anchors 50 by aligning and fastening the apertures 83 with the apertures 76 of the anchors. The housings 62 of the base 12 can then be lowered over respective anchor attachment portions 80 of the top caps 70. The bottom cap 64 can be coupled to the top cap 70 by aligning and fastening the apertures 76 of the bottom cap with the apertures 82 of the top cap. In this manner, the sealing portion 72 of the bottom cap 68 effectively seals the top end 66 of the housing 62 and the sealing portion 78 effectively seals the bottom end 64 of the housing.
In some implementations, a moisture-resistant material can be poured over or coated on the base 12 and caps 68, 70 to protect the components of the tower foundation 10 from moisture. The moisture-resistant material can be any of various materials known in the art, such as, for example, asphaltic sealant, paint and concrete. Alternative to, or in addition to, a moisture-resistant material, the components of the tower foundation 10 can be galvanized to protect them against the negative effects of moisture.
In several preferred embodiments, the tower foundation 10 is installed without a concrete cap or pouring concrete over the foundation. As described above, conventional tower foundations having large concrete caps or embedments often require a waiting period of about 3-4 weeks after the pouring of the concrete before the support column and supported structure are secured to the foundation. Because the tower foundation 10 does not include a concrete cap or covering in preferring embodiments, the waiting period required to allow the concrete to set is eliminated and the entire tower, including support column and supported structure can be installed at one time, e.g., in a single day.
After installation, the tower foundation 10, according to some embodiments, is configured for easy removal and reuse, such as at another location. As described above, after installations, structural elements of a tower foundation may fail or the tower foundation may no longer be needed in a particular location. In one particular implementation, the tower foundation 10 is removed by decoupling the bottom caps 68 from the anchors 50, e.g., by removing the fasteners, and lifting the base 12 and caps 68, 70 away from the anchors. The anchors 50 can be rotated in a loosening direction using, for example, the same device used to install the anchors. The base 12, caps 68, 70, and anchors 50 can then be moved to a different installation site and reinstalled.
Because the top caps 70 are coupled to the anchors 50 via the bottom caps 68, rotation of the top caps 70 also rotates the anchors 50. Therefore, if the base 12 has been moved (e.g., tilted, raised, lowered, shifted) due to the extraneous factors, such as movement in or shifting of the ground, large overturning forces, etc., the anchors 50 can be adjusted after installation by rotating the top cap 70 to adjust the orientation base 12 if necessary. In certain implementations, this can be accomplished using the same device, e.g., torque motor, used to install the anchors 50.
Referring to FIGS. 4 and 5, a tower foundation 110 similar to tower foundation 10 is shown. Like the tower foundation 10, the tower foundation 110 includes arms 120 secured to and extending radially from a central support column 130. The arms 120 are each secured to the central support column 130 at first inner ends 124 and coupled to anchor attachment systems 160 at second outer ends 126. As shown, the first inner ends 124 of the arms 120 are at least partially secured to the central support column 130 and the second outer ends 126 are at least partially secured to the housing 162 of a respective anchor attachment system 160 by brackets 170, 172, respectively. The brackets 170, 172 can be welded to the support column 130 and housings 162, respectively, and fastened to the arms 120 with fasteners 174 or weldments. The brackets 170, 172 can each have a pair of vertical portion flanges between which a vertical portion 122 of a respective arm 120 is secured.
The arms 120 can be I-beams that have two horizontal portions 123 between which the vertical portion 122 extends. Each horizontal portion 123 of the arms 120 includes a set of apertures 125. Alternatively, in certain implementations, the arms 120 can be beams of other shapes, such as tube steel having a circular, square or rectangular cross-sectional shape, with apertures similar to apertures 125.
Similar to tower foundation 10, the tower foundation 110 includes a pair of vertically spaced-apart stiffener plates 140 a, 140 b secured to the outer surfaces of the housings 162 and the outer surface 132 of the support column 130. The stiffener plates 140 a, 140 b can be secured to the housings 162 and support column 130 by using any of various coupling techniques, such as welding. The stiffener plates 140 a, 140 b each include sets of apertures 142 alignable with the apertures 125 of the horizontal portions 123 of the respective arms 120. Accordingly, the arms 120 can be further secured to the support column 130 and housings 162, and the stiffener plates 140 a, 140 b can be secured to the arms 120, by extending fasteners, such as fasteners 144, through the apertures 125, 144 and tightening the fasteners against the stiffener plates and arms (see FIG. 5).
The anchor attachment systems 160 can be similar to the anchor attachment systems 60 of the tower foundation 10. Alternatively, the anchor attachment system 160 can include elements for facilitating any of various coupling or fastening techniques known in the art. Similarly, the anchors 150 can be anchors similar to anchors 50 described above or alternatively, can be any of various anchors or piles known in the art.
Like the tower foundation 10, the tower foundation 110 can be installed above the ground, below the ground, or partially below the ground in a manner similar to that described above for the tower foundation 10.
