US20040182607A1 - Method of forming concrete pilings using a reverse circulation drilling system - Google Patents
Method of forming concrete pilings using a reverse circulation drilling system Download PDFInfo
- Publication number
- US20040182607A1 US20040182607A1 US10/704,386 US70438603A US2004182607A1 US 20040182607 A1 US20040182607 A1 US 20040182607A1 US 70438603 A US70438603 A US 70438603A US 2004182607 A1 US2004182607 A1 US 2004182607A1
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- Prior art keywords
- driver
- arms
- pilot bit
- underreaming
- bit
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- 238000005553 drilling Methods 0.000 title claims description 29
- 239000000463 material Substances 0.000 claims abstract description 7
- 230000002093 peripheral effect Effects 0.000 claims description 6
- 238000004891 communication Methods 0.000 claims description 4
- 238000007599 discharging Methods 0.000 claims description 2
- 239000012530 fluid Substances 0.000 claims 2
- 230000009977 dual effect Effects 0.000 description 18
- 239000012634 fragment Substances 0.000 description 5
- 239000011435 rock Substances 0.000 description 4
- 239000002689 soil Substances 0.000 description 4
- 229910000831 Steel Inorganic materials 0.000 description 3
- 238000013461 design Methods 0.000 description 3
- 238000007789 sealing Methods 0.000 description 3
- 239000010959 steel Substances 0.000 description 3
- 238000006073 displacement reaction Methods 0.000 description 2
- NJPPVKZQTLUDBO-UHFFFAOYSA-N novaluron Chemical compound C1=C(Cl)C(OC(F)(F)C(OC(F)(F)F)F)=CC=C1NC(=O)NC(=O)C1=C(F)C=CC=C1F NJPPVKZQTLUDBO-UHFFFAOYSA-N 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 230000000717 retained effect Effects 0.000 description 2
- 230000000712 assembly Effects 0.000 description 1
- 238000000429 assembly Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000004886 head movement Effects 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
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- 238000013508 migration Methods 0.000 description 1
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- 125000006850 spacer group Chemical group 0.000 description 1
- UONOETXJSWQNOL-UHFFFAOYSA-N tungsten carbide Chemical compound [W+]#[C-] UONOETXJSWQNOL-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B4/00—Drives for drilling, used in the borehole
- E21B4/06—Down-hole impacting means, e.g. hammers
- E21B4/14—Fluid operated hammers
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D5/00—Bulkheads, piles, or other structural elements specially adapted to foundation engineering
- E02D5/22—Piles
- E02D5/34—Concrete or concrete-like piles cast in position ; Apparatus for making same
- E02D5/38—Concrete or concrete-like piles cast in position ; Apparatus for making same making by use of mould-pipes or other moulds
- E02D5/385—Concrete or concrete-like piles cast in position ; Apparatus for making same making by use of mould-pipes or other moulds with removal of the outer mould-pipes
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D5/00—Bulkheads, piles, or other structural elements specially adapted to foundation engineering
- E02D5/22—Piles
- E02D5/34—Concrete or concrete-like piles cast in position ; Apparatus for making same
- E02D5/46—Concrete or concrete-like piles cast in position ; Apparatus for making same making in situ by forcing bonding agents into gravel fillings or the soil
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B10/00—Drill bits
- E21B10/26—Drill bits with leading portion, i.e. drill bits with a pilot cutter; Drill bits for enlarging the borehole, e.g. reamers
- E21B10/32—Drill bits with leading portion, i.e. drill bits with a pilot cutter; Drill bits for enlarging the borehole, e.g. reamers with expansible cutting tools
- E21B10/327—Drill bits with leading portion, i.e. drill bits with a pilot cutter; Drill bits for enlarging the borehole, e.g. reamers with expansible cutting tools the cutter being pivoted about a longitudinal axis
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B21/00—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor
- E21B21/16—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor using gaseous fluids
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B7/00—Special methods or apparatus for drilling
- E21B7/20—Driving or forcing casings or pipes into boreholes, e.g. sinking; Simultaneously drilling and casing boreholes
- E21B7/201—Driving or forcing casings or pipes into boreholes, e.g. sinking; Simultaneously drilling and casing boreholes with helical conveying means
- E21B7/203—Driving or forcing casings or pipes into boreholes, e.g. sinking; Simultaneously drilling and casing boreholes with helical conveying means using down-hole drives
Definitions
- the present invention is related to forming concrete pilings, and particularly forming concrete pilings down hole, pneumatic, percussive hammer drilling systems.
- Eccentrically mounted underreamers which include an arm which travels in an orbit for underreaming operation, and which are retractable toward the hole axis for tool removal purposes.
- Other known underreaming equipment utilizes three bit mounted plates which are outwardly displaceable, bit which incorporate a total working surface which is substantially less than the perimeter of the bore. Such undersized plates are subject to excessive wear and result in slow drilling operation. Underreaming can also be achieved by use of a crown or ring bit, but components of those bits must be left in the underreamed area when drilling is complete, which is costly and otherwise unacceptable in some drilling operations.
