Patent Publication Number: US-2013232780-A1

Title: Foundation for supporting a pole

Description:
FIELD OF THE INVENTION 
     The present invention relates to a foundation for supporting a pole. 
     BACKGROUND 
     Outdoor poles are often used to support antennas, lights, cameras, cables or other similar components. It can be costly and time-consuming to erect and replace such poles and there is often pressure to construct foundations and poles within a two day period in order to minimize construction time activity while also yielding a vertical pole that will remain vertical over many years. Outdoor poles are intended to remain secure and stable in the soil for many years. However, various forces, primarily wind, and other weather related factors such as frost create a load bearing on the pole and foundation that could cause the pole to become unstable or “tilted” (non vertical) in the soil. To prevent this, outdoor poles require a structurally adequate and lasting foundation. Commonly, foundations for outdoor poles are either constructed with a direct imbedment section into soil or constructed using concrete or high early strength concrete with rebar placed in the concrete for resilience and strength. Constructing direct imbedment foundation usually results in a tilted pole (or tilted over time pole) and does not facilitate correction of the verticality. Constructing a reinforced concrete foundation is costly and time consuming. 
     Further, installing a conventional rebar reinforced concrete outdoor pole foundation requires multiple steps that take a number of days or weeks to complete. It generally takes about a week to two weeks in order to prepare and install a conventional foundation in the soil and to secure a pole to it. 
     Therefore, there is a need for a foundation for supporting a pole that is quick to construct, cure, that can withstand the various forces experienced by a pole installed outdoors, that conforms to the National Design and Construction Standards, including Canadian standard CSA S27-01 (“Antennas, Towers and Antenna Supporting Towers”) and United States standard TIA-222-G (“Structural Standards for Steel, Antennas, Towers, and Antenna Supporting Structures”) and facilitates installation of a pole that remains vertical. 
     SUMMARY 
     According to one aspect, provided is a foundation for supporting a pole, the foundation being disposed at least in part in a hole in a soil where the pole is to be installed, the foundation comprising: a casing defining an internal cavity and having an exterior surface; a substance including at least concrete disposed inside the cavity and inside a gap defined between the exterior surface of the casing and an interior surface of the hole; and a pole connector connected to an upper portion of the casing for connecting the pole to the foundation. 
     According to another aspect, the substance fills the internal cavity and the gap. 
     According to another aspect, the casing defines an aperture at an upper end thereof for receiving the substance, and wherein the pole connector is disposed in the aperture. 
     According to another aspect, the casing defines at least one aperture fluidly communicating the internal cavity with the gap for allowing the substance to flow from the internal cavity to the gap. 
     According to another aspect, at least one conduit has a first portion disposed in the internal cavity of the casing and a second portion passing through one of the at least one apertures defined by the casing and extending externally of the casing. 
     According to another aspect, at least one wire passes through one of the at least one conduit for connecting one of a power source external to the casing to an electrical component secured to the pole, and an antenna system attached to the pole to a receiver external to the pole. 
     According to another aspect, the pole connector comprises a plurality of nut and bolt attachments; and wherein the nut and bolt attachments provide an adjustable connection for the pole such that an angle of the pole relative to vertical can be altered by adjusting at least one of the nut and bolt attachments. 
     According to another aspect, the substance is high early strength concrete. 
     According to another aspect, the pole connector comprises a plate defining an aperture. 
     According to another aspect, provided is a pole and foundation assembly comprising: a foundation assembly having a foundation as defined above; and a pole connected to the pole connector. 
     According to another aspect, provided is a method for installing a pole and foundation assembly. The method comprises: forming a hole in the ground sized to receive a casing in a spaced relationship to define a gap between an exterior surface of the casing and an interior surface of the hole; placing the casing in the hole in the spaced relationship, the casing defining an internal cavity; pouring a substance into an open end of the casing such that the substance fills at least a majority of the internal cavity, the substance including at least concrete; filling at least a majority of the gap with the substance; waiting for the substance to harden; and after the substance has hardened, securing a pole to a pole connector connected to an upper portion of the casing. 
     According to another aspect, filling at least a majority of the gap with the substance comprises filling at least the majority of the gap with the substance flowing from the internal cavity to the gap via at least one aperture defined in the casing and fluidly communicating the internal cavity with the gap. 
     According to another aspect, prior to pouring the substance, at least one conduit extending through one of the at least one aperture is provided such that a first portion of the conduit is disposed in the internal cavity of the casing and a second portion of the conduit extends externally of the casing. 
     According to another aspect, at least one wire passes through the pole and the at least one conduit for connecting one of a power source external to the pole to an electrical component secured to the pole and an antenna system attached to the pole to a receiver external to the pole for transmitting electrical data between the antenna and the receiver. 
