GB2060742A

GB2060742A - Driving sheet piles

Info

Publication number: GB2060742A
Application number: GB7935508A
Authority: GB
Original assignee: Sanwa Kizai Co Ltd
Current assignee: Sanwa Kizai Co Ltd
Priority date: 1979-10-12
Filing date: 1979-10-12
Publication date: 1981-05-07
Also published as: GB2060742B

Abstract

An apparatus for driving sheet piles into the ground. The apparatus has a drive assembly (18) movable along upstanding guide rails (17) which rotates an auger screw (19) extending downwardly therefrom. Releasably holding the opposite ends of a deep-arch steel pile P to be driven, a tubular enclosure (20) is loosely sleeved around the auger screw (19) and is suspended from the drive assembly via a pair of hydraulic cylinders (22), the sheet pile being normally introduced into the ground by the revolving auger screw (19). For penetration into and through a hard formation or for final embedment of the sheet pile the hydraulic cylinders (22) are operated to exert a downward thrust on the tubular screw enclosure (20). A swivel union mechanism (21) connecting the screw enclosure (20) to the cylinders (22) permits the enclosure (20) to rotate around the auger screw (19) so that successive deep-arch sheet piles can be alternately turned in opposite directions as they make up a wall. <IMAGE>

Description

SPECIFICATION Apparatus for driving sheet piles into the ground This invention relates to an apparatus for driving or introducing sheet piles, for example steel piles of deep-arch or channel-shaped section, into the ground by augering, for example to construct cofferdams, piers, retaining walls and like structures.

Typical of the prior art sheet pile drivers are the drop hammer, the diesel hammer, and the vibratory hammer or driver. All such known machines drive sheet piling by impact or a rapid longitudinal oscillation imparted thereto, giving rise to such public nuisances as noise and the vibration of the ground. These restrict, or even prohibit, the use of the prior art machines in certain parts of cities or residential areas.

A recent proposition, intended to avoid the above problems, calls for the use of apparatus incorporating an auger for introducing deep-arch steel sheet piles into the ground. The apparatus presses down the sheet pile while simultaneously augering into the ground to loosen the soil on the concave side of the pile.

The auger incorporated in this known apparatus is, however, such that the sheet pile being driven has only its top end affixed to the auger screw drive assembly or to the mast. Thus, particularly if the sheet pile is of great length, it is prone to buckling or bending during driving. This of course prevents the driving of successive piles into exact positions required and the construction of a proper wall.

It is an object of this invention to provide an improved apparatus for driving sheet piles, particularly those of the deep-arch type, into the ground with great accuracy and reliability and with as little bending, buckling or warping of the piles as possible.

According to the invention there is provided an apparatus for driving sheet piles into the ground, comprising upstanding guide means, drive means movable up and down along the guide means, an auger screw connected to the drive means and extending downwardly therefrom, the auger screw being rotated by the drive means, a tubular enclosure encompassing the auger screw so as to permit relative rotation thereof, means connecting the tubular enclosure to the drive means so as to permit at least the simultaneous up-and-down motion of the enclosure together with the auger screw, means adjacent the upper end of the enclosure for releasably clamping one end of a sheet pile, and means adjacent the lower end of the enclosure for so engaging the other end portion of the sheet pile as to disengage from the sheet pile at least upon upward motion of the enclosure together with the auger screw.

The invention further provides an apparatus for driving sheet piles, into the ground, each sheet pile having connector means formed thereon, the apparatus comprising upstanding guide means, drive means including a mounting frame and movable up and down along the guide means, an auger screw connected to the drive means and extending downwardly therefrom, the auger screw being rotated by the drive means, a tubular enclosure constituting a sleeve round the auger screw so as to permit relative rotation thereof, swivel union means disposed under the drive means and rotatably supporting the tubular enclosure, the swivel union means permitting the auger screw to pass rotatably therethrough, first actuator means connecting the swivel union means to the mounting frame of the drive means and adapted to exert a downward thrust on the tubular enclosure via the swivel union means, means for restraining the drive means from upward displacement during the exertion of the downward thrust on the tubular enclosure by the first actuator means, second actuator means for rotating the tubular enclosure around the auger screw, means adjacent the upper end of the tubular enclosure for releasably securing one end of a sheet pile thereto, and means adjacent the lower end of the tubular enclosure for engaging the connector means adjacent the other end of the sheet pile, the engaging means disengaging from the connector means when with said one end of the sheet pile released from the releasably securing means, the drive means is moved upwardly along the guide means.

