US1831209A - Method of and apparatus for making cast-in-place piles - Google Patents

Description

Nov. 10, 1931. J. l-L THORNLEY E'r AL METHOD OF AND APPARATUS FOR MAKING CAST-IN-PLACE PILES Filed Nov. 2. 1927 'Patented Nav. 10, 1931 UNITED STATES' PATENT OFI-'ica JOSEPH H. THQBNLIY, 0I CHICAGO, .ANDl GLENN L. SHEBWOOD, 0l' OAK PANE,

ILLINOIS, AssIoNons To WESTERN A conrona'rIoN or ILLINoIs IOUNDATIQN COHIANY, 0F CHICAGO, ILLINOIS,

METHOD 0I'. AND .APPARATUS FOR MAKING CAST-IN-PLAGE PILES Application led November 8, 1927. Serial No. 230,436.

The'present invention pertains generally to the art of producing foundation iles, and has asone of its objects to provi e an improved method of and apparatus for making cast-in-place concrete piles. More specifically in this regard, the lnvention aims to provide an improved construction of core and casing for sinking the hole in the ground reparatory to forming the, pile therein. IS)uch core and casing are so constructed and arranged that the hole can be sunk by a combination jetting and driving operation, which is particularly eicacious in sandy and other loose soils. The jet discharge occurs down through the core, being arranged to discharge substantially centrally of the lower end of the core so that there is no tendency to jet end of the casing so that the core can bev the hole out sideways with consequent lateral slewing' of the core and casing. One of the features of the construction is the ability to convert the core and casing for use either in a combination jetting and/driving opera-- tion or for use in a driving operation only.

Another object of the invention is to provide improved packing means between the lower end of the core and the side walls of the casing so as to prevent the water and soil from passing upwardly into the casing, thereby retaining the interior of the casing substantially dry and free of soil for the subsequent formation of the concrete pile. This packing means is of considerable importance when using the core and casing in a combination jetting and drivin the successful formation o theycast-in-place pile requires that the interior of the casing be maintained substantially dry and free of soil.

Another object of the invention is to provide improved means for closing the lower withdrawn, preparatory to forming the kconcrete pile in the casing, without permitting the entrance of water and soil into the casing. This closure means is of particularutility in loose, wet soils which tend to enter the lower end of the casing as soon as the core is withdrawn. In its preferred construction, such closure means is in the form of a. plug which seats in the lower end of the operation, since casing `and which has ajet passage therethrough controlled by a check valve which permits the high pressure stream of water fromthe core to pass downwardly through said jet passage during the operationof jetting and driving the hole, but which prevents the return flow of water back into the'casing at the completion of the jetting operation. Such closure plug is left in the bottom of the hole upon the removal of the casing, in which location it serves as a base member for the cast-in-place pile.

Other objects and advantages of our invention will appear from the following detailed description of the preferred apparatus and method for carrying Aout the invention. In the drawings accompanying this description: U

Figure 1 is a vertical sectional view through the core and casing. illustrating the latter engaged in the operation of sinking a .ure 2, showing a modified construction.

f Figure 5 'is a sectional view of a modified form of jet nozzle.

Figure 6 is a sectional view ofy a closure element such as is employed with the constuction shown in Figure 4.

Figure 7 is a fragmentary sectional view illustrating a modied form of packing ring.

Figure 8 is a vertical sectional view showing the use of the closure plug which engages in the lower end ofthe casing; and

Figure 9 is a vertical sectional view illustrating one of the operations in the forma.- tion of the cast-in-place pile.

IReferring to Figure 1, the c ore and casing are indicated at 10 and 11 respectively. The main stem portion of the "core consists of a length of heavy pipe or tubular shell 10',

and similarly the main portion of thecasing consists of a length of heavy pipe or core for connection with a jet opening in the' .and driving operation, a hea shell 11, which surrounds the core. Secured to the up er end of the core stem. 10" is a driving ead 12, and secured to the lower end thereof is a base member 13. Mounted on the upper end of the casing shell 11 is a collar 14 which forms a shoulder under which a hoisting yoke is engaged when it is desired to' pull the casing up out `of the ground.

