US2488073A - Forming cast-in-place concrete incasements of previously driven piles - Google Patents

Description

Nov. 15, 1949 1. H. THORNLEY ET Al. 2,488,073

FORMING CAST-N-PLACE CONCRETE INCASEMENTS 4 OF PREVIOUSLY DRIVEN PILES Filed sept. 15, 1947 3 sheets-sheet 1 24* [i il' Y IIIHIHIII A.

Nov. l5, 1949 J. H. THoRNLl-:Y ET AL 2,488,073

FORMING CAST-IN-PLACE CONCRETE INCASEMENTS OF PREVIOUSLY DRIVEN PILES 3 Sheets-Sheet 2 Filed Sept. l5, 1947 IN VEN TORS.

Y NOV 15, 1949 J. H. THORNLEY ET AL 2,488,073

' FORMING CAST-IN-PLACE CONCRETE INCASEMENTS OF PREVIOUSLY DRIVEN PILES Filed Sept. 15, 1947 3 Sheets-Sheet 5 IN VEN TORS Jasep/z/YZ/zor Patented Nov. 15, 1949 UNITED STATES ATENT OFFICE FORMINGv CAST-IN-PLACE CONCRETE IN- CASEMENTS OF PREVIOUSLY DRIVEN PILES Application September 15, 1947, Serial No. 774,006

11 Claims.

The present invention relates to an improved method of and apparatus for forming cast-inplace concrete incasements on previously driven piles.

The invention has been devised primarily for forming cast-in-place concrete incasements over previously driven structural steel piles of H-beam section, I-beam section or other desired structural shape. However, as We shall hereinafter describe, the invention is also applicable to other types of previously driven piles.

In constructing foundations for buildings, bridges and the like, there are many situations where structural steel piles afford distinct advantages over the use of other types of foundation columns. For example, structural steel piles have a very high load-bearing value when extended down to bed-rock, or hardpan or like firm bearing material. These structural steel piles also have the ability to carry high tensile loads as well as compression loads.

The mechanical driving ofthe structural steel piles down to their full bearing depth by the use of a pile driver or the like affords one expeditious manner of sinking these structural steel piles because it avoids the expense and hazard of digging out holes by manual labor.

It is desirable that the driven pile be protected against rusting, electrolysis or otherv corrosion occurring in the ground. I-Ieretofore, it has been attempted to provide such protection by merely painting the piles or `coating them with some protective material applied in liquid form. I-Iowever, the extreme abrasion encountered by such piles in being driven downthrough loose rock, gravel, sand and the like is practically certain to scratch a considerable part of this thin coating olf the pile. Consideration has also been given to incasing the pile in a concrete sheath before driving. However, the above described mechanical driving of these structural steel piles usually makes it impracticable to encase the pile in concrete before driving because the heavy blows of the pile driving hammer are almost certain to shatter the concrete.

The fundamental object of our invention is to provide an improved method of and apparatus for forming a cast-in-place incasement over a structural steel pile after the latter has been driven into the ground by a pile driving hammer or the like. By being cast-in-place after the completion of the driving operation this concrete incasement does not receive the driving blows of' the pile driving hammer. Our improved apparatus comprises a tubular core and casing as-vr sembly which is driven down over the previously driven pile, the core having an apertured closure head at its lower end whichis adapted to have a relatively snug sliding fit down over the pile, and the casing having a relatively snug sliding fit down over this closure head. The core and casing assembly are adapted to drive the soil away from around the previously driven pile, and to define a surrounding space between the pile and the interior of the casing for receiving the concrete which forms the cast-in-place incasement.

