Abstract:
The present invention relates to a concrete pile construction method and an apparatus used for improving soft earth ground by constructing reinforced bar concrete pile structures in the earth. The purpose of the present invention is to provide a process for securing firm concrete piles having a reinforced bar core with uniform concrete by means of a pile apparatus in which projections are radially formed and a conical-shaped bit is formed pointedly on said pile apparatus.

Description:
RELATED APPLICATIONS  
       [0001]    This application claims priority to Korean Patent Application No. 2001-0044782, filed on Jul. 25, 2001. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates to a piling apparatus and a process for the purpose of improvement of soft-ground earth in which buildings and marine structures are built thereon.  
         DESCRIPTION OF THE PRIOR ART  
         [0003]    In the prior art, there has been provided injection holes having a desired diameter and depth for constructing a reinforced bar concrete pile in the earth. The purpose of which is to improve the existing soft-ground. In this case, reinforced bars are charged into concrete injection holes, and concrete is injected, filled, and stamped. Finally, through curing, the reinforced bar concrete pile is constructed.  
           [0004]    Until now, Pedestal pile, Franki pile, Beneto pile, Calweld, Reverse circulation method, etc., have been used for forming injection holes for concrete.  
           [0005]    However, there have been problems such as unevenness of an inner peripheral surface of the concrete injection holes, which causes a position of the reinforced bars that are inserted or arranged therein to become irregular and uneven resulting in very low reliability of strength of the concrete pile deposited therein. For this reason, secure and reliable methods and devices for piling construction have been requested.  
           [0006]    Therefore, there is a need in the art to provide a method and an apparatus for reinforcing concrete pile structures in which the reinforced bar is evenly sunk in the soft-ground earth.  
         SUMMARY OF THE INVENTION AND ADVANTAGES  
         [0007]    The pile apparatus of the present invention basically comprises a tube rod having duplicated tubes of concentric circles of large and small diameters, and a conical bit on which diamond shaped projections are formed. The above bit is vertically penetrated in the earth with vibration which is exerted during the concerned piling works. Reinforced concrete bars bundled into a desired shape, is charged into the earth through the space of the smaller diameter inner tube and kneaded concrete is supplied through an injection hose in the desired spot of the earth by vibration. Then, the above pile apparatus is drawn up slowly with vibration, and concrete, injected through the injection hose, fills up spaces and clearances between the projections and inner wall of the pile apparatus. Then, finally the reinforced bar inserted and charged into the earth, is evenly surrounded with homogeneous concrete, and finally it is planted in the solidified concrete. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    [0008]FIG. 1 is a perspective view of an embodiment of an concrete pile apparatus in accordance with the invention.  
         [0009]    [0009]FIG. 2 is a cross sectional view of the concrete pile constructed in the earth, after solidification of concrete injected through an concrete injection hose of the invention.  
         [0010]    [0010]FIG. 3 is a partial view of an opened state of triangle segments each having a triangular shape in the lowest end of the concrete pile apparatus in accordance with the invention.  
         [0011]    [0011]FIG. 4 illustrates conically closing the bit and an end part of each segment which is engaged in the groove formed in the metallic weight at the lowest position of the bit.  
         [0012]    [0012]FIG. 5 is a schematic sectional view of the inside of the bit of the present invention for explaining that each segment can be pivotally jointed and moved in the directions shown, and the reinforced bar is descended to the earth, and thereafter, concrete is injected through the injection hose into the soft ground earth.  
         [0013]    [0013]FIG. 6 is a longitudinal section view of the concrete pile apparatus of the present invention, sunk by vibration of vibrators provided in the projections of the bit, which exerts vibrations successively during the work. This shows that the bit of the pile apparatus is in a closed state in the lowest position.  
         [0014]    [0014]FIG. 7 is a schematic longitudinal section view prior to injection of the concrete through the injection hose. In this case, reinforced bars are inserted in the inner tube fixed in the inner wall of the outer tube of the tube rod, and also are penetrated in the soft-ground earth with vibration.  
         [0015]    [0015]FIG. 8 is a schematic longitudinal section view which shows injecting and filling the concrete to spaces formed in the earth. Then, the apparatus is drawn up slowly soon after the injection of the concrete.  
         [0016]    [0016]FIG. 9 is a schematic and longitudinal section view which shows that the pile apparatus is completely drawn up, and the reinforced bar remains in the solidified pile of the concrete formed in the earth. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0017]    The present invention is described in detail hereunder, referring to the embodiments illustrated in the attached drawings.  
