U.S. patent application number 12/122632 was filed with the patent office on 2009-11-19 for pile mandrel with extendable reaming members.
This patent application is currently assigned to W.T.W. CONSTRUCTION, INC.. Invention is credited to William Wright.
Application Number | 20090285637 12/122632 |
Document ID | / |
Family ID | 41316318 |
Filed Date | 2009-11-19 |
United States Patent
Application |
20090285637 |
Kind Code |
A1 |
Wright; William |
November 19, 2009 |
PILE MANDREL WITH EXTENDABLE REAMING MEMBERS
Abstract
A set of one or more reaming members is secured to a pile
mandrel. Each reaming member is moveable between a first position
where the reaming member extends a first distance from a center of
the pile mandrel, and a second position where the reaming member
extends a second distance from the center of the pile mandrel. An
apparatus including a pile mandrel and one or more reaming members
attached to the mandrel is driven into soil, creating a hole
extending down from a surface of the soil. While the reaming
member(s) are below the surface of the soil, the reaming member(s)
are extended to an extended position; the pile mandrel is rotated
with the reaming member(s) extended to ream a section of the hole
to a second diameter that is larger than the first diameter; the
reaming member(s) are retracted, and the mandrel is removed from
the hole.
Inventors: |
Wright; William; (Portland,
OR) |
Correspondence
Address: |
Goff Patent Law PLLC
P.O. Box 625
Brush Prairie
WA
98606
US
|
Assignee: |
W.T.W. CONSTRUCTION, INC.
Portland
OR
|
Family ID: |
41316318 |
Appl. No.: |
12/122632 |
Filed: |
May 16, 2008 |
Current U.S.
Class: |
405/232 |
Current CPC
Class: |
E02D 5/36 20130101; E02D
5/44 20130101 |
Class at
Publication: |
405/232 |
International
Class: |
E02D 13/00 20060101
E02D013/00 |
Claims
1. An apparatus comprising: a pile mandrel that is adapted to be
driven into soil by a pile hammer, the pile mandrel defining: a top
opening located near a top end of the pile mandrel, the top opening
being positioned to receive grout to be fed through the pile
mandrel; and a bottom opening located near a bottom end of the pile
mandrel, the bottom opening being positioned to pass grout from the
pile mandrel; and a set of one or more reaming members secured to
the pile mandrel, each of the one or more reaming members being
moveable between a first position where the reaming member extends
a first distance from a center of the pile mandrel, and a second
position where the reaming member extends a second distance from
the center of the pile mandrel, the second distance being different
from the first distance.
2. The apparatus of claim 1, wherein each of the one or more
reaming members comprises a curved bar.
3. The apparatus of claim 1, wherein each of the one or more
reaming members is pivotally connected to the pile mandrel.
4. The apparatus of claim 1, wherein, when the pile mandrel has
been driven into soil, interaction between the one or more reaming
members and the soil can bias each of the one or more reaming
members between the first and second positions.
5. The apparatus of claim 1, wherein, when the pile mandrel has
been driven into soil, rotating the pile mandrel in a first
direction biases each of the one or more reaming members toward the
first position.
6. The apparatus of claim 1, wherein, when the pile mandrel has
been driven into soil, rotating the pile mandrel in a first
direction biases each of the one or more reaming members toward the
first position, and rotating the pile mandrel in an opposite second
direction biases each of the one or more reaming members toward the
second position.
7. The apparatus of claim 1, wherein the set of one or more reaming
members comprises multiple reaming members.
8. The apparatus of claim 1, wherein the set of one or more reaming
members comprises multiple rows of reaming members.
9. An apparatus comprising: a pile mandrel; a set of one or more
reaming members mounted on the pile mandrel, each of the one or
more reaming members being moveable between a first position where
the reaming member extends to a first radius from a center of the
pile mandrel and a second position where the reaming member extends
to a second radius from the center of the pile mandrel, the second
radius being different from the first radius; a hammer that is
adapted to drive the pile mandrel into soil; and a drill that is
adapted to rotate the pile mandrel while the pile mandrel is at
least partially in the soil; wherein rotation of the pile mandrel
while the one or more reaming members are in the soil biases the
one or more reaming members between the first and second
positions.
