US 3690109 A
Pile or like structural column produced in earth situs by drilling with continuous flight auger to define cavity of requisite depth, withdrawing auger by successive incremental extents and maintaining auger affixed against axial movement at top of each said extent while feeding and compacting column-forming material, through hollow shaft of auger, into each respective cavity extent, until series of successively formed extents produce integrated column. Closure on inner end of hollow auger shaft operable to stop flow of material at any depth of cavity. For forming concrete pile, closure means operable to form enlarged base or bulb of self-hardening material at bottom of cavity to increase load-bearing capacity of the formed pile.
Claims available in
Description (OCR text may contain errors)
[ 1 Sept. 12,1972
FOREIGN PATENTS OR APPLICATIONS 293,396 8/1916 Germany..................6l/53.52 959,646 6/1964 GreatBritain............6l/53.64
Primary Examiner--Jacob Shapiro Attorney-William Cleland ABSTRACT Pile or like structural column produced in earth situs by drilling with continuous flight auger to define cavity of requisite depth, withdrawing auger by successive incremental extents and. maintaining auger affixed against axial movement at top of each said extent while feeding and compacting column-forming materia1, through hollow shaft of auger, into each respective cavity extent, until series of successively formed extents produce integrated column. Closure on inner end of hollow auger shaft operable to stop flow of PRODUCING PILE OR LIKE STRUCTURAL COLUMNS IN SITU Lee A. Turzillo, 2078 Glengary Rd., Akron, Ohio 44313 March 16, 1970  Appl. No.: 19,906
.61/53.64, 61/11, 61/56.5, 61/63 Int. Cl. .....E02d 5/34, E02d 5/56, E02b 11/00  Field of Search......61/53.64, 53.66, 53.52, 53.6, 61/53.62, 63, 56.5
References Cited UNITED STATES PATENTS United States Patent Turzillo  METHOD AND MEANS FOR  Inventor:
material at any depth of cavity. For forming concrete pile, closure means operable to form enlarged base or bulb of self-hardening material at bottom of cavity to increase load-bearing capacity of the formed pile.
15 Claims, 10 Drawing Figures 642XX wwummm mmmuooao 66 .55 unuu $2 mmmm m m w M n d hm de wm mmm LDWTGB 789990 666667 999999 111111 87 2 9 049898 642322 7 5 6 D oo 4 6 2699 392272 333333 PATENTEB SEP 12 m2 SHEET 1 [IF 5 INVENTDR. 4 14781121110 BY wwfiw z PATENTED SEP 12 '97? sum 2 or 5 INVENTOR. Lee A. 72021110 14 for/76y PATENTEDSEP 12 I972 SHEET 4 [1F 5 mum m A e e L PHENTEDSEP 12 Ian SHEET 5 [IF 5 T m m r mm A e 6 L BY v Attorney METHOD AND MEANS FOR PRODUCING PILE OR LIKE STRUCTURAL COLUMNS IN SITU BACKGROUND OF INVENTION A co-pending U. S. patent application Ser. No. 763,047 discloses apparatus which generally suitable for practicing the method steps of the above referred to incremental procedure for providing pile or other structural columns in situ. One important object of the present incremental method is to provide a more dependable way for producing concrete piles, sand drains and like columns, by which the shape, size and materialcompaction characteristics of the formed columns can be readily controlled and observed above ground to obtain best results. With particular'reference to production of concrete piles, the present method obviates the prior art problem of feeding more material into the drilled cavity than necessary for particular pur- SUMMARY OF INVENTION The method and means of the invention is for providing a concrete pile or other structural column in an earth situs, and includes rotating a relatively large hollow-shafted auger to form a bore of selective full depth in the situs, with a smaller auger selectively rotatable and axially shiftably mounted in shaft of the larger auger and withdrawing the augers from the formed bore by a plurality of increments of total depth thereof. Upon withdrawal of the augers to define a first hollowbore increment, the smaller auger is selectively axially shifted to project into the bore increment to open a closure carried on the smaller auger, and thereby to open the end of the hollow shaft. The smaller auger is, then rotated for forcible conveyance of fluid bore-filling material through the hollow shaft of the larger auger, until material becomes packed in afirst closed hollow bore increment, as by pressure applied by the screw action of the smaller auger. This material compacting procedure is repeated in each successive closed, hollow-bore increment, until a full structural column is formed. The small auger may be selectively withdrawn to close the inner end of the large auger shaft, to stop inward movement of material at any desired depth of bore, such as a predetermined excavation level below the existing earth surface to avoid wasting material. Projection of the rotating smaller auger into the bore increments assures maintenance of a uniform mixture of a fluid concrete mix therein, for example.