The apparatus preferably not only augers the pile into the soil but also, as required, directly thrusts down the pile, so that the pile can be efficiently placed in any formation.

In an advantageous form of the invention a sheet pile to be driven can be readily mounted in position thereon and, after being placed in the soil, readily disengaged therefrom. Also the apparatus is advantageously such that successive deep-arch sheet piles can be driven after being alternately turned in opposite directions to make up a wall in interlocking relationship.

In use of the apparatus of the invention, the sheet pile is held fast against the enclosure of the auger screw and is secured thereto at both of its top and bottom ends. The sheet pile is therefore prevented from being bent or buckled during driving. Besides carrying the sheet pile as described above, the screw enclosure serves the additional purpose of protecting the pile from damage by the revolving auger screw.

In a preferred embodiment of the invention, the screw enclosure is suspended from the mounting frame of the drive means via a pair of hydraulic cylinders and a swivel union mechanism. The pair of cylinders thrusts down the pile-carrying screw enclosure so as to drive the sheet pile into and through a hard stratum or to obtain its final embedment. Since the cylinders act between the drive means and the screw enclosure, the apparatus includes means for restraining the drive means from upward displacement during operation of the cylinders.

The swivel union mechanism permits the screw enclosure to be revolved around the auger screw at least through 1 80 degrees, for example, by means of motor-driven worm gearing. This mechanism greatly facilitates the construction of a wall by setting and driving the successive interlocking sheet piles with each adjacent pile turned in the opposite direction.

In the accompanying drawings: FIG. 1 is a side elevation of the sheet pile driving apparatus constructed in accordance with this invention, the apparatus being shown in the act of driving a deep-arch steel sheet pile into soil; FIG. 2 is a relatively enlarged, partial side elevation showing in more detail a drive assembly, auger screw, sheet pile clamping mechanism, and associated parts of the apparatus of FIG. 1; FIG. 3 is a front elevation of the parts shown in FIG. 2; FIG. 4 is a diagrammatic representation of a tackle arrangement for lifting and lowering the drive assembly and other means carried thereby and of a tackle arrangement for use in thrusting down an enclosure of the auger screw together with a sheet pile mounted thereon, in the apparatus of FIG. 1;; FIG. 5 is a relatively enlarged elevation, in vertical section, of a swivel union mechanism rotatably connecting the screw enclosure to the drive assembly in the apparatus of FIG. 1, the view also showing a worm gearing for rotating the screw enclosure around the auger screw; FIG. 6 is a relatively enlarged, horizontal sectional view taken along the line 6-6 in FIG. 2 and showing in particular a sheet pile clamping mechanism on the screw enclosure; FIG. 7 is a relatively enlarged, horizontal sectional view taken along the line 7-7 in FIG. 1 and showing in particular the way in which a sheet pile is releasably engaged at or adjacent its bottom end with the screw enclosure; FIG. 8 is a partial elevation showing in particular a retainer plate affixed to the screw enclosure for releasably engaging the sheet pile as in FIG. 7;; FIG. 9 is a partial perspective view of a sheet pile, showing in particular a pair of connector plates on the sheet pile to be releasably engaged with the retainer plate of FIG. 8, in the manner shown in FIG. 7; FIG. 10 is a partial elevation showing in particular a modification of means for restraining the drive assembly from upward displacement during exertion of a downward thrust on the screw enclosure, in the apparatus of FIG. 1; FIG. 11 is a horizontal sectional view taken along the line 11-11 in FIG. 10; FIG. 12 is a partial perspective view showing in particular a pair of retainer rods affixed to the screw enclosure as an alternative to the retainer plate of FIG. 8; FIG. 13 is a partial perspective view showing in particular alternative means for securing the retainer rod pair of FIG. 12 to the screw enclosure; and FIG. 14 is a partial perspective view showing in particular a pair of connector rings secured to a sheet pile for releasable engagement with the retainer rod pair of FIG. 1 3 or 14.