     According to another aspect, the pole connector is adjusted to adjust an angle of the pole relative to vertical. 
     According to another aspect, the pole connector comprises a plurality of nut and bolt attachments; and the step of adjusting comprises adjusting at least one of the nut and bolt attachments. 
     Embodiments of the present invention each have at least one of the above-mentioned aspects, but do not necessarily have all of them. It should be understood that some aspects of the present invention that have resulted from attempting to solve one or more of the above mentioned problems may satisfy other problems not specifically recited herein. 
     Additional and/or alternative features, aspects, and advantages of embodiments of the present invention will become apparent from the following description, the accompanying drawings, and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a better understanding of the present invention, as well as other aspects and further features thereof, reference is made to the following description which is to be used in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a partially cut away side elevation view of an installed pole and foundation assembly; 
         FIG. 2  is a perspective view of a portion of a casing and of a conduit of the pole and foundation assembly of  FIG. 1 ; 
         FIG. 3  is a partial cross-sectional view of the casing of the pole and foundation assembly of  FIG. 1  in the soil; 
         FIG. 4  is a partial cross-sectional view of the casing of the pole and foundation assembly of  FIG. 1  in the soil partially filled with concrete; 
         FIG. 5  is a close-up view of a pole connector of the pole and foundation assembly of  FIG. 1 ; 
         FIG. 6  is a side elevation view of a portion of the pole and foundation assembly of  FIG. 1 ; and 
         FIG. 7  is a flowchart depicting a method for supporting a pole. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a foundation  100  supporting a pole  108  that together form a pole and foundation assembly  101 . The foundation  100  is disposed in part in the soil  104  below a top surface  120  thereof. The foundation  100  includes a casing  102  having multiple apertures  110 , concrete (described below with reference to  FIG. 3 ) and a pole connector  106 . The apertures  110  are formed in a side of the casing  102 . A conduit (or conduits)  112  (shown in dotted lines in  FIG. 1 ) passes through one of the apertures  110 . A wire (or cables)  114  is disposed inside the conduit  112 . A power source  116  is external of the casing  102  and is electrically connected to one end of the wire  114 . A street light  118  is attached to the pole  108  and is electrically connected to another end of the wire  114 . It is contemplated that other kinds of electrical or video components, such as a camera, could be attached to the pole  108 . An antenna system  124  is attached to the top of the pole  108 . In other embodiments, there is no antenna system  124  attached to the pole  108 . In other embodiments, there is no electrical component attached to the pole  108 . 
     The power source  116  provides electricity to the street light  118  through the wire (cable)  114 . The wire (cable)  114  passes through the casing  102  and through an interior passage in the pole  108  to connect to the street light  118 . A second conduit  113  passes through one of the apertures  110  with a second wire (cable)  115  passing through it. A receiver is external of the casing  102 . The second conduit  113  passes underground from the casing  102  to the receiver so that the second wire (cable)  115  passing through the second conduit  113  connects to the receiver. The second wire (cable)  115  extends from the receiver through the second conduit  113 , through the casing  102  to the pole  108 . The second wire (cable)  115  passes from the casing  102  and extends internally of the pole to the antenna system  124 . The second wire (cable)  115  transmits signals from the antenna  124  to the receiver and vice versa. It is contemplated that the second wire (cable)  115  can travel from the casing  102  externally of the pole  108  to the antenna  124 . It is recognized that the two wires (cables)  114 ,  115  can pass through the same conduit  212 . In further embodiments there can be more than two wires (cables)  114  passing through one or more conduits  212  in the casing  102 . The antenna system  124  can be a cellular radio antenna, for example. 
     Referring to  FIG. 2 , the casing  102  defines an internal cavity  208  and has an exterior surface  202 . The casing  102  is cylindrical. In alternative embodiments, the casing  102  can have different shapes including, but not limited to, rectangular or multi-sided. The casing  102  has a plurality of apertures  110  through its external surface  202  leading to the internal cavity  208 . For example, the casing  102  can have fifteen apertures  110  with three sets of five apertures  110  equally separated and vertically and equally disposed along the casing  102 . Two such apertures  110  are shown in  FIG. 2 . In yet further alternative embodiments, the casing  102  has one aperture  110 . The casing  102  is made of galvanized steel and serves as the structural foundation portion to support the pole  108  above. It is contemplated that the casing  102  could be made of other materials such as stainless steel or fibre reinforced structural material. 
     The casing  102  has an upper end  204  and a lower end  307  (see  FIG. 3 ). The upper end  204  of the casing  102  defines an aperture  210 . The aperture  210  leads to the internal cavity  208  of the casing  102 . The apertures  110  fluidly connect the internal cavity  208  of the casing  102  with the exterior of the casing  102 . 