Neat cement or mortar may be initially pumped through the smaller auger shaft, before the closure or bit is moved to open the inner end of the larger auger shaft prior to initial withdrawal of the same, thereby to form a concrete base or bulb in the earth, at the bottom of the drilled bore, for increasing the point-bearing load capacity of the finished concrete pile supported thereon (see Figure 1).
As an additional feature of the invention, a remote controlled earth cutting blade is provided at the lower end of the large auger to effect, upon rotation of the auger, radial extension of the auger flighting and thereby enlarge the diameter of the drilled cavity, at the bottom thereof. This enlargement is filled with selfhardenable cementitious material, which upon hardening, forms a base or bulb on which the ultimately formed pile is supported to have substantially increased point-bearing load capacity.
Other objects of the invention will be manifest from the following brief description and the accompanying drawings. I
Of the accompanying drawings:
FIG. 1 is a vertical cross section, partly broken away, through a completed concrete pile produced in an earth situs by one embodiment of the improved method of the invention.
FIG. 2 is a vertical cross section, on the same scale and partly broken away, illustrating the general type of equipment referred to herein, including an auger within an auger, and suitable for practicing the improved methods hereof, at a point in which a pile cavity has been bored to full depth.
FIG. 3 is an enlarged vertical cross section, corresponding to the lower portion of FIG. 2, but illustrating a first stage of incremental withdrawal of the larger auger, at which fluid cementitious material is about to be forced into the first of a plurality of hollow incremental cavity extents.
FIG. 4 is a view corresponding to Figure 3, illustrating a subsequent operation of force feeding fluid, selfhardening cementitious material through the large auger shaft into the first said cavity extent.
FIG. 5 is a view corresponding to FIG. 4, illustrating completion of the first said concrete pile increment, and initial movement of the auger within auger, toward a second incremental stop position for filling a second incremental cavity extent.
FIG. 6 is a fragmentary cross section corresponding to FIG. 5, but showing the larger auger withdrawn from the cavity to a point above the completed pile, and the smaller auger retracted within the larger auger to close the inner end of the hollow shaft thereof, to obviate leaving excess concrete above an excavation line or level.
FIG. 7 is a fragmentary cross section corresponding to FIG. 2, on a reduced scale illustrating use of a similar auger within an auger combination, as for forcefully feeding material into a bore made by the larger auger,
such as for producing a sand drain in the situs.
FIG. 8 is a fragmentary view corresponding to the lower portion of FIG. 6, but with the smaller auger withdrawn to closed position of a closure thereon.
FIG. 9 is an enlarged-scale view of the lower portion of the apparatus shown in FIG. 7, but illustrating use of a power-adjustable blade extension on the large auger flighting, for forming a cavity enlargement as a matrix for a concrete base or bell to increase the point-bearing load capacity of a concrete pile formed by the method of the invention.
FIG. 10 is a horizontal cross section, taken on the line 10-10 of FIG. 9, and on the same scale.
