Abstract:
A method for installing a foundation in a ground for supporting a structure thereon, the method comprising the drilling of a main column borehole in the ground along an axis parallel to an axis of a force exerted by a load of the structure, inserting a main column into the main column borehole, drilling at least one anchor borehole at an angle away from the main column, inserting an anchor into each of the at least one anchor borehole, injecting a sealant into each of the at least one anchor borehole, after the sealant is dry securing a base to a top of the main column, securing to the base and placing under tension each anchor inserted into each of the at least one anchor borehole, the tension being such as to counteract radial forces to be induced by the structure to a longitudinal axis of the main column.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefits of U.S. provisional patent application No. 62/333,601 filed on May 9, 2016, which is herein incorporated by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates to a foundation for the support of a structure and method of installation. More specifically, the present disclosure relates to a foundation for supporting load support structures such as electrical transmission towers. 
       BACKGROUND 
       [0003]    Installing foundations for securing load support structures, for example electrical transmission towers, in soft soil can be impractical and expensive as common techniques are very labor intensive. 
         [0004]    Accordingly, there is a need for an anchoring base and method of installation that alleviates those disadvantages. 
       SUMMARY 
       [0005]    It is a main advantage of the disclosed foundation and method of installation to provide for an efficient way to securely put in a foundation for the support of a structure in soft soils. 
         [0006]    In order to do so, the foundation consists in a main column and one or more anchors held together by a base. 
         [0007]    The foregoing and other objects, features, and advantages of this foundation will become more readily apparent from the following detailed description. 
         [0008]    Accordingly, there is provided a method for installing a foundation in a ground for supporting a structure thereon, the method comprising: 
         [0009]    a) drilling of a main column borehole in the ground along an axis parallel to an axis of a force exerted by a load of the structure; 
         [0010]    b) inserting a main column into the main column borehole; 
         [0011]    c) drilling at least one anchor borehole at an angle away from the main column; 
         [0012]    d) inserting an anchor into each of the at least one anchor borehole; 
         [0013]    e) injecting a sealant into each of the at least one anchor borehole; 
         [0014]    f) letting the sealant dry; 
         [0015]    g) securing a base to a top of the main column; 
         [0016]    h) securing to the base and placing under tension each anchor inserted into each of the at least one anchor borehole, the tension being such as to counteract radial forces to be induced by the structure to a longitudinal axis of the main column. 
         [0017]    There is also provided a method as described above, wherein the main column borehole is drilled into a bedrock under the ground to a depth such as to support the load or such that a soil composing the ground is sufficiently dense so as to support the load. 
         [0018]    There is further provided a method as described above, wherein the main column is selected from a group consisting of a hollow tube, a solid cylinder and an H-beam. In the case where the main column is hollow, the method further comprises filling the main column with a dense and incompressible material, thereby increasing the compressive strength of the main column. The clearance between the main column and a wall of the main column borehole may also be filled with a sealant. 
         [0019]    There is still further provided a method as described above, wherein the at least one anchor borehole is drilled into a bedrock under the ground to a depth so as to support the tension for counteracting the radial forces induced by the structure or such that a soil composing the ground is sufficiently dense so as to support the tension for counteracting the radial forces induced by the structure. 
         [0020]    There is also provided a kit for installing a foundation in a ground for supporting a structure thereon, the kit comprising: 
         [0021]    a main column; 
         [0022]    a base configured to be secured to a top end of the main column and to support the structure; 
         [0023]    at least one anchor; and 
         [0024]    a securing element associated with each of the at least one anchor; each securing element being configured to place under tension and secure the associated anchor to the base. 
         [0025]    The main column in the kit may be in the form of a hollow tube, a solid cylinder or an H-beam. The kit may further comprise a tension application mechanism allowing for power to be simultaneously applied on each of the at least one anchor when secured to the base. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0026]    Embodiments of the disclosure will be described by way of examples only with reference to the accompanying drawing, in which: 
           [0027]      FIG. 1  is a top view of the foundation in accordance with an illustrative embodiment of the present disclosure; 
           [0028]      FIG. 2  is a cutaway side elevation of the foundation of  FIG. 1  positioned in the soil; 
           [0029]      FIG. 3  is a close-up detail of  FIG. 2 ; 
           [0030]      FIG. 4  is a cutaway top view of the main column along axis C-C of  FIG. 3 ; and 
           [0031]      FIG. 5  is an isometric view of the base and the anchors; and 
           [0032]      FIG. 6  is a flow diagram of the foundation for the support of a structure installation procedure in accordance with the illustrative embodiment of the present disclosure. 