10. The apparatus of claim 9, wherein: rotation of the pile mandrel
in a first direction while the one or more reaming members are in
the soil causes the one or more reaming members to engage the soil
to bias the one or more reaming members toward the first position;
and rotation of the pile mandrel in a second direction, which is
opposite to the first direction, while the one or more reaming
members are in the soil causes the one or more reaming members to
engage the soil to bias the one or more reaming members toward the
second position.
11. The apparatus of claim 9, wherein the drill is adapted to
engage the pile mandrel to lift the pile mandrel while the pile
mandrel is at least partially in the soil.
12. The apparatus of claim 11, wherein the drill is adapted to
simultaneously rotate and lift the pile mandrel while the pile
mandrel is at least partially in the soil.
13. The apparatus of claim 9, wherein each of the one or more
reaming members is able to pivot between the first position and the
second position.
14. The apparatus of claim 9, wherein the drill and the hammer are
secured to a single support structure.
15. A method comprising: driving an apparatus into soil, the
apparatus including a pile mandrel and one or more reaming members
attached to the mandrel, wherein driving the apparatus into soil
includes displacing the soil outwardly and downwardly from the pile
mandrel, creating a hole extending down from a surface of the soil,
the hole having a first diameter; while the one or more reaming
members attached to the pile mandrel are below the surface of the
soil: extending the one or more reaming members from a retracted
position to an extended position; rotating the pile mandrel with
the one or more reaming members in the extended position to ream a
section of the hole to a second diameter that is larger than the
first diameter; and retracting the one or more reaming members from
the extended position; removing the pile mandrel from the soil;
filling the hole with a substantially liquid material; and allowing
the substantially liquid material to solidify.
16. The method of claim 15, wherein extending the one or more
reaming members comprises rotating the pile mandrel in a first
direction.
17. The method of claim 16, wherein extending the one or more
reaming members comprises engaging the soil with the one or more
reaming members.
18. The method of claim 16, wherein retracting the one or more
reaming members comprises rotating the pile mandrel in a second
direction.
19. The method of claim 18, wherein retracting the one or more
reaming members comprises engaging the soil with the one or more
reaming members.
20. The method of claim 15, further comprising lifting the pile
mandrel while rotating the pile mandrel with the one or more
reaming members in the extended position.
Description
TECHNICAL FIELD
[0001] The description relates generally to forming piles and more
particularly to a pile mandrel with extendable reaming members.
BACKGROUND
[0002] In modern engineering practice, piles in the ground are used
to improve naturally poor foundations. By the use of piles,
structural loads are transmitted to lower levels of the soil (as
used herein, soil refers to loose soil as well as compacted soil
and rock), generally via friction, but sometimes by bearing, or a
combination of both. A piled foundation is often a requirement of
the building codes where unsuitable soil fails to provide the
required level of support to foundations and footings. This is done
to prevent the settling or collapse of structures due to
insufficient foundation support, and to ensure even and equal
settling of a structure after construction.
[0003] Many different types of support piles have been used. Timber
was perhaps the first piling material while other materials
including steel and concrete were used later. Steel piles include
HP sections and steel pipe (usually concrete filled). Concrete
piles can be either precast (including both the reinforced and
pre-stressed types) or cast-in-place. Cast-in-place concrete piles
can further be separated into the non-displacement type (typically
auger-cast-piles where soil is removed from the hole and brought to
the surface) or the displacement type (where soil is forced to be
displaced downwardly and/or to the side of the hole, but the soil
is not brought to the surface). Cast-in-place concrete displacement
piles may be cast directly against the surrounding soil. Enlarged
base piles are also cast directly against the surrounding soil.
