Piling

Claim 3

A method as in claim 1, said tip being tapered to increase in diameter from the bottom upwards, the maximum horizontal cross-sectional area of the tip being about 5 to 15 times the cross-sectional area of the stem, the taper being less than about 3 inches per foot and the axial height of said tip being at least about 2 feet.

Claim 4

A method as in claim 2 in which the depth of said cavity is 3/10 to 7/10 of the axial height of the tip, and in which said cavity is lined with thin corrugated tubular metal shell, said stem being of thin corrugated tubular metal shell whereby said poured concrete is surrounded by said corrugated metal shell within said cavity and within said stem.

Claim 5

A method as in claim 1 in which said tubular stem is a thin metal shell incapable of withstanding the pile driving blows needed to force said pile to its driven load carrying position and the tip having a cross-sectional area which is at least twice, and up to 15 times, the cross-sectional area of the stem.

Claim 6

A method as in claim 1 in which said pile is driven until the resistance to the driving force indicates that the desired load bearing capacity is attained, said bearing layer being loose granular soil having an N value of less than 30.

Claim 7

A method as in claim 4, in which said pile is driven until the resistance to the driving force indicates that the desired load bearing capacity is attained, said bearing layer being loose granular soil having an N value of less than 30, said tip being tapered to increase in diameter from the bottom upwards, the maximum horizontal cross-sectional area of the tip being about 5 to 15 times the cross-sectional area of the stem, the taper being less than about 3 inches per foot and the axial height of said tip being at least about 2 feet, the depth of said cavity being 3/10 to 7/10 of the axial height of the tip, said poured concrete is surrounded by said metal shell within said cavity and within said stem, the axial height of said tip being less than one-third of the overall height of said pile.

Claim 8

A method as in claim 4 in which said tip has a diameter of about 24 inches at its base, a diameter of about 30 inches at the top, an axial height of about 60 inches and a taper of about three-fifths inch per foot and said stem has a diameter of about 14 inches, and the depth of said socket is about 0.4 to 0.6 of the height of the tip, the ground-engaging surfaces of said tip being of smooth concrete, said tip having a circular cross-section.

Claim 9

Process as in claim 1 in which said hammer is driven at 50 to 120 blows per minute with a pile driving energy of above 15,000 foot pounds per blow.

Claim 10

A method as in claim 1 in which said cavity extends down, from a level at which the horizontal cross-sectional area of said tip is substantially at its maximum, for a distance which is at least three-tenths of the axial height of the tip and less than seven-tenths of that height, said cavity being lined with a central tubular liner rigidly embedded in the concrete of said tip, said mandrel extending into and having its lower portion housed in said cavity to align said tip and stem during the driving of said pile, said liner and said stem being of corrugated tubular metal.

Claim 11

A method as in claim 9 in which said unitary body of hardened concrete is in contact with, and conforms to, the corrugations of said liner and said stem and said hammer is driven at 50 to 120 blows per minute with a pile driving energy of above 15,000 foot pounds per blow, and in which the pile is driven until the resistance to the driving force indicates that there is adequate load bearing capacity, said loose granular soil having an N value of less than 30.

Claim 12

A load-carrying pile in place in the ground, comprising a metal tube attached to a tip of pre-cast reinforced concrete having a substantially flat base and a central cavity aligned with said tube, said tube extending into said cavity, the base of said central cavity being spaced above the base of said tip so that between said bases there is a mass of the concrete of said tip of sufficient strength to receive and transmit the pile-driving forces needed to force said tip and tube to the fully driven load-carrying position, and a body of concrete, emplaced after said tip and tube have been forced to said position, filling said cavity and extending up into said tube above said tip, said body having a structure unstressed by said driving, said tip being tapered to increase in diameter from the bottom upwards, the maximum horizontal cross-sectional area of the tip being at least twice, and up to 15 times, the cross-sectional area of the tube, the taper being less than about 3 inches per foot and the axial height of said tip being at least about 2 feet, said pile extending through non-bearing soil to a bearing layer of loose, granular soil, said layer having an N value less than 30, said tip being embedded in said loose granular soil which has been compressed by the driving of said tip thereinto.

Claim 13

A load-carrying pile in place in the ground, comprising a metal tube attached to a tip of pre-cast reinforced concrete having a substantially flat base and a central cavity aligned with said tube, said tube extending into said cavity, the base of said central cavity being spaced above the base of said tip so that between said bases there is a mass of the concrete of said tip of sufficient strength to receive and transmit the pile-driving forces needed to force said tip and tube to the fully driven load-carrying position, and a body of concrete, emplaced after said tip and tube have been forced to said position, filling said cavity and extending up into said tube above said tip, said body having a structure unstressed by said driving, said tip being tapered to increase in diameter from the bottom upwards, the maximum horizontal cross-sectional area of the tip being at least twice, and up to 15 times, the cross-sectional area of the tube, the taper being less than about 3 inches per foot and the axial height of said tip being at least about 2 feet, said pile extending through non-bearing soil to a bearing layer of loose, granular soil, said layer having an N value less than 30, said tip being embedded in said loose granular soil which has been compressed by the driving of said tip thereinto.

Claim 14

A pile as in claim 11 in which said tube is incapable of withstanding the pile driving blows needed to force said pile to its driven load-carrying position.

Claim 15

A pile as in claim 12 in which said tube is of corrugated metal shell.

Claim 16

A pile as in claim 11 in which the base of said tip has a diameter of at least 8 inches, and the depth of said cavity is at least three-tenths and less than seven-tenths of the axial height of said tip.

Claim 17

A pile as in claim 11 in which the axial height of said tip is less than one-third of the overall height of said pile.

Claim 18

A pile as in claim 12 in which the base of said tip has a diameter of at least 8 inches, and the depth of said cavity is at least three-tenths and less than seven-tenths of the axial height of said tip, and the axial height of said tip is less than one-third of the overall height of said pile.

Claim 19

A pile as in claim 16 in which said tip has a diameter of about 24 inches at its base, a diameter of about 30 inches at the top, an axial height of about 60 inches and a taper of about three-fifths inch per foot and said tube has a diameter of about 14 inches, and the depth of said socket is about 0.4 to 0.6 of the height of the tip, the ground-engaging surfaces of said tip being of smooth concrete, said tip having a circular cross-section.

Claim 20

A pile as in claim 11 in which said cavity has a depth of 3/10 to 7/10 of the axial height of said tip, the depth being measured downward from the level at which the horizontal cross section of the tip reaches its maximum.

Claim 23

Process as in claim 19, said cavity having a depth of at least three-tenths of the axial height of said tip, said depth being measured downward from the level at which the horizontal cross section of the tip is a maximum.