Abstract:
Piling, apparatus and methods for pouring a concrete piling in situ around pre-positioned reinforcing rods inside removable hollow pipe sections that have been screwed into the ground. A final coupler pipe section including a removable coupler device is releasably attached to a reducer section and helical screw anchor that are left in the ground. The pipe sections are connected end to end by helical flanges and are screwed into the ground using the helical screw anchor. Once the pipe sections are screwed into the ground to a desired depth, the coupler device is operated to release the coupler section from the reducer section and the coupler device is extracted from the pipe sections. Reinforcing rods are disposed inside the pipe sections and reducer section. Concrete is poured into the pipe sections and reducer section to encase the reinforcing rods. The pipe sections including the coupler section are then removed from the ground and reused.

Description:
BACKGROUND 
   The present invention relates generally to piling apparatus and methods for placing or installing reinforced concrete piles into the ground without utilizing a pile driver or an auger. 
   Pilings are often used to support buildings, bridges, antenna structures, or other structures, for example. Conventionally, reinforced concrete piles are placed in the ground by one of two methods. The first method places a precast reinforced concrete pile into the ground by using a pile driver and hammering the pile into the ground. The second method places a reinforced concrete pile into the ground by drilling a circular hole using an auger, removing the soil, placing a pre assembled circular, for example, steel reinforcing rod cage into the hole and pouring wet concrete into the hole to encase the steel reinforcing rod cage. 
   More particularly, conventional helical pilings typically include one or more helical screw(s) or helices. The shaft is rotated to force the helical screw downwardly into the earth. The piling is screwed downwardly until the screw is seated in a region of soil sufficiently strong to support the load from the structure that it is to support. An additional piling is attached or spliced to a previously screwed piling to increase the depth of the overall piling. To accomplish this, adjacent round or circular ends of the pilings are reconfigured to have a generally square shape with rounded corners. The adjacent ends are configured to have male and female cross-sections so that the piles slide together forming a telescoping joint and are spliced to make a continuous piling. 
   U.S. Pat. No. 6,814,525 issued to Whitsett discloses conventional piling apparatus and installation methods. The Whitsett patent discloses in its Abstract, for example, that an “in-situ pile apparatus includes a helical anchor to which a plurality of elongated generally cylindrically shaped sections can be added. Each of the sections has a specially shaped end portion for connecting to another section. An internal drive is positioned in sections inside the bore of each of the connectable pile sections. The internal drive includes enlarged sections that fit at the joint between pile sections. In one embodiment, the internal drive can be removed to leave a rod behind that defines reinforcement for an added material such as concrete. The rod also allows for a tension rod connection from the anchor tip to an upper portion attachment point.” 
   Conventional composite helical pipe piling apparatus is distributed by MacLean Dixie HFS. This piling apparatus could include reinforcing rods and a concrete core within the steel pipe piles hollow inside, however, the steel pipe piling would remain in the ground. 
   It would be desirable to have a reinforced concrete piling apparatus that may be installed in the ground without requiring a pile driver or an auger. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The various features, functionalities and practical advantages of the present invention may be more readily understood with reference to the following detailed description taken in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which: 
       FIG. 1  is an elevational view of exemplary piling apparatus; 
       FIG. 2  is an enlarged view of a coupler assembly used in the apparatus shown in  FIG. 1 ; 
       FIG. 3  is a plan view of the coupler assembly shown in  FIG. 2  with shear pins not engaged; 
       FIG. 4  is a sectional view of the coupler assembly shown in  FIG. 2  taken along the lines  4 - 4 ; 
       FIG. 5  is a plan view of the coupler assembly shown in  FIG. 2  with shear pins engaged; 
       FIG. 6  is a sectional view of the coupler assembly shown in  FIG. 5  taken along the lines  5 - 5 ; 
       FIGS. 7-9  illustrate installation of exemplary piling apparatus; 
       FIG. 10  illustrates an installed piling comprising j-shaped bolts; and 
       FIG. 11  is an enlarged view of a portion of  FIG. 10  showing the j-shaped bolts in more detail. 
   

   DETAILED DESCRIPTION 
   Disclosed are piling apparatus and methods for installing piling apparatus into the ground without the use of a pile driver or an auger. In accordance with the teachings disclosed herein, a helical screw anchor and coupling device are used to pull pipe sections down into the ground. A preassembled circular, for example, steel reinforcing rod cage is placed into the pipe sections in the ground. Wet concrete is poured into the pipe sections in the ground to encase the steel reinforcing rod cage. The pipe sections are then removed. Removal of the pipe sections from the helical screw anchor is accomplished using the coupling device. 