Referring particularly to FIG. 2 of the drawings, there is illustrated apparatus 10 for practicing the method of the invention to produce a unitary concrete pile 11 in an earth situs, as shown in FIG. 1. Such apparatus may include a sectional, continuous flight, hollow-shafted auger 12 rotatably mounted on a suitable carriage 13, which is vertically movable, by means of a hoist cable 14, on guide rails 15 of a drilling rig R. A reversing-type hydraulic motor 16 on the carriage 13 is selectively operable as for. rotating the auger 12 about a vertical axis thereof, through a connecting chain drive 17. The auger 12 is thereby vertically operable at will,
to drill a bore or cavity 18 of any predetermined depth, and likewise to withdraw the auger.
For feeding column-forming material, such as hydraulic cement mortar 19, into the bore from a hopper 28, the hollow shaft 20 may have a smaller hollow-shafted auger 21, or other material pumping or conveying means, independently rotatably mounted thereon, as best shown in FIGS. 2 and 7. Referring to FIG. 2, in particular, the driving bit or closure 22, which normally would be affixed to the lower end of the larger auger, is in this case non-rotatably affixed to the lower end of the smaller auger shaft 21, and is provided with a peripheral seat portion 23 normally held in abutment with the lower end of the larger auger shaft 20, to prevent passage of materials into or out of the shaft passage 24. The smaller auger 21, however, is selectively vertically reciprocable, between extended and retracted conditions with respect to said lower end of the larger auger shaft 20, to open and close the lower end of passage 24 therethrough, as by means of simultaneously operable hydraulic cylinders 25, 25 mounted on the carriage 13 and selectively operable to reciprocate a support 26 for a hydraulic motor 27, which rotatably carries the smaller auger 21. Motors 16 and 27 may be synchronized to rotate as one in clockwise direction, during the operation of large auger 12 for drilling the bore 18. When the bore .has been drilled to requisite depth, however, as shown in FIG. 2, joint rotation of the two augers 12 and 21 may be stopped, and the hydraulic cylinders 25,25 are selectively operable to ram the smaller auger 21 downwardly with respect to the larger auger 12, thereby to open the lower end of shaft passage 24, as shown in FIGS. 3 to 5. While the larger auger 12 may be withdrawn from the formed earth bore 18, with the cored earth retained in the auger flighting as shown in FIGS. 2 to 9 by means of hoist cable 14, it is adapted to be stopped and held affixed at any point while the hydraulic motor 27 is selectively operated to rotate the smaller auger in counter-clockwise direction, uniformly and continuously to feed concrete, sand, or other porous materials from a hopper 28 affixed on carriage 13 (see FIG. 2), downwardly through the auger shaft passage 24, and out through the open lower end of the same, with resultant uniform spreading and force-feeding of the material into the closed cavity increment l8i defined by the selective location of the fixedly spaced inner end of the auger 12.
For the purposes described, the closure or bit 22 may be fishtail shaped to have curvate portions 29,29 which dig into the soil during the bore-drilling operation. In the reverse rotational operation of the bit 22 with the small auger, however, said curvate portions conversely will tend to pack the filler material downwardly by holding the larger auger temporarily affixed for a relatively short period. While the smaller auger is rotated as described, the fluid mortar can be fed or conveyed mechanically by the flighting of the smaller auger into the closed cavity increment l8i until a suitable back pressure is built up against the cavity walls, which will cause relatively slight upward movement of the larger auger which is visibly manifested by corresponding slight movement at the upper end of the large auger.
