US2996887A

US2996887A - Core structures for driving and retapping shell type piles

Info

Publication number: US2996887A
Application number: US772515A
Authority: US
Inventors: Willard H Rice; Edward A Smith
Original assignee: Raymond International Inc
Current assignee: Raymond International Inc
Priority date: 1958-11-07
Filing date: 1958-11-07
Publication date: 1961-08-22
Anticipated expiration: 1978-08-22

Description

Aug- 22, 1961 w. H. RlcE ET AL 2,996,887

CORE STRUCTURES FOR DRIVING AND RETAPPING SHELL TYPE PILES Aug' 22, 1961 w. H. RlcE E1' AL 2,996,887

CORE STRUCTURES FOR DRIVING AND RETAPPING SHELL TYPE PILES 725 INVENTORS.

T/V/L 1. ,q/PDH E/CE.

BY E'D WAfPajM/TH.

2396387 CORE STRUCTURES FR DRIVING AND 'RE- TAPPING SHELL TYPE PILES Willard H. Rice, Berkeley Heights, and `Edward A. Smith, Cliatham, NJ., assignors to [Raymond international, Inc., New York, N.Y,, a corporation of New Jersey 'Filed Nov. 7, '1958, Ser. No. '772,515 S Claims. ((Cl. 61-5337) This invention pertans to improvements in core structures utilized for driving piles of the steel shell type, and more especially to such as are assembled in use from various components which are thereafter dis-assembled for shipment.

When the driving piles of the type aforesaid, utilizing a core to support and carry the shell during the driving, the cores heretofore utilized have consisted of heavy steel members joined by various means, such as by the use of screw-threaded male and female joints, or by socket and tenon joints that are locked together by key pieces or pins to secure the joint. The object of such constructions is to permit of assembling shipable lengths in various sizes of cores to make up an assembly of various sizes and/or lengths to suit various pile driving conditions.

The present means of joining these Sections together have proved costly and ineffective, because the driving impact is so great that in the case of the socket and tenon joint connections, the pins elongate and the tenons become loose in their sockets, and, in the case of the screw-threaded connections, the threads deform, and once any looseness, however slight, thus develops, the wear is accelerated. This results in an expensive reconditioning with loss of time on the job and even defective work, because looseness in the joints often results in the pile shell being driven out of Vertical alignment, even to the extent that rejection may be required. 'The present invention in one of its aspects overcomes these defects and disadvantages inherent in the present types of cores for driving piles of the steel shell type. t

Another problem which has confronted the industry with respect to driven piles of the steel shell type, arises when a previously driven pile defiects out of Vertical alignment due to soil shifting and/or when Soil pressures cause prevously driven shells to uplift and thus lose their bearing value. In such cases, it is necessary to re-enter the shell and re-drive or re-tap the pile to its proper original bearing value. In such instances it is often diflicult or impossible to re-enter the shell because of local deformations or lack of Vertical alignment.

At the present time, such piles must be re-driven by means of a flexible driving core that is constructed of Sections of steel tubing connected by ball and socket joints utilizing connecting pins to integrate the assembly. Durng driving, however, these pins pound out rather easily. Also any pin may break and cause the core to fall apart to the hazard of the workmen in the area and also causing considerable amount of lost time. The present invention in another of its aspects provides a flexible type of driving core that cannot fall apart and which is otherwise vastly Superior to existing constructions.

In its basic concept, the present invention provides an assemblable and dis-assemblable core structure comprising in its essentials, a core head, a plurality of tubular core Sections and a core tip, having means for joining said sections end to end between the core head and tip, this means including a cable extending within the core Sections between the core head and tip and secured at its opposite ends to the core head and tip, respectively, in such manner that the cable is highly ten- 'ice sioned or pre-stressed, whereby the cable maintains the various components aforesaid in compressive assembly.

In accordance with the preferred embodiment of the invention for driving shell type piles, the core Sections are provided at their opposite ends vvith complementary socket and tenon terminations for joining, and the core head including an adapter section and the core tip are similarly joined to the assembled core Sections. The cable referred to has anchoring lugs swaged to its opposite ends, which preferably take the form of threaded fittings, one end of which threads into a tapped bore of the core anchor tip while the opposite fitting extends through an axial bore of the core head and is secured thereto by a nut threaded onto the fitting and seating on the upper face of the core head. The pre-stressing of the cable is elfected by means of a hydraulic jack temporarily mounted in the core head, and when the necessary tension has thus been established in the cable, i

the nut referred to is screwed into tight seating engagement with the core head, and the hydraulic jack assembly removed.