- FIG. 5 is a cross-sectional view of the down-hole pneumatic hammer assembly, including the bit assembly.
- FIG. 5A is a perspective view of an alternative design for the hammer barrel of the down-hole pneumatic hammer assembly.
- FIG. 7A is a perspective view of the pilot bit on the embodiment of FIG. 6A.
- FIG. 7B is a bottom view of the pilot bit shown in FIG. 7A.
- FIG. 9A is an end view of the underreamer arm shown in FIG. 8.
- FIG. 9B is an outer side view of the underreamer arm shown in FIG. 8.
- FIG. 12 an enlarged exposed view of the bit assembly shown in FIG. 11.
- FIGS. 13 and 14 are horizontal sectional views taken along line 3 - 3 of FIG. 11 and showing the lower portion of the driver receiving the underreaming arms with the arms shown extended and retracted;
- FIG. 15 is a vertical sectional view taken along line 5 - 5 of FIG. 13 showing a fragment of the driver bottom wall and an arm locking pad thereon;
- FIG. 16 is a vertical sectional view taken along line 6 - 6 of FIG. 11;
- FIG. 17 is a perspective view of an underreamer arm.
- a reverse circulation drilling system shown generally at 10 , includes a head assembly 11 , a dual wall pipe assembly 12 , and a down hole pneumatic hammer 13 within a bore casing 14 .
- head assembly 11 includes a casing driver 15 for driving the bore casing 14 downwardly as the bit advances, and a power head assembly 16 of standard design for rotating the bore casing 14 it is driven downwardly.
- Casing driver 15 includes an annular hammer 17 which reciprocates vertically as compressed air is alternatively admitted to chambers above and below hammer 17 .
- Hammer 17 impacts on anvil 18 , which in turn impacts on casing cap 19 .
- dual wall pipe assembly 12 is assembled from individual segments, each of which includes an inner pipe 31 and an outer pipe 33 .
- Each segment includes a threaded male connector 33 and a threaded female connector 35 at opposite ends.
- Male connector 14 and female connector 15 each includes air ports 36 and 37 respectively which are in communication with outer annulus 24 of dual wall pipe assembly 11 .
- dual wall pipe assembly is threaded in to central member 22 of power head 16 .
- dual wall pipe assembly 11 is connected to the box 38 , which in turn is threaded into back head 40 of down-hole hammer 13 .
- Ports 42 an 44 communicate with annulus 24 of the dual wall pipe assembly to route compressed air therefrom into the down hole hammer.
- down-hole hammer 13 includes box 38 threaded onto back head 40 .
- a sleeve 41 and a hammer barrel 42 are threaded into back head 40 .
- a centrally located discharge tube 43 is pressed into sleeve 41 .
- a wear sleeve 44 is fitted around hammer barrel 40 , and press fitted over ring 45 and onto shoulder 46 of back head 40 .
- Sleeve 41 and barrel 42 define an annular upper air chamber 48 .
- Central evacuation tube 43 and barrel 42 define an annular lower air chamber 50 .
- the lower end of barrel 42 abuts bit driver 52 , and also includes a perimetrical lip 54 which engages wear sleeve 44 to center barrel 42 in the wear sleeve.
- a bit assembly for use with the present invention is shown in FIGS. 6-10.
- a bit assembly consists of a bit driver 52 , a pilot bit 82 , and arms 88 a - c .
- Bit driver 52 includes an upper shank 83 having a recessed chamfer 84 , camming surfaces 85 a and 85 b , and a lower portion 86 .
- Lower portion 86 includes three peripheral recesses 87 a - c .
- Hardened drilling buttons preferably made of a carbide material, are mounted on the peripheral and bottom surfaces of the pilot bit (Fig. 7).
- the overall diameter of the bit assembly is less than the inner diameter of the bore casing, permitting the bit assembly to be withdrawn from the bore.
- the overall diameter of the underreamer assembly is less than the inside diameter of the casing, permitting withdrawal of the entire underreamer bit assembly through the casing if necessary.
- compressed air is delivered into annular chamber 59 through port 37 , radial ports 60 , annulus 62 and axial ports 64 .
- hammer 53 is shown during its downward stroke. Lip 66 is engaged with lip 68 , sealing off chamber 48 . Lip 72 is engaged with lip 74 , sealing off chamber 50 . Port 78 is closed. As piston 53 continues downwardly, port 76 is uncovered, exhausting chamber 48 . At about the same time, lip 74 disengages from lip 72 , admitting a fresh charge of compressed air into chamber 50 to raise piston 53 to its upper position after it has struck bit driver 52 . As piston 53 rises, port 78 is uncovered, exhausting chamber 50 .
- the flow of compressed air through the bit assembly is essentially continuous, and provides a continuous evacuation of drilling debris from the drilling face of the bore.
- the essentially constant diameter of the evacuation tube and inner wall of the dual wall pipe assembly provides a constant air velocity, which further aids debris removal.
- the continuous removal of debris through the central evacuation tube promotes continuous drilling. It is seldom, if ever necessary to stop drilling and raise the bit to clear debris from the bore. Significant improvements in drilling rates can directly result.