Referring generally to FIGS. 1 to 6, the steps of the improved method represented therein, include first drilling a bore 18in the earth formation E, as by means of the continuous flight, hollow-shafted auger 12, to predetermined full depth as shown in FIG. 2. Next, the auger 12 is withdrawn from the formed bore 18 by means described above, by successive incremental stages, to a succession of stop positions of auger. l2, defining a plurality of cavity increment extents, from each of which the earth of the situs is removed upwardly by the large auger fiighting and the inner end of the fixed auger 12 is presented toward the respective hollow cavity increment or extent l8i Starting with the first incremental stage, the large auger 12 is withdrawn from the bore 18, a given first incremental extent to a momentarily stopped position, as shown in Figure 3, while the smaller auger may be retained inwardly extended from the end of the larger auger as shown in FIG. 3, or at least sufficiently to maintain the closure 22 in open position for downward, pressure-fed movement of the fluid hydraulic cement mortar, or like self-hardening cementitious material, from supply hopper 28, first to fill the first cavity increment with the mortar and then to compact the same against the resistence of the enclosing walls of the cavity, including portions of the auger flighting and augered earth retained in the flighting. For this purpose, the end of the small auger may be retained either extended or withdrawn with respect to the larger auger shaft, while said larger auger is being withdrawn to the next incremental stop position, as shown in FIG. 5, which corresponds to FIG. 4 except that the first pile increment 11 i will have been compactly formed as described above, aided by delayed, fluid-agitating retention of substantial fiighted extent of the small auger in the fluid mortar (see chain-dotted lines in FIG. 5). This procedure is repeated until a unitary pile 11 of selective extent is formed, as shown in FIGS. 1 and 6, wherein the top of the formed pile is at or below-surface point which subsequently, by excavating, will terminate at the desired elevation. This cut-off procedure is accomplished without waste of cement mortar because the small auger is easily operable from above ground to move the closure 22 to the closed position thereof, as shown in FIG. 6, to stop the flow of fluid material precisely at any desired elevation, after which both augers can be removed from cavity 18 along with the core of augered earth material remaining in in the large auger flighting. Upon setting and hardening of the cement mortar in the successively formed incremental column extents lli the same will have been amalgamated into an integral pile body of substantially uniform density (see FIG. 1).
For certain types of less densified soils of the situs, the load carrying capacity of the finished pile may be increased by, at cavity-forming method stage shown in FIG. 2, pumping chemical or cement grout through the small auger shaft 21, to permeate the soil of the situs and form a so-called bulb or base 11b, which, upon setting and hardening, provides improved point-bearing support for the subsequently completed pile body 11 (see FIG. 1).
FIGS. 7 and 8 illustrate a modified form of auger equipment 10a, suitable for practicing methods of the invention to produce piles or columns of any fluid or flowable material, including self-hardenable cementitious material such as cement mortar, or porous material such as sand.
For producing a sand or porous drain column in an earth situs E, for example, the augering equipment of FIGS. 7 and 8 may include a relatively large, sectional continuous flight auger 35 releasably affixed by means of a coupling 36, to an adaptor tube 37, rotatably mounted on a carriage 38 which is, by a hoist cable 39, vertically movable along guide rails 40 of drilling rig 41. A reversible hydraulic motor 42, on carriage 38, is selectively operable through adaptor 37 to rotate the auger 35 about a vertical axis of the same for drilling a large diameter bore 46 of requisite extent in the situs E, in accordance with methods to be described later. Cutting teeth 47 or other driving means may be provided on the lower end of auger 35.
A hopper 48 may be affixed on lower part 4911 of a two-part carriage 49, to be vertically movable therewith along the upright guide rails 40, by means of a hoist cable 50, either concurrently with or independently of the carriage 38. For this purpose, the hopper 48 converges to a tubular section 51 having non-rotatable, quickly releasable connection to the carriage 38 to communicate the interior of the hopper with the cylindrical passage 52 through adaptor tube 37 to the passageway 53 of the large auger 35, without interfering with rotation of the auger. To this end, the hopper section 51 may have affixed to its lower end a centrally apertured annulus 54, held complementally and nonrotatably seated in peripheral seat means 55 on carriage 38, as by a plurality of quick-acting, springpressed latches 56,56 provided on a fixed part of the carriage 38.
