US1954070A - Pile - Google Patents

Description

G. COOK April 10, 1934.

FILE

Filed Aug. 4, 1932 Aliorneys I zak Patented Apr. 10, 1934 UNITED STATES PATENT OFFICE 3 Claims.

las one hundred feet or more until they are carried to such a depth that they will have a solid foundation to bear the required load without tipping or yielding after the load has been applied thereto. These piles must be driven through all different types of soil and great difficulty has hithertofore been experienced in driving the piles through quicksand, hardpan and certain other types of soil. The pile commonly used today for deep driving is equipped with a conical .point at its lower end and, as such a point strikes a body of quicksand while the pile is being driven, the uicksand has an action very similar to the action of a block of resilient rubber when a pencil is pressed against the same. In other words, as the pile is struck by the hammer of the pile driver, the uicksand will yield slightly to permit slight downward movement of the pile,

while during the interval between the next stroke of the hammer, the quicksand acting almost as a spring will force the pile up almost to its original position. For this reason, it has been the common practice to jet piles through quicksand where this is possible. The jetting operation is exceeding slow, expensive and generally unsatisfactory and it is exceedingly difficult if not impossible to jet piles through quicksand at great depths.

When piles are driven deep into the ground, it is necessary to first drive one section ofpiling,

then splice another section of piling thereto,

then drive the second section and continue in like manner until the pile has been driven to the proper depth to have a solid foundation. Steel pipe piling is commonly used and it has been the common practice to first drive one section of pipe,

then apply a second sectionof pipe to the upper end of the first section and then weld the two sections together after a sleeve has been applied about the joining ends of the two sections. This welding operation takes up considerable time and holds up the work of an entire driving crew until completed. It is therefore desirable to provide a suitable splice for steel pipe piling which will eliminate the necessity for welding adjacent sections of pipe together and at the same time will prevent moisture from entering the pipe sections at the joints between adjacent sections. It is also desirable to provide a suitable splice for use either between the sections of steel pipe piling or between the sections of precast concrete piling which will permit proper driving of the piles after adjacent sections have been secured together by means of the splice.

The driving head used for most'piles is provided with a flat upper surface or-a surface conforming in contour to the lower surface of the follower. block of the pile driver. When such a driving head is used, it is almost impossible to maintain the pile driver derrick exactly in plumb with the pile at all times and as a result, the blow from the hammer of the pile driver is often transmitted unevenly to the top of the pile, thereby concentrating the blow at one point at the top of the pile. When steel pipe piling is used, the upper end of the uppermost pipe section off a portion of the pipe section or to substitute a new pipe section before driving operations can be continued. This results in a great wastage of material, labor and time. When precast concrete piling is used, the uneven blow of the hammer will often chip or crack the upper end of the pile being driven, whereupon the pile must be cut off or a new section of pile substituted. It is desirable therefore to provide a driving head which will equalize the blow of the hammer of a pile driver on all portions of the head of the pile, whether the pile driver derrick is exactly in plumb with the pile being driven or not.

It is one of the main objects of the present invention to provide a novel and improved point for piles which will cut its own way through all different types of soil and which, in particular, will permit the pile to which it is attached to be driven readily through quicksand and hardpan without jetting.

It is another object to provide a novel and improved splice for connecting sections of piling, which splice when used with tubular steel piling, will eliminate the necessity for welding the pipe sections together and which when used in connection with such piling as precast concrete pilthe blow of the pile driving hammer on all points of the upper end of the pile and at the same time will prevent buckling, chipping or cracking of the upper end of the pile.

These and other objects and advantages of the present invention will more fully appear from the following description made in connection with the accompanying drawing, wherein like reference characters refer to the same or similar parts throughout the various views, and, in which,

Fig. 1 is a view partly in front elevation and partly in vertical section illustrating my invention as embodied in a tubular steel piling;

Fig. 2 is a bottom View of the point shown in Fi 1;

Fig. 3 is a horizontal section taken on the line 33 of Fig. 1 as indicated by the arrows;

Fig. 4 is a View partly in front elevation and partly in vertical section, illustrating my invention as embodied in a precast concrete piling;

Fig. 5 is a plan view of the driving head shown in Fig. 4;

Fig. 6 is a horizontal section taken on the line 66 of Fig. i as indicated by the arrows; and

Fig. 7 is a bottom view of the point illustrated in Fig. 4.