In accordance with the preferred flexible core embodiment of the invention, the core structure comprises a series of steel sleeves and interposed driving balls which latter are seated in socket adapters disposed on each side thereof `which in turn are fitted to the adjacent core sleeves by means of socket and tenon joints, this assemblage being interposed between a core tip at the base and a top core adapter and associated cable seat block at the top. This assemblage is held together by a pre-stressed cable which is auchored at its lower end to the core tip in any suitable manner, as by means of a swaged or anchoring lug, and which is secured at its upper end to the cable seat block by means of a swaged or threaded anchoring lug which eXtends through an axial bore of the cable seat block and is secured thereto by a nut threaded thereon and engaging the upper surface of the cable seat block. Pre-stressing of the cable is effected in the same manner as above described, with reference to the first mentioned embodiment of the invention.

Having thus described the invention in general terms, reference Will now be had to the accompanying drawings for a more detailed description, wherein:

FIGURES 1 to 7, inc., illustrate the embodiment of the invention 'first described, comprising the relatively rigid core structure assembly for driving piles of the steel shell type; FIG. 1 being a view in elevation of the assembled core structure; FIG. 2 an exploded view of the FIG. 1 assembly; FIG. 3 a transverse section taken at 3-3 of FIG. 1; and FIGS. 4-7, inc., being an enlarged axial sectional elevation of the FIG. 1 tube assembly. FIGURE 8 is a view in elevation and partly in section of the hydraulic ram assembly for prestressing the cable.

FIGURES 9 to 13, inc., illustrate the fiexible core modification of the invention above mentioned for reseating previously driven defleoted or uplifted shell type piles; FIG. 9 being a view in axial sectional elevation through a driven pile with the flexible core inserted therein for re-seating; FIG. 10 a view in elevation of the assembled core structure itself; FIGS. 11 and 12 enlarged views in axial section showing the essenti'al components of the FIG. 10 core assembly; FIG. 13 a transverse section through one of the drving ball assemblies as taken at 13-413 of FIG. 12; and FIG. 14 a fragmentary perspective view of a portion of the FIG. 10 assembly illustrating the action of the lifting stops associated with the driving balls, ras the 'core structure is being withdrawn 'from the Shell of FIG. 9.

Referring to the FIGS. 1-7, inc., embodiment, a core head 10, is assembled in a socket and tenon joint 11 onto an adapter section 12, comprising an upper section 12a sleeved into a lower section 12b and welded thereto at 120. The adapter section 12 is in turn assembled in a socket and tenon joint 13 onto a tubular core section 14. Locking pins are insertedV as at 13a, in aligned bores of the socket and tenon members of joint l13, these pins being held in place by keeper lwashers, as at 13h, to prevent relative rotation of the adapter and

core Sections

12, 14. Core section 14 has a socket member 14a sleeved into its lower end and welded thereto at 14b. Core section 14 is in turn assembled in la socket and tenon joint 15 onto a second tubular core section 16, having a tenon member '16a sleeved into its upper end and welded thereto at 16h for connecting with the socket member 14a of core section 14. The

core Sections

14, 16 are held against relative rotation by locking pins, as at 16a, inserted in aligned bores of the socket and

tenon components

14a, 16a, these pins being secured by keeper washers as at 16d.

Core section 16 terminates at its lower end in a socket sleeve 168 for pro-viding a socket and tenon connection 17 to a core tip=18, to which end the core tip has sleeved into its upper end a tenon member 18a welded thereto at 18h. To assure a tight fit, the joint 17 is supplemented by a liner sleeve '180. To prevent relative rotation between core Sections 16 and core tip 18, locking pins are inserted, 'as at 18d, 188, in aligned bores of the socket and

tenon members

16a, 18a, these pins being secured by keeper washers, as at l. A core anchor tip 19 of the configuration shown in FIG. 7, is inserted in a complementary recess 20 formed in the base of 'the core tip 18.