- FIGS. 6B and FIGS. 11-17 An alternative bit assembly is shown in FIGS. 6B and FIGS. 11-17.
- the reference numeral 101 indicates generally the present drill bit assembly for attachment to the lower end of pneumatic down hole hammer.
- a driver at 102 includes a shank 103 of a diameter and splined for attachment to the percussive hammer. Integral with the shank is a driver head 104 . About head 104 are circumferencially spaced channels 105 for upward passage of earthen particles or debris. An axially extending bore 106 of the driver receives a pressurized downward air flow for particle removal. Head 104 is cross bored off center at 107 to receive pin 108 engageable with a later described pilot bit of the drill assembly.
- a lowermost surface 110 of the driver head 104 defines a series of cylindrical sockets 111 uniformly spaced apart and from vertical axis at A of the driver (FIG. 13). Each socket has a companion elongate recess 113 formed in the lower portion of the driver to receive a limit stop pin of a later described underreamer arm. Additionally, lowermost surface 110 of head 104 is provided with multiple arm lock pads 114 in the form of downward projections which serve to lock each underreamer arm in an extended operative position.
- An internal wall of the driver includes segments 116 and 117 which define an open area which receives a cam block 118 and permits head movement thereabout. Irregular wall surfaces, 116 - 117 alternately abut the cam block to limit driver rotation during arm positioning as later discussed.
- a set of underreamer arms are indicated generally at 119 in FIG. 12 with the following description of one arm applicable to all of the arms at 120 which are generally of angular shape in plan view.
- an arm pivot post 121 seats in a socket 111 formed in the underside of head 14 of the driver.
- a limit stop post or pin 122 of the arm projects upwardly into an elongate recess 113 in the underside of the driver head 104 with an end wall 113 A of the recess limiting outward displacement of arm limit stop pin 122 .
- a pilot bit is generally indicated at 130 and includes a main body 131 having an uppermost surface 132 on which is centrally located cam block 118 with walls 136 . Integral with cam block 118 is a pedestal 137 having an annular groove 138 thereabout to receive head carried pin 8 in a tangential manner. Groove 130 is oversize to permit upward displacement of driver 12 during arm positioning and subsequent locking of the arms.
- a compressed air central passageway is at 139 of the bit and is in registration with driver air passageway 106 . Spaced about the lower perimeter 131 of drill bit 130 are channel 141 through which debris flows upwardly past the arms during a drilling operation.
- a bottom wall 142 of the drill bit defines radially disposed air channels 143 which are served with compressed air flows via internal passageways served by axial passageway 139 .
- the lowermost surface 142 of the drill bit is suitably equipped with tungsten carbide buttons or other wear resistant members 144 commonly used in earth drilling equipment.
- pilot bit 130 advances into the ground with the underreamer arms locked in a deployed position below and radially beyond the advancing end of the casing at C. Casing movement is facilitated by the relatively large underreamed area, and if required, by the casing driver 15 .
- linkage 21 operates a valve to provide compressed air to the pneumatic hammer 17 and associated porting casing driver 15 .
- the driver is partially rotated in the direction opposite to drilling rotation to shift the arm pivot pins and specifically the arm inner ends along cam block walls 36 to retract each arm.
- Arm retraction is aided by the beveled arm outer edges 123 A engaging the bottom edge of casing C during retraction at the end of a drilling operation to permit removal of the drill bit assembly through the casing.
- FIGS. 18A and 18B The down-hole percussive hammer and underreamer bit is shown generally at 1810 .
- Assembly 1810 is operated to form hole 1820 as described above.
- valve 1830 is closed to isolate the central channel 1840 from the vacuum unit (not shown). Concrete is then pumped into central channel 1840 through inlet 1850 . Low-pressure air is also introduced into through air inlet 1860 to slightly pressurize casing 1870 . Once the concrete has filled central channel 1840 , the casing is slowly removed from the bore as more concrete is pumped into central channel 1840 .
- the concrete flows downwardly through central channel 1840 and out through bit 1880 into the bottom of hole 1820 .
- a small spacer 1890 is mounted onto the bottom of bit 1880 to keep it spaced above the concrete surface to ensure a flow path for the concrete into the hole.
- the low-pressure air provides a pressure in the casing to resist intrusion of the concrete into the hammer and casing.
- the lift rate of the casing is matched to.the fill rate of the concrete, thereby filling the hole with concrete as the hammer and casing are removed, and preventing the intrusion into hole 1820 as discussed above. In this way, and uniform concrete piling can be formed nearly simultaneously with the boring of hole 1820 , resulting in a much more reliable and strong piling, and a more cost efficient method as well.
- a structural I-beam can be inserted into the uncured concrete using conventional driving and vibrating methods.
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- Environmental & Geological Engineering (AREA)
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Abstract
A method of boring a hole in which a down hole hammer is pneumatically operated to form a hole, and a cementous material is injected into the hole through a passage in the down hole hammer.
Description
- The present invention is related to forming concrete pilings, and particularly forming concrete pilings down hole, pneumatic, percussive hammer drilling systems.
