Patent Publication Number: US-2023140266-A1

Title: Tower base for piling foundation

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is related to and claims priority to U.S. Provisional Pat. Application Serial No. 63/275,694, filed on Nov. 4, 2021, the entire contents of which are herein incorporated by reference. 
    
    
     TECHNICAL FIELD 
     This application relates generally to piling foundations, and, more specifically, to a base structure or “grillage” for mounting equipment, for example, to a multi-pile foundation. 
     BACKGROUND 
     Power transmission lines often extend for long distances across remote and sometimes rugged terrain. Transmission lines are suspended on power transmission towers installed at intervals along the length of the power transmission lines. Traditionally, power transmission towers are wooden poles sunk into holes in the soil or metal structures situated on concrete foundations, for example. Moving equipment into remote and rugged locations to construct and install traditional foundations for power transmission towers presents many challenges. Thus, it would be desirable to provide a base structure for power transmission towers, for example, that avoids, alleviates, or otherwise minimizes known issues associated with traditional foundations. 
     SUMMARY OF THE INVENTION 
     Certain exemplary aspects of the invention are set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of certain forms the invention might take and that these aspects are not intended to limit the scope of the invention. 
     In a first set of embodiments of the invention, a base structure for a piling foundation is provided. The base structure includes an upper plate and a lower plate. The lower plate is spaced a distance below the upper plate and is oriented substantially parallel to the upper plate. The base structure also includes a number of webs. The number of webs connect the upper plate and the lower plate and are configured to add structural integrity to the base structure. Further, the upper plate and the lower plate each include a number of plate apertures therethrough. 
     In one embodiment, the number of webs may be cylindrical webs, radial webs, tangential webs, and/or angled webs. Further, the upper plate and the lower plate may include a number of equipment apertures. Each equipment aperture may be configured to receive a fastener for securing operating equipment to the base structure. 
     In another embodiment, the upper plate and the lower plate may be substantially square-shaped and each of the upper plate and the lower plate may include four plate apertures. Alternatively, the upper plate and the lower plate may be substantially circle-shaped and each of the upper plate and the lower plate may include eight plate apertures. 
     In yet another embodiment, the upper plate and the lower plate may be formed of steel. Further, the number of webs may be formed of steel and may be welded to the upper plate and to the lower plate. 
     In another set of embodiments of the invention, a piling foundation assembly for supporting operating equipment is provided. The assembly includes a number of piles installed into a ground. Each pile of includes a free end that extends above the ground. The assembly also includes a base structure configured to support the operating equipment. The base structure includes an upper plate and a lower plate. The lower plate is spaced a distance below the upper plate. The base structure also includes a number of webs. The number of webs connect the upper plate and the lower plate. The base structure is attached to the free ends of the piles. 
     In one embodiment, each pile may further include a pile cap coupled to the free end of the pile. The pile cap may include a receiving sleeve, configured to surround and receive the free end of the pile, and a cap plate, affixed atop the receiving sleeve and configured to receive the base structure thereon. Further, the upper plate and the lower plate may each include at least one plate aperture therethrough. Each cap plate may also include a cap plate aperture. Additionally, a fastening member may be threaded through the cap plate aperture, the at least one plate aperture of the lower plate, and the at least one plate aperture of the upper plate to attach the base structure to the pile. Furthermore, at least one washer may be positioned around the fastening member above the at least one plate aperture of the upper plate to aid in attaching the base structure and to the pile. 
     In another embodiment, the upper plate and the lower plate may include a number of equipment apertures. Each equipment aperture may be configured to receive a fastener for securing the operating equipment to the base structure. Further, the operating equipment may be a power transmission tower or a portion thereof. 
     In a further set of embodiments of the invention, a method of installing a piling foundation assembly is provided. The method includes installing a number of piles into a ground. Each pile includes a free end that extends above the ground. The method further includes coupling a number of pile caps to the free ends of the number of piles. Each pile cap includes a cap plate. The method also includes positioning a base structure on top of the pile caps such that a lower plate of the base structure contacts the cap plates of the respective pile caps. The method additionally includes securing the base structure to the piles. 