The core and casing are driven by a ile driving hammer which is fragmentaril i ustrated at 16, such hammer bein gui ed between the leads 17 Iof a typicar pile driver derrick. The upper ends of the core and casinv' receive the guiding iniiuence of the derric leads, either through direct engagement of the core head 12 therewith or through the engagement of the core head with the base of the hammer 16. The driving blows imparted to the core head 12 are transmitted to the upper end of the casing 11 either through direct engagement ofthe under side of the core head with the collar 14, or through an angularly shaped surface 18 on the underside of the core head which maintains the outwardly swaged joint'between the casing shell 11 and the collar 14.

In certain soil conditions the hole in which the Sile is to be formed can be sunk more rapi ly by a combination jetting and driving operation, i. e., by forcing a. high pressure discharge of water into the lsoll below the core and casing, and concurrently therewith imparting driving blows to the core and casing from the pile driving hammer 16. Under soil conditions most frequently encountered, however, it is more desirable to sink the hole solely by a driving operation. The necessity of having two types of apparatus for these different soil vconditions is objectionable, and oneof the features of the resent invention is the provision of one orm of apparatus which can be readil converted for operating under either soil condiion. Owing to the extreme vibration which is set up in the core in the driving thereof, it is preferable that the water jet apparatus be removed from the core when the hole is to be sunk solelyI by a driving operation, and one of the features of the invention is the arrangement whereby this is made possible.

Referring to Figure 1, it will be seen that the core head 12 is provided with a relatively y large opening 19 in the side thereof, this opening communicating with the hollow interior of the core shell 10. When the apparatus is to be used in a combined etting flexible hose or like conduit 21 is inserte through the opening 19 and is threaded dow through the core base 13.

Referring to Figure 2, it will be seen that such base is rigidly secured to the lower end of the core shell 10', the latter preferably having a swaged joint engagement in an annular groove or recess 22 in the top of the base. An annular neck portion 23 extends upwardly within the shell 10', and this neck portion is formed with a tapered or funnel shaped opening 24 which serves to guide the water conduit 21v down into the Jet passage 25 which extends axially down through the ba`se.\f\l3. Suitably secured to the lower end of\the conduit 21 is a nipple 26 which is externally threaded at 27 for effecting attachment to the base. If desired, the nipple 26 may be provided with a nozzle extremity 28 through which the water is discharged down into the soil below the core. In the construction shown in Figure 2, the attachment of the nipple 26 to the core base 13 is effected through a removable plate 29. This plate has a central boss 31 which is internally threaded for receiving the threaded portion 27 of the nipple. The plate is secured to the bottom of the core base by cap screws 32 which pass up through openings into the plate and tap into threaded holes in the core base. The under side of the plate 29 may be formed with recesses or pockets 33 for receiving the heads of the cap screws 32.

When the core and casing are to be used in a combined jetting and driving operation, a cord having a suitable weight at the end thereof is inserted through the opening 19 in the driving head 12 of the core, and this weighted cord is threaded down through the core and through the base 13, the tapered opening 24 guiding the same down through the jet passage 25. The hose 21 with the nipple 26 attached thereto is then fastened to the upper end of the cord and is drawn down through the core to bring the nipple 26 down below the base 13. The attaching plate 29 is then screwedover the threaded portion 27 of the nipple, and the assembly of the device is completed by securing said plate to the base 13 through the placing of the cap screws-32. These operations are, of course, performed while the core and casing are supported above ground level between the derrick leads 17. A source of water supply under pressure is connected to the upper end of the hose 21 so that concurrently with the driving of the core and .casing a jet discharge will occur down through the nozzle 28 for jetting out the soil in advance of the core and casing.