- Eccentrically mounted underreamers are known which include an arm which travels in an orbit for underreaming operation, and which are retractable toward the hole axis for tool removal purposes. Other known underreaming equipment utilizes three bit mounted plates which are outwardly displaceable, bit which incorporate a total working surface which is substantially less than the perimeter of the bore. Such undersized plates are subject to excessive wear and result in slow drilling operation. Underreaming can also be achieved by use of a crown or ring bit, but components of those bits must be left in the underreamed area when drilling is complete, which is costly and otherwise unacceptable in some drilling operations.
- However, it remains a difficult task to form concrete pilings in soils wherein large rocks are dispersed in a relatively non-compacted soil. As the percussive hammer is removed from the freshly bored hole, the dispersed rocks in the soil can be urged toward the hole, and prevent the filling of the entire hole with concrete as required for structural integrity. In cases where a steel I-beam must be included in the piling, the problem can be even more severe because the rock intrusion can prevent the insertion of the steel beam.
- A need remains, therefore, for a method of forming concrete pilings in soils having suspended rocks and boulders that using current methods, can intrude into the hole before the concrete and steel are inserted.
- In my U.S. Pat. No. 5,511,628, which is hereby expressly incorporated by reference into this application, I disclosed a pneumatic down-hole drill with a central evacuation outlet. The apparatus of U.S. '628 permits continuous evacuation of large debris fragments through a central axial bore formed in the bit and through a central evacuation tube attached thereto. Compressed air is directed downwardly through peripheral channels, under the drill bit, and into a central evacuation tube. The flow of compressed air through the central evacuation tube provides continuous and efficient removal of earthen fragments from the bore, including rapid removal of fragments which would be too large for removal through peripheral pathways along the casing.
- FIG. 1 is a partial cross-sectional view of a drilling assembly according to the present invention.
- FIG. 2 is an expanded partial cross-sectional view of the assembly shown in FIG. 1, showing the power head assembly, compressed air inlet collar, and the upper terminus of the dual wall pipe assembly.
- FIG. 3 is an expanded cross-sectional view of the assembly shown in FIG. 1, showing the casing driver in greater detail.
- FIG. 4 is an expanded cross-sectional view of assembly shown in FIG. 1, showing the dual wall pipe assembly and the box and back head assembly connecting the lower terminus of the dual wall pipe assembly to the down-hole pneumatic hammer.
- FIG. 5 is a cross-sectional view of the down-hole pneumatic hammer assembly, including the bit assembly.
- FIG. 5A is a perspective view of an alternative design for the hammer barrel of the down-hole pneumatic hammer assembly.
- FIG. 6A is an exploded perspective view of a first embodiment of a bit assembly according to the present invention.
- FIG. 6B is an exploded perspective view of a second embodiment of a bit assembly according to the present invention.
- FIG. 7A is a perspective view of the pilot bit on the embodiment of FIG. 6A.
- FIG. 7B is a bottom view of the pilot bit shown in FIG. 7A.
- FIG. 8 is a perspective view of an underreamer arm used in the embodiment shown in FIG. 6A.
- FIG. 9A is an end view of the underreamer arm shown in FIG. 8.
- FIG. 9B is an outer side view of the underreamer arm shown in FIG. 8.
- FIG. 10 is a bottom view of the bit driver of the embodiment shown in FIG. 6A, showing the axial surfaces which define the recesses which receive the underreamer arms, and the axial surfaces bear against the underreamer arms to rotate the arms about the pilot bit for extension and retraction.
- FIG. 11 is side elevation view of the bit assembly shown in FIG. 6B.
- FIG. 12 an enlarged exposed view of the bit assembly shown in FIG. 11.
- FIGS. 13 and 14 are horizontal sectional views taken along line3-3 of FIG. 11 and showing the lower portion of the driver receiving the underreaming arms with the arms shown extended and retracted;
- FIG. 15 is a vertical sectional view taken along line5-5 of FIG. 13 showing a fragment of the driver bottom wall and an arm locking pad thereon;
- FIG. 16 is a vertical sectional view taken along line6-6 of FIG. 11; and
- FIG. 17 is a perspective view of an underreamer arm.
- FIG. 18A is a cross-sectional schematic view of the upper portion of a down-hole percussive apparatus that is adapted for practicing the claimed method.
- FIG. 18B is a cross-sectional schematic view of the lower portion of a down-hole percussive apparatus that is adapted for practicing the claimed method.