A reversible hydraulic motor 58 mounted on upper part 49b of the two-part carriage 49, releasably attached to part 49a thereof, carries a relatively small, sectional auger device 59 adapted to extend through the hollow shaft 57 of the large auger 35, selectively to be rotated at the same time or independently thereof, in any rotational direction. For ease of changing the lengths of both augers at the same time, the small auger device 59 may have a releasable coupling of known type, slightly below the coupling 36 of the large auger. In this way, the small auger selectively may be made to extend either beyond the inner end of the large auger as shown in FIG. 7, or to position a combined driving bit and closure member 61, affixed on the hollow shaft portion 59d of the small auger within the passageway 53 of the larger hollow shaft 57. Auger device 59 may be reciprocated toward and from the FIG. 6, closed position of closure 61, by releasing latch means 56 and thereby, through cable 50, to raise or lower the carriage 49 with hopper 48thereon. This actuation of car- 7 riage 49 also may be utilized to empty hopper 48, or to inspect soil of the situs collected in the flighting of the small auger. Alternatively, the auger device 59 may be similarly reciprocated or retracted, without hopper 48, by releasing upper carriage part 49b from carriage part 49a at 49c.
For certain purposes, fluid hydraulic cement mortar or grout, under pressure, may be pumped through the hollow shaft of small auger 59, through a suitable swivel connector 64 at the upper end thereof.
Referring further to FIG. 7, while the small auger device 59 may be of the substantially continuous-flight type, the present invention contemplates provision of substantial extents 59a and 59b of spiral flighting at the upper and lower ends of small auger shaft 590 and a substantial intermediate extent 590 of the smaller auger adapted to be contained within the large auger shaft 57 (see FIGS. 7 and 8). Affixed to the upper portion of the intermediate shaft extent 59c or otherwise within or below hopper 48 there may be at least one fluid pump P, which utilizes a screw-like rotor (not shown) and operable by rotation of .auger device 59 to pump fluid material, such as cement mortar, granular materials, or mixes and the like, including sand. By rotation of auger device 59 within the large auger shaft 57, therefore, fluid material from hopper 48 is fed to pump P, which I accelerates movement of the material through the large auger shaft in the open position of closure, shown in FIG. 7, which corresponds to the first incremental stop position of the larger auger as is shown and described above in connection with FIGS. 3 and 4. As before, the fluid sand may be forced into each cavity increment as shown in FIG. 7, in which the pressurized fluid material is being mixed and further compacted within the confined cavity space, by the rotating auger flight extent 59b. When each said cavity space has been compactly filled with material the closure 61 may be moved to closed position before starting upward movement of the larger auger, as shown in FIG. 8, or the small auger extent 59b may be extended and rotating in a manner to keep the filler material compacted. The segmental step process may be repeated as described until the desired upward extent of formed sand or other column is accomplished, at which time the small auger may be withdrawn to the closed position of closure 61, to accomplish full withdrawal of the larger auger without unnecessary loss of filler material.
Referring to FIGS. 9 and 10, there is illustrated a modified form of the soil augering means best shown in FIG. 1, but in which a cutter plate or blade is mounted on the lowermost portion of the flighting 12f of large auger 12, to be selectively slidable toward and from a position in which a substantial extent of the blade will project into the earth of the situs, as shown in chain-dotted lines in FIG. 10, for enlarging the diameter of a substantial vertical extent 71 of the lower end of the cavity 18, by appropriate axial movement of the large auger while being rotated in cavity boring direction (see FIGS. 9 and 10). For this purpose a hydraulically, actuated piston unit 72, mounted on the underside of the large auger flighting 12f, is selectively operable by suitable remote control means (not shown), to extend the blade 70 beyond the peripheral edge of said auger flighting 12f, as shown in chaindotted lines in FIG. 10. The projected blade 70 is adapted, with appropriate rotation and axial movement of the large auger 12, to feed the material scooped from the augered enlargement 71 up the large auger flighting 12f, for removal of the scooped material along with the earth core from the augered cavity 18. This feature makes it possible to form a concrete base or bulb 11d,
in the enlarged cavity portion 71, which becomes an integral part of the completed concrete pile 11.