When the apparatus is to be used for sinking a hole solely by a driving operation it is desirablethat the hose 21 be removed fromthe core, so as to avoid subjecting the same to the severe vibration and whipping movement which yis set up in the hose underthe impulse of the driving blows on the core. In removing the hose it is desirable that the base end of the core be closed oil' completely 'so as to prevent soil being driven up into` the hollow core, and to prevent the entrance of lo portion thereof is solid for closing olf the lower end of the Vjet assage 25. The operations of removing t e hose 21 and substltuting the closure plate 34 for theattaching plate 29 can`be quickly and easily performed, and thereupon the apparatus is ready foruse in the drivmg operatlon.

Fi 1re 4 illustrates a modified method of attaching the nipple 26 to the core base 13.

In this instance a nozzle member 36 issecured to the core base, and the nipple 26-is secured to said nozzle member. vThe nozzle comprises an externally threaded neck 'portion 37 which screws into a threaded counter bore 38 formed in the lower end of the base 13. The threaded portion 27 of theA nipple 26 screws into a threaded counter bore in the upper end of :the .neck portion 37. The water is discharged down'through a nozzle passage 39 which eX.- tends down to the tip of the nozzle. g Figure 5 illustrates a modified form of nozzle member 36. In this construction the pas sage 39 communicates with a plurality of branch passages 41 which 'open outwardly throu h the tapered outer sides of the nozzle.

These ranch passages are preferably slightly inclined in an upward direction towards their points of discharge from the nozzle. The object of the construction shown in Flgure 5 is to prevent soil being forced into the nozzle passage under the impact of the driving blows, and thus cloggin the nozzle. It will be evident that there w1ll be practically no tendenc for the soil to be forced into the upwardlry inclined branch passages 41, the

45 pressure 'of the water discharged therethrough being ample to maintain these assages clear at all times. The manner o attaching the nipple 26 to either form of nozzle 36 or 36', and of mounting such nozzle in the core base 13 will be obvlous from the foregoing description. When the jetting apparatus 1s removed, as forv placing the core and casing inconditio'n for a drivlng operation, the )et passage'25 is closed by screwing a plusg 43 up into the threaded counter bore uch p u 38. g is illustrated in Figure 6 and comprises a solid neck portion 44 which is threaded for engaging 1n the counter bore 38 so :Io make the combined jetting and driving operation practicable, it is important that an effective seal be maintained between the lower end of the core and the vinner walls of the casinv 11. vIf water and soil shouldbe allowed to flow upwardly between the core and casing in an lapglreciable quantities, itwill' e have provided an improved form of packing means between the lower end of the core and casin which effectively prevents the entrance o water and soil between vthe two. Referring again to Fivure 2, it will be seen that the core base 13 is ofs slightly smaller diameter than the interior of the casing so intervening space between the two is closed of by one or more packing rings 46, two of such rings being shown. Each ring engages in an annular groove 47 formed in the outer surface of the core base. The attaching plate 29 may be extended across the bottom groove 47 to hold the lower packing ring 46 in place. Each packing ring consists of a length of tarred rope which is forcedinto the groove 47. The width or vertical dim'ension of the groove is narrower than the normal diameter of the rope, so that the latter must be com-v pressed into the Groove, with the result that the outer sides ofD the rope are caused to project outwardly into close fitting en lagement with the inner wall of the casing. his provides an efficient form of packing ring and one-which can be renewed cheaply and with little diiculty.

In Figure 7 we have shown a modified form of packln ring consisting of a length of 'heavy rub er hose,'or a continuous hollow rubber ring,

designated 48. A plurality of spaced holes 49 are provided in thel under slde of this ring, in positionto permit the entrance of the water which is confined below the core base into the ring. This water,

walls. of the casing. Thls expansible form of ring is preferably employedat the lower end of the core base, with a rope rino' 46 mounted vin the upper groove 47, althougch, if desired, type of ring-48 may be em the expansible ployed in both grooves. When employing a jet nozzle of the type shown in Figures 4 and 5 the lower groove 47 is spaced upwardly from the lower edge of the core base 13 so that the upper and lower walls of the groove will be defined by the core base.