Referring first to the embodiment of the invention illustrated in Figs. 1, 2 and 3, there is shown a piling including a plurality of steel pipe sections 8 interconnected by splices 9, only one of which is illustrated, and which when completed will be filled with concrete 10, the concrete only being shown in the lowermost sections. Secured to the lowest pipe section 8 is a point 11, while secured to the uppermost or top section 8 is a driving head 12. A follower block 13 forming part of the equipment of a standard pile driver, shown applied to the driving head 12 and this follower block, in accordance with standard practice, carries at its upper end a cushioning block 14 adapted to cushion the blow of the hammer of the pile driver on the follower block 13.

The point 11 of the pile includes a cone 11a of hollow construction, which cone at its upper and base end is joined by an upwardly projecting outer flange 11b and a shorter upwardly projecting inner flange 11c inwardly spaced from the outer flange 11b to form an annular recess for reception of the lowermost pipe section 8. The outer upper edge of the inner flange 11c and the inner upper edge of the outer flange 11b are rounded or beveled as shown to permit ready in sertion of a pipe section 8 within the recess formed between the two flanges. Joining the cone 11a in evenly spaced circumferential relation from the central longitudinal axis of the cone are triangular outwardly directed Wings 110! which extend preferably radially relative to the central longitudinal axis of the cone. The bases of these triangular wings 11d are disposed downwardly and particular attention is called to the fact that the lower edges of the wings 11d project downwardly at least even with the point of the cone 11a. The lower edges of the wings 111) may .be sharpened if desired, although this is not absolutely necessary.

When the point 11 is applied to the lowermost pipe section 8, packing material 15 such as hemp impregnated with an elastic cement is first disposed within the recess formed between the flangesllc and 11b of the point, whereupon the lower end of the pipe section 8 is fitted within the recess and a heavy weight such as the hammer of apile driver is applied against the upper end of the pipe section 8 to force the lower end of the pipe section into tight engagement with the cemented packing 15. When the elastic cement is used with the packing material 15, a water proof and sealed joint is made between the lowermost pipe section 8 and the point 11.

The driving head 12 has a dome-shaped top surface 12a, the convexity of which is considerably greater than the concavity of the bottom surface 13a of the particular follower block 13 in connection with which the driving head 12 is used. From its dome-shaped top surface, the driving head 12 flares downwardly and outwardly slightly to be loosely received within the recess in the lower portion of the follower block and a downwardly projecting outer flange 12b projects below the main body portion of the driving head. The head 12 preferably, although not necessarily, is hollowed out as shown in Fig. 1, and a short inner flange 120 projects downwardly from the main body portion of the head in inwardly spaced relation from the outer flange 12b, to form an annular recess within which the upper end of the particular pipe section 8 being driven will be received. Preferably, the outer lower edge of the inner flange 12c and the inner and lower edge of the outer flange 121) are rounded or beveled as shown, to permit the driving head 12 to be readily applied to the pipe sections 8.

After the point 11 has been applied to the lower end of the first pipe section 8 to be driven, the driving head 12 is applied to the upper end of this first pipe section, whereupon the pipe section is driven into the ground until the upper end of the pipe section is nearly level with the surface of the ground. The driving head is then removed whereupon if the pile is to be driven deeper, a second pipe section 8 must be spliced to the first pipe section driven. For this purpose the splice 9 is used. However, before the splice 9 is applied to the upper end of the first pipe section 8, this pipe section together with the hollow portion of the point 11 will be first filled with plastic concrete to a level slightly below the top of the pipe section. The splice 9 may then be used. This splice 9 comprises a central ring-like web or body 9a joining relatively long outer up and down turned outer flanges 92) and also joining relatively short up and down turned inner flanges 9c inwardly spaced from the outer flanges 9b to form upper and lower annular recesses between the inner and outer flanges. The outer edges of the inner flanges 9c and the inner edges of the outer flanges 9b are rounded or beveled as shown to permit pipe sections 8 to be readily applied to the splice to be received within the recesses specified. To connect the second pipe section 8 to the first and already driven pipe section 8, elastic cement impregnated packing 16 made from hemp or similar material, is first laid in place within the recesses between inner flanges 9c and the outer flanges 9b, whereupon the second pipe section 8 is slid in place within the upper annular recess of the splice 9, so that the lower end of the second pipe section makes a tight and water proof joint with the splice by reason of the elastic cement treated packing 15. The second pipe section 8 with the splice 9 connected thereto is then ap plied over the upper end of the first or driven pipe section 8 and pressure is applied against the upper end of the second pipe section to slide the splice 9 downwardly on the first pipe section until the upper end of the first pipe section is snugly received within the lower annular recess of the splice 9 and a water proof connection is made between the splice 9 and the first pipe section 8 by reason of the elastic cement treated packing 16. The driving head 12 may then be applied to the second pipe section 8 whereupon the second pipe section may be driven and ad- At all times while the pile is being driven, the.