- Referring now to FIG. 1, a reverse circulation drilling system, shown generally at10, includes a
head assembly 11, a dualwall pipe assembly 12, and a down holepneumatic hammer 13 within abore casing 14. Turning to FIGS. 2 and 3,head assembly 11 includes acasing driver 15 for driving thebore casing 14 downwardly as the bit advances, and apower head assembly 16 of standard design for rotating thebore casing 14 it is driven downwardly.Casing driver 15 includes anannular hammer 17 which reciprocates vertically as compressed air is alternatively admitted to chambers above and belowhammer 17. Hammer 17 impacts onanvil 18, which in turn impacts oncasing cap 19.Casing cap 19 is sealed against the inner surface ofbore casing 14 to permit pressurization, throughport 20, ofbore casing 14 betweencasing cap 19 and downhole hammer assembly 13. Pressurization of the casing provides a downward flow of air between the casing and the down hole hammer, preventing upward migration of debris between the down hole hammer and casing, which can hinder the removal of the hammer.Power head assembly 16 is connected toanvil 18 throughlinkage assembly 21 to impart rotation to the dual pipe assembly and the down hole hammer.Power head assembly 16 is of a design generally known in the field, other than itcentral member 22, which is threaded onto the upper end of dualwall pipe assembly 14, includes a central bore in communication with the dual wall pipe assembly to extend the debris discharge path through the power head to theelbow 29. The joint ofcentral member 22 and thedual wall pipe 14 includes aport 23 for admitting air to theannulus 24 between theinner wall 25 and the outer wall 26 of the dual wall pipe assembly.Collar 27 is mounted around the joint, and includesair inlet 28, through which compressed air is admitted into the dual wall pipe assembly for driving the down hole hammer as further described below. Anelbow 29 is rotatably mounted and sealed to the upper end ofcentral member 22.Elbow 29,central member 22 and theinner wall 25 of dualwall pipe assembly 14 together form a central drilling debris discharge tube for continuously discharging drilling debris from the down hole hammer as will also be described more fully below. - Turning also to FIG. 4, dual
wall pipe assembly 12 is assembled from individual segments, each of which includes aninner pipe 31 and anouter pipe 33. Each segment includes a threadedmale connector 33 and a threadedfemale connector 35 at opposite ends.Male connector 14 andfemale connector 15 each includesair ports outer annulus 24 of dualwall pipe assembly 11. At its upper end, dual wall pipe assembly is threaded in tocentral member 22 ofpower head 16. At its lower end, dualwall pipe assembly 11 is connected to thebox 38, which in turn is threaded intoback head 40 of down-hole hammer 13.Ports 42 an 44 communicate withannulus 24 of the dual wall pipe assembly to route compressed air therefrom into the down hole hammer. - Turning now to FIG. 5, down-
hole hammer 13 includesbox 38 threaded ontoback head 40. Asleeve 41 and ahammer barrel 42 are threaded intoback head 40. A centrally locateddischarge tube 43 is pressed intosleeve 41. A wear sleeve 44 is fitted aroundhammer barrel 40, and press fitted overring 45 and ontoshoulder 46 ofback head 40.Sleeve 41 andbarrel 42 define an annularupper air chamber 48.Central evacuation tube 43 andbarrel 42 define an annularlower air chamber 50. The lower end ofbarrel 42 abuts bitdriver 52, and also includes aperimetrical lip 54 which engages wear sleeve 44 to centerbarrel 42 in the wear sleeve.Hammer 53 is slidingly fitted intobarrel 42 for reciprocation.Bit driver 52 is slidably fitted intobarrel 42 belowhammer 53, and over the lower end ofcentral evacuation tube 43.Bit driver 52 is retained inbarrel 42 by a plurality of keys 56, each of which is fitted into a keyway 58 andannular recess 60 ofbit driver 52. (See also applicant's U.S. Pat. No. 5,511,628, incorporated by reference above, for detail of an alternate barrel assembly incorporating a like key and keyway assembly for mounting the bit driver in the hammer barrel.) The key-keyway assembly permits the bit assembly to advance ahead of the dual wall pipe assembly during drilling. - Bit assemblies for use with the present invention are shown in FIGS. 6-10. In one embodiment (FIG. 6A), a bit assembly consists of a
bit driver 52, apilot bit 82, andarms 88 a-c.Bit driver 52 includes anupper shank 83 having a recessedchamfer 84, camming surfaces 85 a and 85 b, and alower portion 86.Lower portion 86 includes threeperipheral recesses 87 a-c. Hardened drilling buttons, preferably made of a carbide material, are mounted on the peripheral and bottom surfaces of the pilot bit (Fig. 7).Arms 88 a-c are nested atoppilot bit 82, and slide thereon in an prescribed arcuate path defined by as will be described. Each of the arms includes a raisedboss 89 which is received into corresponding recess 90 of bit driver 52 (FIG. 10). Raisedboss 89 serves several functions. First, impact forces from the hammer are transmitted downwardly to thepilot bit 52 throughbit driver 52,boss 89, andarm 88. Second,boss 89 is received and retained in recess 90, where it rotates through a limited arc to extend and retractarm 88. Witharm 88 in its retracted position,surface 91 isadjacent camming surface 85 a. in this configuration, the overall diameter of the bit assembly is less than the inner diameter of the bore casing, permitting the bit assembly to be withdrawn from the bore. Asarm 88 is rotated clockwise aboutpilot bit 82 by clockwise rotation ofbit driver 52, angled surfaces 85 a engage surface 92 and urgearm 88 outwardly. The rotation and extension ofarm 88 continues untilsurface 92 a is abutssurface 85 b, andsurface 92 b abutssurface 85a, lockingarm 88 in its extended position. To unlock and retractarm 88,bit driver 52 is rotated in the opposite direction. In its fully retracted position, the overall diameter of the underreamer assembly is less than the inside diameter of the casing, permitting withdrawal of the entire underreamer bit assembly through the casing if necessary. This feature represents a significant advance over known underreamers, which cannot be retracted and withdrawn through the casing if necessary. - In operation, compressed air is delivered into