FIG. 1 shows the sheet pile driving apparatus of this invention mounted on a crawler-type carrier 1 5. As will be seen from this Figure and also from FIGS. 2 and 3, the sheet pile driving apparatus comprises a normally vertical mast or leader 1 6 having a pair of parallel guide rails 1 7 (one shown) secured thereto and extending therealong, a drive assembly 1 8 movable along the guide rails 17, an auger screw 1 9 connected to and extending downwardly from the drive assembly 18 thereby to be rotated about its own axis, a tubular screw enclosure 2Q loosely disposed as a sleeve around the auguer screw 1 9 and securely but releasably carrying a steel sheet pile P of the deep-arch type to be driven into the ground G, and a swivel union mechanism 21 connecting the screw enclosure 20 to the drive assembly 1 8 via a pair of hydraulic thrust cylinders 22. The swivel union mechanism 21 and the thrust cylinders 22 coact to permit the pile-carrying screw enclosure 20 to travel with the auger screw 1 9 along the guide rails 17, thrust into soil as required, and revolve around the auger screw.

As shown in FIG. 1 the crawler-type carrier 1 5 supports the mast 1 6 via a pair of back stays 23 (one shown) and a pivotal connection 24, permitting the mast to pivot between an upstanding or working position- and a recumbent or non-working position. FIG. 1 shows the mast 1 6 in the working position, erected vertically on the ground G. The mast 1 6 has the guide rails 1 7 affixed to its front side or its side away from the carrier 1 5.

The drive assembly 18 includes a mounting frame 25. This mounting frame has two vertically spaced pairs of opposed shoes 26, as best seen in FIG. 2, projecting rearwardly therefrom into sliding engagement with the guide rails 1 7 on the mast 1 6. The drive assembly 1 8 is therefore movable up and down along the guide rails 17.

FIG. 4 diagrammatically depicts a tackle arrangement 27 for effecting the up-and-down motion of the drive assembly 18 along the guide rails 1 7. Operated by a winch 28 on the carrier 15, the tackle arrangement 27 includes a wire rope 29 extending from the winch 28 past a sheave 30 on the carrier up to a sheave 31 on a multi-sheave block 32 on the top of the mast 1 6. The wire rope 29 is further passed over a row of four sheaves 33 on the multi-sheave block 32 and another row of four sheaves 34 on the drive assembly mounting frame 25 as shown and is anchored at 35 to the multi-sheave block.

Thus the drive assembly 1 8 travels up and down along the guide rails 17 as the winch 28 winds up and pays off the wire rope 29. The arrowheads in FIG. 4 indicate the direction of movement of the wire rope 29 during the downward travel of the drive assembly 18, that is, during sheet pi[e driving operation.

With reference again to FIGS. 2 and 3, the drive assembly 18 includes a screw drive motor 36 and a transmission 37 such as a gearbox, both mounted on the mounting frame 25. The transmission 37 has an output shaft 38 coaxially connected to a shaft 39 of the auger screw 19, the shaft 39 being referred to below as the screw shaft. The auger screw 1 9 further includes a continuous helical blade 40 formed on the screw shaft 39 and ends in an ordinary drilling head 41 (FIG. 1).

The transmission output shaft 38 and the screw shaft 39 are both hollow and are intercommunicated for the passage of a fluid therethrough. The transmission output shaft 38 at its top end is communicatively connected to a supply conduit 42 via a swivel coupling 43. During sheet pile driving or augering any desired fluid can be delivered from the supply conduit 42 into the screw shaft 39 via the transmission output shaft 38 and discharged into the drill hole through an outlet opening (not shown) in the drilling head 41.

Loosely enveloping the auger screw 19 so as to leave exposed only its drilling head 41, the tubular screw enclosure 20 is suspended from the drive assembly mounting frame 25 via the swivel union mechanism 21 and the thrust cylinder 22. No direct mechanical connection exists between the auger screw 1 9 and its enclosure 20.