       
    
    
       [0033]    Similar references used in different Figures denote similar components. 
       DETAILED DESCRIPTION 
       [0034]    Generally stated, the non-limitative illustrative embodiments of the present disclosure provide a foundation for the support of a structure and method of installation. The foundation is used to support load support structures such as electrical transmission towers. 
         [0035]    Referring to  FIGS. 1 to 3 , the foundation  10  in accordance with an illustrative embodiment of the present disclosure is composed of a main column  12  (for example a hollow tube, solid cylinder, H-beam, etc.) for supporting a load F, generally three or more anchors  14  and a base  16  securing the anchors  14  to the main column  12 . Referring more specifically to  FIG. 3 , the anchors  14  are removably secured to the base  16  using respective securing elements  18 , which are configured to secure the anchors  14  at an angle β, measured between the axis  1   a  of the main column  12  and the axis  2   a  of the anchor  14 , and an angle α between each adjacent anchor  14 . 
         [0036]    Referring to  FIG. 4 , the dimensions of the main column  12 , for example diameter d 2  and thickness d 3  in the case of a hollow tube, are determined by the load F to be supported and the length of the main column  12 . Drilling a borehole for the insertion of the main column  12  is performed in the ground  1  along an axis parallel to the axis of the force exerted by the load F (i.e. the main column  12  does not need to be vertical) to a depth c 1  determined by the depth c 2  of the bedrock  3  and the drilling depth c 3  into the bedrock  3  or, alternatively, until the soil  1  is sufficiently dense, so as to support the load F. The borehole diameter d 1  should be large enough to allow insertion of the main column  12 . 
         [0037]    Referring back to  FIG. 3 , in the case where the main column  12  is hollow, its center is filled with a dense and virtually incompressible material  20 , such as a slurry of 30 MPA concrete with expander (for example Intraplast®-N), to increase the compressive strength of the main column  12 . Optionally, the clearance between the main column  12  and the wall of the borehole can also be filled with a sealant  22  such as a slurry of 30 MPA concrete with expander. 
         [0038]    Then, with reference to  FIG. 1 , the anchors  14  are positioned so as to define an angle α between each adjacent anchor  14 . In the illustrative embodiment there three anchors  14  are used, which means that angle α is 120°. It is to be understood that in an alternative embodiment more than three anchors  14  may be used, in which case angle α will be set so that adjacent anchors  14  are all equidistant. In a further alternative embodiment, the angle between adjacent anchors  14  may vary such that anchors  14  are not all equidistant in order to accommodate specific radial forces and/or terrain configurations. Referring to  FIG. 2 , drilling of a borehole for the insertion of each anchor  14  is performed at angle β that is determined by the radial forces induced by the structure to be supported by the base  16 . In the illustrative embodiment angle β is between 15° and 60°. It is to be understood that in alternative embodiments this angle may vary depending on conditions of the soil, specific type of structure to be supported, etc. Furthermore, in the illustrative embodiment angle β is identical for each anchor  14 , however, in alternative embodiments angle β may vary for one or more anchor  14  in order to provide proper tensioning (i.e. stripping force) T of the main column  12 . In a further alternative embodiment, for example when the foundation  10  is used to support an electrical transmission tower, the radial forces may be only generally perpendicular to the electrical lines, the lines themselves acting as anchors. In this case, only two (and exceptionally only one) anchors  14  may be used, each on opposite sides and generally perpendicular to the transmission lines. It is to be understood that the angle between each anchor  14  and the transmission line may vary depending on radial forces and other considerations such as common wind conditions. 
         [0039]    With reference to  FIG. 2 , the drilling depth a 1  for the anchors  14 , composed of the depth a 2  to the bedrock  3  and the drilling depth a 3  into the bedrock  3 , is determined by the depth c 2  of the bedrock  3 , angle β and the drilling depth into the bedrock a 2  necessary in relation to the tension T required for counteracting the radial forces exerted by the structure. Alternatively, the drilling depth a 1  for the anchors  14  may be determined by the depth for which the soil  1  is sufficiently dense so as to support the required tension T. Referring to  FIG. 3 , once the anchors  14  have been inserted into their respective borehole, a sealant  22  is injected, for example as a slurry of 30 MPA concrete with expander. 