Further in reference to FIGS. 9 and 10, it is readily apparent that the blade 70 may be adjusted to extend beyond the cutting edge of the auger flighting a lesser extent than shown, as for example a fraction of an inch, thereby during rotative withdrawal of the large auger, to provide scoring or grooving on the walls of at least one of the cavity increment extents 18i. The subsequently formed and hardened concrete pile for example, by extension into the scores or grooves in the cavity walls will, by increasing the shear resistence of the hardened pile, increase the ultimate load bearing capacity of the pile correspondingly. This scoring procedure can be utilized in forming concrete piles by other methods utilizing hollow-shafted augers.
In practice of the foregoing and related methods for producing concrete piles, load-bearing capacities of the finished piles may be substantially increased by, before or while pumping the fluid cement mortar into each closed cavity increment, forcing chemical or cement grout through the small auger shafts 21 or 59 of FIGS. 2 and 7, respectively. The relatively more fluid grout is thereby displaced by the heavier pressurized cement mortar, and is forced into the cavity wall areas of the respective cavity extents to permeate radially into the surrounding earth, including fissures, crevices and voids therein. The grout-permeated earth hardens substantially as integral reinforcing extensions of the hardened concrete piles, with very substantial increase in said pile load-bearing capacities. The degree of penetration of the more fluid grout will depend upon the permeability of the surrounding soil, but is to a substantial degree measurable by the total amount of grout pumped into the cavity and/or the amounts pumped into the cavity increments.
In a modified use of the apparatus generally described above, and particularly as described above in reference to FIGS. 1 to 6, for producing columns of either self-hardenable cementitious material or porous materials, the following method procedure is calculated to produce highly satisfactory results. After screwing the larger auger into the situs to full depth of the cavity 18, the large auger is withdrawn by a plurality of separate incremental steps to successive stop positions of the larger auger, as shown in FIGS. 4 and 5, each time at a given withdrawal speed while rotating the smaller auger 21 at a second rate of speed, calculated mechanically to force-feed the fluid material from the hopper axially into the respective cavity increment at a faster linear speed than the rate of withdrawal of the larger auger. As the larger auger is thus withdrawn toward any given said stop position, however, the continued relatively fast rotation of the smaller auger, including a substantial flighted extent thereof presented below the inner end of the larger auger (see FIGS. 4 and 5), force-feeds the fluid material into the corresponding cavity increment l8i, rapidly to fill the same to a point of refusal at which the fluid material becomes static in the large auger shaft passage 24, as well as in the supply hopper. Full or maximum compactionand densifying of the fluid material fed or conveyed into each closed cavity increment 181' will be readily discernible at each said point or period of refusal by observing an accompanying static condition of the material in the hopper, or by slight upward movement of the larger auger, after which the operation is repeated until the incremental column is completed, generally as shown in FIG. 1. In addition, the above-described force-feeding rotation of the smaller auger may be accompanied by reciprocation of the same to provide pumping action in the discharged fluid material.
Modification of the invention may be resorted to without departing from the spirit of the invention or the scope of the appended claims.
What is claimed is:
I 1. A method as for providing in an earth situs a column or structural formation of material different from that of the situs, comprising the steps of: screwing a continuous flight hollow-shafted auger inwardly into the situs to form a pile cavity therein of requisite depth; and withdrawing said auger, substantially without retraction of soil carried by the auger flighting into the cavity, by a plurality of successive incremental stages to stop positions of the auger defining a plurality of corresponding cavity increment extents in which the inner end of the auger is substantially non-rotatably presented to the respective said cavity increment extents; fluid column-forming material being force fed through the hollow shaft of the auger into the successive said cavity increment extents, in upward progression, while the auger is in corresponding said stop positions thereof rapidly to fill the respective cavity increment extents one upon the other: and the steps of the method including rotation of a second auger within said auger shaft, with a flighted extent of the second auger presented within the respective cavity increment extent, for downward compaction of the fluid fill material against the resistance of the enclosing walls of the formed cavity, whereby an integrated column of selective total length is formed in said pile cavity.