Cast-in-place concrete displacement piles may also be cast against
a metal pipe or metal shell, which has previously been driven into
the ground. It has been known to vibrate a pile pipe, or even to
turn it with a drill, to break the pipe free from the surrounding
soil and remove it.
[0004] One displacement-type method of forming cast-in-place
concrete piles includes driving a hollow steel mandrel into the
ground with a boot or foot covering a hole at the bottom of the
mandrel. After the mandrel is driven to the desired depth, the
steel mandrel is removed, and the boot remains in the ground at the
bottom of the resulting hole. Concrete is fed through the steel
mandrel to fill the hole as the mandrel is being driven into the
ground, as it is being removed from the ground, or both. After the
mandrel is removed, rebar or some other reinforcing material may be
inserted into the concrete before the concrete solidifies.
[0005] One type of cast-in-place concrete pile is the bell pile. A
bell pile includes one or more bottom or mid-sections that flare
outward and downward in a frustroconical or bell shape. Thus, these
sections have larger diameters than the remainder of the pile. Such
large diameter sections below the surface can be advantageous
because they increase the pile's resistance to upward forces on the
pile. As an example, a typical process for forming a bell pile
includes: (1) centering, (2) starting to drill, (3) inserting a
stand pipe, (4) feeding bentonite into the hole in the soil, (5)
drilling to the specified depth, (6) inserting a belling bucket,
(7) reaming the bore hole bottom with the belling bucket, (8)
measuring the depth, (9) setting up an iron reinforcement cage,
(10) inserting a tremie tube, (11) cleaning slime with an air lift,
(12) filling the hole with concrete, and (13) removing soil that
was brought to the surface during drilling and belling.
SUMMARY
[0006] The present inventor recognized shortcomings of prior pile
forming tools and techniques. For example, bell piles are difficult
and expensive to form because of the steps involved, and because
bell piles are formed with a non-displacement process.
Non-displacement processes result in soil being brought to the
surface. Thus, that soil must be disposed of, which can be a costly
and difficult process, especially if the subterranean soil has been
contaminated. Displacement-type steel pipe pile techniques that
fill the pipe with concrete and leave the pipe in the ground are
expensive because of the price of the steel pipes, and such piles
do not produce sufficient resistance to upward lift forces in many
situations. Displacement-type concrete pile techniques that remove
the steel pipe-type mandrel from the ground can also suffer from
insufficient resistance to upward forces in many situations, and it
is often difficult to remove the mandrel because of frictional
forces between the mandrel and the surrounding soil.
[0007] Accordingly, there existed a need to provide a way to form
piles that overcomes one or more of these problems. The described
embodiments address this need, which has not heretofore been
recognized and addressed.
[0008] According to one embodiment, a pile mandrel can be adapted
to be driven into soil by a pile hammer. The pile mandrel can
define a top opening located near a top end of the pile mandrel,
with the top opening being positioned to receive grout to be fed
through the pile mandrel. The pile mandrel can also define a bottom
opening located near a bottom end of the pile mandrel, with the
bottom opening being positioned to pass grout from the pile
mandrel. A set of one or more reaming members can be secured to the
pile mandrel. Each of the one or more reaming members can be
moveable between a first position where the reaming member extends
a first distance from a center of the pile mandrel, and a second
position where the reaming member extends a second distance from
the center of the pile mandrel.
[0009] When the pile mandrel has been driven into soil, interaction
between the one or more reaming members and the soil can bias each
of the one or more reaming members between the first and second
positions. In addition, rotating the pile mandrel in a first
direction can bias each of the one or more reaming members toward
the first position, and rotating the pile mandrel in an opposite
second direction can bias each of the one or more reaming members
toward the second position.
