Abstract:
A segmented piling system and a process of installing the system for supporting a structure on unstable soil. A first or starter pile segment is driven into the soil adjacent the structure. A connecting rod is inserted into the upper end of the starter pile segment. A second or follower pile segment is placed on the upper end of the starter pile segment, over the connecting rod, and driven into the soil, driving the starter pile segment further into the soil. That step is repeated with additional connecting rods and follower pile segments until the pile (i.e., the combination of pile segments and connecting rods) are driven the desired amount into the soil, whereupon the top of the pile is supportingly connected to the structure.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates, in general, to segmented pre-cast concrete piling systems used for underpinning existing buildings. 
     2. Information Disclosure Statement 
     Pre-cast concrete piles have been in use for the purpose of supporting and/or leveling structures for a number of years. These piles are vertically stacked one upon another and driven into the soil to a point of refusal at which a load bearing capacity may be obtained. These segmented piles, installed properly, provide greater support than a shallow method of underpinning, however, there are problems with the existing art. 
     In unstable soils, there is great potential for upward, downward, and lateral movement. These factors affect the integrity of the pile, as existing segmented piles have no, or very little, lateral support to prevent separation of the pile segments thus causing misalignment, separation of the pile, and loss of support. 
     Another important factor with segmented piling systems is proper alignment during installation. With no, or very little, lateral support between segmented piles using existing procedures, it is difficult to insure proper alignment and prevention of lateral movement during, and after, installation. 
     Knight, U.S. Pat. No. 5,288,175, issued Feb. 22, 1994, discloses a continuously reinforced segmental precast concrete underpinning pile system including a plurality of precast concrete piles and a high strength wire strand joining each of the piles. 
     Willcox, U.S. Pat. No. 5,505,561, issued Apr. 9, 1996, discloses a self-piloting compressible piling system including a plurality of pre-formed pile sections having bores therethrough and adapted to be arranged in end-to-end relation such that the bores are concentrically collinear, an auger plate positioned beneath the lowest of the pile sections, and a tension-bearing cable attached to the auger plate and extending through the bores of the pile sections to load the pile sections and auger plate in compression. 
     Nothing in the known prior art, either singly or in combination, discloses or suggests the present invention. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention is intended for the purpose of repair and prevention of settlement of structures located on unstable soil. The present invention provides proper alignment of segmented piling system during installation, verification of depth during installation, prevention of lateral movement of the piling system during installation and throughout the life of the piling system. The increase in bending strength and lateral support in the piling system results in improved long term structural support for the building being supported. 
     A key concept of the present invention is to provide a system including a unique combination of a starter pile segment, a plurality of follower pile segments, and a plurality of connecting rods which allows the pile segments to be driven into the soil one pile segment at a time with each pile segment aligned, collinear and concentric with one another. 
     The present invention relates to a segmented pre-cast concrete piling system used for underpinning existing buildings. The piling system of the present invention provides a continuous connection of components for vertical and horizontal control of the piling itself during installation and throughout the life of the piling. The significant improvement of the present invention over the prior art is the increased lateral support and bending strength of the piling system provided by installation of steel connecting rods interconnecting segmented concrete pilings. The significant increase in bending strength of the piling system provides for improved vertical support of an existing structure. 
     It is an object of the present invention to provide a segmented piling system for underpinning existing buildings, including a plurality of segmented piles with each pile interconnected by connecting rods. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     FIG. 1 is a somewhat diagrammatic, cross-sectional view of the foundation and adjacent features of an existing structure. 
     FIG. 2 is a cross-sectional view similar to FIG. 1 but showing initial steps of the process of installing a segmented piling system of the present invention. 
     FIG. 3 is a cross-sectional view similar to FIG. 2 but showing further steps of the process of installing a segmented piling system of the present invention. 
     FIG. 4 is a cross-sectional view similar to FIG. 3 but showing further steps of the process of installing a segmented piling system of the present invention. 
     FIG. 5 is a cross-sectional view similar to FIG. 4 but showing further steps of the process of installing a segmented piling system of the present invention. 
     FIG. 6 is a sectional view similar to FIG. 5 but view from the front, and showing further steps of the process of installing a segmented piling system of the present invention. 
     FIG. 7 is a front elevational view of a first or starter pile segment of the segmented piling system of the present invention, with portions thereof broken away for clarity. 
     FIG. 8 is a bottom plan view of FIG.  7 . 