annular chamber 59 throughport 37,radial ports 60,annulus 62 andaxial ports 64. In FIG. 5, hammer 53 is shown during its downward stroke.Lip 66 is engaged withlip 68, sealing offchamber 48.Lip 72 is engaged withlip 74, sealing offchamber 50.Port 78 is closed. Aspiston 53 continues downwardly,port 76 is uncovered, exhaustingchamber 48. At about the same time,lip 74 disengages fromlip 72, admitting a fresh charge of compressed air intochamber 50 to raisepiston 53 to its upper position after it has struckbit driver 52. Aspiston 53 rises,port 78 is uncovered, exhaustingchamber 50.Lip 74 engageslip 72, sealingchamber 50.Port 76 is sealed bypiston 53, andlip 66 disengages fromlip 68, admitting a fresh charge of compressed air intochamber 48. The fresh charge of compressed air inchamber 48drives piston 53 downwardly to begin another stroke. The compressed air exhausted intoports central evacuation tube 43, carrying with it drilling debris and earthen fragments dislodged by the bit. As an added precaution against drilling debris becoming lodged betweenarms 88 a-c and the pilot bit, in the bit assembly embodiment shown in FIG. 6B,port 91 is provided through which compressed air can be discharged to clear debris. - The flow of compressed air through the bit assembly is essentially continuous, and provides a continuous evacuation of drilling debris from the drilling face of the bore. Moreover, the essentially constant diameter of the evacuation tube and inner wall of the dual wall pipe assembly provides a constant air velocity, which further aids debris removal. The continuous removal of debris through the central evacuation tube promotes continuous drilling. It is seldom, if ever necessary to stop drilling and raise the bit to clear debris from the bore. Significant improvements in drilling rates can directly result. In addition, it is possible to obtain a relatively accurate “core” sample from the bore which can provide useful information in both exploratory and environmental applications.
- An alternative bit assembly is shown in FIGS. 6B and FIGS. 11-17. The
reference numeral 101 indicates generally the present drill bit assembly for attachment to the lower end of pneumatic down hole hammer. A driver at 102 includes ashank 103 of a diameter and splined for attachment to the percussive hammer. Integral with the shank is adriver head 104. Abouthead 104 are circumferencially spacedchannels 105 for upward passage of earthen particles or debris. An axially extendingbore 106 of the driver receives a pressurized downward air flow for particle removal.Head 104 is cross bored off center at 107 to receivepin 108 engageable with a later described pilot bit of the drill assembly. - A
lowermost surface 110 of thedriver head 104 defines a series ofcylindrical sockets 111 uniformly spaced apart and from vertical axis at A of the driver (FIG. 13). Each socket has a companionelongate recess 113 formed in the lower portion of the driver to receive a limit stop pin of a later described underreamer arm. Additionally,lowermost surface 110 ofhead 104 is provided with multiplearm lock pads 114 in the form of downward projections which serve to lock each underreamer arm in an extended operative position. An internal wall of the driver includessegments cam block 118 and permits head movement thereabout. Irregular wall surfaces, 116-117 alternately abut the cam block to limit driver rotation during arm positioning as later discussed. - A set of underreamer arms are indicated generally at119 in FIG. 12 with the following description of one arm applicable to all of the arms at 120 which are generally of angular shape in plan view. With attention also to FIG. 17, an arm pivot post 121 seats in a
socket 111 formed in the underside ofhead 14 of the driver. A limit stop post or pin 122 of the arm projects upwardly into anelongate recess 113 in the underside of thedriver head 104 with anend wall 113A of the recess limiting outward displacement of armlimit stop pin 122. Arm top and bottom walls are at 123-124 which both terminate outwardly in beveled armouter edges 123A-124A, the lower beveled edge being provided with carbide inserts orbuttons 125. Aninner side wall 126 of anarm 120 moves about in relation to a later described cam block during arm deployment and retraction. A rearwardly beveled (relative arm rotation) arm end wall is at 127.Beveled arm edge 123A is engageable with the lower edge of a hole installed casing to contribute to inward arm movement during arm retraction at the end of a drilling operation. An arm shoulder at 128 cooperates with thelock pads 114 on the driver when deployed. Theinner side wall 126 of eacharm 120 travels along a wall surface of the cam block during arm positioning. - A pilot bit is generally indicated at130 and includes a
main body 131 having anuppermost surface 132 on which is centrally locatedcam block 118 withwalls 136. Integral withcam block 118 is apedestal 137 having anannular groove 138 thereabout to receive head carried pin 8 in a tangential manner.Groove 130 is oversize to permit upward displacement ofdriver 12 during arm positioning and subsequent locking of the arms. A compressed air central passageway is at 139 of the bit and is in registration withdriver air passageway 106. Spaced about thelower perimeter 131 ofdrill bit 130 arechannel 141 through which debris flows upwardly past the arms during a drilling operation. Abottom wall 142 of the drill bit defines radially disposedair channels 143 which are served with compressed air flows via internal passageways served byaxial passageway 139. Thelowermost surface 142 of the drill bit is suitably equipped with tungsten carbide buttons or other wearresistant members 144 commonly used in earth drilling equipment. - In drilling and underreaming