In certain implementations, the tower foundations 10, 110 may also include a stiffener plate (not shown) secured to the inner surface of the support column. The stiffener plate can have a substantially annular shape. The stiffener plate can promote rigidity in and strengthen the support column at the junction between the arms and the column.
In certain applications of the tower foundations 10, 110, certain applications of other tower foundations, or any other application in which embedment anchors, such as anchors 50, are used, it may be desirable to increase the lateral load rating of the anchors. In some embodiments, an anchor's resistance to lateral loads may be increased by utilizing the passive pressure of the soil in which the anchor is embedded. Basically, the higher the passive pressure of the soil against the anchor, the higher the anchor's resistance to lateral loads. Some structures and methods may be utilized to increase the passive pressure of soil against each anchor. For example, a grouted column of concrete may be positioned around the embedded anchor along a substantial length of the anchor. In another example, a larger diameter anchor may be driven into the soil around the anchor. The larger diameter anchor may then be coupled to the smaller anchor using any of various coupling mechanisms and/or coupling techniques known in the art. Alternatively, in some implementations, a concrete anchor cap embedded in the soil to encase the upper portion of the anchor may be used.
Preferably, however, a lateral support device, such as lateral support device 200 of FIG. 6, is used to effectively increase the passive pressure of the soil against each anchor 50 and increase the lateral load rating of each anchor. Generally, the lateral support device 200 is driven into the soil about an embedded anchor. In some embodiments, because the lateral support device 200 substantially envelopes an anchor 50, it can be defined as a lateral support sleeve. The embedded anchor is at least partially laterally supported by the lateral support device 200. The lateral support device 200 is configured to contact a large portion of the soil. Essentially, the larger the area of the lateral support device 200 in contact with the soil, the higher the passive pressure of the soil against the lateral support device. Because the embedded anchor is laterally supported by the lateral support device 200, the increased soil contact area of the lateral support device effectively increases the passive pressure of the soil against the embedded anchor, and thus the anchor's resistance to lateral loads.
As shown in FIG. 6, the lateral support device 200 increases the soil contact area of the anchor 50 via a plurality of fins 230. The fins 230 extend from an elongate central body 210. Preferably, the central body 210 is a hollow tubular member having an outer surface 212 and an opposing inner surface 214. The inner surface 214 defines a channel 216 (e.g., anchor receptacle) extending the length of the central body 210, which is defined between a first end 218 and second end 220 of the central body (see also FIG. 7). As shown, the central body 210 is configured such that the cross-sectional shape of the channel 216 along a plane perpendicular to its length is substantially circular. In other implementations, the cross-sectional shape of the channel 216 can be any of various shapes as desired without departing from the essence of the present disclosure. Desirably, the cross-sectional shape and size of the channel 216 corresponds with the cross-sectional shape and size of the anchor 50. However, as will be described below, in certain embodiments, the cross-sectional shape and size of the channel 216 need not correspond with the shape and size of the anchor 50 to achieve at least some of the advantages described herein.
Each fin 230 includes a plate-like element extending lengthwise from a first end 232 to a second end 234. The length of each fin 230 can be the same as the length of the central body 210 as shown. However, in some embodiments, the length of the fins 230 is shorter than the length of the central body 210. Additionally, although all of the fins 230 in the illustrated embodiment have the same length, in other embodiments, the fins 230 can have different lengths. The fins 230 each have a height defined between an inner edge 236 and an outer edge 238. The height of the fins 230 can be the same or different. The length and height of the fins 230 can be selected to provide a desired resistance to lateral forces or lateral load rating. More specifically, the area of the fins 230 contactable with soil can be predetermined by selecting a desired length to height combination of the fins.
The fins 230 are secured to and extend away from the outer surface 212 of the central body 210. In the illustrated embodiments, the fins 230 are positioned about the outer surface 212 an equidistance apart from each other and extend substantially perpendicularly away from the central body (see, e.g., FIG. 7). However, in other embodiments, the fins 230 need not be equidistant apart from each other and can extend at an angle less than ninety-degrees if desired based on, e.g., the particular application or location in which the foundation is installed. For example, variably positioned fins 230 in an angular arrangement may be desirable in a geographic location where the direction of wind is substantially constant. The second end 234 of each fin can be angled relative to the ground 52 to facilitate entry into and passage through the ground 52. In the illustrated embodiment, the lateral support device 200 includes four fins 200. However, the lateral support device 200 can include any number of fins 230 as desired in view of lateral load rating, manufacturing, installation, cost, and other considerations.