[0010] According to another embodiment, a set of one or more
reaming members can be mounted on a pile mandrel. Each of the one
or more reaming members can be moveable between a first position
where the reaming member extends to a first radius from a center of
the pile mandrel and a second position where the reaming member
extends to a second radius from the center of the pile mandrel. In
addition, a hammer can be adapted to drive the pile mandrel into
soil, and a drill can be adapted to rotate the pile mandrel while
the pile mandrel is at least partially in the soil. Rotation of the
pile mandrel while the one or more reaming members are in the soil
can bias the one or more reaming members between the first and
second positions.
[0011] According to yet another embodiment, an apparatus is driven
into soil. The apparatus can include a pile mandrel and one or more
reaming members attached to the mandrel. Driving the apparatus into
the soil can include displacing the soil outwardly and downwardly
from the pile mandrel, creating a hole extending down from a
surface of the soil. While the one or more reaming members attached
to the pile mandrel are below the surface of the soil, the one or
more reaming members can be extended from a retracted position to
an extended position; the pile mandrel can be rotated with the
reaming member(s) in the extended position to ream a section of the
hole to a second diameter that is larger than the first diameter;
and the one or more reaming members can be retracted from the
extended position. The pile mandrel can be removed from the soil,
the hole can be filled with a substantially liquid material, such
as grout, and the substantially liquid material can be allowed to
solidify.
[0012] This Summary is provided to introduce a selection of
concepts in a simplified form. The concepts are further described
below in the Detailed Description. This Summary is not intended to
identify key features or essential features of the claimed subject
matter, nor is it intended to be used to limit the scope of the
claimed subject matter. Similarly, the invention is not limited to
implementations that address the particular techniques, tools,
environments, disadvantages, or advantages discussed in the
Background, the Detailed Description, or the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a front view of a driven apparatus of a pile
forming apparatus according to one embodiment.
[0014] FIG. 2 is a sectional view taken along line 2-2 of FIG. 1,
but not showing the enlarged diameter section of the pile mandrel
formed by reinforcing plates.
[0015] FIG. 3 is a sectional view similar to FIG. 2, except that
the reaming members are in an extended position in FIG. 3, while
they are in a retracted position in FIGS. 1-2.
[0016] FIG. 4 is a top view of the driven apparatus of FIG. 1.
[0017] FIG. 5 is a cut-away front plan view of a pile forming
apparatus according to one embodiment.
[0018] FIG. 6 is an enlarged cut-away front view of the drill head
and the top of the driven portion of the pile driving apparatus of
FIG. 5.
[0019] FIG. 7 is sectional view taken along line 7-7 of FIG. 6.
[0020] FIG. 8 is a sectional view similar to FIG. 7, but
illustrating the mandrel interface plate being engaged by the
rotation of the drill head.
[0021] FIG. 9 is a sectional view taken along line 9-9 of FIG.
8.
[0022] FIG. 10 is a flowchart illustrating a method of forming a
pile according to described embodiments.
[0023] FIG. 11 is front cut-away view of the driven apparatus of
FIG. 1 being driven into soil.
[0024] FIG. 12 is a view similar to FIG. 11, but with the driven
apparatus being raised and rotated.
[0025] FIG. 13 is a view similar to FIG. 12, but with the reaming
members extended to form a large diameter section of a pile
hole.
[0026] FIG. 14 is view similar to FIG. 13, but with the reaming
members retracted after having formed a large diameter section of a
pile hole.
[0027] FIG. 15 is a front partially sectional cut-away view of a
pile with a subterranean large diameter section.
[0028] The description and drawings may refer to the same or
similar features in different drawings with the same reference
numbers.
DETAILED DESCRIPTION
[0029] Referring to FIGS. 1-3, a driven apparatus (110) for forming
cast-in-place piles is illustrated. The driven apparatus (110)
includes a hollow mandrel (112) having a top end (114) and an
opposing bottom end (116). Near the bottom end (116) of the mandrel
(112), the driven apparatus (110) includes reaming members (120).
As will be described in more detail below, after the driven
apparatus (110) has been driven downward to form a pile hole in
surrounding soil, the mandrel (112) can be rotated in a forward
direction to loosen the mandrel from the surrounding soil (see FIG.