     Still referring to  FIG. 2 , the conduit  112  has a first portion  212  and a second portion  214 . The first portion  212  of the conduit  112  is disposed in the internal cavity  208  of the casing  102 . The second portion  214  of the conduit  112  passes from the internal cavity  208  of the casing  102  through one of the apertures  110  in the casing  102  and extends externally of the casing  102 . The wire  114  (shown in dotted lines where obstructed from view) passes through the inside of the conduit  112 . Similarly, the second conduit  113  has a first portion  213  and a second portion  215  with the first portion  213  disposed in the internal cavity  208  of the casing  102  and the second portion  215  passing from the internal cavity  208  through one of the apertures  110  and extending externally of the casing  102 . The second wire  115  passes through the inside of the second conduit  113 . The conduits  112 ,  113  can be of different lengths and/or diameters. For example, the conduit  112  can extend from the power source  116  to the pole connector  106 . By way of further example, the second conduit  113  can extend from the receiver to the pole connector  106 . In another example, the conduit  112  can extend from the power source  116  through the soil  104 , the aperture  110 , the internal cavity  208  of the casing  102  and an interior passage in the pole  108  to the street light  118 . 
       FIG. 3  shows the casing  102  disposed in part in a hole  302  in the soil  104 . The casing  102  is substantially vertical. The hole  302  has an interior surface  304  facing the casing  102 . A gap  306  is defined between the exterior surface  202  of the casing  102  and the interior surface  304  of the hole  302 . Each aperture  110  in the casing  102  fluidly communicates the internal cavity  208  with the gap  304 . Concrete  308  is disposed inside the internal cavity  208  and inside the gap  304  and completely fills the internal cavity  308  and the gap  304 . It is contemplated that other substances having at least some concrete could be used, such as high early strength concrete. For example, it is contemplated that for some applications only high early strength concrete could be used. In this figure, the second conduit  113  (not visible) is behind the first conduit  112 . 
     In the embodiment shown in  FIG. 3 , the pole connector  106  is connected to the upper end  204  the casing  102 . In alternative embodiments, the pole connector  106  can be attached to the side of the casing  112 . By way of further example, the pole connector  106  can be connected to an upper portion of the casing  112  other than the upper end  204 . The pole connector  106  connects the pole  108  to the casing  102  such that the pole  108  is supported in an upright (i.e. vertical) position (see  FIG. 1  for example). 
     More specifically, the pole connector  106  connects the upper end  204  of the casing  102  to a bottom end  312  of the pole  108 . When the pole  108  is connected to the casing  102  using the pole connector  106 , the pole  108  stands upright and is supported by foundation  100 . 
     According to an alternative embodiment, the gap  304  and the internal cavity  208  are only partially filled with concrete  308 . For example,  FIG. 4  shows the casing  102  disposed in part in a hole  302  in the soil  104  with the majority of the volume of the gap  304  and the internal cavity  208  filled with concrete  308 . In one embodiment, the concrete  308  requires a relatively low twenty-eight day strength of 15 to 20 MPa given that its function is to provide incompressible fill material around and up through the casing and be impervious to water and contains an air entraining agent. In another embodiment, the substance is quick setting high early strength concrete  308  in order to facilitate “next day” installation of the pole  108  to be attached to the top of the casing  102 . 
       FIG. 5  is a close-up view of an embodiment of the pole connector  106 . The pole connector  106  comprises a number of nut and bolt attachments  502 , which themselves comprise nuts  504  and bolts  506 . The nut and bolt attachments  502  attach the pole  108  to the casing  102  such that the angle of the pole  108  relative to the soil can be altered by adjusting one or more of the nut and bolt attachments  502 . For example, the nuts  504  that secure the pole  108  to the bolt  506  can be adjusted in order to adjust the positioning of the pole  108  on the bolt  506 . This results in a corresponding adjustment in the angle of the pole  108  relative to the casing  102 . 
     The pole connector  106  further comprises a plate at the top end  204  of the casing  102 . The plate has a central aperture and a number of smaller apertures around the exterior of the central aperture. The smaller apertures receive the bolts  506  so that when the plate is on the top end  204  of the casing  102  one end of the bolt  506  extends into the internal cavity  208  and the other end of the bolt  506  extends upward to attach to the pole  108 . When the internal cavity  108  filled with concrete  308  the bolt  506  is partially immersed in the concrete  308 . When the concrete  308  hardens the bolts  506  become secured in the concrete and thus secured to the pole  108 . The bottom end  312  of the pole  108  has a flange  180  that is connected to the pole  108 . The flange  180  has apertures that receive the bolt  506  so as to fasten the pole  108  to the casing  102 . 