     FIG. 9 is a front elevational view of a second or follower pile segment of the segmented piling system of the present invention, with portions thereof broken away for clarity. 
     FIG. 10 is a bottom plan view of FIG.  9 . 
     FIG. 11 is a front elevational view of a first embodiment of a connecting rod of the segmented piling system of the present invention. 
     FIG. 12 is a bottom plan view of FIG.  11 . 
     FIG. 13 is a front elevational view of a second embodiment of a connecting rod of the segmented piling system of the present invention. 
     FIG. 14 is a bottom plan view of FIG.  13 . 
     FIG. 15 is an assembled view of a first or starter pile segment of FIG. 7, a plurality of second or follower pile segments of FIG. 9, and a plurality of connecting rods of FIG.  11 . 
     FIG. 16 is an assembled view of a first or starter pile segment of FIG. 7, a plurality of second or follower pile segments of FIG. 9, and a plurality of connecting rods of FIG.  13 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A first preferred embodiment of the segmented piling system of the present invention is shown in FIGS. 4-6 and  15 , and identified by the numeral  11 . The piling system  11  is designed for supporting an existing building B or other structure on unstable soil S. 
     The piling system  11  includes starter pile segment  13  having a first or lower end  15 , a second or upper end  17 , a longitudinal axis  19  extending between the first and second ends  15 ,  17 , and an aperture  21  in the second end  17  extending along the longitudinal axis  19 . The aperture  21  preferably extends only halfway toward the first end  15  as clearly shown in FIG. 7, etc. The starter pile segment  13  may be constructed in various manners, out of various materials (e.g., concrete, polymer, etc.) and in various sizes and designs as will now be apparent to those skilled in the art. Thus, for example, the starter pile segment  13  is preferably cast or otherwise constructed as a one-piece, integral unit out of standard 7000 psi (pounds per square inch) concrete as a right cylinder approximately 12 inches (30.48 centimeters) in length and approximately 6 inches (15.24 centimeters) in diameter with the aperture  21  being approximately 6 inches (15.24 centimeters) in length and approximately 0.625 inches (1.5875 centimeters) in diameter. 
     The piling system  11  includes at least one and preferably a plurality of follower pile segments  23  for coacting with the starter pile segment  13  to form an elongated pile P. Each follower pile segment  23  has a first or lower end  25 , a second or upper end  27 , a longitudinal axis  29  extending between the first and second ends  25 ,  27 , and an aperture  31  extending along the longitudinal axis  29 . The aperture  31  may include a first aperture or section in the first end  25  of the follower pile segment  23 , and a second aperture or section in the second end  27  of the follower pile segment  23 . However, the aperture  31  is preferably a through aperture that extends completely through the follower pile segment  23  from the first end  25  through the second end  27  as clearly shown in FIG. 9, etc. 
     Thus, the system  11  preferably includes a first follower pile segment  23 ′ for placement on the second end  17  of the starter pile segment  13  (see FIGS. 4-6,  15  and  16 ), a second follower pile segment  23 ″ for placement on the second end  27  of the first follower pile segment  23 ′ (see FIGS. 5,  6 ,  15  and  16 ), perhaps a third follower pile segment  23 ′″ for placement on the second end  27  of the second follower pile segment  23 ″ (see FIGS. 5,  6 ,  15  and  16 ), and additional follower pile segments  23  for being stacked on top of the second follower pile segment  23 ″ and one another with the actual number depending on the desired height or depth of the finished pile P (i.e., how far it is desired to drive or force the pile P into the soil S), which, in turn, depends on the condition of the soil S and the like as will be apparent to those skilled in the art. 
     Each follower pile segment  23  is preferably identical to one another and may be constructed in various manners, out of various materials (e.g., concrete, polymer, etc.) and in various sizes and designs as will now be apparent to those skilled in the art. Thus, for example, each follower pile segment  23  is preferably cast or otherwise constructed as a one-piece, integral unit out of standard 7000 psi (pounds per square inch) concrete as a right cylinder approximately 12 inches (30.48 centimeters) in length and approximately 6 inches (15.24 centimeters) in diameter with the aperture  31  being approximately 12 inches (30.48 centimeters) in length and approximately 0.625 inches (1.5875 centimeters) in diameter. 