2). The mandrel (112) can then be pulled up from the hole. As the
mandrel (112) is being pulled up, grout can be fed through the
mandrel (112) to fill the pile hole. Once the mandrel (112) has
begun to be raised from the bottom of the pile hole, the mandrel
(112) can be rotated in a backward direction (see FIG. 3). This
rotation forces the reaming members (120) to engage the surrounding
soil, thereby pivoting the reaming members (120) to an extended
position shown in FIG. 3. With the reaming members (120) in this
extended position, the mandrel (112) can continue to be raised
while rotating it in the backward direction so that the reaming
members (120) ream a subterranean large diameter section of the
pile hole. When a sufficient large diameter section has been
reamed, the mandrel can be rotated in the forward direction to
rotate the reaming members back into the retracted position shown
in FIGS. 1-2. The mandrel can then be raised out of the pile hole.
Grout can be fed through the mandrel (112) to fill the pile hole
with grout as the mandrel (112) is being raised. This results in a
pile having a subterranean large diameter section, with a small
diameter section above the large diameter section.
[0030] These tools and techniques produce substantial benefits that
are not present in or predictable from prior pile forming tools and
techniques. Because the pile can include a subterranean large
diameter section, the pile can have a greater resistance to upward
forces than conventional cylindrical piles with no such large
diameter sections. Such conventional piles can be pulled up without
displacing a significant amount of soil. However, for the pile with
the large diameter section to be pulled up, the soil above the
large diameter section would have to be displaced. In addition,
cast-in-place piles can be formed inexpensively with the tools and
techniques described herein. This is in part because the described
technique is a displacement technique that does not bring
significant amounts of soil to the surface, so there is no need to
dispose of such surface soil. In addition, typically only a small
boot on the bottom of the mandrel of the driven apparatus is left
in the ground. Thus, the material cost for each pile is less than
in many prior displacement cast-in-place techniques, where an
entire steel pipe was left in the ground for each pile.
[0031] The subject matter defined in the appended claims is not
necessarily limited to the benefits described herein. A particular
implementation of the invention may provide all, some, or none of
the benefits described herein. Although operations for the various
techniques are described herein in a particular, sequential order
for the sake of presentation, it should be understood that this
manner of description encompasses rearrangements in the order of
operations, unless a particular ordering is required. For example,
operations described sequentially may in some cases be rearranged
or performed concurrently. Techniques described herein with
reference to flowcharts may be used with one or more of the systems
described herein and/or with one or more other systems. In
addition, the apparatuses defined herein may be used in a manner
other than the described methods or techniques. For example, in
some situations the driven apparatus described below may be driven
into the ground, rotated only in the forward direction or not
rotated at all, and removed without extending the reaming members.
This could result in a pile without the large diameter section
described below (such as the pile hole of FIG. 12 filled with grout
and possibly with reinforcing members), which may be desirable in
some applications. Moreover, for the sake of simplicity, flowcharts
may not show the various ways in which particular techniques can be
used in conjunction with other techniques.
[0032] Referring still to FIGS. 1-4, and describing the driven
apparatus (110) in more detail, the driven apparatus (110) includes
the pile mandrel (112) having a top end (114) and an opposite
bottom end (116), defining a bottom hole (118) where grout can exit
the mandrel (112). The mandrel (112) can be a round steel pipe,
such as standard steel pipes that are typically used for piles and
as mandrels for existing pile driving techniques. However, the pipe
could be made of some other material that is sufficiently strong
and durable, and it could have some other shape, such as a hollow
octagonal cross section. The reaming members (120) can be curved
claw-shaped steel rods with square cross sections. Each reaming
member (120) illustrated in FIGS. 1-4 includes a tip (122) that is
sloped outwardly away from the mandrel. In the retracted position,
the tip sits adjacent to the mandrel and the rod bends around the
mandrel to a base (124) of the reaming member (120). A reaming
member support (130) supports each reaming member (120). The
reaming member supports (130) can be curved steel supports welded
to the mandrel (112). Each support (130) defines a recess that
receives the base (124) of a corresponding reaming member (120). A
support pin (132) extends through each support (130) and through
the base (124) of each reaming member (120). Thus, the support pin
(132) secures the corresponding reaming member (120) to the
corresponding reaming member support (130), but allows the reaming
member (120) to pivot between the retracted position shown in FIG.