Another object or feature of the invention is the use of a small batch of concrete or like loose material which is driven down into the ground along with the core and casing assembly, this batch of concrete being confined within the lower end of the casing in advance of the apertured closure head of the core, where it functions to seal off the core and casing assembly against the entrance of dirt as the core and casing assembly are driven down over the previously driven pile. This batch of concrete also functions as a scratching and scouring medium for cleaning the dirt ofi the sides of the structural steel pile as the core and casing assembly are driven down over the pile, so that the subsequently poured charge of concrete can bond directly to the cleaned surfaces of the structural steel column. In addition, this plug-like batch of concrete which is carried in the lower end of the core and casing assembly serves as a temporary sealing plug for temporarily sealing the lower end of the casing around the structural steel pile while the core is being withdrawn from the casing after driving and while the main batch of concrete is being poured into the surrounding space between the structural steel pile and the casing for forml ing the cast-in-place incasement.y

Other objects, features and advantages of the invention will be apparent from the following detail description of two preferred embodiments thereof. In the accompanying drawings illustrating such embodiments:

Figure l is a fragmentary side elevational View of the casing part of the core and casing assembly adapted to drive piles of H-beam section;

Figure 2 is a transverse sectional view of this casing;

Figure 3 is a fragmentary side elevational View of the core part of the core and casing assembly;

` Figure 4 is a transverse sectional View of the core taken on the plane of the line 1 -4V of Figure 3 showing the H-shaped aperture in the closure plate at the bottom end of the core;

Figure 5 is a fragmentary side View showing the rst step in the operation' of engaging the core and casing assembly over the upper end of the previously driven steel pile, showing the scouring batch of concrete interposed between the lower end of the core and casing assemb-ly and the upper end of the pile;

Figure 6 is a transverse sectional view taken approximately on the plane of the line 6 5 of Figure showing the engagement of the core and casing assembly down over the structural steel pile;

Figure 7 shows the further step of driving the core and casing assembly down into the ground around the previously driven pile, with the scouring and plugging batch of concrete driven down in advance of the core;

Figure 8 illustrates the next step wherein the core is removed while the casing remains temporarily in the ground to receive the poured batch of concrete which is to form the incasement;

Figure 9 shows the next step wherein the casing is removed while the concrete incasement remains in place surrounding the previously driven Dile;

Figure 10 is a transverse sectional view of the incased pile at the completion of the above operations, and

Figures 1l, 12, 13 and 14 are views similar to Figures l, 2, 3 and 4 showing a modified construction adapted for use in connection with cylindrical piles.

.The casing and core assembly shown in Figures 1, 2, 3 and 4 comprises the outer casing designated 20 and the inner core designated 2|. In its preferred form for use with piles of H-beam section, the casing 20 is preferably constructed of two inwardly facing channels 22 joined by cross-plates 23 suitably welded, either to the outer sides or the inner sides of the channel flanges 22. A heavy driving head or collar 24 is secured around the outer side of the casing at its upper end to receive driving blows from the pile driving hammer, and also to facilitate connection with a hoisting tackle when the casing is to be pulled up out of the ground.

The core part of this assembly comprises two longitudinally extending T-bars 26 disposed back to back in spaced relation to dene a guideway 21 therebetween, asclearly shown in Figure 4. At the upper end of the core 2| these two T-bars are welded to the underside of a solid driving head 28. This driving head receives the driving blows of the pile driving hammer in the operation of sinking the core and casing assembly around the previously driven pile. At the lower end of the core structure the two T-bars 26 are welded to an apertured closure plate 29. This closure plate is formed with an H-shaped opening 3| cut entirely down through the plate, this H-shaped opening being of the proper proportions to fit down over the H-shaped section of the previously driven pile. A clearance of approximately one quarter of an inch or so is desirable between the H-shaped slot and the adjacent surfaces of the H-beam pile so as to accommodate irregularities in the surface of the pile and also the rough working conditions characteristic of operations in the eld. The perimeter of this closure plate 29 has approxi-v mately the same working clearance within the inside surfaces of the casing 210.

The core structure 2| is approximately a foot or so shorter in length than the casing 20, so that when the core is assembled within the casing with the top driving plate 28 of the core resting on the top driving ring 24 of the casing the lower end of the core will be spaced upwardly from the lower end of the casing. This defines a pocket or cavity Within the lower end of the core and casing as- 4 sembly adapted to receive the scouring and plugging batch of concrete, said pocket or cavity being indicated at 34 in Figure 5. This pocket or cavity may be of any desired vertical depth.

