US 3289420 A
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Dec. 6, 1966 A. L. GUY BQWAZQ METHOD FOR DRIVING FILES Filed March 18, 1964 2 Sheets-Sheet 1 STEAM HOSE STEAM HAMMER Fl 6- I- NEW SECTION p M WATER CONDUIT 3O INITIAL SECTION INVENTOR.
ARTHUR L. GUY,
HARD PACKED SAND FORMATION Dec. fi, 1966 A. L. GUY
METHOD FOR DRIVING FILES 2 Sheets-Sheet 2 INVENT OR.
ARTHUR L. GUY,
Filed March 18, l964 FIG. 4.
FIG- 35- ATTORNEY.
United States Patent Ofiice 3 189,420 Patented Dec. 6, 1966 3,289,420 METHOD FOR DRIVING PILES Arthur L. Guy, Metairie, La., assignor, by mesne assignments, to Esso Production Research Company, Houston, Tex., a corporation of Delaware Filed Mar. 18, 1964, Ser. No. 352,923 4 Claims. (Cl. 61-535) The present invention generally concerns the construction of drilling platforms and particularly concerns the manner of forming foundations for such drilling platforms.
In driving piles, especially those to be used to carry ofifshore drilling structures, by ordinary hammer means adequate pile penetrations cannot be achieved in dense sands because of the great build-up of end bearing on the piles in the sand formation. Pile driving in such sands often results in premature refusal, particularly for tension or hold-down requirement.
The invention to be described herein overcomes the disadvantages inherent in ordinary pile driving techniques and achieves deep penetrations of piles into dense sand formations with a minimum of pile driving difiiculty.
In accordance with the invention, pilings such as steel tubings or cylinders are driven with a hammer in a conventional way while simultaneously jetting water into the sand into which the piling is driven to reduce the resistance to pile penetration.
A primary object of the invention is to provide an improved method and apparatus for driving piles into dense sands.
The above and other objects and advantages of the invention will be apparent from the following, more detailed description of the invention when taken with the drawings in which:
FIG. 1 is a side elevation of apparatus embodying the invention and illustrating driving of the piles;
FIGS. 2 to 4 are side elevations of a pile to be driven into the underlying sand and illustrating positioning of the jet assembly and its action within the pile in accordance with the method of the invention; and
FIG. 4A is a side elevation of the upper end of FIG. 4 illustrating the driving head and anvil welded to the pile.
In the drawings FIG. 1 shows a barge on which is mounted a platform 11 and a crane 12 from which is suspended a steam hammer 13 used to drive piles 14 into the dense sand formation 15. A zone of less dense sand or mud 16 is located above formation and below water 17 on which water barge 10 floats. One pile has been driven through to refusal and the other pile consisting of an initial pile section 14a and an upper, new pile section 14b is being driven into sand formation 15 by means of a driving head 18 on which is mounted steam hammer 13. The sections of pile are welded together and to driving head 18 as indicated at 19.
FIGS. 2 to 4 show pile section 14a in position for penetration into sand formation 15. In FIG. 3 a jetline assembly 20 is shown arranged in pile section 14a. Assembly 20 includes a hollow, tubular jet-line member 21 provided with an opening 22 at its upper end and perforations 23 adjacent its lower end. Centralizers 24' are arranged along its length to maintain tube 21 upright and centrally positioned within pile section 14a. Cable loops 25 are provided adjacent the upper end of tube 21 to aid in placing it within and removing it from pile 14. One end of a hose 22a is attached to opening 22 and is used to feed water to tube 21. The other end connects to a surface water source which supplies water to tubing 21 from which the water jets through perforations 23 and aids in washing assembly 20 through mud 16 to the tip of pile 14 (see FIG. 3). Hose 22a. is then removed from opening 22 as shown in FIG. 4, which figure also shows the lower end of new pile section 14b welded to the top of pile section 14a and assembly 20 extending through zone 16. Jet-line member 21 penetrates formation 15 as water within piling 14 passes into opening 22 through jet-line member 21 and jets from perforations 23.
FIG. 4A shows driving head 18 including the anvil portion 18a thereof welded to the section of pile 14b. Water fill-up lines 30 and an air line 31 are connected to driving head 18 to supply water or air to the driving head 18 and piles 14. The upper end of head 18 is closed by means of plate 32 positioned below the anvil portion 18a.