     In one embodiment, the number of piles may be installed into the ground substantially vertically. Further, the piles may be helical piles. Additionally, the method may also include trimming the free end of one or more of the piles such that the respective free ends of the piles extend to substantially the same height above the ground. 
     In another embodiment, the step of coupling the pile caps may further include securing the pile cap to the pile by threading a fastening member through a receiving sleeve of the pile cap and through the free end of the pile. Additionally, the step of securing the base structure may further include threading a fastening member through a cap plate aperture of the cap plate and through at least one plate aperture of the base structure. 
     Other aspects, features, benefits, and advantages of the present invention will become apparent to a person of skill in the art from the detailed description of various embodiments with reference to the accompanying drawing figures, all of which comprise part of the disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various additional features and advantages of the invention will become more apparent to those of ordinary skill in the art upon review of the following detailed description of one or more illustrative embodiments taken in conjunction with the accompanying drawings and pictorial views. The accompanying drawings and pictorial views, which are incorporated in and constitute a part of this specification, illustrate one or more embodiments of the invention and, together with the general description given above and the detailed description given below, serve to explain the one or more embodiments of the invention. Like reference numerals are used to indicate like parts throughout the accompanying drawings and pictorial views. 
         FIG.  1    is an environmental pictorial view of a first embodiment of a base structure. 
         FIG.  2    is a close-up pictorial view of the base structure of  FIG.  1   . 
         FIG.  3    is a close-up pictorial view of the base structure of  FIG.  1   , with the operating equipment removed for illustrative purposes. 
         FIG.  4    is a side elevation view of the base structure of  FIG.  1   . 
         FIG.  5    is an isometric view of the base structure of  FIG.  1   . 
         FIG.  6    is an exploded isometric view of the base structure of  FIG.  1   . 
         FIG.  7    is a cross-sectional view of the base structure of  FIG.  1    taken along line 7-7 of  FIG.  5   . 
         FIG.  8    is a sectional view of the base structure of  FIG.  1    taken along line 8-8 of  FIG.  7   . 
         FIG.  9    is a further sectional view of the base structure of  FIG.  1    taken along line 9-9 of  FIG.  7   . 
         FIG.  10    is a close-up pictorial view of a second embodiment of the base structure. 
         FIG.  11    is a close-up view of the base structure of  FIG.  10    with the operating equipment removed for illustrative purposes. 
         FIG.  12    is a side elevation view of the base structure of  FIG.  10   . 
         FIG.  13    is an isometric view of the base structure of  FIG.  10   . 
         FIG.  14    is an exploded isometric view of the base structure of  FIG.  10   . 
         FIG.  15    is a cross-sectional view of the base structure of  FIG.  10    taken along line 15-15 of  FIG.  13   . 
         FIG.  16    is a sectional view of the base structure of  FIG.  10    taken along line 16-16 of  FIG.  15   . 
         FIG.  17    is a sectional view of the base structure of  FIG.  10    taken along line 17-17 of  FIG.  15   . 
         FIG.  18    is a sectional view of the base structure of  FIG.  10    taken along line 18-18 of  FIG.  15   . 
         FIG.  19    is a sectional view of the base structure of  FIG.  10    taken along line 19-19 of  FIG.  15   . 
     
    
    
     DETAILED DESCRIPTION 
     The exemplary embodiments described herein are provided for illustrative purposes and are not limiting. Other exemplary embodiments are possible, and modifications may be made to the exemplary embodiments within the scope of the present disclosure. Therefore, this detailed description is not meant to limit the scope of the present disclosure. 