Referring now to Figure 5 illustrating a first step in the typical use of our core and casing assembly, the previously driven pile of H-beam section is indicated at 35, this pile having been driven to the desired depth with a portion of its upper end projecting above the ground line or grade level. A shallow excavation 36 is formed in the ground around the upper end of the previously driven pile, and into this excavation or hole is placed a charge of concrete 31 which functions as the scouring and sealing plug to be carried down with the core and casing assembly. The upper end of the H-beam pile 35 projects slightly above this batch of concrete 31. The core and casing assembly is then lowered down over the upper end of the pile, and the core is lined up to have the H-shaped opening 3| slide down over the H-beam 35. Thereupon, the core and casing are lowered So that the core closure plate 29 slides down over the H-beam pile 35 and so that the casing 2 moves down over the upper portion of the batch of concrete 31, whereby the cavity 34 created in the lower end of the casing 20, below the closure plate 29, confines the upper part of the batch of concrete 31, as clearly shown in Figure 5. In this position of the parts, the top driving head 28 on the core is resting upon the top driving ring 24 of the casing. The core and casing assembly is now driven downwardly by blows from the pile driving hammer. In the initial downward movement of the lower edge of the casing 2|! into the batch of concrete 31, a substantial part of this batch is forced upwardly into the cavity 34 for tightly compacting the concrete within said cavity. This heavy pressure exerted on theconcrete 31 forces it into the aforementioned clearance areas which are defined between the edges of the H-shaped opening 3| and the side surfaces of the H-beam 35. The batch of concrete 31 is preferably mixed so that it will be suiciently stiff or coarse to substantially restrict its flow through these relatively small clearance areas. Some of this concrete may work upwardly through these clearance areas within the H- shaped opening 3|, but in so doing this concrete will exert a vigorous scraping or scouring action on the adjacent surfaces of the H-beam pile 35 for cleaning these surfaces. The batch of concrete 31 is suiciently large so that this batch does not become depleted to any great extent by ejection or extrusion up through the clearance areas while the core and casing assembly is being driven down over the pile to the desired depth.

Figure '1 illustrates how a plug 31 of concrete is carried down from the batch 31 conned within the cavity 34 of the core and casing assembly. This plug 31 receives the full pressure of the driving blows exerted on the core and casing assembly, and functions as a driving and sealing plug for penetrating the soil and for sealing the lower end of the core and casing assembly against soil, sand, rocks, gravel or water tending to work upwardly past the closure head 29 into the casing area 39 above this closure head. The concrete performs such sealing function around the perimeter of the closure head 29 as well as in the H-shaped opening 3|. In addition, this concrete plug 31 performs a very vigorous scouring or abrasive action against the surfaces of the H-beam pile 35 by reason of the extreme pressure of the concrete against the surfaces of the z pile. Hence, all of theV surfaces of the pile are cleaned thoroughly so that the later batch of concrete which is dumped into the space 39 can establish effective bonding with the surfaces of the pile to form a watertight cast-in-place incasement around the pile. In the operation of driving the core and casing assembly down over the H-beam pile, the core and casing assembly is accurately guided with respect to the pile by reason of the guiding function of the T-bars 26 of the core structure (Figure 6). The guiding contact of the H-beam web against the opposing surfaces of the T-bars establishes the guided relation in one plane, and the engagement of the H-beam flanges against the edges of the crossflanges of the T-bars establishes the guided relation in the other plane.

The core and casing assembly may be driven down to the whole depth of the pile to form a concrete incasement for the entire length of the pile, or the core and casing assembly may be driven down to some intermediate depth if incasing the entire length of the pile is not feasible or not advantageous. It is not uncommon for these structural steel piles to be driven to depths of 100 feet or more, and if it is desired to incase the entire length of the pile in concrete it will be seen that the core and casing assembly must be of substantially corresponding length. In operations of this magnitude the pile and the core and casing assembly usually consists of two or more sections which are secured together successively as they are driven down into the ground. Figure 8 illustrates the core and casing assembly as having been driven to a depth short of the lower end of the pile; as for example in situations Where the lower end of the pile is socketed in bed rock, hardpan or other firm bearing material. When the downward driving of the core and casing assembly is discontinued, the plug 31 of concrete remains confined within the cavity portion 34 of the casing to function as a closure plug or hard packed seal to prevent the entrance of mud or water up around the pile into the space 39 within the casing. The core structure 2l is now lifted up entirely out of the casing, the concrete plug 3T continuing to maintain a hard packed seal in the lower end of the casing notwithstanding the removal of the core structure. The casing is then filled with a large charge of concrete 40 which completely iills the space 3S and establishes intimate bonding with the cleaned surfaces of the pile. This charge of concrete 40 is preferably a soft workable mix which will completely fill the space 3d in intimate contact with the H-beam pile, whereby to avoid any bridging or cavities and insure that the surfaces of the H-beam are effectively sealed at all points against water, electrolysis or other corrosion.