In order to hold the FIGS. 4-7, inc., assembly tightly together, a cable 26 extends within the tubular core adapter, core and core tip Sections 12-18, inc., between the core anchor tip 19 and the core head 10, being Secured thereto, respectively, as follows. At its opposite ends the cable 26 has swaged thereto tanchoring lugs 27, 28, the ends of which are externally threaded as at 29, 30, respectively. The threaded end 29 of 'the lower lug 27 is screwed into a threaded bore 31 of the core anchor tip *19. The upper anchoring lug 28 extends through an axial bore 32 of the core head with its threaded end 30 projecting -therethrough as shown, and having a lock nut 33 threaded thereon, which seats on the upper face 34 of the core head as shown. To prevent the threaded connection 29, 31 between the lower anchoring lug 27 and the core anchor tip 19 from slipping or loosening, a locking pin 35 extends through transverse bores of components 19, 27 as shown. At the upper end of the cable 26, a locking pin 36 of bifurcated or clawlike configuration is driven through aligned transverse bores, as at 37, of the core head 10 and adapter section 12 components, the legs of this locking pin spanning the

fiattened faces

38, 39 of the anchoring lug 28. This prevents relative rotation between the core head and

adapter sections

10, 12.

The locking nut 33 threaded onto the .threaded projecting end 30 of the anchoring lug `holds the assembly in the final pre-stressed condition of the cable 26 which is obtained with the apparatus shown in PIG. 8 and in the following manner. In order to pre-Stress the cable 26, a hydraulic jack 40 is mounted on a jack pedestal 41 supported on the core head as shown. The projecting upper threaded end 30 of the upper anchoring lug 28 has threaded thereon a coupling 42, into which is screwed an adapter screw 43. The adapter screw 43 extends through the jack 40, and is provided on its upper projecting end with a thrust washer 44, and a nut 45, the later threaded thereon thus to hold the assembly together. Also the hydraulic jackv 40 acts against this washer 44 and nut 45 during the tensioning operation.

Tensioning is accomplished by applying hydraulic pressure to the jack through inlet 46, by conventional hand pumping means until the pressure gauge shows the proper amount of cable tension. The lock nut 33 is 'then tightened against the core head 10, after which pressure of the hydraulic jack is released. Then the lock nut '45 and 'l washer 44 -are removed, following which the hydraulic jack and

jack pedestal

40, 41 are lifted off. The adapter screw 43 and coupling 42 are unscrewed, thus restoring the assembly to 'the condition shown in FIG. 4. The core assembly of FIGS. l and 4-7, inc., is thus made ready for use, the cable 26 being now tensioned or pre-stressed, maintains the entire core structure in compressive assembly. With the cable thus tensioned, the locking pins, as as 36, 13a, 116c, 1811, hold the various core components against relative rotation as above described, thereby also to prevent relative rotation of the cable extremities, thus to prevent loss of tension due to loosening of the cable.

For utilizing the thus assembled and pre-stressed core assembly for driving the shell type piles, a driving head 50 is imposed on the core head 10 and the core form inserted in a Shell type pile 51 of stepped taper configuration corresponding to that of the core structure as at 52, 53, at which points, driving rings, as at 54, 55, are interposed in the shell assembly, the inner inclined faces of which are engaged by the stepped Shoulders on the core structures, as at 56, 57, for concurrently applying driving force between the core structure and the shell 51 at the successive Stepped-in elevations thereof, the core also applying driving force to the base of the shell, by coaction between the core anchor tip 19 resting on the boot 58 on which the shell pile 51 is pre-assembled.

The advantages of the core construction above discussed are ease and simplicity of assembly, comprising standard and interchangeable parts which can be combined in any way to suit variable job requirements. Also ease of maintenance of components and quick field replacement and/or repair. Also the pre-tensioned assembly is sufficiently strong to assure that the components will remain tight at all times, thereby minmizing wear and repair of core joints. Also there is the added factor of Safety in case of breakage of core sleeves which nevertheless remain together because of the cable.

Referring now to FIGS. 8-14, inc., the flexible retapping core embodiment of the invention thereof, comprises a top core head adapter 60, into which is fitted the upper end of a cable seat block 61, by means of the socket and tenon connection 62 shown. The core head adapter 60 and the cable seat block 61 are fastened together by means of locking pins 63 extending through transverse bores of these components as shown, the locking pins in turn being held in position by means of set screws 64. A steel sleeve 65 is sleeved onto the lower projecting end of the cable seat block 61, as at 66, and held against relative rotation by locking pins inserted in algned bores of these components, as at 66a, the pins being secured by keeper washers, as at 66h.

