US3426538A - Method of making sand drains in situ - Google Patents

Description

Sheet INVENTOR. LEE A. TURZILLO ATTQRNEY Feb. 11, 1969 A. TuRzlLLO METHOD OF MKING SAND DRAINS IN SITU Filed Mamme, 1965 Feb. 11, 1969 L A. TuRziLLo METHOD OF MAKING SAND DRAINS IN SITU Sheet Filed March 19, 1965 INVENTOR. LEE A. TURZILLO ATTORNEY United States Patent O 6 Claims Int. Cl. E021 11 /00; E02d 5 /34 ABSTRACT OF THE DISCLOSURE Method and rrneans for providing in an earth situs a pile or other structural column different from that of the situs, includes screwing hollowshafted auger into situs to form bore, and smaller auger is selectively axially shifted in the hollow shaft to move closure carried by smaller auger to selectively adjusted spacing of closure from closed position against inner end of hollow shaft. Larger auger progressively -Withdrawn from bore while rotating smaller auger in hollow shaft, forcibly to convey bore filling material through hollow shaft, past closure and be dispersed and compacted within the bore. Other means provided, separately supplying fluid material to bore through shaft of smaller auger for `combination with materials conveyed into bore by auger ilighting.

This invention relates to a method and apparatus for making sand drains, concrete piles, and other columnar structures in an earth situs.

Heretofore, sand drains have been made for the purpose of accomplishing more effective Water drainage in porous soils in the earths surface. Generally, a deep bore was drilled or cored in the earth and a metal casing Was forced vertically into the same and lled with sand, and then the casing was removed to leave a core of Iwaterpervious sand in the bore. Such sand drains were not always satisfactory, however, because of a tendency for the sand to bridge between opposite wall portions of the casing to leave voids or pockets which tended to prevent uniform distribution and packing of the sand as necessary for attaining effective drainage. The process of installing and removing the casing, however, tended to score and smear the surface portions of the bore, and reduced the effective permeability of the same. In other words, it was found that sand could not be satisfactorily fed into the bored holes through pipes or tubes because of a strong tendency for the sand to bridge across the inside of the passages thereof and, thereby, clog thev same.

One object of the present invention is to provide an -improved method and apparatus for forming sand drains in the earth, by which the resultant sand drainage core will be uniformly packed and free of voids.

Another object of the invention is to provide an improved method and apparatus for making sand drains, concrete piles, and other columnar structures to the full depth of drilled -holes in the earth, progressively and simultaneously with removal of the earth materials from the hole 'with the drill.

Still another object of the invention is to provide an improved method for making `an effective and eiiicient sand drain, and other columnar structures, in the earth, to completion, with approximately the same amount of equipment handling as for augering the hole for the 3,426,538 Patented Feb. 11, 1969 columnar structure, and in substantially the same length of time as nonmally required to auger said hole.

These and other objects of the invention will be manifest from the following brief description and the accompanying drawings.

Of the accompanying drawings:

FIGURE l is a vertical cross-section through a sand drain in the earth, made by use of the improved method and apparatus of the invention.

FIGURE 2 is a vertical cross-section, on the same scale and partly broken away and in section, illustrating the improved said drain making equipment, at a point in the method Where the sand drain hole has been bored to full depth.

FIGURE 3 is an enlarged vertical cross-section, corresponding to the lower portion of FIGURE 2, but illustrating the beginning of the operation of uniformly distributing sand within the bored hole.

FIGURE 4 is a view corresponding to FIGURE 3, illustrating another initial but subsequent period in the sand distributing operation of said equipment.

Referring particularly to FIGURE 2, there is illustrated apparatus 10 for practicing the method of the invention for making a sand drain 11 in an earth situs (see FIG- URE 1). Such apparatus may include a sectional, continuous flight, hollow-shaft auger 12 rotatably mounted on a suitable carriage 13, which is vertically movable, by 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 to rotate the auger 12 about a vertical axis thereof, through a connecting 'chain drive 17. Thus, the auger 12 is vertically operable to drill a bore 18 of any predetermined depth.

