U.S. patent application number 14/285986 was filed with the patent office on 2014-09-11 for self-centralizing soil nail and method of creating subsurface support.
This patent application is currently assigned to R&B LEASING, LLC. The applicant listed for this patent is Colby Barrett, Timothy Allen Ruckman. Invention is credited to Colby Barrett, Timothy Allen Ruckman.
Application Number | 20140255107 14/285986 |
Document ID | / |
Family ID | 42285173 |
Filed Date | 2014-09-11 |
United States Patent
Application |
20140255107 |
Kind Code |
A1 |
Barrett; Colby ; et
al. |
September 11, 2014 |
SELF-CENTRALIZING SOIL NAIL AND METHOD OF CREATING SUBSURFACE
SUPPORT
Abstract
A subsurface support is provided comprising a soil nail having
an outer member and an inner member placed within the outer member.
The soil nail includes features that maintain a uniform spaced
relationship between the inner and outer members. The soil nail may
be installed by drilling or launching through a launching device.
The spaced relationship between the inner and outer members may be
achieved by crimping the outer member, or by use of an insert
installed between the inner and outer members. In other
embodiments, the support is made of composite construction
materials, and having a self-drilling capability. The soil nail has
two primary members, namely, an outer threaded member, and an inner
threaded member that is placed through the outer member The outer
member is made from fiberglass, and a metallic drill bit is secured
to a distal end of the soil nail. The inner member is preferably
steel. The dual piece construction provides superior tensile and
compressive strength, particularly for applications in which a
coupler is used to join outer members to extend a length of the
soil nail. A method is also provided to improve pull-out capacity
by galvanizing the inner and outer members
Inventors: |
Barrett; Colby; (Fruita,
CO) ; Ruckman; Timothy Allen; (Phoenix, AZ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Barrett; Colby
Ruckman; Timothy Allen |
Fruita
Phoenix |
CO
AZ |
US
US |
|
|
Assignee: |
R&B LEASING, LLC
Fruita
CO
|
Family ID: |
42285173 |
Appl. No.: |
14/285986 |
Filed: |
May 23, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12646573 |
Dec 23, 2009 |
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14285986 |
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|
11693584 |
Mar 29, 2007 |
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12646573 |
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11460317 |
Jul 27, 2006 |
7338233 |
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11693584 |
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10741951 |
Dec 18, 2003 |
7226247 |
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11460317 |
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Current U.S.
Class: |
405/259.5 |
Current CPC
Class: |
E02D 5/80 20130101; E02D
5/808 20130101; E02D 3/12 20130101 |
Class at
Publication: |
405/259.5 |
International
Class: |
E02D 3/12 20060101
E02D003/12 |
Claims
1. In combination, a soil nail and a spacer placed over the soil
nail, comprising: a soil nail having proximal and distal ends; and
a spacer placed over said soil nail, said spacer having an inner
portion with an opening through which said soil nail is received,
and a plurality of radial projections connected to an outer surface
of said inner portion, said radial projections spaced from one
another around said outer surface and extending radially away from
said inner portion.
2. A soil nail comprising: a tubular outer member having a length,
proximal and distal ends, an exterior surface, and an interior
surface defining a central bore extending through said tubular
outer member; a crimped feature formed on at least one portion of
said outer member, said crimped feature creating a smaller diameter
area within said central bore of said outer member and creating at
least one groove on said exterior surface of said outer member; and
an inner member placed longitudinally through said bore of said
outer member and passing through said crimped feature.
3. A soil nail, as claimed in claim 2, wherein: said crimped
feature is formed on at least one pair of opposing sides of said
outer member.
4. A soil nail, as claimed in claim 2, wherein: said crimped
feature is formed on two pair of opposing sides of said outer
member.
5. A soil nail, as claimed in claim 2, wherein: said crimped
feature includes a plurality of crimped features, a first crimped
feature formed at a distal end of said outer member, a second
crimped feature formed at a proximal end of said outer member, and
a third crimped feature formed between said proximal and distal
ends of said outer member.
6. A soil nail, as claimed in claim 2, further including: a
self-drilling bit secured to a distal end of said outer member.
7. A soil nail, as claimed in claim 2, wherein: said outer member
includes a pair of outer members placed end to end, and a threaded
coupler interconnecting abutting ends of the pair of outer members,
thereby providing an extended length for a continuous outer
member.
8. A soil nail, as claimed in claim 2, wherein: said inner member
extends beyond both said proximal and distal ends of said outer
member.
9. A soil nail, as claimed in claim 2, wherein: said inner member
comprises a metallic cylindrical shaped bar.
10. A soil nail, as claimed in claim 2, wherein: said inner member
maintains a uniform concentric spaced relationship with an interior
surface of said outer member.
11. A method of installing a subsurface support comprising:
providing a tubular outer member having a length, and proximal and
distal ends; creating crimped features on the outer member to
narrow a diameter of an interior bore extending through the outer
member; emplacing the outer member into the ground; filling the
outer member with cementious material; inserting an inner member
through the bore of the outer member such that said inner member
maintains a substantially uniform concentric relationship with an
interior surface of said outer member by said crimped features.