     With general reference to  FIGS.  1 - 19   , a piling foundation assembly  10  or portions thereof in accordance with embodiments of the invention are shown. As set forth in greater detail below, the present invention provides a piling foundation assembly  10  including a base structure  16  that can be prefabricated and then mounted on a plurality of piles  12  to create a foundation for operating equipment  18  (e.g., a power transmission tower). The base structure  16  can receive vertical or angled operating equipment  18  to support power transmission lines or power substation equipment, for example. Installation of piles  12  (e.g., helical piles) to support the base structure  16  is less destructive to the environment and requires less invasive equipment to be moved to the site to install in comparison to traditional (e.g., concrete) foundations. For example, no field welding is required, so a pile  12  can be installed in any weather conditions and is more easily removable. Thus, the present invention provides a base structure  16  for operating equipment  18  (e.g., power transmission towers) that avoids, alleviates, or otherwise minimizes known issues with traditional foundations. The elements and features of the piling foundation assembly  10  are set forth in further detail below to clarify the functional advantages and other benefits of the invention. 
     Referring now to  FIGS.  1 - 9   , a first embodiment of a piling foundation assembly  10  is shown. The piling foundation assembly  10  generally includes a plurality of piles  12 , a plurality of pile caps  14  affixed to the piles  12 , and a base structure  16  situated atop and attached to the pile caps  14 . Operating equipment  18  (shown in  FIG.  1   , for example) is supported atop the base structure  16  above the ground  20 . In the depicted embodiment, the operating equipment  18  is a power transmission tower (e.g., for supporting high-voltage power lines). It will be appreciated that other types of operating equipment  18  could also be supported by the base structure  16 . For example, the operating equipment  18  could instead be a pole or tower for supporting a portion of a power-generation substation. 
     Referring specifically to  FIGS.  1 - 4   , each pile  12  is installed deep into the ground  20  such that a free end  22  of the pile  12  extends above the ground  20 . Particularly, the piles  12  are installed deep enough in the ground  20  to provide effective support for the base structure  16  and the operating equipment  18  mounted to the base structure  16 . In the depicted embodiment, the piles  12  are installed into the ground  20  so as to have a generally vertical orientation. However, piles  12  could alternatively be installed into the ground  20  at an angle to the vertical, such as at 30° to vertical. Further, the piles  12  may be installed into the ground  20  splayed outwardly at an angle away from the base structure  16 . Alternatively, the piles  12  may be installed into the ground  20  at angles to the vertical, but in opposing directions with respect to each other. The installed piles  12  may be helical piles, which include helically-arranged blades for engaging the ground. Helical piles can be particularly advantageous when used in conjunction with some specific operating equipment  18  and/or installation environments (e.g., particular local geology). It will be appreciated that the principles of the present invention are also generally applicable to other pile installation configurations and other pile types (e.g., driven piles). 
     Each pile  12  has a pile cap  14  coupled to a free end  22  (e.g., the end of the pile  12  that extends above the ground  20 ) thereof. The pile cap  14  may include a cap plate  24  and a receiving sleeve  26 . The cap plate  24  is secured to the top of the receiving sleeve  26 . The receiving sleeve  26  fits around (e.g., “receives”) a free end  22  of a pile  12  when a pile cap  14  is coupled to a pile  12 . The pile cap  14  may be secured to a pile  12  in a number of ways. For example, the receiving sleeve  26  of a pile cap  14  may include one or more sleeve apertures  28  and the free end  22  of a pile  12  may include one or more corresponding pile apertures  30  that extend transversely through the free end  22  of the pile  12 . The receiving sleeve  26  may be secured to the pile  12  by a fastening member  32 , such as a bolt or similar mechanical fastener, that is inserted through (e.g., received in) aligned sleeve apertures  28  and pile apertures  30 . 