The lateral support device 200 can be installed in any number of ways using any number of techniques. Referring to FIGS. 8-10, in one embodiment, the lateral support device 200 is installed using an installation tool 250 and a driving device 270. The installation tool 250 can be an elongate length of pipe, tubing, or rod securable to the upper attachment end portion 56 of an embedded anchor 50 in axial alignment with the anchor. The installation tool 250 is extendable lengthwise upwardly away from the anchor 50 and the ground 52 in which the anchor is embedded (see FIG. 8). For facilitating attachment to the anchor 50, the installation tool 250 has apertures 258 alignable with corresponding apertures 54 of the upper attachment end portion 56 of the anchor. With the apertures 54, 258 aligned, fasteners can be extended through the aligned apertures to secure the installation tool 250 to the embedded anchor 50.
The installation tool 250 has an outer surface 252 and an opposing inner surface 254. Also, the installation tool 250 has an outer cross-sectional size and shape perpendicular to its length and defined by the outer surface 252. The outer cross-sectional size and shape of the installation tool 250 corresponds with the cross-sectional size and shape of the channel 216. Preferably, the size of the installation tool's cross-section is just smaller that the channel's cross-section such that the installation tool 250 is slidable within the channel 216 and the tool maintains the lateral support device 200 in axial alignment with the tool and anchor 50 as the tool slides within the channel.
During installation, the installation tool 250 is secured to the embedded anchor 50 as described above and the lateral support device 200 is slid over and downwardly along the installation tool and the upper attachment end portion 56 of the anchor 50 until the device contacts the ground 52 (see FIG. 9 showing the upper attachment end portion 56 in hidden view). The length of the installation tool 250 is selected such that a portion of the tool extends upwardly through and beyond the lateral support device 200 when the device is in contact with the ground. The driving mechanism 270 is then secured to or makes contact with the exposed portion of the installation tool 250 to drive the lateral support device 200 into the ground 52. In some embodiments, the driving mechanism 270 is a hydraulic jack that utilizes the installation tool 250 as leverage to drive the lateral support device 200 into the ground 52.
As the lateral support device 200 is driven into the ground, the installation tool 250 and anchor 50 act as guides for maintaining the device in a proper orientation, e.g., axial alignment with the anchor. The lateral support device 200 is driven into the ground 52 a desirable distance, e.g., a distance sufficient to position the first ends 232 of the fins 230 flush with or below the surface of the ground 52. Once satisfactorily driven into the ground 52, the installation tool 250 can be removed from the anchor 50 and the tower foundation 10, 110 can be secured to the anchor as described above. Preferably, this process is repetitively performed until a respective lateral support device 200 is secured to each of the plurality of anchors 50.
When installed, in one embodiment, the channel 216 of the lateral support device 200 and outer surface of the anchor 50 are shaped and sized such that the inner surface 214 of the device is in substantial contact with the outer surface of the anchor. In some instances, the anchor 50 is secured to the lateral support device 200 via a press-fit connection. The contact or direct engagement between the two surfaces provides the connection whereby lateral loads on the anchors 50 are transferred from the anchors 50 to the lateral support devices 200. The lateral loads transferred to the lateral support devices 200 are then transferred to the supporting soil through the fins 230.
In one alternative embodiment, the channel 216 of the lateral support device 200 and outer surface of the anchor 50 are differently shaped and/or sized such that the inner surface 214 of the device is not in substantial contact with the outer surface of the anchor. For example, the cross-sectional area of the channel 216 can be significantly larger than the outer cross-sectional area of the anchor 50. In this embodiment, a gap exists between the inner surface 214 of the lateral support device 200 and the outer surface of the anchor 50. To facilitate load transfer between the anchor 50 and the lateral support device 200, the gap can be filled with grout, which provides indirect contact or engagement between the anchor and device.
Although the illustrated embodiments include one lateral support device 200 for each anchor 50, in other embodiments, two or more lateral support devices 200 can be installed about each anchor without departing from the spirit of the invention.
The lateral support device 200 and installation tool 250 can be made from any of various rigid materials, such as steel, aluminum, composite materials, and fiber-reinforced plastic. In certain implementations, the lateral support device 200 is made from and metal and the fins 230 are welded to the central body 210.
As discussed above, although the lateral support device 200 and installation tool 250 are shown in conjunction with tower foundations 10, 110, they are not limited to use with such foundations. For example, the lateral support device 200 and installation tool 250 described herein can be used with any tower foundation system that uses embedment anchors or any other application in which embedment anchors are used.
The present disclosure may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims

1. A lateral support device for an anchor embedded in the ground, comprising:

a central body defining an interior channel sized to receive the embedded anchor; and

a plurality of fins coupled to and extending outwardly away from the central body;

wherein the central body and plurality of fins are embeddable within the ground to position the embedded anchor within the interior channel.

2. The lateral support device of claim 1, wherein when the central body and plurality of fins are embedded in the ground to position the embedded anchor within the interior channel, lateral loads on the embedded anchor are transferred to the central body, from the central body to the plurality of fins, and from the plurality of fins to the ground.

3. The lateral support device of claim 1, wherein the central body has an elongate tubular shape and each of the plurality of fins extends along an entire length of the central body, each fin being substantially parallel to the length of the central body.

4. The lateral support device of claim 3, wherein each fin comprises a leading edge angled relative to the length of the central body.

5. The lateral support device of claim 1, wherein the plurality of fins are positioned about an outer periphery of the central body equidistantly apart from each other.

6. The lateral support device of claim 1, wherein each of the plurality of fins extends substantially transversely away from the central body.

7. An anchoring system, comprising:

an anchor embeddable into the ground; and

a lateral support sleeve comprising an anchor receptacle, the lateral support sleeve being embeddable into the ground about the anchor such that the anchor is positioned within the anchor receptacle, wherein the lateral support sleeve comprises a plurality of fins.

8. The anchoring system of claim 7, wherein the plurality of fins each extends substantially parallel to the anchor when the anchor and lateral support sleeve are embedded into the ground.

9. The anchoring system of claim 7, wherein a cross-sectional size and shape of the anchor receptacle is substantially the same as a cross-sectional size and shape of the anchor such that when the anchor is positioned within the anchor receptacle the anchor is in substantial contact with the anchor receptacle.

10. The anchoring system of claim 7, wherein at least one of a cross-sectional size and shape of the anchor receptacle is different than at least one of a cross-sectional size and shape of the anchor such that a gap is definable between the anchor and the anchor receptacle when the anchor is positioned within the anchor receptacle.

11. The anchoring system of claim 7, further comprising a plurality of anchors embeddable into the ground and a plurality of lateral support sleeves each being embeddable into the ground about a respective one of the plurality of anchors.

12. A method for installing an anchoring system, comprising:

removably coupling an installation tool to an anchor embedded in the ground;

movably coupling a lateral support device to the installation tool;

while movably coupled to the installation tool, driving the lateral support device into the ground about the embedded anchor; and

after driving the lateral support device about the embedded anchor, removing the installation tool from the anchor.

13. The method of claim 12, wherein the lateral support device comprises an anchor receptacle and a plurality of fins extending away from the anchor receptacle, and wherein movably coupling the lateral support device to the installation tool comprises inserting the installation tool into the anchor receptacle.

14. The method of claim 13, wherein driving the lateral support device into the ground about the embedded anchor comprises inserting the embedded anchor into the anchor receptacle.

15. The method of claim 14, further comprising positioning a grout-like material between the embedded anchor and the anchor receptacle.

16. The method of claim 14, wherein inserting the embedded anchor into the anchor receptacle comprises press-fitting the embedded anchor into the anchor receptacle.

17. The method of claim 12, wherein when removably coupled to the embedded anchor, the installation tool is aligned with and extends substantially parallel to the embedded anchor.

18. The method of claim 12, wherein driving the lateral support device comprises moving the lateral support device along the installation tool, the installation tool maintaining the lateral support device in alignment with the embedded anchor as the lateral support device moves along the installation tool.

19. A tower foundation system, comprising:

a base;

a plurality of anchors coupleable to the base and embeddable into the ground to secure the base to the ground; and

a plurality of lateral support sleeves each securable to a respective one of the plurality of anchors, each lateral support sleeve being embeddable into the ground about the respective anchor, wherein each lateral support sleeve comprises a plurality of fins.

20. A method for installing a tower foundation, comprising:

embedding an anchor in the ground;

securing an installation tool to the anchor;

positioning a lateral support device over the installation tool, the lateral support device comprising a plurality of fins;

driving the lateral support device along the installation tool and into the ground about the anchor;

after driving the lateral support device, removing the installation tool from the anchor; and

securing a foundation base to the anchor.