Patent Publication Number: US-2016230364-A1

Title: Pile coupling for helical pile/torqued in pile

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority to U.S. Patent Application No. 62/112,952, filed Feb. 6, 2015, the entire contents of which are incorporated by reference. 
    
    
     TECHNICAL FIELD 
     This disclosure generally pertains to pile couplings for helical piles or torqued in piles and more specifically to a pile coupling that is configured to better distribute applied torsional loads in use. 
     BACKGROUND 
     Helical or torqued in piles are used in various aspects of construction in order to establish compression or tension resistance in a supporting medium (e.g. soil, rock, etc.). Helical piles, for example, have a helical fighting on a first pile section defined by a pile shaft that is contacted to a surface of the supporting medium. Upon rotation, the helical fighting pulls the first pile section into the supporting medium. After the first pile section has reached a certain depth, a second pile section having a welded or forged coupling, is attached to the first pile section using at least one bolt through formed holes. Rotation of the second pile section applies a torque to the first pile section to continue the rotation and drive the helical pile to a greater depth in the supporting medium. Subsequent pile sections may be sequentially attached to enable the pile to reach a predetermined depth. 
     Conventional pile couplings are forged or welded to one end of the pile shaft and often are inserted into the second pile section within or around the first pile section and then fastened to the previous pile section together by inserting one or more pins through side holes formed in the pile coupling and the first pile section. Unfortunately, the applied torque that is produced during helical pile installation is significant and will cause elongation in the side holes. Further, the torque transfer depends on the weld at the coupling and weld failure is a recurrent problem. Some known pile couplings incorporate an additional forged end which is provided in order to help transfer the torsion load, but this latter feature is expensive to incorporate and involves additional welding. As a result, an improved pile coupling is therefore desired. 
     A pile coupling that would transfer a large portion of the torsional load directly down the pile shaft would advantageous, thereby resisting the torque that is to be resisted by the pins alone. 
     Therefore and according to a first aspect, there is provided a pile assembly comprising a first pile section defined by a first end that is configured for engaging a supporting medium and an opposing second end. A second pile section has a first end engageable with the second end of the first pile section, each of the first and second pile sections having mating end fittings that create an interlocking fit. The pile assembly further includes a sleeve sized to overlay the first and second engaged ends of the first and second pile sections, the sleeve having at least one through hole aligned with at least one corresponding through hole of the first pile section, the at least one through hole being sized for receiving a fastener for securing the sleeve to the first pile section. 
     According to another aspect, there is provided a pile comprising a first pile section defined by a first end that is configured for engaging a supporting medium and an opposing second end and a second pile section having a first end engageable with the second end of the first pile section. A sleeve is sized to overlay the first and second engaged ends of the first and second pile sections, the sleeve having at least one through hole aligned with at least one corresponding through hole of the first pile section, the at least one through hole being sized for receiving a fastener for securing the sleeve to the first pile section and in which the sleeve is defined by a pair of sleeve sections, each sleeve section having a mated fitting at one end that creates an interlocking fit when the sleeve sections are engaged with one another. 
     In each of the above, the mated fittings are defined so as to create an interlocking fit between the pile sections or between the sleeve portions, thereby more effectively distributing an applied torsional load. 
     An advantage realized is that the herein described pile enables greater distribution of an applied torsional load between engaged pile sections, particularly on the fasteners of the pile coupling, thereby ensuring greater reliability and fewer failures or delays. 
     These and other embodiments, features and advantages will become apparent to those skilled in the art when taken in reference to the following more detailed description of various embodiments of the invention in conjunction with the accompanying drawings that are first briefly described. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings illustrate presently preferred embodiments of the invention and together with the general description give above and the detailed description given below, serve to explain the salient features of the invention. 
         FIG. 1  is a partial perspective view of a torqued in pile assembly in accordance with an embodiment, partially assembled, the pile including first and second pile sections with each of the pile sections including mated fittings at engageable ends forming a pile coupling; 
         FIG. 2  is the perspective view of the pile of  FIG. 1 , still in the partially assembled condition, further depicting a sleeve overlapping the engageable ends of the first and second pile sections; 
         FIG. 3  is a sectioned end view of the pile depicting the engaged ends of the first and second pile sections; and 
         FIG. 4  is a perspective view of another torqued in pile made in accordance with another embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     The following discussion relates to a torqued in pile in accordance with certain embodiments. However, the inventive concepts are effective whether the pile is a helical pile having fighting, a bored in pile or a torqued down pile. As shown in  FIG. 1 , a pile assembly  100  is provided that includes a first pile section  102  and a second pile section  114 . Each of the first and second pile sections  102 ,  114  according to this embodiment are defined by hollow pile shafts, each pile section being made from steel, aluminum or other suitable material. The first pile section  102  according to this embodiment includes a driving tip  104  formed at a distal end  106  that is configured to be driven into a supporting surface (not shown) such as soil, rocks, etc. An opposing proximal end  108  of the first pile section  102  includes a first mated fitting  110  that is monolithically formed in a circumference of the proximal end  108 . In the example of  FIG. 1 , the first mated fitting  110  is preferably defined by a set of precision cuts extending monolithically along the circumference that are sized and configured to match those formed as part of a corresponding mated fitting  112  of the second pile section  114 , the latter fitting  112  being formed on the distal end  117  of the second pile section  114 . More specifically and when engaged, the mated fittings  110 ,  112 , as configured, produce or create an interlocking fit between the first and second pile sections  102 ,  114 . The types of cuts and the degree of irregularity of the cuts provided in each mated fitting  110 ,  112  can be varied provided an interlocking fit is created between the pile sections  102 ,  114  (and also any succeeding pile sections (not shown in this view) sequentially added to the second pile section  114 . Preferably, the cuts used to create the mated fittings  110 ,  112  are formed using precision cutting apparatus. The presently depicted version represents the cuts as matching recesses  111  and axial projections  113 , but the formed cuts can be suitably angled and spacially distributed, as needed. 
     According to this embodiment, the proximal end  108  further comprises at least one through hole  116  that extends through the diameter of the first pile section  102 . More specifically and according to this embodiment, two sets of through-holes  116  are present in spaced relation proximate the proximal end  108  of the first pile section  102 . 
     As shown in  FIG. 2 , a sleeve  200  is disposed about the connection point of the first and second pile sections  102 ,  114 . For illustrative purposes, the first pile section  102  and the second pile section  114  are shown in this figure in an un-connected state though the sleeve  200  is attached following their engagement. According to this embodiment, the sleeve  200  is a hollow cylindrical section made from steel, aluminum or other suitable structural material that is sized to axially overlay the proximal end  108  of the first pile section  102  and the engaged distal end  117  of the second pile section  114  as part of the pile coupling. The sleeve  200  further includes at least one set of corresponding through-holes  202 . For purposes of assembly, the sleeve  200  includes two sets of through-holes  202  which are configured and spaced to be aligned with the two sets of through-holes  116  formed on the first pile section  102 . A bolt or other fastening member (not shown) is inserted through each aligned sets of through-holes  116 ,  202 . A weld  204  is used to attach the sleeve  200  to the second pile section  114 . In some embodiments, a second weld (not shown) may also be used to attach the sleeve  200  to the first pile section  102 . 
     In operation and when a torque is applied to the coupled pile assembly  100 , the torsional load is adequately supported by the bolt(s), the weld(s)  204 , as well as the mated pile sections  102 ,  114  due to the inclusion of the sleeve  200  and the interlocking fit created by the mated fittings  110 ,  112 . 
     The interlocking configuration between the first and second pile sections  102 ,  114  provides additional strength and enables better distribution of torsional loads during the pile installation, as shown in the end view of  FIG. 3 . 
     Other embodiments that embody the inventive concepts are possible. A second embodiment is described with reference to  FIG. 4 . For the sake of clarity, the same reference numbers are used for like parts. In this embodiment, a first pile section  102  and a second pile section  114  are provided. Unlike the prior embodiment, the engaged ends of the first pile section  102  and the second pile section do not include mated fittings and in which the ends of the pile sections are maintained in abutting relation. As in the previous embodiment, a sleeve  400  is assembled in overlaying fashion to the first and second pile sections  102  and  114 , respectively. According to this embodiment, however, the sleeve  400  is a hollow substantially cylindrical component that comprises a first sleeve section  401  and a second sleeve section  406 . The first sleeve section  401  includes at least set of through holes  402  and a mated fitting  404  at one end. In this specific embodiment, the first sleeve portion  401  has a pair of spaced sets of through holes  402  that are aligned with the through holes  116  of the first pile section  102  in a manner previously discussed wherein each through hole  116 ,  402  is sized to receive a threaded or riveted connector (not shown). 
     The second sleeve portion  406  has a corresponding mated fitting  408  that engages the mated fitting  404  defined on the engaged end of the first sleeve portion  401  and creates an interlocking fit therebetween, in a manner akin to that between the first and second pile sections  102 ,  114  of the prior embodiment. Preferably, the mated fittings  404 ,  408  are defined by precision cuts monothically made in the circumference at the engaged ends of each sleeve portion  401 ,  406 . In terms of the cuts made, the shape of irregularity of the mated fittings may be varied, with the intent of the formed connection being to transfer torque and relieve the fasteners of the majority of the stress created during installation of the pile as a result of the interlocking fit. The second and first sleeve portions  406 ,  401  are attached to the first pile section  102  and second pile section  114 , respectively, by welds. In operation, the interlocking sleeve portions  401 ,  406  act to better distribute the torsional load applied to the pile sections. 
     PARTS LIST FOR FIGS.  1 - 4   
     
         
           100  pile assembly 
           102  first pile section 
           104  driving tip 
           106  distal end, first pile section 
           108  proximal end, first pile section 
           110  first mated fitting 
           112  second mated fitting 
           111  recesses 
           113  axial projections 
           114  second pile section 
           116  through holes, first pile section 
           117  distal end, second pile section 
           200  sleeve 
           202  through holes 
           204  weld 
           400  sleeve 
           401  first sleeve portion 
           402  through hole 
           404  mated fitting 
           406  second sleeve portion 
           408  mated fitting 
           412  welds 
       
    
     It will be readily apparent that other variations and modification are possible within the inventive ambits of the present invention, and in accordance with the following claims. For example, the pile sections of the first embodiment could be used in concert with the interlocking sleeve portions according to the embodiment according to  FIG. 4 .