In operation, referring particularly to FIGS. 1 and 2, the initial section of pile 14a is welded to driving head 18, and then pile section 14a is driven down to the hard, dense sand formation 15 by means of steam hammer 13. When pile 14a reaches refusal in sands 15, the pile driving hammer 13 is removed from anvil 18a, the weld connection between head 18 and pile section 14a is severed and jet-line assembly 20 with hose 22a connected to it is inserted in the top of pile section 14a and washed down to the tip of the pile by pumping water through hose 22a. Hose 22a is afterwards removed from its attachment to opening 22. Jet-line member 21 is positioned open-ended inside pile section 14a in this manner (see FIG. 4). Then driving head 18 (and anvil portion 18a thereof) is welded to the upper end of a new pile section 1417. Crane 12 then picks up and carries the welded driving head and pile section to the top of pile section 14a where pile section 1412 is welded to it. Then, fill-up lines 30 are connected to driving head 18 and water is pumped into the driving head to fill the pile sections with water to a desired level. An air space 33 is left in driving head 18 and also, if needed, in a portion of pile section 1412 as shown. As water fills the pile sections above jet-line member 21, it will flow into jet-line member opening 22, down through jet-line member 21, and into formation 15 at the tip of the pile (see FIG. 4). A large, hydrostatic pressure is eX- erted on the underlying sand formation 15 by means of this closed hydrostatic system.
As formation 15 at the tip of pile section 14a begins to take water, driving with steam hammer 13 through driving head 18 of the piling is commenced. Resistance to driving of the pile is reduced by the jetting action of the water through the jet-line member 21 which permits additional penetration of the pile. The column of air 33 remains trapped so that the energy of driving is expended to the walls of the pile and not against the-water column inside the pile. Air supply connection 31 is used to replenish the air supply in the event air should be lost or dissipated through the water.
Additional sections of pile are added to achieve the desired pile penetration. To add sections of pile, the driving head is removed by cutting olf its connection tothe last section of pile added. Then, the upper end of the new pile section to be added to the pile is welded to the driving head after which the lower end of the new pile section is welded to the last section of pile added.
Having fully described the nature, method, objects, and advantages of my invention, I claim:
1. A method for driving hollow, tubular pile sections into the ground in a substantially vertical direction in which a driving member adapted to be attached to a hammer is attachable to the upper end of each pile section to be driven and in which said driving member includes a hollow section closed at its upper end and provided with means for supplying water and air to the interior thereof, comprising the steps of:
arranging in a longitudinally extending position in a previously driven pile section a tubular means provided with openings at its upper and lower ends adapted to jet water contained in said piles from 4. A method as recited in claim 3 in which said pile said lower openings; sections are driven into sand formations underlying waattaching a new pile section to said driven pile section; ter in which a more dense formation material underlies attaching said driving member to said new pile section, a zone of less dense material including the steps of:
the interior of said hollow section being in fluid comdriving piling to refusal through said zone of less dense munication with the interior of said new pile section; material prior to the step of positioning said tubular adding water to said pile sections until the level of said means in said piling;
column of water is above the level of the upper openremoving said driving member; and
ing in said tubular means; then after positioning said tubular means in said pile maintaining an air column at least in a portion of the section, circulating Water through the opening in hollow section of said driving member above said the upper end of said tubular means and out the water column; and lower ends thereof to wash said tubular means down then hammering said driving member and said attached said piling to the lower tip thereof through the less pile sections into the ground while simultaneously dense material with the upper open end of said tubujetting Water under hydraulic Pressure into the lar means remaining above the uppermost level of ground through said tubular means. i less dense materiaL 2. A method as recited in claim 1 in which additional sections of piling are added when necessary by discon- References Cited by the Examiner necting said driving member, attachlng a new pile section to said driving member, and then attaching said new UNITED STATES PATENTS pile section to the pile section to which said driving mem- 911,971 2/1909 Gilbreth 61-53.74
ber had been attached. I 955,729 4/ 1910 Welsh 61--53.74 X 3. A method as recited in claim 2 in WhlCl] said water 3 5 01 11 1955 Lacy et 1 175 7 X column is maintained above the level of said tubular means and air is supplied to the interior of said hollow CHARLES OCONNELL Primary Emmi-nan section of said driving member, when necessary, to maintain said air column. JACOB SHAPIRO, Examiner.