As shown in detail in FIG. 5, the swivel union mechanism 21 comprises a hollow support frame 44 and a sleeve 45 rotatably supported therein by bearings 46. The sleeve 45 is locked against endwise or axial motion relative to the support frame 44. Two flanged tubular coupling members 47 and 48 connect the sleeve 45 coaxially to the screw enclosure 20, causing simultaneous rotation of the latter with the former. The upper end portion of the screw shaft 39, on which the helical blade 40 is not formed, extends coaxially through the sleeve 45 and the coupling members 47 and 48 with considerable clearance.

In order to rotate the screw enclosure 20 around the auger screw 19, the swivel union mechanism 21 is provided with a motor 49 fixedly mounted within its support frame 44. The motor 49 has an output shaft 50 having a worm 51 nonrotatably mounted thereon. The worm 51 is meshed with a worm wheel 52 immovably encircling the sleeve 45 of the swivel union mechanism 21. Thus, the motor 49 rotates the sleeve 45 and hence the screw enclosure 20 via the worm gearing through at least 1 80 degrees.

This rotation of the screw enclosure 20 around the auger screw 1 9 is necessary, in constructing a wall by burying a plurality or multiplicity of interlocking deep-arch sheet piles in the ground, to turn each adjacent pile in the opposite direction.

The support frame 44 of the swivel union mechanism 21 has a pair of lateral extensions 53 projecting in the opposite lateral directions therefrom. The pair of hydraulic thrust cylinders 22 extends between these support frame extensions 53 and the drive assembly mounting frame 25 and act to thrust the pile-carrying screw enclosure 20 into the ground as required. During this downward thrust of the screw enclosure 20 by the thrust cylinders 22 the drive assembly 18 must be restrained from upward displacement along the guide rails 1 7 to bear the reactive force of the thrust, for example, as by the following means.

As shown partly in FIG. 1 and 2 and wholly in FIG. 4, one example of reaction bearing means takes the form of a tackle arrangement 54. The reaction bearing tackle arrangement comprises a pair of sheaves 55 and 55a and another pair of sheaves 56 and 56a, both mounted on opposite sides of the drive assembly mounting frame 25, a row of three sheaves 57, 58 and 59 on the bottom end of the mast 16, two other sheaves 60 and 61 on the carrier 15, a winch 62 on the carrier, and a wire rope 64 arranged in the following manner.

Anchored at one end 63 to the bottom end of the mast 16, the wire rope 64 extends therefrom to the winch 62 after passing over the sheaves 55, 57, 56, 56a, 58, 55a, 59, 60 and 61, in that order.

Thus, as the winch 62 winds up the wire rope 64 as indicated by the arrowheads, the tackle arrangement 54 exerts a downward pull on the drive assembly 1 8 thereby causing the same to bear the reactive force of the thrust being applied to the screw enclosure 20 by the thrust cylinders 22.

The tubular screw enclosure 20 has means for releasably carrying the sheet pile P to be driven.

The releasably carrying means comprises a clamp mechanism 65 (FIGS. 2, 3 and 6) for engaging the top end of the sheet pile, and means 66 (FIGS. 7 and 8) for engaging the bottom end portion of the sheet pile.

The clamp mechanism 65 includes, or is mounted on, a holder band 67 embracing the screw enclosure 20. This holder band has a pair of halves hinged together at 68 and separably bolted together at 69. The clamp mechanism holder band 67 can therefore be shifted to and immovably retained in any desired position on the screw enclosure 20 to adjust to the length of the sheet pile P. The holder band shown in phantom in FIG. 2 represents one such possible position of the holder band 67 on the screw enclosure 20.

Projecting forwardly or leftwardly (as viewed in FIGS. 2 and 6) from the clamp mechanism holder band 67 are a pair of brackets 70 between which there is connected a pivot pin 71. A pair of Lshaped clamping pawls 72 are rotatably mounted on the pivot pin 71, for pivotal motion toward and away from an abutment 73 extending downwardly from the holder band 67. The clamping pawls 72 are pin-jointed to the piston rod 74 of a hydraulic clamping cylinder 75 pivoted at 76 on the holder band 67. The clamping cylinder 75 extends and contracts to pivot the clamping pawls 72 into and out of abutting engagement with the abutment 73.