wings 11d of the point will cut their way through the soil encountered. The wings are particularly effective to permit ready passage .of the .pile through uicksand and 'hardpan. The lower edges of the wings strike the uicksand or hardpan at thesame time as, or ahead of the time when the peak of the cone lla strikes the same and as a result. radial cuts emanating fromthe central longitudinal axis of the cone 11a and projecting beyond the outer surfaces of the cone,

are made through the quicksand or hardpan. be-' fore the main body of the cone is driven into In connection with uicksand, these cuts act in'the same manner as would a series.

the same.

of radially extending cuts in a stretched rubber membrane to permit the passage of a sharpened pencil or other conical member therethrough. In

other words, the wings 11d prevent the elastic action of the uicksand which has hithertofore offered so much difficulty to the driving of piles through uicksand. After the hammer of the pile driver has acted on the pile, to move the point of the pile into the quickstand, there is no marked tendency for the pile to retreat or rise from the quicksand as is the case when other types of'pile points are used. Of course, it is not necessary to jet the pile through quicksand when my point is used. When hardpan is .encounterediby the point, the point readily cuts its way through the hardpan, due to the provision of the wings 11d, and as a result the cone 11a may readily slip through the hardpan. The wings 11d also act to guide the pile as it is being driven and they act to prevent the pile from being deflected from a straight path.

By provision of the two flanges 11b and lie of the point, the lower end of the lowermost pipe section 8 is embraced at all sides and the lower end of the pipe section is thus prevented from splitting or buckling.

The lower inner flange 9c of the splice 9 acting in conjunction with the concrete 10 inserted within the pipe section 8 below the splice prevents the concrete from rising through the reaction created when the pile is struck by the hammer of the pile driver. Care should be taken when the pipe sections 8 are filled with concrete to carry the level of the concrete above the position or at least to the position that the lower edge of the lower inner flange 9c of the splice will take when the splice is applied. Of course, by use of the splice described, it becomes unnecessary to delay driving operations until a weld or welds can be made between sleeves and the ends of adjoining pipe sections and yet an absolutely water tight connection can be made between adjacent pipe sections. By reason of the dome-shaped top surface 12a of the driving head 12, the blow delivered by the hammer of the pile driver will be evenly distributed on the entire upper edge of the uppermost pipe section 8 even when the pile driver derrick is slightly out of plumb with the pile being driven. The force of the blow of the hammer is thus prevented from being concentrated at one point on the upper edge of the uppermost pipe section as often occurs when a driving head having a flat top surface of standard type is used, and thus there is no tendency for the uppermost pipe section 3 to buckle or split at its upper end. Of course,

\ the inner and outer flanges 12c and 12b of the driving head embrace'the uppermost portion of the upper pipe. section at all points and these flanges also aidmaterially to prevent buckling of the pipe section.

Referring to Figs. 4, 5,. 6 and '7 of the drawing, there is illustrated a square precast concrete pile embodying the main features of my invention. Concrete pile sections are designated by the numeral 17 and preferably there will be embedded in the concrete forming these sections,

vertical reinforcing rods 18 tied together by helical reinforcing members 19. Although the sections 1'7 may be made of any desired shape in horizontal cross section, they are shown as of square formation. .A pile point is designated by the numeral 20, a splice by the numeral 21, a driving head by the numeral 22, a cushioning block by the numeral 23, a follower block by the numeral 24 and a cushioning block mounted in the top of the follower block by the numeral 25.

