Piling

Abstract

A pile comprising a hollow steel bottom portion of convex polygonal cross-section having at least four substantially equal sides. This bottom portion is driven into the ground and is then filled with concrete.

We claim:  
     
         1 . A pile comprising a hollow uniformly tapered steel body constructed and arranged to be the lower, soil-penetrating portion of a driven pile, said tapered body having a cross-section, taken perpendicular to a longitudinal axis, which is a convex polygon having 8 to 24 sides, said sides being substantially equal in length, said body being about 3 to 13 meters long, having a lower diameter which is about 200 mm to 400 mm and a larger upper diameter which about 300 mm to 600 mm and being of steel about 5 to 13 mm thick formed from a unitary sheet folded into said tapered polygon shape and having its longitudinally extending free edges welded together, said body having a closure at its bottom to substantially prevent ingress of the soil into said body during the driving of the pile.  
     
     
         2 . A pile as in  claim 1 , said polygon being a substantially regular polygon.  
     
     
         3 . A pile as in  claim 2 , the very top of said body being formed to a circular cross-section such that said top can engage with, match and be butt-welded to the end of a straight pipe of corresponding circular cross-section.  
     
     
         4 . A driven pile in place in the ground, said pile having at its lower end the body of  claim 1  filled with concrete.  
     
     
         5 . A pile as in  claim 3  having a pre-stressed pre-cast concrete pile section of larger cross-sectional area than said top spliced to said top.  
     
     
         6 . A pile as in  claim 3  having a pipe of circular cross-section substantially the same as said circular cross-section of said hollow body butt-welded to said very top, said pipe having a top portion which is spliced to a pre-stressed pre-cast pile section of larger cross-sectional area than that of said pipe circular cross-section.  
     
     
         7 . A pile comprising a bottom portion which is a hollow uniformly tapered steel body having a cross-section, taken perpendicular to a longitudinal axis, which is a convex polygon having at least 4 sides, said sides being substantially equal, said hollow body being filled with concrete, the top of said hollow body carrying a first connector constructed and arranged to firmly couple said bottom portion to a pre-cast concrete pile section resting on said bottom portion in axial alignment with said bottom portion, said first connector having anchoring rods secured thereto and extending downwardly into, and bonded to, said concrete filling.  
     
     
         8 . A pile as in  claim 6  and including a pre-cast pile section resting on said bottom portion and having at its lower end a second connector which is coupled to said first connector, said connectors including a male cap presenting an axially extending projection of less diameter than that of said top and a female cap presenting an axially extending depression for receiving said projection, said projection and depression having opposed grooves forming therebetween a locking passage and a rod in said passage locking said male and female caps together.  
     
     
         9 . A pile having a uniformly tapered hollow steel bottom portion having a cross-section, taken perpendicular to a longitudinal axis, which is a convex polygon having at least four sides, said sides being substantially equal in length and, resting on said tapered portion, a straight steel pipe having a cross-section, taken perpendicular to a longitudinal axis, which is circular, the very top end of said tapered bottom portion being formed to a circular cross-section of substantially the same diameter as, and matching with, the cross-section of said pipe and the bottom end of said pipe being butt-welded to said top of the hollow tapered bottom portion so that the load transfer from said pipe to said bottom portion is made by continuous bearing of said pipe and said bottom portion, said pile being filled with concrete, the top of said pipe carrying a first connector constructed and arranged to firmly couple said straight portion to a pre-cast concrete pile section resting on the top of said pipe in axial alignment with said straight pipe, said first connector having anchoring rods secured thereto and extending downwardly into, and bonded to, said concrete filling in said pipe.  
     
     
         10 . A pile as in  claim 8  and including a pre-cast pile section resting on said pipe and having at its lower end a second connector which is coupled to said first connector, said connectors including a male cap presenting an axially extending projection of less diameter than the top of said pipe and a female cap presenting an axially extending depression for receiving said projection, said projection and depression having opposed grooves forming therebetween a locking passage and a rod in said passage locking said male and female caps together.  
     
     
         11 . Process which comprises driving the body of  claim 1  into the ground by hammer blows transmitted to said very top of circular cross-section and filling said body with concrete.  
     
     
         12 . Process as in  claim 11  and including the step of attaching to said top a straight precast concrete pile section and continuing the driving of the resulting composite pile into the ground.  
     
     
         13 . Process as in  claim 12  in which said uniformly tapered steel body is filled with wet concrete after being driven into the ground, applying to the top of said body a first connector constructed and arranged to firmly couple said body to said pre-cast concrete pile section, said first connector having downwardly directed anchoring rods secured thereto so that said rods become embedded in the wet concrete, and allowing said wet concrete to harden in anchoring contact with said rods before said continuing of said driving.  
     
     
         14 . Process as in  claim 11  in which a straight steel pipe of circular cross-section substantially the same as said circular cross-section of said hollow body is butt-welded to said very top, the resulting composite pile is driven into the ground and filled with wet concrete and a first connector constructed and arranged to firmly couple said pipe to a straight pre-cast concrete pile section is applied to the top of said pipe, said first connector having downwardly directed anchoring rods secured thereto so that said rods become embedded in the wet concrete, and said wet concrete is allowed to harden in anchoring contact with said rods.  
     
     
         15 . A pile as in  claim 1  in place in the ground, said pile having been driven only until said tapered body is largely embedded in, and supported by, cohesive soil.  
     
     
         16 . A pile as in  claim 15  in which said cohesive soil is over-consolidated clay.  
     
     
         17 . A structure supported by piles, said supporting piles comprising a pile as set forth in  claim 15 .  
     
     
         18 . A structure as in  claim 17  in which said cohesive soil is over-consolidated clay.  
     
     
         19 . Process which comprises driving a pile as set forth in  claim 1  into the ground until said tapered body is largely embedded in cohesive soil, stopping said driving, and than building a structure supported by said pile while said tapered body is so embedded.