For clamping the sheet pile P by the clamp mechanism 65 of the foregoing construction the top end of the pile is placed between clamping pawls 72 and abutment 73, as indicated by the dot-and-dash lines in FIG. 2, while the clamping cylinder 75 is held contracted. The clamping pawls 72 clamp the sheet pile P against the abutment 73 upon subsequent extension of the clamping cylinder 75.

FIGS. 7, 8 and 9 show the details of the above mentioned means 66 for releasably engaging the bottom end portion of the sheet pile P. The engaging means comprise a retainer plate 77 of rectangular shape bracketed at 78 to the screw enclosure 20 at or adjacent its bottom end. The retainer plate 77 has top and side edges bevelled at 79 and 80 for a purpose hereinafter made apparent.

The sheet pile P to be engaged by the retainer plate 77 is of the deep-arch type, as has been mentioned, comprising a web 81 and a pair of oppositely sloping flange walls 82 on both sides of the web. On the concave side of the sheet pile P, and adjacent its bottom end, a pair of spaced, coplanar connector plates 83 are secured to the sloping side walls 82 so as to extend toward each other. The retainer plate 77 on the screw enclosure 20 is relatively slidable into and out of the space 84 between the web 81 and connector plate pair 83 of the sheet pile P. Once engaged with the sheet pile P as in FIG. 7, the retainer plate 77 disengages the same only upon relative longitudinal motion between sheet pile and screw enclosure.

In the operation of the sheet pile driving apparatus constructed as in FIGS. 1 through 9 the mast 16 may be erected on the ground, and the enclosed auger screw 19 may be held uprightly on the ground by holding the drive assembly 18 in a suitable position on the mast, as shown in FIG. 1.

The vertical position of the clamp mechanism 65 on the screw enclosure 20 is varied as required to adjust to the length of the sheet pile to be driven, by shifting its holder band 67 along the screw enclosure. The clamping cylinder 75 must be contracted.

The sheet pile P to be driven is lifted, for example by a crane, and held lengthwise against the screw enclosure 20, with the concave side of the pile orientated toward the enclosure and with the connector-plate carrying end of the pile orientated downwardly. The sheet pile P may then be slid down the screw enclosure 20 so as to receive the retainer plate 77 on the screw enclosure in the space 84 between the web 81 and connector plate pair 83 of the pile. Then, with the top end of the sheet pile web 81 placed between clamping pawls 72 and abutment 73 of the clamp mechanism 65, the clamping cylinder 75 is extended thereby causing the clamping pawls to press the sheet pile web immovably against the abutment as shown in FIG. 2.

Upon completion of the mounting of the sheet pile P on the screw enclosure 20, the screw drive motor 36 of the drive assembly 18 is set in motion to provide rotation of the auger screw 1 9 in a predetermined forward direction via the transmission 37. The auger screw 19 drills into the ground G, on the concave side of the sheet pile P as shown in FIG. 1, as the winch 28 of the tackle arrangement 27 gradually pays off the wire rope 29. During this augering operation a fluid such as water or a bentonite solution may be pumped into the hollow screw shaft 39 via the supply conduit 42 and the transmission output shaft 38, the fluid being introduced into the drill hole out of the outlet opening (not shown) in the drilling head 41 for purposes well known in the art.

Both the top and bottom ends of the sheet pile P being driven are secured to the screw enclosure 20 and are thus locked against displacement.

Therefore, under the combined weight of the drive assembly 18, auger screw 19, etc., the sheet pile P is smoothly introduced into the drill hole without buckling or bending.

In order to penetrate a hard ground formation, or to obtain final embedment of the sheet pile P, the winch 62 of the reaction bearing tackle arrangement 54 is operated to wind up the wire rope 64 as shown in FIG. 4, thereby exerting a downward pull on the drive assembly 18.

Simultaneously, the pair of thrust cylinders 22 are both extended to thrust down, via the swivel union mechanism 21, the screw enclosure 20 together with the sheet pile P carried thereby. The thrust cylinders 22 will effectively thrust down the pilecarrying screw enclosure 20 since the reaction bearing tackle arrangement 54 enables the drive assembly 1 8 to bear the reactive force of the thrust.