At is lower end the sleeve 65 is connected by a socket and tenon joint 67 to an upper socket adapter 68, these components also being held against relative rotation by locking pins, as at 68a, secured by keeper washers, as at 681), in the manner above described. Between the socket adapter 68 and a corresponding lower socket adapter 69 there is interposed a driving ball 70, of Spherical Shape as shown. The driving ball is equipped with replaceable driving lugs, as at 72. Mounted on the

socket adapters

68 and 69, are canted guide and lifting stops, as at 72a, 72b, which facilitate entry and withdrawal of the core structure with respect to a driven shell to be re-set.

The lower socket adapter 69 is in turn connected by a socket and tenon joint 73 to the upper end of a steel sleeve 74 like sleeve 65, these components likewise being held against relative rotation by locking pins, as at 74a, secured by keeper washers, as at 741), in the manner above described. The assembly is continued in like fashion as shown in FIG. 10, successively through ball and socket joint 75, sleeve 76, socket joint 77, sleeve 78, socket joint 79, sleeve 80, socket joint 81, sleeve 82, socket joint 83, and sleeve '84, which latter is fitted by a Socket and tenon joint 85, to the core tip 86 at the base of the assembly, these components likewise being held against relative rotation by looking pins, as at 85a, Secured by 'keeper washers, as at 85b.

A Steel cable 90 is threaded through the various components of the assembly passing up the interior of the Steel sleeves Such as 84, '82, '801, etc., as shown, and through axial bores of the socket and tenon joints such as 83, 81, 79, etc., as at 87. The lower end of the cable is forged to a bottom anchor 91, fitted by its taper Shape 92 to a correspondingly tapered bore in the core tip 86. To secure the anchor 91 to the core tip 86, locking screws 93 are threaded thereinto and through a bottom closure cap 94, the latter to prevent damage to the lower cable anchor.

Forged to the upper end of the cable 90, is a top anchor Screw 95, disposed in an aXial bore 96 of the core head adapter 61, anchor screw 95 having threaded thereon a lock nut 97 which seats on the upper face of the cable seat block '61, whereby the cable holds the entire assembly together. Pre-stressing of the cable 90 is elfected in the same manner above described with reference to FIG. 8. For this operation, the core head adapter 60 is removed by removal of the set screws 64 and looking pins 63, and the hydraulc jack assembly of FIG. 8 mounted atop the cable Seat block 61 and the pre-stressing effected as in FIG. 8 whereupon the lock nut 97 is screwed into engagement with the upper face of the cable seat block, the hydraulic jack equipment removed and the core head adapter 60 replaced as shown in FIG. 11. The core structure is now ready for use.

As thus assembled with the cable pre-Stressed, the core Structure is pin connected at the top, as at 100', to a conventional core head 10'1 and pile driving hammer. The unit is then lowered into a previously driven Shell, as at 102, FIG. 9, and each joint slips sufficiently to allow easy entry, by virtue of the guiding action of the lifting stops 72h. Since the Shell 102 is of Stepped taper configuration, the driving lugs 72 of the successive driving balls are adjusted to engage the driving rings, as at 103, FIG. 12, of the Shell 102 at their appropn'ate levels, So that all of the driving balls will concurrently apply driving force to the successive Sections of the Shell in the manner illustrated in FIG. 12, in which the dotted lines Show the driving lug adjustment for engaging a higher level driving ring of the Shell. Upon Seating the bottom closure cap 86 on the boot 104 of the Shell assembly, the hammer drives the pile until it reseats itself in the Soil to the proper load bearing value after which the retapping core is easily withdrawn, by coaction of the upper guide members 72a and lifting stops 72b in the manner illustrated in FIG. 14.

Because of this construction, applicant provides a readily assemblable and dS-assemblable tapping core for 'reentry of a previously driven core which has lost its bearing value due to having been deflected or uplifted. Such a pile may be redriven to its proper bearing value by introducing a flexible core as described herein.