     It is recognized that there can be other types of pole connectors  106  for connecting the pole  108  to the casing  102 . For example, the pole connector  106  can be a flat plate defining an aperture. The pole  108  can be secured within the aperture of the plate with the plate attached to the casing  102  such that the pole  108  aligns with the casing  102 . The pole connector  106  can be integral with the casing  102  or with the pole  108 . By way of further example, the pole connector  106  can be disposed in the aperture  210  at the upper end  204  of the casing  102 . Different types of poles  108  can be attached to the casing  102  using the pole connector  106 . 
       FIG. 6  shows a section of the pole  108 . The pole  108  includes an access cover  602 , brackets  604  and nut and bolt  606 . The street light  118  is attached to the pole  108  by the nuts and bolts  606  of one of the brackets  604 . There can be additional brackets  604  on the pole  108  at different heights depending on the desired placement of the street light  118  or other electrical component. More than one electrical component can be supported by the pole  108 . 
       FIG. 7  is a flow chart showing a method  700  for installing a pole and foundation assembly  101  of the type described above. 
     At step  702  a hole  302  is formed in the soil  104 . The hole  302  can be manually dug into the soil or formed by a machine such as an auger. The hole  302  is sized to receive the casing  102  in a spaced relationship to define a gap  306  between the exterior surface  202  of the casing  102  and the interior surface  304  of the hole  302 . The hole  302  is complimentary in shape to the casing  102  so that the casing  102  can fit into the hole with a substantially uniform space (or gap  304 ) surrounding the casing  102  between the interior surface  302  of the hole and the exterior surface  202  of the casing  102 . It is contemplated that the shape of the hole  302  could differ from the shape of the casing  102 . 
     At step  704  the casing  102  is placed in the hole  302  in the spaced relationship. The casing  102  is placed vertically in the hole  302  so that the open top end  210  is accessible from above the ground  104 . It is contemplated that the top of the casing  102  can be flush with the surface of the ground  104  or slightly above in order to protect the pole base from accumulating water or ice. 
     At step  706 , the concrete  308  is placed (or poured) into the open end  210  of the casing  102  such that the concrete  308  fills at least a majority of the internal cavity  208  of the casing  102 . Before the concrete  308  is placed into the casing  102 , the casing  102  can be straightened so that it is substantially vertical. 
     As the concrete  308  is placed into the casing  102 , it flows from the internal cavity  208  into the gap  304  via the apertures  110 . In this way the concrete  308  that is placed into the internal cavity  208  of the casing  102  fills both the internal cavity  208  and the gap  304  at the same time (step  708 ). The concrete  308  is placed into the open end  210  such that it fills all of the voids in the gap  304 . In an alternative embodiment, the substance  308  is placed directly into the gap  304  and directly into the internal cavity  208 . The concrete  108  is placed such that it completely fills the gap  304  and the internal cavity  208  thus preventing moisture from entering into the internal cavity  208  of the casing  102 . 
     The next step, shown at  710 , is to wait for the concrete  308  to harden sufficiently. This can take twelve hours or more. When the concrete  308  hardens, the casing  102  is secured in the hole in the ground  104  thereby forming a foundation for the pole  108 . 
     At step  712 , the pole  108  is secured to the pole connector  106 . During this step  712 , prior to securing the pole  108  to the pole connector  106 , the wires and cables  114 ,  115  extending from the internal cavity  208  through the open end  210  are connected to the street light  118  (or other electrical component) and the antenna  124  respectively. 
     The method  700  of installing a pole and foundation assembly  101  explained above takes about two days to complete. Steps  702  to  708  are done on one day. The concrete hardens overnight (step  710 ). On the following day the pole  108  is secured to the casing  102  (step  712 ). 
     The determination of the length, diameter and thickness of the casing  102  that should be used, the size of the hole and the amount and type of concrete  308  to use is dependent on the size of the pole  108  and the load applied to the pole  108  (e.g. the weather, the number and type of components attached to the pole  108  and whether an antenna  124  is attached to the pole  108 ). Further, the type of soil in the ground is also a consideration when selecting the properties of the foundation and pole assembly  101 . 
     It is understood that the concrete  308  fills the internal cavity  208  and the gap  304  and serves only as an incompressible fill material that is impervious to water. The insertion galvanized steel section (i.e. the casing  102 ) serves as the structural foundation and facilitates conduits that may be required to enter below grade and exit up thru the surface of the interior (to facilitate flexible electrical and/or transmission lines required to be installed inside the pole section above grade). The casing  102  defining the internal cavity  208  represents the primary structural component of the foundation design. 
     Modifications and improvements to the above-described embodiments of the present invention may become apparent to those skilled in the art. The foregoing description is intended to be exemplary rather than limiting. The scope of the present invention is therefore intended to be limited solely by the scope of the appended claims.