         [0040]    Once the sealant  20  is dry, the base  16  is secured at the top of the main column  12 . The design of the base  16  varies according to the structure to be supported, the type of main column  12  used and the number of anchors  14 . After securing the base  16  at the top of the main column  12  (for example by soldering or bolting), each of the anchors  14  is secured using a respective securing element  18  and placed under tension T using a tension application mechanism that allows for power to be simultaneously applied on each anchor  14  along axis  2   a . The tension T to be applied depends on the radial forces to the axis  1   a  (i.e. longitudinal axis) of the main column  12  to be counteracted according to the structure installed to ensure the stability of the main column  12 . 
         [0041]    Referring now to  FIG. 6 , there is shown a flow diagram of the foundation for the support of a structure installation procedure  100  in accordance with the illustrative embodiment of the present disclosure. Steps of the procedure  100  are indicated by blocks  102  to  118 . 
         [0042]    The procedure  100  starts at block  102  with the drilling of a borehole in the ground  1  along an axis parallel to the axis of the force exerted by the load F for the insertion of the main column  12 . The borehole is drilled to a depth c 1  determined by the depth c 2  of the bedrock  3  and the drilling depth c 3  into the bedrock  3  or, alternatively, until the soil  1  is sufficiently dense, so as to support the load F. The diameter of the borehole is such as to be large enough to allow insertion of the main column  12 . 
         [0043]    At block  104 , the main column  12  is inserted into the borehole and, optionally at block  106  in the case where the main column  12  is hollow, its center is filled with a dense and virtually incompressible material  20 , such as a slurry of 30 MPA concrete, to increase the compressive strength of the main column  12 . 
         [0044]    Optionally still, at block  108 , the clearance between the main column  12  and the wall of the borehole is filled with a sealant  22  such as a slurry of 30 MPA concrete with expander. 
         [0045]    Then, at block  110 , boreholes are drilled, at an angle β and spaced apart at an angle α, for the insertion of each anchor  14 . The drilling depth a 1  for the anchors  14 , composed of the depth a 2  to the bedrock  3  and the drilling depth a 3  into the bedrock  3 , is determined by the depth c 2  of the bedrock  3 , angle β and the drilling depth into the bedrock a 2  necessary in relation to the tension T required. Alternatively, the drilling depth a 1  for the anchors  14  may be determined by the depth for which the soil  1  is sufficiently dense so as to support the required tension T. 
         [0046]    The angle β is determined by the radial forces induced by the structure to be supported by the base  16 . In the illustrative embodiment angle β is between 15° and 60°. It is to be understood that in alternative embodiments this angle may vary depending on conditions of the soil, specific type of structure to be supported, etc. In the illustrative embodiment, angle β is identical for each anchor  14 , however, in alternative embodiments angle β may vary for one or more anchor  14  in order to provide proper tensioning T of the main column  12 . 
         [0047]    The angle α between each adjacent anchor  14  is generally set so that adjacent anchors  14  are all equidistant. However, in an alternative embodiment, the angle between adjacent anchors  14  may vary such that anchors  14  are not all equidistant in order to accommodate specific radial forces and/or terrain configurations. 
         [0048]    At block  112 , the anchors  14  are inserted into their respective borehole following which, at block  114 , a sealant  22  is injected, for example as a slurry of 30 MPA concrete with expander. 
         [0049]    Once the sealant  20  has dried, the base  16  is secured, at block  116 , at the top of the main column  12 . The design of the base  16  varies according to the structure to be supported, the type of main column  12  used and the number of anchors  14 . 
         [0050]    Finally, at block  118 , after securing the base  16  at the head of the main column  12 , each of the anchors  14  is secured using a respective securing element  18  and placed under tension T using a tension application mechanism that allows for power to be simultaneously applied on each anchor  14  along axis  2   a . The tension T to be applied depends on the radial forces to the axis  1   a  of the main column  12  to be counteracted according to the structure installed to ensure the stability of the main column  12 . 
         [0051]    The present foundation for the support of a structure and method of installation is applicable when the overburden layer  2  is more than 10 feet before reaching the bedrock  3 . If the bedrock  3  is reached before 10 feet, the same technique applies with a main column  12  but without the anchors  14  as described hereinabove. 
         [0052]    Although the present disclosure has been described with a certain degree of particularity and by way of illustrative embodiments and examples thereof, it is to be understood that the present disclosure is not limited to the features of the embodiments described and illustrated herein, but includes all variations and modifications within the scope of the disclosure as hereinafter claimed.