     With continued reference to  FIGS.  1 - 4   , the cap plates  24  of the pile caps  14  are disposed in a generally horizontal orientation when the pile caps  14  are coupled to the free ends  22  of the piles  12 . In other words, the cap plates  24  are oriented generally transverse to the lengthwise axis of the respective piles  12 . Moreover, the cap plates  24  are disposed in generally the same horizontal plane as each other. Thus, the cap plates  24  provide a plurality of generally horizontal (e.g., level), coplanar locations for supporting the base structure  16 . Pile caps  14  are coupled to the free ends  22  of the piles  12  before the base structure  16  is positioned on top of the pile caps  14 . In some instances, it may be necessary to trim a free end  22  of a pile  12  before coupling a pile cap  14  to the pile  12 . For example, after piles  12  are installed into the ground  20 , the various free ends  22  of the piles  12  may be at different heights and require trimming so that all the free ends  22  extend to generally the same height above the ground  20 . After trimming, the pile caps  14  may be coupled to the free ends  22 . The base structure  16  then may be situated atop (e.g., rest on) and secured to the piles  12  by the pile caps  14 . 
     Referring now to  FIGS.  5 - 9   , the base structure  16  includes an upper plate  34  and a lower plate  36 . The upper and lower plates  34 ,  36  are spaced apart and are oriented generally parallel to each another. The upper and lower plates  34 ,  36  include respective lower surfaces  38 ,  40  and upper surfaces  42 ,  44 . Specifically, the upper plate  34  includes lower surface  38  and upper surface  42 . The lower plate  36  includes lower surface  40  and upper surface  44 . The lower surface  40  of the lower plate  36  defines a lower plane  46  of the base structure  16  and the upper surface  42  of the upper plate  34  defines an upper plane  48  of the base structure  16 . As shown in  FIG.  4   , for example, the upper and lower plates  34 ,  36  have a general planar configuration. The upper and lower plates  34 ,  36  may be formed of steel or a similar suitable material. It is to be understood that the upper and lower plates  34 ,  36  could have alternative configurations and could be formed of alternative materials. 
     The base structure  16  also includes a plurality of webs  50 ,  52 ,  54  that are positioned generally between the upper plate  34  (e.g., upper plane 48) and the lower plate  36  (e.g., lower plane  46 ), and may be formed of steel or a similar suitable material. The webs  50 ,  52 ,  54  may be fixedly attached to the upper and lower plates  34 ,  36 , such as by welding or similar rigid attachment. Specifically, the webs  50 ,  52 ,  54  are secured (e.g., by welding) to the upper surface  44  of the lower plate  36  and to the lower surface  38  of the upper plate  34 . The plurality of webs  50 ,  52 ,  54  may include cylindrical webs  50  (shown in  FIGS.  6  and  7   , for example), radial webs  52  (shown in  FIGS.  6  and  7   , for example), and tangential webs  54  (shown in  FIGS.  6  and  7   , for example). It is to be understood that the webs may take on other shapes and orientations. Further, the webs  50 ,  52 ,  54  may be formed of steel or a similar suitable material. 
     Referring now to  FIGS.  4 - 9   , the upper and lower plates  34 ,  36  include a plurality of plate apertures  56 . The space between the plate apertures  56  of the upper plate  34  and the plate apertures  56  of the lower plate  36  may be surrounded by a cylindrical web  50  or other structure (shown in  FIGS.  5  and  6   , for example). Further, each cap plate  24  includes a cap plate aperture  58  (shown in phantom in  FIG.  4   , for example). The cap plates  24  and upper and lower plates  34 ,  36  are secured together by fastening members  32  received in aligned cap plate apertures  58  and plate apertures  56 . The fastening member  32  passes through the cap plate aperture  58  of the cap plate  24 , a plate aperture  56  in the lower plate  36 , and a plate aperture  56  in the upper plate  34 . A threaded member  60  (e.g., a nut) may be attached to the fastening member  32  at or near the cap plate  24  of the pile cap  14  to further secure the base structure  16  to the pile  12 . An additional threaded member  60  may be fixedly attached to the pile cap  14  (e.g., the cap plate  24 ), such as by welding, so as to be aligned with the cap plate aperture  58 . A fastening member  32  extending through the cap plate aperture  58  may then be threaded into the threaded member  60  attached to the cap plate  24 . 