When the sheet pile P is driven into the ground to a required depth, the clamping cylinder 75 of the clamp mechanism 65 is contracted, thereby causing the clamping pawls 72 to pivot away from the abutment 73 and hence to unclamp the top end of the sheet pile. Then the wire rope 29 of the tackle arrangement 27 is wound up by the winch 28 to lift the drive assembly 18 along the guide rails 17.

Upon consequent upward travel of the screw enclosure 20, the retainer plate 77 thereon will slide out of the space 84 between the web 81 and the connector plates 83 of the sheet pile P. The auger screw 1 9 and its enclosure 20 can therefore be easily withdrawn from within the drill hole, leaving only the sheet pile P therein. During the withdrawal of the enclosed auger screw 1 9, the screw drive motor 36 may be rotated in the reverse direction thereby causing the auger screw to backfill the drill hole.

The next sheet pile to be driven is then mounted in position on the screw enclosure 20 through the above described procedure. The motor 49 within the support frame 44 of the swivel union mechanism 21 is then set into rotation thereby turning the pile-carrying screw enclosure 20 around the auger screw 1 9 until the sheet pile is orientated in the opposite direction with respect to the previously driven pile.

Subsequently interlocked with the first sheet pile, the second pile can be placed in the ground in the foregoing manner. Thus a desired wall can be constructed by successive sheet piles driven into the ground in interlocking relationship and with each adjacent pile turned in the opposite direction.

FIGS. 10 and 11 show means, alternative to the reaction bearing trackle arrangement 54 of FIG. 4, for restraining the drive assembly 1 8 from upward displacement during the downward thrust of the screw enclosure 20 by the thrust cylinders 22. The restraining means include a series of teeth 90 formed at constant longitudinal spacings on the mast 1 6 and disposed between the pair of guide rails 1 7 so as not to impede the travel of the drive assembly 1 8 therealong.

For selectively engaging the teeth 90 on the mast 16 a catch 91 is pivotally supported between a pair of brackets 92 projecting rearwardly from the mounting frame 25 of the drive assembly 18. Also pivotally mounted between the bracket pair 92, a hydraulic cylinder 93 has a piston rod 94 pin-jointed to the catch 91.

The extension of this cylinder 93 results in the pivotal motion of the catch 91 into engagement with the underside of one of the teeth 90. The drive assembly 1 8 is then locked against upward motion along the guide rails 1 7.

FIGS. 12, 13 and 14 are illustrations of modified means for releasably securing the bottom end of the sheet pile to the screw enclosure 20. The modified means include, instead of the retainer plate 77 of FIGS. 7 and 8, a pair of retainer rods 77a each disposed parallel to the screw enclosure 20 and rigidly connected to one end of the enclosure, either by respective brackets 78a as in FIG. 12 or by a common Tshaped bracket 78hays in FIG. 13. These retainer rods 77a are adapted to move relatively into and out of a pair of transversely spaced connector rings or half rings 83a formed on the sheet pile P as in FIG. 14. If desired, however, the retainer rods 77a may be employed in combination with the connector plate 83 of FIG. 9.

Claims

1. An apparatus for driving sheet piles into the ground, comprising upstanding guide means, drive means movable up and down along the guide means, an auger screw connected to the drive means and extending downwardly therefrom, the auger screw being rotated by the drive means, a tubular enclosure encompassing the auger screw so as to permit relative rotation thereof, means connecting the tubular enclosure to the drive means so as to permit at least the simultaneous up-and-down motion of the enclosure together with the auger screw, means adjacent the upper end of the enclosure for releasably clamping one end of a sheet pile, and means adjacent the lower end of the enclosure for so engaging the other end portion of the sheet pile as to disengage from the sheet pile at least upon upward motion of the enclosure together with the auger screw.

2. An apparatus according to claim 1, wherein the connecting means includes actuator means for exerting a downward thrust on the enclosure, and wherein the apparatus further comprises means for restraining the drive means from upward displacement along the guide means during the exertion of the downward thrust on the enclosure by the actuator means.

3. An apparatus according to claim 1 , wherein the connecting means includes swivel union means connecting the enclosure to the drive means so as to permit rotation of the enclosure around the auger screw, and wherein the apparatus further comprises means for rotating the enclosure around the auger screw.