     The piling system  11  includes at least one and preferably a plurality of connecting rods  35 , with each connecting rod having a first or lower end  37 , a second or upper end  39 , and a longitudinal axis  41  extending between the first and second ends  37 ,  39 . Each connecting rod  35  is provided for extending between and axially aligning a pair of pile segments  13 ,  23  as will hereinafter become apparent. 
     Thus, the system  11  preferably includes a first connecting rod  35 ′ having a first end  37  for extending into the aperture  21  in the second end  17  of the starter pile segment  13  (see, in general, FIGS. 3 and 15) and a second end  39  for extending into the aperture  31  in the first end  25  of the first follower pile segment  23 ′ (see, in general, FIG.  15 ), a second connecting rod  35 ″ having a first end  37  for extending into the aperture  31  in the second end  27  of the first follower pile segment  23 ′ (see, in general, FIG.  15 ), etc., perhaps a third connecting rod  35 ′″ having a first end  37  for extending into the aperture  31  in the second end  27  of the second follower pile segment  23 ″ (see, in general, FIG.  15 ), etc., and additional connecting rods  35  with each having a first end  37  for extending into the aperture  31  in the first end  25  of a lower follower pile segment  23 , etc., with the actual number of connecting rods  35  depending on number of pile segments  23  used in finished pile P. 
     Each connecting rod  35  is preferably identical to one another and may be constructed in various manners, out of various materials (e.g., steel, polymer, etc.) and in various sizes and designs as will now be apparent to those skilled in the art. Thus, for example, each connecting rod  35  is preferably cut or otherwise formed out of substantially rigid steel rod as a one-piece, integral unit approximately 12 inches (30.48 centimeters) in length and approximately 0.625 inches (1.5875 centimeters) in diameter so as to fit into the apertures  21 ,  31  in the pile segments  13 ,  23  with the lower half of the length of each connecting rod  35  extending into the aperture  21 ,  31  of a lower pile segment  13 ,  23  and with the upper half of the length of each connecting rod  35  extending into the aperture  31  of an upper pile segment  23 . 
     A modified embodiment of the connecting rod  35  is shown in FIGS. 13,  14  and  15 , in which the connecting rod  35  includes a flange  42  positioned half way between the first and second ends  37 ,  39  thereof. The flange  42  may be formed as a integral part of the remainder of the connecting rod  35 , or as a separate piece welded or otherwise secured to the shaft of the connecting rod  35 , etc. 
     The preferred process of installing a segmented piling system  11  for supporting an existing building B or other structure on unstable soil S usually starts with an engineering study to determine the proper number, locations and sizes of piling systems  11  needed for the specific building B on the specific soil S. Next, a hole H is excavated to expose the bottom of the foundation F of the building B at the location it is desired to install a segment piling system  11  (see FIGS.  2 - 6 ). The hole H is excavated beneath the foundation F a distance sufficient to allow a worker to place a jack  43 , or other means for applying force, and at least one pile segment  13 ,  23  (see FIG.  2 ). Once the hole H is excavated, a worker places the starter pile segment  13  in the hole H on the soil S at the spot beneath the foundation F that it is desired to form the pile P. The jack  43  or other such means is placed between the second end  17  of the starter pile segment  13  and the bottom of the foundation F (see FIG.  2 ). The jack  43  may be of various types, etc., but is preferably a pneumatic or hydraulic construction type jack with an electric pump, etc., such as disclosed in Willcox, U.S. Pat. No. 5,505,561, issued Apr. 9, 1996, and in Knight, U.S. Pat. No. 5,288,175, issued Feb. 22, 1994 (see jack  8 ), both of which are hereby incorporated herein by reference. The jack  43  is then activated to drive or force the starter pile segment  13  into the soil S until the second end  17  of the starter pile segment  13  is adjacent the bottom of the hole H. Next, the jack  43  is deactivated to withdraw the jack head  45  away from the bottom of the foundation F, and allow the worker to move the jack  43  from the starter pile segment  13  and insert the first end  37  of the first connecting rod  35 ′ into the aperture  21  in the second end  17  of the starter pile segment  13  (see FIG.  3 ). The worker can then place the first end  25  of the first follower pile segment  33 ′ onto the second end  17  of the starter pile segment  13  with the second end  39  of the first connecting rod  35 ′ being inserted into the aperture  31  in the first end  25  of the first follower pile segment  33 ′ (see FIG.  4 ), whereby the longitudinal axes  19 ,  29 ,  41  of the starter pile segment  13 , first follower pile segment  23 ′ and first connecting rod  35 ′ will be aligned, collinear and concentric with one another. The jack  43  is then placed between the