2 and the extended position shown in FIG. 3. The pin (132) can be
any type of conventional pin that will hold the reaming member in
place, such as an all-threaded rod. Other types of fasteners, such
as screws, bolts, and hard-rolled pins could be used as
alternatives to an all-threaded rod. Each reaming member (120) is
prevented from pivoting outward beyond the extended position by
contact with the corresponding reaming member support (130), and is
prevented from pivoting inward beyond the retracted position by
contact with the mandrel (112). Many other configurations and
shapes of reaming members and supports are possible and will be
apparent to those skilled in the art. For example, the reaming
members could be flattened fins or round rods, rather than square
cross-sectioned rods.
[0033] Referring still to FIGS. 1-4, the driven apparatus (110)
includes shield plates (140) that are secured to the mandrel (112),
such as by welding, to create a larger diameter section of the
mandrel (112) below the reaming members (120). The shield plates
(140) form an annular shoulder (142) below the reaming members
(120). The shield plates (140) can shield and protect the reaming
members (120) and reaming member supports (130) from the
surrounding soil as the driven apparatus (110) is driven into the
soil. The shield plates can be a unitary part (rather than multiple
plates), and they can be an integral part of the mandrel (112). As
an alternative, the shield plates can be secured in some way other
than by welding, such as with bolts or other fasteners.
[0034] An interface plate (150), which can be a generally
rectangular plate as illustrated, is secured to the top of the
mandrel (112). The interface plate (150) can be secured by welding
or in some other manner. The interface plate (150) defines a
centrally located top grout hole (152) (see FIG. 4) therein so that
grout can be pumped through the top hole (152) in the plate (150)
and the mandrel (112), and into the hollow mandrel (112) when
filling a pile hole with grout.
[0035] Referring to FIG. 1, the driven apparatus (110) also
includes a boot (160) that protects the bottom end (116) of the
mandrel (112) and forces soil outward to form a hole with a larger
diameter than the mandrel (112) itself, as the driven apparatus
(110) is driven into the soil. The boot (160) includes a round
steel bottom plate (162) that is positioned below the bottom of the
mandrel (112) as well as a hollow cylindrical side wall (164) that
extends up from the periphery of the bottom plate (162) and around
the bottom of the mandrel (112). Alternatively, the side wall can
have a diameter less than the diameter of the bottom plate, and the
side wall can extend upwardly within the hollow bottom of the
mandrel (112). As yet another alternative, the boot can include an
outer wall extending around the bottom of the mandrel (112) (as
illustrated) and an inner wall extending up within the bottom of
the mandrel (112), so that the mandrel (112) is seated between the
two walls of the boot. One such configuration may be more
advantageous for one type of soil, and another such configuration,
or even some other boot configuration, may be more advantageous for
another type of soil. The boot (160) is not fastened to the mandrel
(112), and it is typically left in the bottom of a pile hole when
the remainder of the driven apparatus (110) is removed.
[0036] As illustrated in FIG. 2, when the driven apparatus (110) is
rotated in a forward direction (170) while the reaming members
(120) are in a pile hole, the reaming members (120) are biased by
surrounding soil into the retracted position. On the other hand,
when the driven apparatus (110) is rotated in a backward direction
(172) with the reaming members (120) in a pile hole, the tips (122)
of the reaming members (120) engage the surrounding soil to pivot
the reaming members outwardly to the extended position shown in
FIG. 3. Thus, when the driven apparatus is in the soil, the reaming
members (120) can be pivoted between the retracted and extended
positions by simply rotating the driven apparatus (110) in the
forward direction (170) or the backward direction (172).