   Referring to the drawing figures,  FIGS. 1-6  illustrate various views of exemplary piling apparatus  10 . More particularly,  FIG. 1  is an elevational view of exemplary piling apparatus  10 .  FIG. 2  is an enlarged view of a coupler section  20  of the apparatus  10 .  FIG. 3  is a plan view of the coupler section  20  shown in  FIG. 2  with shear pins  44  not engaged.  FIG. 4  is a sectional view of the coupler section  20  shown in  FIG. 2  taken along the lines  4 - 4 .  FIG. 5  is a plan view of the coupler section  20  shown in  FIG. 2  with shear pins  44  engaged.  FIG. 6  is a sectional view of the coupler section  20  shown in  FIG. 5  taken along the lines  5 - 5 . 
   As shown in  FIG. 1 , the exemplary piling apparatus  10  comprises an anchor assembly  11  that includes a helical screw anchor  12  having a plurality of helices ( 12   a ), an extension shaft  13 , a tapered reducer section  14 , and a lower pipe section  15  having a plurality of shear pin holes  16  disposed around its periphery. During use, the anchor assembly  11  is screwed into the ground to a depth such that the shear pin holes  16  are several inches above ground level. 
   The piling apparatus  10  also comprises a coupler section  20 , shown in detail in  FIGS. 2-6 , that includes a coupler pipe section  21  with an inner splice ring  22  attached to the coupler pipe section  21 , and a helical flange  23  attached at its upper end of the coupler pipe section  21 . A coupler  25  is disposed within the coupler pipe section  21 . A short square shaft bar  24  extends from an upper end of the coupler  25  above the helical flange  23 . The short square shaft bar  24  is coupled to the coupler  25  as will be described below. Details of the coupler section  20  are provided with reference to  FIGS. 3-6 . 
   The coupler pipe section  21  is coupled to a pipe section  30  with the standard width helices  32 . The short square shaft bar  24  is coupled to a section of square shaft bar  33  that extends through the pipe section  30 . Additional pipe sections  30  are coupled to the previous pipe section  30  as required. A final pipe section  34  without the intermediate helices is disposed at the upper end of the apparatus  10 . 
   As is shown in  FIGS. 3 and 4 , the coupler pipe section  21  is welded  49  to the splice ring  22 . The coupler  25  comprises a plurality of thrust plate guide plates  41  that are attached to a lower coupler plate  42 . A thrust plate  43  is disposed within the plurality of thrust plate guide plates  41 . A plurality of transversely slidable shear pins  44  are slidably attached to the lower coupler plate  42 . The shear pins  44  are aligned with a corresponding plurality of shear pin holes  45  in the inner splice ring  22 . In addition, the shear pin holes  45  in the inner splice ring  22  align with the shear pin holes  16  in the lower pipe section  15 . Note that any number of shear pins  44  and corresponding shear pin holes  45 ,  16  may be employed. The actual number of shear pins  44  and shear pin holes  45 ,  16  may vary depending on the overall design. 
   The short square shaft bar  24  is attached to a threaded rod  48  that extends through a nut  47  welded to an upper coupler plate  46 . The threaded rod  48  extends through the lower coupler plate  42  and is attached to the thrust plate  43 . A plurality of shear pin slide guides  51  are attached to the lower coupler plate  42  through which the shear pins  44  slide. The shear pins  44  are attached to the upper coupler plate  46  by way of a plurality of shear pin position arms  52 . 
   The coupler pipe section  20  with the coupler  25  and splice ring  22  are placed into the lower pipe section  15  and oriented such that the shear pins  44  in the coupler  25  are aligned with the shear pin holes  45  in the inner splice ring  22  and shear pin holes  16  in the lower pipe section  15 . Horizontal movement of the shear pins  44  is controlled by rotating the threaded rod  48 , which causes the upper coupler plate to lower toward the lower coupler plate and force the shear pins  44  outward, and vice versa. This is illustrated in  FIGS. 3 ,  4 ,  5  and  6 . 
     FIGS. 7-9  illustrate installation of exemplary piling apparatus  10 .  FIG. 10  illustrates installed piling apparatus  10  comprising j-shaped bolts  61 .  FIG. 11  is an enlarged view of a portion of  FIG. 10  showing the j-shaped bolts  61  in more detail. The j-shaped bolts  61  are attached by way of nuts to an extension shaft plate  62  disposed in the reducer section  14 . 