     Referring now to  FIGS.  2 - 4   , a slotted washer  62  having a slot  64  may be positioned around the fastening member  32  above a plate aperture  56  of the upper plate  34 , and a threaded member  60  may be threaded onto the fastening member  32  above the slotted washer  62  (as shown in  FIG.  2   , for example). Optionally, an additional washer  66  with a central aperture  68  can be stacked on top of the slotted washer  62  before the threaded member  60  is threaded on the fastening member  32 . The slotted washer  62  and the washer  66  allow for forces imparted on the base structure  16  to be distributed along the base structure  16  and to the piles  12  extending therefrom. Advantageously, the plate apertures  56  may be oversized relative to the fastening member  32 , such as being elongated in one or more axes transverse to the fastening member  32 , to aid in the alignment and securing of the base structure  16  to a the pile  12 . The combination of an oversized plate aperture  56  with both a slotted washer  62  and a washer  66  allows for some error in the positioning of the fastening member  32  through the cap plate aperture  58  of the cap plate  24 , the plate aperture  56  in the lower plate  36 , and the plate aperture  56  in the upper plate  34 . For example, the base structure  16  can be secured to the pile  12  without the base structure  16  and the pile  12  being perpendicular to each other at least in part because of the “wiggle room” afforded by the oversized plate apertures  56 , slotted washers  62 , and washers  66 . 
     Referring now to  FIGS.  3 - 7   , both the upper and lower plates  34 ,  36  of the base structure  16  include a number equipment apertures  70  that are configured to receive a fastening member  32 , such as a bolt or similar, for securing the operating equipment  18  to the base structure  16 . For example, the operating equipment  18  may be secured to the base structure  16  by fastening members  32  received in the equipment apertures  70 . Further, both the upper and lower plates  34 ,  36  include an equipment opening  72  configured to receive the operating equipment  18  or a part thereof (shown in  FIG.  3   , for example). Like the plate apertures  56 , the space between the equipment openings  72  in the upper and lower plates  34 ,  36  may be surrounded by a cylindrical web  50  or other similar structure. 
     Different numbers of piles  12  could be used depending on the nature of the operating equipment  18  and the installation environment (e.g., geology of the location). Specifically,  FIGS.  1 - 9    show an embodiment of a square-shaped base structure  16  for use with four piles  12 . The base structure  16  of  FIGS.  1 - 9    includes a number of cylindrical webs  50 , radial webs  52 , and tangential webs  54 . The webs  50 ,  52 ,  54  add strength and structural integrity to the base structure  16 —particularly, torsional strength to prevent (or at least reduce the likelihood of) the base structure  16  twisting under the load (e.g., bending moment) applied by the operating equipment  18 . 
     Further alternative base structure  16  embodiments are contemplated. The size and shape of the base structure  16  as well as the number of piles  12  employed therewith can vary. For example, a triangular base structure  16  for use with three piles  12  could be employed, a pentagonal base structure  16  for use with five piles  12  could be employed, a hexagonal base structure  16  for use with six piles  12  could be employed, and so on. Generally, base structures  16  could be in the shape of a (regular) polygon of n-sides with a corresponding n-number of piles  12 . The piles  12  may be arranged at or near to the vertices of the polygonal base structure  16 . Further variations on size and shape of the base structure  16  as well as the number of piles  12  employed therewith beyond those shown in  FIGS.  1 - 9    and those described above are contemplated. 
     Particularly,  FIGS.  10 - 19    show an embodiment of a circular base structure  16  for use with eight piles  12 . The base structure  16  of  FIGS.  10 - 19    includes a number of cylindrical webs  50 , radial webs  52 , tangential webs  54 , and angled webs  55 . Like with the embodiment shown in  FIGS.  1 - 9   , the webs  50 ,  52 ,  54 ,  55  of the embodiment shown in  FIGS.  10 - 19    add strength and structural integrity to the base structure  16 . However, the embodiment depicted in  FIGS.  10 - 19    includes features angled webs  55 , which are not featured in the embodiment depicted in  FIGS.  1 - 9   . Further alternative base structure  16  embodiments may include a number of webs  50 ,  52 ,  54 ,  55  including cylindrical webs  50 , radial webs  52 , tangential webs  54 , and angled webs  55 . A base structure  16  for use with a larger number of piles  12  (for heavier operating equipment  18 , for example) may feature more webs  50 ,  52 ,  54 ,  55  than a base structure  16  for use with a smaller number of piles  12  (for lighter operating equipment  18 , for example). 