The nal operation is that of removing the casing structure 2G while maintaining the concrete incasement 4D in r'rn pressure engagement against'the H-beam pile. YThis casing removal operation'is diagrammatically illustrated in Figure 9. In the performance of such operation, the core structure 2l is reinserted into the casing With the apertured closure plate 29 sliding down over the H-beam. This closure plate 29 isA weight of the core structure 2l and also the weight of the pile driving hammer upon this charge of concrete 40 while pulling the casing 2B up out-of the ground. This may be desirable under some conditions to prevent any possibility of upward displacement or separation of the plastic sheath of wet concrete 40. The finished cast-in-place concrete incasement is illustrated in Figure 10. The concrete sheath has the sectionaly outline defined by the shape of the casing structure 29, and completely incases all parts of the H-beam pile. The casing structure '2,0 is shown as being of rectangular cross-section; but it will be understood that this casing might be of cir-- cular cross-section, in which case the upper and lower heads 28 and 29 of the core structure would also be of circular formation.

Figures 11, 12, 13 and 14 mostrate a modified construction of core and casing assembly for use in conjunction with cylindrical piles. These cylindrical piles may be pipe section piles, wood` piles or even pre-cast concrete piles, which latter piles might have developed cracks, spalling or damage, thereby making it desirable to form a cast-in-place concrete incasement around such pre-cast concrete piles. In this modified construction casing section 20a is a cylindrical seccylindrical exterior of the previously driven pile 35a. The use of this modified construction of cylindrical core and casing assembly is substan-v tially the same as that described above.

The scouring and sealing plug 31 of loose abrasive material, used in each of the preceding embodiments, is preferably composed of a moder-Vv ately stiif concrete mix and is usually satisfactory for substantially all normal working conditions, but we also contemplate the use of gravel, sand, cinders and the like, which may be satisfactory under some working conditions.

While We have illustrated and described what we regard to be the preferred embodiments of our invention and the preferredl methods of carrying the invention into eiect, nevertheless it will be understood that such are merely exemplary and that numerous modifications and rearrangements may be made therein without departing from the essence of the invention.

We claim:

1. The method of forming a cast-in-place concrete incasement over a previously driven pile, Which-'comprises placing a casing over the upper end of the pile, interposing a plug of loose material between the casing and the pile, driving the casing down over the pile with the plug of loose material moving down bodily with the casing to function as a driving and scouring plug whereby Y to scour the side` surfaces of the pile and to substantially close the lower end of the casing, and then forming a cast-in-place concrete incasement within the space between the pile and said casing.

2 The method of forming a cast-in-place concrete incasement over a previously driven pile, which comprises placing a core and casing assembly over the upper end of the pile, said core and casing elements both being tubular to receive the pile and said core being shorter to define a cavity within the lower end of the casing, interposinga batch'of concrete within said cavity between the casing and the pile, driving the core and casing assembly down over the pile with the batch of concrete moving down bodily with the core and casing assembly over the pile to function as a scouring and sealing plug adapted to scour the side surfaces of the pile and to seal the lower' end of the casing againstthe entrance of soil and water, then withdrawing the core, forming a castin-place concrete incasement within the space between said pile and casing, and then withdrawing the casing.

3. The method of forming a cast-in-place concrete incasement on a, previously driven pile which comprises placing an apertured closure member over the previously driven pile, placing a casing over said closure member, said casing being spaced from said pile, sinking said closure member` and casing down into the ground around said previously driven pile, and introducing concrete into the space between said casing and said pile to form the cast-in-place concrete incasement.