Alternatively, the reaming members (120) can be biased between the
forward and reverse positions in some other manner, such as by
using springs, rams, or drive motors.
[0037] Referring now to FIGS. 5-9, a pile forming apparatus (200)
is illustrated. The pile forming apparatus (200) includes a driving
apparatus (210) that includes an upright guide structure (220) that
includes main vertically extending guides (224) and side vertically
extending guides (228). The guide structure (220) can be made of
standard steel, as with other standard pile driving guide
structures. A hammer (240) includes a hammer support structure
(242) that supports the hammer and engages the main guides (224) so
that the hammer (240) rides vertically up and down on the main
guides (224). The hammer (240) can include a cylinder (244) that
can house a piston that is attached to a downwardly extending
hammer shaft (248), which is in turn secured to a downwardly
extending hammer head (250). The hammer head (250) can open
downwardly to receive the interface plate (150) and the top end
(114) of the mandrel (112) so that the hammer can force the driven
apparatus (110) downwardly into the soil. The hammer (240) can be a
conventional type of pile driver, such as a drop hammer, a diesel
hammer, a hydraulic impact hammer, or a vibratory driver.
[0038] Referring still to FIGS. 5-9, the driving apparatus (210)
also includes a drill (260), which includes a drill support
structure (262) that engages the side guides (228) so that the
drill (260) can ride vertically on the side guides (228). A drill
support line (264), such as a rope or a steel cable extends up from
the drill (260) so that the drill (260) can be raised or lowered by
raising or lowering the drill support line (264). The drill also
includes a downwardly-extending drill shaft (268) that is secured
to a drill head (270) that extends down from the drill shaft (268)
so that the drill (260) can be operated to rotate the drill head
(270).
[0039] The drill head (270) can be formed of steel plates, and can
include a ceiling (272), walls (276) that extend down from the
ceiling (272), a bottom lip (278) that extends in from the bottom
of the walls (276). (See FIG. 9.) Thus, the bottom lip (278) forms
a rectangular opening (280) into a cavity (282) formed by the
ceiling (272), walls (276), and lip (278) of the drill head (270).
If the drill is hydraulic, then it can be powered by hydraulic
lines (290), although the drill could be powered by an electric
motor or in some other manner. A grout supply line (292) also
extends to the drill (260) to feed grout through the drill
(260).
[0040] The opening (280) in the drill head (270) is sized so that
it can receive the interface plate (150) of the driven apparatus
(110). (See FIG. 7.) Thus, the interface plate can extend through
the opening (280) and into the cavity (282) in the drill head
(270). (See FIG. 9.) The drill (260) can be a conventional drill
such as the drills that are used to rotate augers in
non-displacement pile driving techniques. The drill (260) and the
hammer (240) can both be secured to the same support structure
(220), as illustrated in FIG. 5, or they can be supported by
separate structures and/or operate independently of each other.
[0041] As noted above, the driven apparatus (110) can be positioned
so that the top end (114) of the mandrel (112) extends into the
cavity (282) in the drill head (270), as illustrated in FIGS. 5-9.
In this drilling position, grout can be fed through the drill
(260), down through the top grout hole (152) in the interface plate
(150) and the mandrel (112), and through the mandrel (112). The
grout can thereby be fed into a pile hole through the opening at
the bottom of the mandrel (112). Moreover, as illustrated in FIG.
8, when the drill head (270) is rotated, the walls (276) of the
drill head (270) engage the interface plate (150) of the driven
apparatus (110) to rotate the driven apparatus (110). Additionally,
in this engaged position, when the drill (260) is pulled up, the
lip (278) of the drill head (270) engages the interface plate (150)
to pull the driven apparatus (110) up as well (except that the boot
is left in a pile hole rather than being pulled up). (See FIG.
9.)