operation pilot bit 130 advances into the ground with the underreamer arms locked in a deployed position below and radially beyond the advancing end of the casing at C. Casing movement is facilitated by the relatively large underreamed area, and if required, by thecasing driver 15. In one embodiment, if the drill bit assembly advances more than a predetermined distance ahead of the casing,linkage 21 operates a valve to provide compressed air to thepneumatic hammer 17 and associated portingcasing driver 15. - At completion of the operation, the driver is partially rotated in the direction opposite to drilling rotation to shift the arm pivot pins and specifically the arm inner ends along
cam block walls 36 to retract each arm. Arm retraction is aided by the beveled armouter edges 123A engaging the bottom edge of casing C during retraction at the end of a drilling operation to permit removal of the drill bit assembly through the casing. - In operation with
arms 53 a-c extended, exhaust air from the down-hole hammer flows fromport 42 through driver 51,arms 54 a-c, pilot bit 56, and into central evacuation tube 1 (FIG. 2), carrying with it drilling debris. Applicant's routing of exhaust air from the down-hole hammer through the driver and into the underreamer assembly to continuously clean drilling debris from the underreamer assembly represents a significant improvement in the drilling art. - Turning now to FIGS. 18A and 18B, the method of the present invention will now be described. The down-hole percussive hammer and underreamer bit is shown generally at1810.
Assembly 1810 is operated to formhole 1820 as described above. Oncehole 1820 is formed,valve 1830 is closed to isolate thecentral channel 1840 from the vacuum unit (not shown). Concrete is then pumped intocentral channel 1840 throughinlet 1850. Low-pressure air is also introduced into through air inlet 1860 to slightly pressurizecasing 1870. Once the concrete has filledcentral channel 1840, the casing is slowly removed from the bore as more concrete is pumped intocentral channel 1840. The concrete flows downwardly throughcentral channel 1840 and out through bit 1880 into the bottom ofhole 1820. A small spacer 1890 is mounted onto the bottom of bit 1880 to keep it spaced above the concrete surface to ensure a flow path for the concrete into the hole. The low-pressure air provides a pressure in the casing to resist intrusion of the concrete into the hammer and casing. The lift rate of the casing is matched to.the fill rate of the concrete, thereby filling the hole with concrete as the hammer and casing are removed, and preventing the intrusion intohole 1820 as discussed above. In this way, and uniform concrete piling can be formed nearly simultaneously with the boring ofhole 1820, resulting in a much more reliable and strong piling, and a more cost efficient method as well. - In an optional following step, after the hammer and casing have been removed and the hole filled with concrete, a structural I-beam can be inserted into the uncured concrete using conventional driving and vibrating methods.
- The foregoing description of the invention is intended to be illustrative rather than exhaustive. Those skilled in the art will appreciate that numerous changes in detail are possible without departing from the scope of the following claims.
Claims (4)
1. A method of boring a hole:
providing a down hole hammer comprising a driver; a pilot bit rotatably coupled to the driver, the pilot bit having a shank, a peripheral drilling surface, a lower surface, and a bore extending from the lower surface generally upwardly through the shank; a plurality of underreamer arms rotatably mounted intermediate the driver and the pilot bit and including underreaming surfaces, the underreaming arms having an extended position wherein the underreaming surfaces are positioned concentrically outside the pilot bit perimeter; cam surfaces engageable with the underreamer arms for urging the underreaming arms into their extended positions, for locking the underreaming arms into their respective extended positions, and for retracting the underreamer arms responsive to rotational movement between said driver and said pilot bit; and
surfaces defining at least one air passageway between an outer surface of the driver and the bore in the pilot bit;
the least one fluid passageway in communication with a source of a cementous material and at least one said cam surface, and further including a valve operable to discharge the cementous material to said at least one cam surface;
operating the downhole hammer to bore a hole; and,
discharging cementous material into the hole.
2. A down hole hammer comprising:
a driver;
a pilot bit rotatably coupled to the driver, the pilot bit having a shank, a peripheral drilling surface, a lower surface, and a bore extending from the lower surface generally upwardly through the shank;
a plurality of underreamer arms rotatably mounted intermediate the driver and the pilot bit and including underreaming surfaces, the underreaming arms having an extended position wherein the underreaming surfaces are positioned concentrically outside the pilot bit perimeter;
at least one cam surface engageable with the underreamer arms for urging the underreaming arms into their extended positions;
surfaces defining at least one air passageway between an outer surface of the driver and the bore in the pilot bit; and,
the least one fluid passageway in communication with a source of a cementous material and at least one cam surface, and further including a valve operable to discharge the cementous material to the at least one cam surface.