4. The method of forming a cast-in-place concrete incasement on a previously driven pile which comprises placing an apertured drive member over the previously driven pile, the aperture in said member having a relatively close sliding fit with the side surfaces of the pile, placing a casing over said drive member, said casing being spaced from said pile, driving said drive member and casing down into the ground around said pile, iilling the space between the casing and the pile with concrete, and then withdrawing said casing.

5. The method of forming a, cast-in-place concrete incasement on a previously driven pile which comprises placing a core and casing assembly over the upper end of the pile, said core comprising an apertured lower closure plate having a relatively close sliding t with the pile, said casing being spaced from said pile, driving said core 4and casing assembly down into the ground around said pile, withdrawing said core, introducing concrete into the casing to form the cast-inplace concrete incasement around said pile, and stripping said casing from the concrete before the concrete sets.

6. The method of forming a cast-in-place concrete incasement of a previously driven pile which comprises placing a core and casing assembly over the upper end of the pile, said core comprising an apertured lower closure plate having a relatively close sliding fit with the pile, said casing being spaced from said pile, driving said core and casing assembly down into the ground around said pile, withdrawing said core, introducing a charge of concrete into said casing, placing said core back into said casing upon said charge of concrete, and then stripping said casing from said charge of concrete while said core is preventing upward displacement of said concrete.

7. The method of forming a cast-in-place concrete incasement on a previously driven pile which comprises placing an apertured closure plate and a casing over the previously driven pile, introducing a batch of loose abrasive material between the under side of said closure plate .and the pile, driving the closure plate, casing and abrasive material down into the ground around said pile, and then introducing concrete into the casing around the pile.

8. In apparatus for forming a cast-in-place concrete incasement over a previously driven pile, the combination of a core structure comprising a' closure head having an aperture therein adapted to have a sliding it down over said previously driven pile, a stem portion extending upwardly from said closure head, a driving head at the upper end of said stem portion, a casing engaging said core structure with its lower end having a relatively snug sliding nt over said closure plate, and a driving ring at the upper end of said casing adapted to receive driving blows from the driving head of said core structure.

9, In apparatus for forming a cast-in-place concrete incasement over a previously driven pile of H-beam section, the combination of a core structure comprising two parallel T-bars in spaced back-to-back relation, a closure plate secured to the lower ends of said T-bars, said closure plate having an H-shaped opening therein which is adapted to have a relatively snug sliding t down over the H-beam section of the previously Vdriven pile, said T-bars being adapted to move downwardly in guided relation on opposite sides of the web of said H-beam section, a driving plate secured to the upper ends of said T-bars, and a casing surrounding said core structure and having a driving ring at its upper end receiving driving blows from said driving plate, said casing having its lower end extending down over said closure plate in a relatively snug sliding fit and projecting beyond said plate to dene a cavity in its lower end in 'advance of said closure plate which is adapted to receive a batch of concrete or the like to function as a scouring and sealing plug in the casing as the core and casing assembly is driven down over the H-beam pile.

l0. In apparatus for forming a cast-in-place concrete incasement over a previously driven pile of substantially circular outer contour, the combination of a core structure comprising la length of pipe having a bore capable of sliding down freely over the pile, a closure plate secured to the lower end of said pipe provided with a circular opening having a relatively snug sliding t over the pile, a driving plate secured to the upper end of said pipe, and la cylindrical casing surrounding said core structure and having a driving ring at its upper end adapted to receive driving blows from the driving plate of said core structure, the lower end of said casing extending down over said closure plate in a relatively snug sliding fit and projecting beyond said plate to define a cavity in its lower end in advance of said closure plate which is adapted to receive la batch of concrete or the like to function as a scouring and sealing plug in the casing as the core and casing assembly is driven down over the pile.

11. The method of incasing a previously sunk pile in a cast-in-place concrete incasement, which comprises driving a casing down over the pile in spaced relation thereto, utilizing a plug of concrete or like material to substantially close the lower portion of said casing in the driving operation, and then introducing concrete into the space between said casing and pile.

JOSEPH H. THORNLEY. HOWARD F. CAUDILL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 953,088 Hindes Mar. 29, 1910 2,200,524 Watt May 14, 1940 2,428,070 Frenkil Sept. 30, 1947

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