With both embodiments of the invention aforesaid, the pre-Stressed cable by holding all the components of the core structure in compressive assembly, eliminates the necessity for connecting pins at the joints, with resulting disadvantages of the latter above pointed out. It is thus Seen that the core Structures of the present invention are decidedly Superior to those heretofore employed both for driving Shell type piles as well as for re-tapping and re-Seating previously driven piles of this type.

What is claimed is:

1. A core structure for driving Shell type piles, comprising in combination: a core head, a plurality of t-ubular core Sections and a core tip, means joining Said Sections end-to-end between said core head and tip, said means including socket and tenon joints between adjacent core Sections and 'between said core head and tip and the core Sections respectively adjacent thereto, said joining means having longitudinal bores extending therethrough in aligned communication with the interiors of Said tubular Sections, a cable extending Within said tubular core Sections and the bores of Said joining means between Said core head and tip, means Securing the oppo- Site ends of said cable to said core head and tip, respectively, whereby said cable may be placed under a pre- Selected tension to maintain said core head and tip and said core Sections therebetween in compressive assem'bly, and means cooperating with Said socket and tenon joints to prevent relative rotation of Said core head and tubular Sections.

2. A core Structure for driving step-tapered Shell-type piles provided with driving rings, comprising in combination: a core head, a plurality of tubular core Sections formed with driving Shoulders and a core tip, means joining Said Sections end-to-end 'between said core head and tip, Said means including socket and tenon joints between adjacent core Sections and lbetween Said core head and tip and the core Sections respectively adjacent thereto, Said joining means having longitudinal bores extending therethrough in aligned communication with the interiors of Said tubular Sections, 'a cable extending Within Said tubular core Sections and the bores of Said joining means between said core head and tip, means Securing the opposite ends of Said cable to' Said core head and tip, respectively, whereby said cable may 'be placed under a preselected tension to maintain said core head and tip and said core Sections therebetween in compressive assembly, and radially disposed pins cooperating With said Socket and tenon joints to prevent relative rotation of said core head and tubular Sections, Said driving Shoulders being adapted to engage cooperating Shoulders on the driving rings of said Shells for transmitting driving forces thereto.

3. A core Structure for driving Shell type piles, comprising in combination: a core head, a plurality of tubular core Sections and a core tip, means joining Said Sections end-to-end 'between Said core head and tip, Said means including ball and Socket joints between said core Sections, bores eXtending through Said joining means and communicating With the interiors of Said tubular core Sections, a cable extending within Said core Sections and bores between said core head and tip, means Securing the opposite ends of said cable to Said core head and tip, respectively, whereby said cable may be placed under a preselected tension to maintain the assembly in compressive condition and driving elements associated with Said balls for engaging and transferring driving forces to Said Shell type piles.

4. A core structure for driving Step tapered Shell type piles, comprising in combination: a core head, a plurality of tubular core Sections and a core tip, means joining Said Sections end-to-end 'between Said core head and tip, Said means including driving balls seated 'for universal movement in socket adapters interposed between Said core Sections, bores extending through Said balls and adapters and communicatng with the interiors of said tubular core Sections, a cable extending within Said core Sections and bores between Said core head and tip, means securing the opposite ends of Said cable to Said core head and tip, respectively, whereby Said cable may be placed under a preselected tension to maintain the assembly in compressive condition, and driving elements associated with Said balls for transferring driving forces tov said Step tapered Shell type piles at the Steps therein.

5. A core Structure 'for driving Shell type piles, comprising in combination: a core head, a plurality of tubular core Sections and a core tip, means joining Said Sections end-to-end between Said core head and tip, Said means including driving balls Seated for universal movement in Socket adapters interposed between Said core Sections, means cooperating with said core sections and said adapters to prevent relative rotation therebetween, said balls and adapters having bores therethrough communicating with the interiors of said tubular core Sections, a cable extending Within said core Sections and bores between said core head and tip, means securing the opposite ends of said cable to said core head and tip, respectively, 'Whereby said cable may be placed under a preselected tension to maintain the assembly in compressive condition, and driving means associated with said driving balls for transferring driving forces to said shell type piles.

References Cited in the file of this patent UNITED STATES PATENTS Pierce Oct. 11, 1927 Watt Jan. 3, 1933 Earley Feb. 2, 1937 Kinneman July 14, 1953 Zublin June 8, 1954 McCune July 5, 1955 FOREIGN PATENTS France 1945 Netherlands 1954