       FIGS.  1 ,  2 , and  10    show operating equipment  18  mounted to the base structure  16 . In addition to operating equipment  18  being mounted generally perpendicularly to the base structure  16  (as in  FIG.  2   , for example), operating equipment  18  can also be mounted to the base structure  16  at an angle to the vertical, extending upwards from the upper surface  42  of the upper plate  34  (as in  FIGS.  1  and  10   , for example). Further, as shown in  FIG.  1   , neighboring piling foundation assemblies  10  may have their respective operating equipment  18  mounted at angles towards each other such that the operating equipment  18  of one piling foundation assembly  10  will intersect with the operating equipment  18  of another piling foundation assembly  10  at a distance above the ground  20 . Such may be desirable if the operating equipment  18  is particularly tall (e.g., a power transmission tower or part thereof) or if the weight of the operating equipment  18  (or something supported by the operating equipment  18 ) is particularly great. 
     Referring generally to  FIGS.  1 - 19   , the piling foundation assembly  10  and accompanying operating equipment  18  may be installed as follows. First, the piles  12  are installed into the ground  20  such that free ends  22  thereof extend above the ground  20 . In some cases, this may include installing a plurality of piles  12  at a generally vertical orientation in the ground  20  and/or a plurality of piles  12  at an angle to the vertical in the ground  20 . The piles  12  may be helical piles having helically-arranged blades for engaging the ground  20 , which is particularly suitable for some operating equipment  18  and installation environments (e.g., local geology). It will be appreciated that the principles of the present invention are also generally applicable to other pile installation configurations and other pile types (e.g., driven piles). If required, the free ends  22  of one or more of the piles  12  may require trimming to an appropriate height above the ground  20 . Then, the pile caps  14  are coupled to the free ends  22  of the piles  12 . The receiving sleeves  26  of the pile caps  14  are placed onto and fit around the free ends  22  of the piles  12 . The pile caps  14  may then be secured to the piles  12 . For example, a fastening member  32  may be installed in respective aligned sleeve apertures  28  and pile apertures  30 . 
     After the pile caps  14  are coupled to the piles  12 , the base structure  16  is positioned above the pile caps  14 . The base structure  16  is moved to bring the base structure  16 , and in particular the lower plate  36 , into contact with the cap plates  24  of the pile caps  14 . The base structure  16  is then secured to the cap plates  24 . For example, a fastening member  32  may be aligned with plate apertures  56  of the upper and lower plates  34 ,  36  and cap plate aperture  58 . The operating equipment  18  may then be positioned atop the base structure  16 . The operating equipment  18  may be secured to the base structure  16  using fastening members  32  and the equipment apertures  70  of the upper and lower plates  34 ,  36 . For example, the operating equipment  18  may be bolted to the base structure  16 . 
     While the present invention has been illustrated by the description of various embodiments thereof, and while the embodiments have been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. Thus, the various features discussed herein may be used alone or in any combination. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details and illustrative examples shown and described. 
     Accordingly, departures may be made from such details without departing from the scope of the general inventive concept. For example, although the base structure  16  and free ends  22  of the piles  12  are shown as being secured to each other via pile caps  14 , in some embodiments, the free ends  22  of one or more of the piles  12  or the pile caps  14  may be secured, such as by welding, directly to the base structure  16 , such as to the upper and lower plates  34 ,  36  thereof. Further, while it is contemplated that some or all of the components of the pile caps  14  and the base structure  16  may be formed of steel, they may also be constructed of any other suitable (e.g., as determined based on the environment the piling foundation assembly  10  is to be installed in and the operating equipment  18  to be supported by the base structure  16 ) other material or materials, such as concrete.