The point. 20 is constructed in much the same manner as the previously described point 11 and it consists of a pyramid 20a, radial wings 20b, joining the pyramid 20a in the same manner as the wings 11d join the cone l1 and having a corresponding function to the wings 11d. A rectangular flange 20c joins the upper or base end of the pyramid 20a and the pyramid is, of course, hollow to receive. the pyramid-shaped lower end of. the lowermost pile section 1'7. The splice 21 comprises a central cross web 21a and rectangular upwardly and downwardly extending flanges 21b joining the edges of the central web 21a. Driving head 22 has a dome-shaped top surface 22a of greater convexity than the concavity of the bottom of the follower block 24 and having the same function relative to the pile as the dome-shaped top surface 12a of the driving head 12. A rectangular flange 22b joins the body of the driving head and projects downwardly therefrom to embrace the upper end of the pile section 17 being driven in much the same manner as the flange 12b in the previously described embodiment and to also embrace cushioning block 23 which is preferably interposed between the top of the uppermost section and the main body of the driving head.

In driving a pile embodying the construction shown in Figs. 4, 5, 6 and '7, the lowermost precast concrete section 1'7 with the point 20 affixed thereto is first driven from the driving head 22 applied thereto, into the ground, whereupon it becomes necessary to connect another or second precast section 17 to the first or driven section. A quantity of molten sulphur 26 is first applied to the upper end of the driven section 1'7, whereupon the splice 21 is slipped over the top of the driven section and pressed firmly against the sulphur 26. This sulphur quickly hardens and sets and acts as an extremely powerful bonding agent to secure the splice 21 to the section 1'7, while at the same time smoothing the top surface of the section 17 so that irrespective of whether the top is perfectly cast or not, the web 21a will have even bearing against all portions of the top of the section 17. A second quantity of molten sulphur 26 may then be poured into the upper portion of the splice 21 whereupon the second precast section 17 may be fitted in place within the upper portion of the splice and the upper sulphur layer 26 will quickly harden and set to bind the upper precast section 17 to the splice 21 and to assure proper bearing of the upper precast section against the splice 21. Additional precast sections 1'7 may be connected to the driven portion of the pile in similar manner until the pile is driven to the proper depth.

Attention should be called to the fact that the wings 11d of the point 11 used with the first described pile and the Wings 20b of the point 20 used in connection with the second described pile, serve to provide stable anchorages for the piles after they have been driven home. The wings tend to prevent tipping of the piles under load.

Piles similar to the first embodiment described, have actually been used successfully under extremely unfavorable conditions. Such piles were driven a hundred and five feet into the ground without diificulty and passed successively through fill, clay, quicksand, and a vein of ground ten feet thick mixed with clay, small stone and hardpan. A large number of piles were driven speedily without loss of a single pile and without loss of pipe. With the precast concrete pile illustrated in Figs. 4, 5, 6 and 7, instead of using the molten sulphur 26 to afiord even bearing surfaces at the joining ends of the pile section 17, any other suitable type of quick drying molten material may be substituted.

It will, of course, be understood that various changes may be made in the form, details, ar rangement and proportions of the various parts without departure from the scope of the present invention, which, generally stated, consists in the matter shown and described and set forth in the appended claims.

What is claimed is:-

1. A pile point comprising an imperforate member tapering from adjacent its upper end to a pointed vertex at its lower end, triangular wings joining the side of said member and projecting outwardly in planes radial to the longitudinal central axis of said member, the lower edges of said wings lying in a plane normal to said axis at the vertex of said member and the outer tips of said lower edges being radially spaced from said axis at least as remotely as any other part of the pile point is spaced from said axis.

2. A pile point comprising a conical imperforate member having a pointed vertex at its lower end, triangular wings joining the sides of said member and projecting outwardly in planes radial to the central longitudinal axis of said member, the lower edges of said wings lying in a plane normal to said axis at the vertex of said member and the lowermost points of the outer edges of said wings being radially spaced from said axis as far as any other part of said pile point is spaced from said axis.

3. A pile point comprising a hollow imperforate member tapering from adjacent its upper end to a pointed vertex at its lower end, the upper end of said member being open, said member at its upper end having inner and outer upwardly projecting concentric flanges defining a groove between them, the inner flange being-considerably shorter than the outer flange and said groove being adapted to receive the end of a pile pipe section, sealing material disposed within said groove and triangular wings extending longitudinally of said member and attached to the outer surface thereof, said wings projecting from said vertex upwardly, said member being adapted to be filled with concrete and said member and wings being formed of metal.

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