         [0018]    The present invention provides a reinforced bar concrete pile construction apparatus  1  that includes a tube rod  10  and a bit  30  as in FIG. 1, for forming a reinforced bar concrete pile CP. The apparatus will be herein referred to as simply the pile apparatus  1 . The bit  30  includes projections  32  that are radially protruding therefrom. The pile apparatus  1  includes a hollow spaced tube rod  10  on which a grooved channel  12  is inwardly and longitudinally formed along with the outer wall surface thereof. An inner tube  17  is concentrically fixed to an outer tube  11  of the same length, having lattices  18  connected and welded thereto. A concrete injection hose  13  is inserted in the grooved channel  12  and is movable upward and downward in the grooved channel  12 . A door plate  14  is pivotally hinge-jointed  15  for covering the grooved channel  12  and for retaining the injection hose  13 . Latches  16  are attached at the left side of the tip portion of the grooved channel  12  for opening and closing the door plate  14  over the channel  12 . The pile apparatus includes a hanger retaining channel tube  22  disposed between said tube rod  10  and said inner tube  17  inside which a hanger chain  2   a  is connected to a coil spring  23  and a hook  24 . The hanger chain  2   a  is moved like a rope up and down therein. The pile apparatus includes flanges  19 ,  19   a  having a plurality of through-holes (not shown) therein for bolting or securing the tube rod  10  and the bit  30 . An upper metal sheet cover  21  having pitted grooves  20 , and an inclined surface extends from the outer wall of the tube rod  10 . A lower metal sheet cover  21   a  having pitted grooves  20   a  and inclined surfaces extends from the outer wall  31  of the bit  30 .  
         [0019]    The bit  30  defines a hollow space  30   a . The bit  30  on which the projections  32  are formed is to be assembled to the tube rod  10  by the flange fixing means previously described.  
         [0020]    The projections  32  have inclined surfaces that create a symmetrically formed diamond-shape. The projections are positioned on the bit  30  and are symmetrically formed about the bit  30 . Vibrators  33  are included in an inner space of the projections  32 .  
         [0021]    Triangle segments  34  have a triangular shape and are pivotally mounted to the outer wall  31  of the bit  30  by being hinge-jointed to the outer wall  31  of the bit  30 . The triangle segments  34  are attached adjacent to a lower peripheral portion  31   a  of the bit  30 .  
         [0022]    A metal weight  36  includes grooves  37  that are formed in the outer peripheral surface thereof. The metal weight  36  is connected to the hanger chain  2   a  extending to the spring  23  of the hook  24 , for engaging and moving the above said triangle segments  34  at lower end portions of the triangle segments  34 .  
         [0023]    As described above, the concrete pile apparatus  1  includes the hollow tube rod  10  as an upper part and the bit  30  as a lower part, and these parts are fastened and assembled by fastening means such as bolts  3  fastening the flanges  19 , 19   a  of the tube rod  10  and the bit  30 .  
         [0024]    The above tube rod  10 , as in FIG. 1 has the grooved channel  12  which is shaped and formed by drawing and shaping longitudinally, inwardly along with the outer peripheral wall of the tube rod  10 .  
         [0025]    This grooved channel  12  securely embraces the concrete injection hose  13  as in FIG. 1 and FIG. 8. As in FIG. 1, the door plates  14  are placed on the outer peripheral wall of the tube rod  10  at left and right sides of a tip portion of the grooved channel  12  for covering the grooved channel  12 . The door plates  14  include hinge-joints  15  and latches  16  attached at right and left sides of the tip portion respectively and the door plates  14  are opened or closed by the latches  16  thereon. Inside the tube rod  10 , inner tube  17  having a small diameter than that of the outer tube  11 , and having both ends open, is concentrically fixed by the lattices  18  welded to the inner wall of the outer tube  11  of the tube rod  10 .  
         [0026]    On the outer peripheral wall of the lowest portion of the tube rod, the flange  19  having through-holes for fastening the bolts  3  therein, is provided with the pitted grooves  20  in which a spanner for fastening the bolts, can be used. The upper steel cover  21  is attached with some gradient, to the tube rod  10 , and an end portion of the flange  19   a  secured to flange  19  is fixed and engaged with that of the bit  30 .  
         [0027]    On the outer peripheral wall  31  of the bit  30 , projections  32  (there are four projections as an example in FIG. 1) having four inclined surfaces, like diamond-shapes, on the outer wall of the bit, are formed. Each projection  32  thereon is radially protruded for forming a homogeneous structure of the concrete pile in the earth  41 . This pile apparatus in which the bit  30  is installed in the lower end of the tube rod  10 , is descended and piled in the earth, by vibration generated by the vibrators  33 .  
         [0028]    A reinforced concrete bar structure  40  is descended through the inner tube  17  of the pile apparatus  1 , settled in the earth and then, concrete is injected through an injection hose  13  accompanied by continuous vibration, so that concrete is homogeneously mixed and filled in the space of the soft-ground earth created by exertion of the projections  32  having vibrators  33  therein, then the pile apparatus  1  is drawn up from the earth.  
         [0029]    At a lower tip portion of the bit  30 , the triangle segments  34  are positioned in a closed state as shown in FIG. 6 and FIG. 7 when the lower end portions of the triangle segments  34  are engaged in the grooves  37  of the metallic weight  36  thereby forming a conical shaped lower tip portion. The triangle segments  34  can also be positioned in an opened state as shown in FIG. 5 and FIG. 8 when released from the grooves  37  of the metallic weight  36 .  