4. An apparatus according to claim 3, wherein the swivel union means comprises a support frame connected to the drive means, and a sleeve rotatably supported by the support frame and connected to the enclosure for simultaneous rotation therewith, the sleeve being locked against axial motion relative to the support frame and loosely surrounding the upper end portion of the auger screw.

5. An apparatus according to claim 4, wherein the rotating means comprises a motor mounted on the support frame, and worm gearing for imparting the rotation of the motor to the sleeve.

6. An apparatus according to claim 4, wherein the support frame of the swivel union means is connected to the drive means via actuator means for exerting a downward thrust on the enclosure, and wherein the apparatus further comprises means for restraining the drive means from upward displacement along the guide means during the exertion of the downward thrust on the enclosure by the actuator means.

7. An apparatus according to claim 2 or 6, wherein the restraining means comprises tackle means mounted on the drive means and on the guide means, the tackle means being adapted to force the drive means downwardly relative to the guide means during the exertion of the downward thrust on the enclosure by the actuator means.

8. An apparatus according to claim 2 or 6, wherein the restraining means comprises a series of teeth formed at longitudinal spacings on the guide means so as to permit the up-and-down motion of the drive means therealong, a catch mounted on the drive means for movement into and out of engagement with any one of the teeth on the guide means, the catch being effective to prevent the upward motion of the drive means along the guide means when engaged with any one of the teeth, and actuator means on the drive means for moving the catch into and out of engagement with any one of the teeth.

9. An apparatus according to any preceding claim, wherein the releasably clamping means comprises an abutment formed on the enclosure, at least one clamping pawl mounted on the enclosure for movement toward and away from the abutment to engage and disengage said one end of the sheet pile, and actuator means also mounted on the enclosure for moving the clamping pawl toward and away from-the abutment.

10. An apparatus according to any preceding claim, wherein the releasably clamping means is mounted on the enclosure via holder means which can be moved along the enclosure and which can be secured thereto in any position thereon to adjust to the length of the sheet pile.

11. An apparatus for driving sheet piles, into the ground, each sheet pile having connector means formed thereon, the apparatus comprising upstanding guide means, drive means including a mounting frame and movable up and down along the guide means, an auger screw connected to the drive means and extending downwardly therefrom, the auger screw being rotated by the drive means, a tubular enclosure constituting a sleeve round the auger screw so as to permit relative rotation thereof, swivel union means disposed under the drive means and rotatably supporting the tubular enclosure, the swivel union means permitting the auger screw to pass rotatably therethrough, first actuator means connecting the swivel union means to the mounting frame of the drive means and adapted to exert a downward thrust on the tubular enclosure via the swivel union means, means for restraining the drive means from upward displacement during the exertion of the downward thrust on the tubular enclosure by the first actuator means, second actuator means for rotating the tubular enclosure around the auger screw, means adjacent the upper end of the tubular enclosure for releasably securing one end of a sheet pile thereto, and means adjacent the lower end of the tubular enclosure for engaging the connector means adjacent the other end of the sheet pile, the engaging means disengaging from the connector means, when, with said one end of the sheet pile released from the releasably securing means, the drive means is moved upwardly along the guide means.

12. An apparatus according to claim 11, wherein the sheet pile comprises a web and a pair of oppositely sloping walls on opposite sides of the web, wherein the connector means comprises a pair of spaced, coplanar connector plates formed on the sloping walls of the sheet pile and extending toward each other, and wherein the engaging means comprises a retainer plate formed on the tubular enclosure, the retainer plate being relatively movable into and out of a space between the web and connector plates of the sheet pile.

1 3. An apparatus according to claim 11, wherein the connector means comprises a pair of transversely spaced connector rings secured to the sheet pile, and wherein the engaging means comprises a pair of spaced retainer rods extending parallel to the tubular enclosure and secured each at one end thereto, the retainer rods being relatively movable into and out of the respective connector rings on the sheet pile.

14. An apparatus for driving sheet piles into the ground, substantially as herein described with reference to any one of the embodiments shown in the accompanying drawings.