[0042] Referring now to 10-15, the use of the pile forming
apparatus (200) will be described. As illustrated in FIG. 10, in
general the use includes driving the driven apparatus into the soil
to form a pile hole (310); reaming a large diameter subterranean
section in the pile hole (320); and removing the driven apparatus
and filling the hole (330).
[0043] More specifically, referring to FIG. 11, the driven
apparatus (110) is driven in a downward direction (400) into soil
(410). To do this, the driven apparatus (110) is placed with the
boot (160) resting on the soil surface (412), and the driven
apparatus is driven down, such as with successive blows from the
hammer (240). As the driven apparatus (110) is forced down, the
boot (160) displaces the soil (410), forcing the soil to the side,
and thereby forming a pile hole (420) with a diameter approximately
equal to the diameter of the boot (160). However, soil (410) may
collapse inward to some extent after the boot (160) passes so that
some sections of the pile hole (420) may have a smaller diameter
than the boot (160), and some sections may have a larger diameter
than the boot (160). After the boot (160) has been driven down to
desired depth, the boot rests on a floor (424) of the pile hole
(420)
[0044] The hammer (240) (see FIG. 5) can then be lifted off the
driven apparatus (110), and the drill head (270) can be positioned
over the interface plate (150), as shown in FIGS. 5-9. As
illustrated in FIG. 12, the driven apparatus (110) (except for the
boot (160)) can then be rotated in the forward direction (170) to
break the remaining driven apparatus loose from the boot (160) and
from the side surface (422) of the pile hole (420). As the
remaining driven apparatus (110) is rotated, it can begin to be
lifted in an upward direction (450) by pulling up on the drill
(260) (FIG. 5). As this happens, grout (440) that is fed through
the mandrel (112) is emptied into the pile hole (420) (see FIGS.
13-15).
[0045] As illustrated in FIG. 13, the remaining driven apparatus
(110) can then be rotated in the backward direction (172) so that
the reaming members (120) pivot to the extended position. As the
driven apparatus (110) continues to be rotated and lifted, the
reaming members (120) ream out a subterranean large diameter hole
section (430) with a side surface (432) having a larger diameter
than the side surface (422) of the remainder of the pile hole
(420).
[0046] Once a desired size of the large diameter hole section (430)
has been reamed, then the remaining driven apparatus (110) is
rotated in the forward direction (170) and is continued to be
raised, as illustrated in FIG. 14. This continues until the driven
apparatus (110) is entirely removed from the pile hole (420), and
the pile hole (420) is filled with grout (440) to the desired
height. One or more reinforcing members (520), such as rebar or a
reinforcing cage, can then be inserted in the grout (440) to form
the resulting pile (510) illustrated in FIG. 15.
[0047] The resulting pile (510) illustrated in FIG. 15 includes the
boot (160) at its bottom, with grout (440) filling the boot (160)
and extending up from the boot (160). The reinforcements (520) are
held within the grout (440). The pile includes a bottom small
diameter section (530) extending up from the boot (160), a large
diameter section (540) with a larger diameter than the small
diameter section (530), and a top small diameter section (550) with
a smaller diameter than the large diameter section (540) (typically
approximately equal to the bottom small diameter section (530)).
The pile could include additional interspersed large and small
diameter sections, as specified for a particular project. Also, the
large diameter section(s) could be located higher or lower on the
pile, as specified for a particular project.
[0048] While the invention has been particularly shown and
described with reference to preferred embodiments thereof, it will
be understood by those skilled in the art that various changes in
form and details may be made therein without departing from the
spirit and scope of the invention. For example, the reaming members
could be used with another type of mandrel, such as a mandrel with
additional flow spaces to assist in the flow of grout into the pile
hole. Such a mandrel and associated apparatus is described in U.S.
Pat. No. 4,992,002, issued Feb. 12, 1991, which is incorporated
herein by reference. As another example, the reaming members may be
positioned in some other manner on a driven apparatus. For example,
the reaming members could be located closer to the bottom of the
mandrel than in the illustrations shown herein.
* * * * *