After the hole has been sunk to the desired depth, the core is lifted out of the casing so as to permit of the formation of t-he pile in the casing. When operating in certain soil conditions, as for example where the soil is comparatively dry, the core can be withdrawn without the possibilty of soil or water rising within the casing. Very frequently, however, soil conditions are encountered at he bottom of the hole which will gement with the side that'the core can slide freely therein. The

result in water and soil owing upwardly into the casing as soon as thecore 1s Swithdrawn. When o erating under these condltions, it is desira le to retain the lower end of the casin closed, after the removal of the core, until t e concrete can be 'dum d into the casing for the formation of the p1 e. For

such situations, we em loy a plug member 51 which is seated in t e lower end o f the casing above ground level before the drlvmg operation is started. Such closure lug may be constructed of wood, or in the orm of a precast concrete block, and has a sloping outer surface 52 which becomes wedged in the lower end of the casing. As we shall hereinafter describe the plug is left in the ound at the base of the nished concrete pi e, and accordingly it is desirable to make the plug of an inexpensive material, such as wood or concrete. These materials do not have much resistance against shatter, particularly from outwardly acting disruptive stresses consequent on driving blows being transmitted to the plug. However, we overcome this dliticulty by the wed ing taper iit between the sloping outer sur a'ce 52 of the plug and `the edge of the casing, which wedging fit confines the plug and serves tocause some of the downward forces acting throughsaid casing to be transmitted to the plug as Ainwardly acting compression stresses in said plug for preventing fracture thereof. This sloping outer surface 52 may be coated with tar or some similar material xto effect watertight sealing engagement with the end of the oasing. When such plug is employed, a suitable spacing element is preferably interposed between the under sideof the core head 12 and the hoisting collar 14 on'theupgaer end of the casing, so that the lower end o will be extended down below the core base a suiiicient distance to gri the plug, the driving blows being transmit ed to the plug, however, from the core for forcing the plug down through the Soil. The plug is preferably constructed so that it can be employed in the combined jetting and driving operation, at which time the -jet discharge will pass down through the plu into the soil below the same. To this en the plug is formed with a central jet passage 53 extending axially of the plug. The upper end of this passage has a tapered counter bore 54 for establishing a close fitting engagement over the jet nozzle at the lower end of the core. It will be understood Athat this counter bore 54 will be made comparatively smallv for receiving the nozzle extremity 28 shown in- Figure 2, or will be made comparatively large for receiving the nozzle member 36 of Figure 4, depending upon which construction is employed. The lower end of the assage 53 is also provided with a relatively arge counter bore 55 in which is located a check valve 56.

C5 This valve member preferably consists ofv a the casing wood plug, either -of square or fluted cross section, for permittin water to pas's downwardl around the va ve member. The uper e ge of said valve member is rounded to ave seating engagement with the lower circular edge 57 of the 'reduced passage 53, such edge forming a valve seat for the valve member 56. To prevent the valve member from dropping down out of the counter bore 55, a plurality of nails 58 may be toe-nailed ito 75 the sides of the counter bore to have their heads disposed below the valveplug, or vin the case of a precast concrete plug, an suitable projection or projections can be em edded in the concrete for preventing displacement of the valve member.

After the closure plug 51 has been seated in the end of the casing the core and casing are sunk by a combined jetting and driving operation, wherein the water discharged from the core passes downwardly through the central passageway 53 of the closure plug for jetti-ng out the soil belowthe plug, ,and concurrently therewith driving blows are transmitted to the core and casing for forcing the plug downwardly through the soil. It will be notedv that the jet discharge is axial with respect to the plu so that uniform jetting ofthe soil to eac side is assured. When the hole has been sunk to the desired depth the jetting and driving operations are discontinued, and the core is lifted out of the casing. At this time, the plug effectively seals the lower end of the casing against the entrance of water and soil, the valve member'56 by its 100 engagement against the seat 57 preventing return flow of water through the passage 53.