3. A downhole hammer according to claim 2 further comprising:
the at least one cam surface including at least one surface for locking the underreaming arms into their respective extended positions.
4. A downhole hammer according to claim 2 further comprising:
the at least one cam surface including at least one surface for retracting the underreamer arms responsive to rotational movement between said driver and said pilot bit.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/704,386 US20040182607A1 (en) | 2002-11-07 | 2003-11-07 | Method of forming concrete pilings using a reverse circulation drilling system |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US42507402P | 2002-11-07 | 2002-11-07 | |
US10/704,386 US20040182607A1 (en) | 2002-11-07 | 2003-11-07 | Method of forming concrete pilings using a reverse circulation drilling system |
Publications (1)
Publication Number | Publication Date |
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US20040182607A1 true US20040182607A1 (en) | 2004-09-23 |
Family
ID=32993964
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US10/704,386 Abandoned US20040182607A1 (en) | 2002-11-07 | 2003-11-07 | Method of forming concrete pilings using a reverse circulation drilling system |
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US (1) | US20040182607A1 (en) |
Cited By (7)
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US20040104049A1 (en) * | 2002-12-02 | 2004-06-03 | Robert Federighi | Apparatus and method for forming a support column in soil |
CN101144278B (en) * | 2006-10-29 | 2012-04-25 | 叶世昌 | Integrated multifunctional hole-drilling pile-filling machine |
CN102926663A (en) * | 2011-11-10 | 2013-02-13 | 广汉市井管厂 | Concentric sliding block simultaneous casing drilling tool, center drilling bit and centralizer |
CN104110032A (en) * | 2014-07-29 | 2014-10-22 | 福建永强岩土股份有限公司 | Large-diameter hollow-cavity long-spiral thin-wall bored concrete pile casing |
CN105625416A (en) * | 2016-03-22 | 2016-06-01 | 陈兆英 | Manufacturing device for T-shaped inserted herringbone piles |
CN105696591A (en) * | 2016-03-22 | 2016-06-22 | 陈兆英 | T-shaped combined herringbone pile manufacturing device |
US20230044315A1 (en) * | 2017-07-24 | 2023-02-09 | Luc Charland | Drilling system and method of using same |
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US4494613A (en) * | 1982-03-11 | 1985-01-22 | Kabushiki Kaisha Komatsu Seisakusho | Method and apparatus for driving hollow piles into the ground |
US5423636A (en) * | 1992-12-10 | 1995-06-13 | Kencho Kobe Co., Ltd. | Cement soil apparatus of underground borer |
US5647690A (en) * | 1995-06-08 | 1997-07-15 | Landau; Richard Erwin | Low cost installation of columns of material |
US5975222A (en) * | 1996-07-01 | 1999-11-02 | Holte; Ardis L. | Reverse circulation drilling system with bit locked underreamer arms |
US6663321B1 (en) * | 1999-06-04 | 2003-12-16 | Voorbij Groep B.V. | Process and device for producing a pile in the earth |
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US4494613A (en) * | 1982-03-11 | 1985-01-22 | Kabushiki Kaisha Komatsu Seisakusho | Method and apparatus for driving hollow piles into the ground |
US5423636A (en) * | 1992-12-10 | 1995-06-13 | Kencho Kobe Co., Ltd. | Cement soil apparatus of underground borer |
US5647690A (en) * | 1995-06-08 | 1997-07-15 | Landau; Richard Erwin | Low cost installation of columns of material |
US5975222A (en) * | 1996-07-01 | 1999-11-02 | Holte; Ardis L. | Reverse circulation drilling system with bit locked underreamer arms |
US6663321B1 (en) * | 1999-06-04 | 2003-12-16 | Voorbij Groep B.V. | Process and device for producing a pile in the earth |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20040104049A1 (en) * | 2002-12-02 | 2004-06-03 | Robert Federighi | Apparatus and method for forming a support column in soil |
CN101144278B (en) * | 2006-10-29 | 2012-04-25 | 叶世昌 | Integrated multifunctional hole-drilling pile-filling machine |
CN102926663A (en) * | 2011-11-10 | 2013-02-13 | 广汉市井管厂 | Concentric sliding block simultaneous casing drilling tool, center drilling bit and centralizer |
CN104110032A (en) * | 2014-07-29 | 2014-10-22 | 福建永强岩土股份有限公司 | Large-diameter hollow-cavity long-spiral thin-wall bored concrete pile casing |
CN105625416A (en) * | 2016-03-22 | 2016-06-01 | 陈兆英 | Manufacturing device for T-shaped inserted herringbone piles |
CN105696591A (en) * | 2016-03-22 | 2016-06-22 | 陈兆英 | T-shaped combined herringbone pile manufacturing device |
US20230044315A1 (en) * | 2017-07-24 | 2023-02-09 | Luc Charland | Drilling system and method of using same |
US11959336B2 (en) * | 2017-07-24 | 2024-04-16 | Luc Charland | Drilling system and method of using same |
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