For feeding Water-pervious material, such as sand 19, into the bore, the hollow shaft 20 may have a smaller hollow-shafted auger 21 independently rotatably mounted thereon, as shown in FIGURES 2, 3, and 4. The driving bit 22, which normally would be aflixed to the lower end of the larger auger, is in this case non-rotatably aixed to the lower end of the smaller auger, and is provided with a peripheral seat portion 23 normally held in abutment with the lower end of the 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 condition with respect to said lower end of auger shaft 20, to open and close the lower end of passage 24, 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 clock- Wise direction, during the operation of auger 12 for drilling the bore 1S. When the bore has been drilled to requisite depth, however, as shown in FIGURE 2, joint rotation of the two augers 12 and 21 is stopped, 4and the hydraulic lcylinders 25, 25 are operated to ram the smaller auger 21 downwardly with respect to the larger auger 12 and, thereby, to open the lower end of shaft passage 24, as shown in FIGURE 3. While the larger auger 12 is slowly raised out of the formed earth bore 18, by means of hoist cable 14, the hydraulic motor 27 is operated to rotate the smaller auger in counter-clockwise direction, uniformly and continuously to feed sand or other porous 3 material from hopper 28, affixed on carriage 13 (see FIGURE 2), downwardly in the auger shaft passage 24, and out through the open lower end of the same, with resultant uniform spreading and packing of the sand from Wall to wall in the bore 18 (see FIGURES 3 and 4).

For the purposes described, the rotating bit 22 may be fish-tail 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, however, said curvate portions conversely will tend to pack the sand downwardly whereby upon complete removal of the combination auger from the bore, the resultant sand drain 11 will be free of objectionable materials and voids and have uniform water permeability (see FIGURE 1).

Accordingly, the steps of the improved method basically include drilling a bore 18 in the earth formation E, requiring soil consolidation for supporting a heavy building or other construction thereon, as by means of the hollow, continuous iiight, hollow-shaft auger 12, to predetermined depth; and while progressively withdrawing the auger to remove the augered earth from the formed bore 18, simultaneously and progressively force feeding sand through the passage in the auger 12 to lill the space within said bore left by progressive removal of auger 12 and the removed earth. As clearly described above, continuous downward feeding of the sand 19 may be accomplished by means of the selectively operable small auger 21 relatively rotatable Within the larger auger shaft passage 24 to force the sand through said passage and into the angered bore. The continuous mechanical impacting of the sand 19 into the angered bore, assures uniform distribution and packing of the sand to the full depth of the bore for most effective and eilicient consolidation of the surrounding earth formations, in accordance with the stated objects of the invention.

It will be readily apparent that the method and apparatus may have uses for other than constructing sand drains. That is, loose materials other than sand may be mechanically fed through the hollow shaft auger 12 and likewise progressively compacted to the full depth of the angered bore. As an example, concrete or other tluid cementitious material may be fed into the bore 18 in this manner to form a solid supporting pile or column, and thereby eliminate the heavy expensive grout-pumping equipment generally required for installing concrete piling.

If it is desired to fill the bore 18 with material under pressure, such as self-hardening fluid grout, the same may be pumped from a suitable source through a swivel joint 31 connected at or near the -upper end of a conduit extension 32 of small auger 21, the passage 33 in the hollow shaft of auger 21, and outlet ports 34, 34 in driving bit 22, and into the bore. Fluid grout, for example, may be pumped in this manner while the end of the larger auger 12 is open at the bottom, as shown in FIGURES 3 and 4, or closed, as shown in FIGURE 1. Water may be pumped through the shaft of small auger 21 while simultaneously feeding Ia bulk material, such as a concrete mix, down the hollow shaft of said larger auger, and these separately introduced materials may be blended together as the auger 12 is withdrawn from the bore, in the manner previously described,

It is also possible by means of the small a-uger 21, for example, to feed granular material, such as pea gravel or coarse aggregate from hopper 28 into the hole 18 (as shown in FIGURES 3 and 4), simultaneously with feeding or pumping fluid grout under pressure through the passage 33 of the small auger, as necessary, to provide a requisite concrete mix in the hole. Accordingly, the materials may be blended to suit varying conditions at different levels within the hole, as an example. In this way, it is possible to form a concrete pile according to Variable specifications, simultaneously with removal of the earth materials from the hole with the hole drilling unit.