The operation `of separating the closure plug 51 from the end of the shell is preferably performed through a comparatively long slug or charge of concrete'61 (Fig. 9) whlch closes the end of the casing againstthe entrance of water andsoil as the plug and casing separate from each other. As soon as the core 10 is withdrawn at the con- 110 clusion of the driving and jetting operation, the charge of concrete 61 is dumped into the casing upon the closure plug 51. Thereupon a suitable -ram or core is lowered into the casing to bear upon the upper end of the charge 61, such ram or core consisting of the same core which has been previously used in sinking the hole, with its jet passage closed against the entrance of concrete, or consisting of any other suitable ram or core for exerting downward pressure on the concrete. Reversely acting forces are now set up in the charge of concrete 61 and in the casing 11 to force the closure plug'51 from the lower end of the casing. This may be accomplished by pulling upwardly on the casing and at the same time establishing a 4downward pressure against the upper end of the ram or core, either by holding a stationary' abutment' against the upper end thereof, or by imparting driving blows thereto. After the casing has been freed from the closure plug 51 an has moved upwardly therefrom the concrete is free to expand outwardly into direct contact with the earth walls of the hole. If desired, driving blows may be continued on the ram so as to cause the charge of concrete to are or bell outwardly below the lower edge of the casing for the purposel of` producing a flared or expanded pedestal portion of larger diameter than the column portion of the pile. It will be noted that the concrete will flow outwardlyaround the sides of the closure plug 51, the latter becoming embeddedin the concrete, in which position it remains as a base element for the pile. Upon the completion of these operations, the ram or core is withdrawn, and la light shell 62 is lowered into the casing 11 to have its lower end bear upon the charge of concrete 61, or to become embedded therein. Thereupon additional concrete is dumped into the shell 62 to form the column portion of the pile extending up to ground level, this additional concrete bonding with the lower charge 61. Any suitable reinforcing means may be inserted 1n the shell 62 prior to the dumping of this additional concrete. As the final step, the casing 11 is then withdrawn, the completed pile consisting of a lower base portion 61` of concrete and the long column portion composed of the light shell 62 and its filling of concrete, suitably reinforced if desired. 4 j

As ari alternative method of forming the m'le. the light shell 62 may be omitted entirely and the additional concrete. which is superposed over thebase charge 61, may be dumped directly into' the casing 11. Prior to the setting of the concrete, the casing is withdrawn, suitable reaction pressure being held against the upper end of the column of concrete, if need be, to strip the concrete out of the casing. According to this latter method, the concrete column portion of the completed pile will contact directly with the earth walls of the hole throughout the entire length of the pile.

What we claim as your invention and desire to secure by Letters Patent is:

1. In apparatus for making cast-in-place piles. the combination of a core and casing for sinking the hole in which the pile is to be cast, a water jet carried by said core, and a closure plug having a push fit in the lower end of said'casing and having 'a passageway therein through which said 'et discharges its stream of water down-into the soil below said plug, said plug being releasable from said casing by vertical separating pressure exerted between said plug and casing after the hole has been sunk to the desired depth for remaining in the hole when the casing is withdrawn.

2. In apparatus for making cast-in-place piles, the combination of a core and casing for sinking the hole in which the pile is to be cast,'a jet passage extending down throughv said core, a closure plu seatin in the lower end of said casing, sai plug aving a passage therethrough communicating with the jet passa e in said .core for dischar ing water 1nto t e soil below said plug, an a check valve in said plug for preventing return How of water and soil through said second named passage, said plug being releasable from said casing by the exertion of separating pressure on said plug and casing after the hole has been sunk to the desired depth.

3. The method of making cast-in-place piles which comprises driving a core and casing down into the round with a closure plug 1n the lower end 0% said casing, the lower end of said core terminatin short of the lower end of said casing, sa1d plug havin sealing engagement in the lower end of sai casing and being driven by said core, withdrawing said core after the hole has been driven, and dumping concrete into said casing and separating said casing from the plug by pressure applied to the concrete.

4. The method of making -cast-inlace piles which comprises driving a core an casing down into the ground with a closure plug closin the lower end ofa said casing, discharging water down throu h said closure plug for jetting out the' soil progressively with the driving operation, and after the hole has been sunk to the desired depth withdrawing the core, dumping concrete into the casing, and separatingthe closure plug from the casing.