   Details regarding an exemplary procedure or method for installing the reinforced concrete piling apparatus  10  without utilizing a pile driver or an auger is as follows. An assembly comprising the helical screw anchor  12 , extension shaft  13 , reducer section  14  and lower pipe section  15  having a plurality of shear pin holes  16  disposed around its periphery are screwed into the ground to a depth such that the shear pin holes  16  are several inches above ground level. Next the coupler pipe section  20  with the coupler  25  and the splice ring  22  are placed into the lower pipe section  15  and oriented such that the shear pins  44  in the coupler  25  are aligned with the shear pin holes  16  in the lower pipe section  15 . 
   The short square shaft bar  24 , which is welded to the threaded rod  48 , is bolted to a short square shaft female end  33 . The short square shaft bar  24  is then rotated counterclockwise. The counterclockwise rotation of the threaded rod  48  forces the upper coupler plate  46  and welded nut  47  downward which in turn causes the shear pin positioning arms  52  to push the shear pins  44  through the shear pin holes  45 ,  16 . Once the shear pins  44  protrude through the shear pin holes  45 ,  16 , torque may be transmitted through the coupler pipe section  20 . 
   A long section of square shaft bar  33  is then bolted to the short section of square shaft bar  33  and a pipe section  30  with the standard width helices  32  is bolted to the coupling pipe section  20  containing the coupling device  25 . All of the pipe sections  20 ,  30  have helical flanges  23 . This serves two purposes. The first is for splicing of the two pipe sections  20 ,  30 . The second is when the pipe sections  20 ,  30  are required to be removed, counterclockwise torque can be applied to the helical flanges  23  and the pipe sections will “unscrew” themselves out of the ground. 
   The torque required for installation and removal is always applied to the pipe sections  20 ,  30 . Because the helical flanges  23  are typically narrow, approximately 2 inches in width, standard width helices  32  may be required for the removal of the pipe sections  20 ,  30 . The bottom one or two pipe sections  30  may require standard width helices to assist with the surface area needed to back out all of the pipe sections  20 ,  30  being removed. 
   Once all of the square shaft bars  13 ,  24 ,  33  and all of the pipe sections  15 ,  20 ,  30  have been screwed into the ground to a desired depth (see  FIG. 7 ) the square shaft bar  33 ,  24  is rotated clockwise. The clockwise rotation of the threaded rod  48  in the coupling device  25  forces the upper coupler plate  46  and welded nut  47  upward which in turn causes the shear pin positioning arms  52  to pull the shear pins  44  out of the shear pin holes  45 ,  16 , thus releasing all of the pipe sections  30  from the lower pipe section  15 , which is left permanently in the ground. The square shaft bars  33 ,  24  and the coupling device  25  are then pulled up through the pipe sections  30  and set aside. 
   Steel reinforcing rods  65  are then placed into the pipe sections  30  (see  FIG. 8 ). Concrete  66  is then poured into the pipe sections  30  in volumes approximating the length of one or more pipe sections  30 . The pipe sections  30  are removed by “unscrewing” them one-by-one, making certain that the top surface of the wet concrete is always above the bottom helical flange  23  of the bottommost pipe section  30 . This may be done by intermittently adding more concrete until all of the pipe sections  30  have been removed so that the hole previously occupied by the pipe sections is completely filled with wet concrete (see  FIG. 9 ). 
   The resulting concrete piling has a capacity in compression that is based on the friction between the soil and the concrete  66  along the length of the concrete piling plus the bearing capacity of the soil below the helical screw anchor  12 . The concrete piling tension capacity, however, is limited to the friction between the soil and the concrete  66  along the length of the concrete piling. Without an apparatus to provide a tension connection between the helical screw anchor  12  and the concrete piling, there would be no method for transferring the bearing capacity of the soil above the helical screw anchor  12 . 
   An exemplary way to transfer tension from the helical screw anchor  12  to the concrete piling is accomplished by attaching j-shaped bolts to the top side of the welded extension shaft plate.  FIG. 10  illustrates a piling comprising j-shaped bolts, and  FIG. 11  is an enlarged view of a portion of  FIG. 10  showing the j-shaped bolts in more detail. The j-shaped bolts transfer the tension from the concrete piling into a welded extension shaft plate  62  and through the extension shaft  13  into helices  12   a  of the helical screw anchor  12 . 
   Thus, apparatus and methods for placing reinforced concrete piles into the ground without utilizing a pile driver or an auger have been disclosed. It is to be understood that the above-described embodiments are merely illustrative of some of the many specific embodiments that represent applications of the principles discussed above. Clearly, numerous other arrangements can be readily devised by those skilled in the art without departing from the scope of the invention.