         [0030]    Each triangle segment  34  that is hinge-jointed to the outer wall  31  of the bit  30  and engaged in the grooves  37  of the metallic weight  36  in the closed state, pivotally moves when opened to the opened state. The triangle segments  34  are released from the metallic weight  36  and swing toward a side wall of the bit  30  when the reinforced bar structure  40  descends downward and engages the triangle segments  34  and the hanging hook  24  is removed from the tube rod  10 . This action releases the tension from the hanging chain  2   a.    
         [0031]    The triangle segments  34  can be released from the grooves  37  of the metallic weight  36  in a number of ways. The hanger chain  2   a  is connected to the metallic weight  36 . Therefore, it is important to release the tension in the hanger chain  2   a  or force the triangle segments  34  from the grooves  37  to release the triangle segments  34  from the metallic weight  36 . In another manner, the reinforced bar structure  40  could be lowered and load the triangle segments  34  thereby pulling the hanger chain  2   a  downward until the triangle segments  34  are released without removing the hanging hook  24 . The reinforced bar structure  40  could also be in place and the triangle segments  34  released as the pile apparatus  1  is ascended upward in much the same manner as previously described. Furthermore, the hanging hook  24  can be removed from the tube rod  10  and slack provided in the hanger chain  2   a  such that when the pile apparatus  1  ascends, the triangle segments  34  are released by gravity and pivot toward the side. In addition, it should be appreciated that any combination or variation of these methods could be used and the manner in which the metallic weight  36  is not intended to limit the present invention.  
         [0032]    Here, after release of the triangle segments  34 , each segment  34  moves to the side wall in the direction shown in FIG. 5 and the hanging hook  24  is moved upward again for its hanging in the upper end of the tube rod  10 , and the metallic weight  36  is engaged upward in the end of the channel tube  22 , by restored elastic power of the coil spring connected to the hanger chain  2   a . Thus, the overall structure of the preferred embodiment of the concrete pile apparatus for movement of the soft-ground earth is described.  
         [0033]    Before practicing concrete pile construction work by the pile apparatus  1  of the present invention, the bit  30  is selected for its diameter and assembled to the tube rod  10  which is suspended by a hanger  2  connected crane, which is done by matching the lower flange  19   a  of the bit  30  and the upper flange  19  of the tube rod  10  by bolting in the pitted grooves  20 ,  20   a.    
         [0034]    The above pile apparatus  1  is to be fully penetrated in the soft-ground earth by driving or descending the pile apparatus  1  to a target level. When it penetrates down to the target level, then the reinforced bar structure  40  of which the bars are bundled with the same length to that of the concrete pile, is charged into the inner tube  17 . Then, it is to be positioned at the bottom of the soft-ground earth from the inner peripheral surface of the inner tube  17 .  
         [0035]    After settlement of the reinforced concrete bar, then concrete is injected with vibration of vibrator  33  and successive vibration is offered on the tube rod  10  and on the bit  30 , and continues when drawing up the apparatus. In this case, the triangle segments  34  are rotatably moved sideward prior to the above operation, and the hanger chain  2   a  is drawn upward through the hanger retaining tube  22  and also the metallic weight  36  is drawn up, as shown in FIG. 8.  
         [0036]    After drawing up the pile apparatus, the hanging hook  24  is manually released from the upper end of the tube rod  10  and the hanger chain  2   a  is drawn downward and the triangle segments  34  are again engaged in the grooves  37  of the metallic weight  36  to be ready to start piling work.  
         [0037]    When the triangle segments  34  are moved from the closed state to the opened state, concrete is discharged through the injection hose  13  and filled in spaces of the soft-ground created by the diamond-shaped projections  32  formed on the outer peripheral surface of the bit  30  and connected to an inner space of the earth created by the remaining portions of the piling apparatus  1 .  
         [0038]    The tube rod  10  of the pile apparatus  1 , inner tube  17  and the bit  30 , is then ascended or drawn upward, and the reinforced bar structure  40  in the inner tube  17 , remains in the inner space of the earth. The concrete C is then discharged from the bit, filled and stamped with vibration in the spaces in the soft-ground earth. In this manner, as illustrated in FIG. 9, the pile apparatus  1  which slowly ascends upward creates a homogeneous concrete pile in which the reinforced bar remains. After the pile apparatus  1  is removed, the reinforced bar concrete pile CP thus formed includes a circular column  40 , and multiple columns of radial protrusions which have smooth and homogeneous load distribution in the pile structure.  
         [0039]    According to the present invention, very homogeneous, secure and strong concrete pile structures, may be obtained and constructed with secured reinforced bars, and stamping of the concrete effected by vibration, may minimize gap and offer fineness and finally enable a strong pile structure.