second end  27  of the first follower pile segment  23 ′ and the bottom of the foundation F, and then reactivated to drive or force the combined first follower pile segment  23 ′, first connecting rod  35 ′, and starter pile segment  13  into the soil S until the second end  27  of the first follower pile segment  23 ′ is adjacent the bottom of the hole H. Next, the jack  43  is deactivated to withdraw the jack head  45  away from the bottom of the foundation F, and allow the worker to move the jack  43  from the first follower pile segment  23 ′ and insert the first end  37  of the second connecting rod  35 ″ into the aperture  31  in the second end  27  of the first follower pile segment  13 ′. The worker can then place the first end  25  of the second follower pile segment  23 ″ onto the second end  27  of the first follower pile segment  23 ′ with the second end  39  of the second connecting rod  35 ″ being inserted into the aperture  31  in the first end  25  of the second follower pile segment  23 ″, whereby the longitudinal axes  19 ,  29 ,  41  of the starter pile segment  13 , first follower pile segment  23 ′, first connecting rod  35 ′, second follower pile segment  23 ″, and second connecting rod  35 ″ will be aligned, collinear and concentric with one another. The jack  43  is then placed between the second end  27  of the second follower pile segment  23 ″ and the bottom of the foundation F, and then reactivated to drive or force the combined second follower pile segment  23 ″, second connecting rod  35 ″, first follower pile segment  23 ′, first connecting rod  35 ′, and starter pile segment  13  into the soil S until the second end  27  of the second follower pile segment  23 ″ is adjacent the bottom of the hole H. These steps can be repeated with additional follower pile segments  23  and additional connecting rods  35  until the pile P is driven into the soil S the desired depth or until the pile P reaches a point of refusal (e.g., is driven to solid soil, bed rock, etc.). The jack  43  is then removed from the hole H and a piling cap  47  may be installed on the second end  27  of the last follower pile segment  23  and joined to the bottom of the foundation F with support blocks  49  and/or shim plates  51  if needed to level and support the building B and interconnect all components. The piling cap  47  preferably has an aperture  53  in the bottom thereof so that a connector rod  35  can be used to align and connect the pile P and piling cap  47 . That is, after the pile P is driven into the soil S the desired depth, etc., and the jack  43  is removed or deactivated, the first end  37  of a final or last connector rod  35  is inserted into the aperture  31  in the second end  27  of the final or last follower pile segment  23 , and the piling cap  47  is installed on the second end  27  of the final or last follower pile segment  23  with the second end  39  of the final or last connector rod  35  extending into the aperture  53  in the piling cap  47 . The piling cap  47  and support blocks  49  may be constructed in various manners, out of various materials (e.g., concrete, polymer, etc.) and in various sizes and designs as will now be apparent to those skilled in the art. Thus, for example, the piling cap  47  is preferably cast or otherwise constructed as a one-piece, integral unit out of standard 7000 psi (pounds per square inch) concrete as a block like member having the aperture  53  formed or drilled into the bottom thereof of a size to accept the second end  37  of a rigid rod  35 . Each support block  49  may be cast or otherwise constructed as a one-piece, integral unit out of standard 7000 psi (pounds per square inch) concrete as a block like member. Each shim plate  51  may be machined or otherwise formed out of metal in a typical wedge-like shape for allowing fine adjustment of the connection between the bottom of the foundation F and the top of the pile P as will now be apparent to those skilled in the art. 
     As thus constructed and used, the preferred embodiment of the present invention provides a system and process for installation of segmented piling system for the purpose of supporting a structure in unstable soil, in which: (1) a hydraulic system can be used to drive a concrete starter cylinder below the foundation of the structure being supported, and install a steel connecting rod into the starter cylinder that protrudes above the starter cylinder; (2) the next segmented cylinder is placed upon the connecting rod that protrudes from the starter cylinder and the two cylinders are then hydraulically driven into the soil for a controlled distance; and (3) this process continues until the segmented pile reaches a point of refusal, at which time a connecting rod is placed into the last installed cylinder and a piling cap is installed upon that connecting rod for the purpose of leveling and supporting the structure and interconnecting all components. 
     Although the present invention has been described and illustrated with respect to preferred embodiments and preferred uses therefor, it is not to be so limited since modifications and changes can be made therein which are within the full intended scope of the invention.