When fluid grout is supplied to the bottom of the hole 18 through the passage 33 of the small auger, with or without additional granular material, as described above, any water and/or residual earth material left in the hole 18 will be displaced by the pressurized grout as the auger unit is progressively withdrawn from the hole.

By reference to FIGURE 2, it will be seen that the aforementioned sand, concrete, pea gravel, coarse aggregate, or blends of materials, can be supplied to the relatively iixed hopper 28 through the open top thereof while the augers 12 or 21 are rotating or stationary. By the same token, materials conveyed upwardly into the hopper by the smaller auger 21 can be viewed or sampled for inspection purposes while the two augers are rotating or stationary.

Other modifications of the invention may be resorted to without departing from the spirit thereof or the scope of the appended claims.

What is claimed is:

1. A method of providing in an earth situs a column of structural formation diiferent from that of the situs, comprising the steps of: screwing a hollow shafted auger inwardly into the situs to form a bore therein of predetermined depth; selectively axially shifting to variable extent a smaller, continuous Hight auger inwardly within the hollow shaft of the larger auger to carry a closure on the inner end of the smaller auger to selectively adjusted spacing of the closure inwardly from a closed position against the inner end of the hollow shaft of the larger auger; and progressively withdrawing the larger auger while rotating said smaller auger within the hollow shaft to convey bore filling material, from a supply thereof at the upper end of the larger auger, through the hollow shaft to be dispersed past the closure progressively to lill the bore.

2. A method as in claim 1, wherein said supply of filler material is fed from a relatively xed hopper commumeating with said hollow shaft of the larger auger, and the smaller auger is reversely rotatable for selectively conveying material up the flighting thereof to the relatively fixed hopper.

3. A method as in claim 2, wherein a second filler material from a source of supply is simultaneously fed downwardly through a passage in the smaller auger to an outlet disposed within the bore below the larger auger for blending convergence with the bore filling material conveyed through said hollow shaft.

4. A method as in claim 1, wherein a second filler material from a source of supply is simultaneously fed downwardly through a passage in the smaller auger to an outlet disposed within the bore below the larger auger for blending convergence with the bore filling material conveyed through said hollow shaft.

5. A method as in claim 1, wherein a second liller material from a source of supply is simultaneously fed downwardly through a passage in the smaller auger to an outlet disposed within the bore below the larger auger for blending convergence with the bore filling material conveyed through said hollow shaft, wherein the separately fed materials include a granular substance and hardenable fluid grout forming `a concrete pile in the bore.

6. A method of providing in a situs of an earth formation, a core of a different structural formation, comprising the steps of: screwing a hollow drill into the earth formation to form a bore of predetermined depth therein; and while progressively withdrawing the drill to remove the cored earth from the bore, simultaneously feeding filler material downwardly through the hollow drill, progressively to lill the space in the bore left below the drill upon said progressive Withdrawal of the drill; said filler material including different materials separately fed toward blending convergence in the space below the drill References Cited UNITED STATES PATENTS Bowslaugh 61-11 Powell 61-53.64 Ranney.

Ryser etal 61-53.64 Case et al. 61-35 Durston et al. 61-63 Durston et al. 61--11 6 8/1965 Phares et al. 61-53.64 9/1965 Moor (wl-53.64 1/1966 Dufresne 61-53.64 9/1966 Landau 61-11 2/1967 Landau 61-11 X FOREIGN PATENTS 1/ 1961 Switzerland. 9/1963 Canada.

U.S. Cl. XR.

UNITED STATES PATENT OFFICE CERTIFICATE 0F CORRECTION Patent No. 3,426,538 February ll, 1969 Lee A. Turzillo It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 6, line 5, cancel "3,030,656 2/1967 Landau 6l-ll X Signed and sealed this 17th day of November 1970.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Edward M, Fletcher, Jr.

Commissioner of Patents Attesting Officer

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