5. The method of making cast-inlace piles which comprises driving a core an casing down into the ground with a closure plug closing the lower end of said casing, withdrawin the core after the hole has been sunk to the esiredl depth, dumping a charge of concrete into the. casing, inserting a. ram into said casing above the charge of con-` crete, forcing the separation .of said closure plug and casing through said charge of concrete, lowering a light shell in said casing into engagement with said charge of concrete, and substantially filling said shell with concrete. 6. The method of making oast-inlace piles which comprises driving a core an casing down into the ground, with the lower end of said casing closed by a-releasable closure plug, dischargingv a stream of water down through said core and through said closure plug for jetting out the soil progressively with the driving operation, withdrawing the core after the hole has been sunk to the desired de th, dumping a charge of concrete into sai casing, inserting a ram into said casing above the concrete and establish-- ing opposlng forcesin said ram and in said casing for releasing said lug from the lower end of said casing, and orming the column 'l0 water down through sai said plug for jetting out the soil below said' plu wlthdrawin said core after the hole has en sunk to t e desired depth, dum ing a charge of concrete into saidcasing an inserting a ram therein, exerting opposite forces on said ram and on said casing for releasing said plug from said casing and A for causing said concrete to expand laterally below the end of said casing, withdrawing said ram and inserting a shell into said casin and dumping additional concrete into sai( shell to form the column portion of the pile. 8. In apparatus for making cast-in-place piles,the combination of a core and casing for sinking the hole in which the pile is to be cast, said core comprising a base portion having sliding movement in said casing, a nozzle associated with said base portion, a conduit extending down through said core and adapted for connection with said nozzle for supplying water thereto, said conduit being removable from said core, a closure plug havinga conical outer surface seating in the lower end of said casing below the base portion of said core, said closure plug having a passage therethrough adapted to communicate with said nozzle for discharging water into the soil below said plug simultaneously with lthe operation of driving said plug through said core and casing, and a check-- valve in said plug for preventing return iow of water and soil through said passage after the jetting operation has been discontinued, said plug being releasable from said casing by relative movement between said core andy transmitted through said core, said closure member having a fluid discharge passageway therethrough, and a check valve associated with said passageway for preventing upward flow therethrough, said closure member being detachable from said casing by vertical reaction pressure acting on said closure member through a pile section within said casing, said closure member remaining in the ground after the core and casing have been with!v drawn.

10. In apparatus for making cast-in-place said closure member, the latter remaimn the ground after the casing has been wlthconcrete piles vthe combination of a casing, a closure mem er having a push fit withinthe lower end of said casing and driven into'the ground with the casing by vertical drivin lows, said closure member having a ilui discharge passageway therethrough, and a,l check valve associated with said passageway-- for preventing upward flow therethrough, said closure member being detachable `from said casing by a vertically acting separatin pressure effective between said casing an drawn.

11. In apparatus for making cast-in-place ,80

the lower edge of said casing, said plug extending up into said casing and engaging said core to be driven thereby, the wedging it of said casing over said tapered surface serving to cause some of the downward forces acting through said casing to be transmitted to the plug as inwardly acting compression stresses in said plug for'preventing fracture of the p lug, and a passageway through said plug for discharging water in a soil jetting operation, said plug being detachable from said casing and remaining in the ground after the casing and core have been withdrawn.

12. The combination of a casing, a core adapted" to be driven down into the groundv within said casing, the lower end of said core terminating short of the lowerend of said195 casing in such driving operation, a closure plug having a tapered outer surface adapted to have a wedging water-tight fit within the loweredge of said casing, the wedging fit of said casing over said tapered surface serving to conine said plug against outwardly acting disruptive stresses tending to shatter the same, said plug extending up into said casing and engaging said core to be driven thereby said plug being detachable from said casing and remaining in the groimd after the casing and core have been withdrawn.

JOSEPH H. THORNLEY. GLENN L. SHERWOOD.

ration, a 85 v

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