2. A method as in claim 1, wherein said hollowshafted auger is maintained in the stopped positions thereof until the column-forming material, forcefully fed to the cavity increment extents is compacted into the enclosing walls defining the same.
3. A method as in claim 1, wherein said columnforming material is self-hardening cementitious materia1.
4. A method as in claim 1, wherein said columnforming material is self-hardening cementitious material, and successive said cavity increment extents are filled therewith integrally to unite with fluid cementitious material of the next preceding filled cavity increment extent.
5. A method as in claim 1, said feeding of fluid column-forming material through said hollow shaft being controlled by reciprocation of an elongated element extending through the hollow shaft for opening and closing a closure on the inner end of the same.
6. A method as in claim 1, said feeding of fluid column-forming material through said hollow shaft being controlled by reciprocation of said second auger through the hollow shaft for opening and closing a closure on the inner end of the hollow shaft.
7. A method as for providing in an earth situs a column or structural formation of material different from that of the situs, comprising the steps of: screwing a hollow-shafted auger inwardly into the situs to form a pile cavity therein of requisite depth; withdrawing said auger by successive incremental stages to stop positions defining a plurality of cavity increment extents in which the inner end of the shaft is presented to the respective said cavity increment extent; feeding fluid columnforming material through the hollow shaft of the auger into each successive said cavity increment extent, in upward progression, while the auger is in corresponding said stop positions to fill the respective cavity increment extents one upon the other until a column of said selective length is formed; the method including pumping relatively thin'solidiflable fluid into said pile cavity to be displaced by said column-forming material and permeate into the earth surrounding the formed column.
8. A method as in claim 7, wherein said columnforming material is hydraulic cement mortar.
9. A method as for providing a concrete or like pile in an earth situs comprising the steps of: screwing a hollow-shafted auger inwardly into the situs to form a pile cavity therein of requisite depth; withdrawing said auger to at least one stop position defining a closed cavity extent beyond the inner end of the shaft; feeding self-hardenable pile-forming cementitious material from a source of supply thereof, through the hollow shaft of the auger into said cavity to displace a more fluid grout also fed into said cavity from a different source thereof, whereby said displaced fluid grout is caused to permeate radially into the soil of the situs and increase the load-bearing capacity of the formed pile.
10. A method as in claim 7, wherein said pile-forming material is hydraulic cement mortar force fed into the closed cavity.
11. A method as for providing in a earth situs a column or structural formation of material different from that of the situs, comprising the steps of: screwing a hollow-shafted auger inwardly into the situs to form a cavity therein of requisite depth; withdrawing said auger by successive incremental stages to stop positions defining a plurality of cavity increment extents in which the inner end of the auger is substantially non-rotatably presented toward each respective said cavity increment extent, while mechanically force-feeding fluid columnforming material from a source thereof to convey said material through the hollow shaft of the auger into each successive said cavity increment extent, in upward progression; and the steps of the method including rotation of a second auger within said auger shaft, with a flighted extent of the second auger presented within the respective cavity increment extent, for downward compaction of the fluid fill material against the resistance of the enclosing walls of the formed cavity, whereby an integrated structural body of selective total length is formed in said pile cavity.
12. A method as in claim 11, wherein the fluid material is fed through said hollow shaft by force-feeding flighting of said second auger within the hollow shaft.
13. A method as in claim 12, wherein said fluid material is in the class including self-hardenable cementitious material and porous materials.
14. A method as in claim 11, wherein said fluid material is in the class including self-hardenable cementitious materials and orous materials.
15. A method as in 0 arm 11, wherein said second auger is reciprocated with respect to said hollowshafted auger while a flighting extent of the second auger is within the material fed into formed cavity.