12. A soil nail, as claimed in claim 10, wherein: said inner member
maintains a uniform concentric spaced relationship with an interior
surface of said outer member.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of co-pending
U.S. application Ser. No. 12/646,573, filed on Dec. 23, 2009,
entitled "SELF-CENTRALIZAING SOIL NAIL AND METHOD OF CREATING
SUBSURFACE SUPPORT", which is a continuation-in-part application of
U.S. application Ser. No. 11/693,584, filed on Mar. 29, 2007
entitled "METHOD AND APPARATUS FOR CREATING SOIL OR ROCK SUBSURFACE
SUPPORT", which is a continuation-in-part application of U.S.
application Ser. No. 11/460,317, filed on Jul. 27, 2006, entitled
"METHOD AND APPARATUS FOR CREATING SOIL OR ROCK SUBSURFACE
SUPPORT", which is a continuation-in-part of U.S. application Ser.
No. 10/741,951, filed on Dec. 18, 2003, entitled "METHOD AND
APPARATUS FOR CREATING SOIL OR ROCK SUBSURFACE SUPPORT", the
disclosures of these applications being hereby incorporated by
reference herein in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to subsurface
supports placed in the ground, and more particularly, to a method
and apparatus for creating soil or rock subsurface supports that
can be used in multiple applications to include support for
excavations as a passive soil nail in tension, bending and/or
shear, support to stabilize sloping terrain as a tieback in
tension, support for an above ground structure as a micropile in
compression and/or shear, or support for an above ground structure
as an anchor in tension. A preferred embodiment of the invention
includes a self-centralizing soil nail having an inner member
centralized within an outer member.
BACKGROUND OF THE INVENTION
[0003] In the construction of buildings, bridges, and other
man-made structures, it is well known to place passive supports
such as footers, piles, and other subsurface supports for
supporting such man-made structures. These types of supports are
passive because the earth around the subsurface support must first
shift or move to mobilize the available tensile, bending, or shear
capacities.
[0004] One particular problem associated with subsurface supports
which may be made of iron, steel, or other metals is that over
time, corrosion takes place which ultimately degrades the ability
of the support to provide designed support for an overlying
structure.
[0005] In addition to providing the above-mentioned subsurface
supports, it is also known to provide ground strengthening by
driving elongate reinforcing members, referred to as soil nails,
into the ground in an array thus improving the bulk properties of
the ground. The soil nails themselves are not used for direct
support of an overlying structure; rather, the soil nails are
simply used to prevent shifting or other undesirable properties or
characteristics of a particular geological formation that is built
upon.
[0006] In some cases, the earth surrounding or near a man made
structure becomes unstable and requires active support, such as by
a tieback. Tiebacks are pre-tensioned subsurface supports that are
used to restrain any movement of surrounding soil and rock.
Tiebacks are similar to passive soil nails in construction, and can
be emplaced in a similar fashion as a soil nail. More recently,
soil nails and tiebacks have also been used to provide temporary
and permanent excavation support and slope stabilization.
[0007] The U.S. Pat. No. 5,044,831 discloses a method of soil
nailing wherein a soil nail is placed in the ground by being fired
from a barrel of a launcher. The soil nail is loaded into the
barrel, and pressurized gas emitted from the barrel forces the soil
nail into the ground to a desired depth. One advantage of using a
soil nail launcher is that the soil nails can be emplaced with a
minimum amount of labor and equipment thereby minimizing
environmental impacts as well as providing a simple and economical
means of strengthening the ground. Drilling is the traditional way
to install soil nails, tiebacks, and anchors.
[0008] Although there are a multitude of subsurface supports and
methods by which subsurface supports can be emplaced, there is
still a need for simple and effective subsurface supports and an
environmentally friendly manner in which subsurface supports are
emplaced.
SUMMARY OF THE INVENTION
[0009] In accordance with the present invention, a method and
apparatus are provided to create a subsurface support device that
is placed in the ground. In a first embodiment of the invention,
the support device of the present invention has many potential
uses. In one use, this support device can be used as a passive soil
nail. In another use, this support device of the present invention
can be used as an active tieback in tension. More generally, for
use as a tieback, this support device can also be referred to as a
soil or rock inclusion. The term inclusion refers to the ability of
the support device to increase the tensile capacity of the rock and
soil. In yet another use, this support device can be used as a
micropile in compression, bending and shear. This support device,
when acting as a micropile, can be physically connected to an
overlying structure. In yet another use, this support device can be
used as an anchor in tension. For example, this support may be
tensioned as by a cable that interconnects the support to a man
made structure.
[0010] Once emplaced, this support device includes a protective
outer member or tube, an inner support member, and a stabilizing
mixture, preferably in the form of grout, cement, resin, or
combinations thereof which fixes the inner support member within
the outer protective member. The stabilizing mixture may also be
referred to as a cementious mixture. The outer protective member
supports the opening into the native rock and soil, and acts as a
housing for the cementious mixture. As discussed further below, the
outer member may be perforated thereby allowing the cement us
material to exit the perforations and increase the overall tensile
and compressive contribution of the support device. The outer
protective member also provides a barrier to prevent water or other
corrosive materials from contacting the inner support member. The
inner support member provides the design tensile and compressive
strength of the support. The inner support member may protrude a
desired distance above the outer member to connect to an overlying
structure to provide support in any desired manner to include
bearing/compression, tension, and/or shear. The diameter and length
of the outer member and inner member can be selected to provide the
necessary support. The outer member and stabilizing mixture provide
strengthening support to the inner member. For example, in
compression, the forces are transmitted from the inner support
member directly to the stabilizing mixture and the outer member. In
tension, forces are also transmitted to the stabilizing mixture and
the outer member thereby greatly increasing the force necessary to
dislodge or pull out the inner member. The method by which the
outer member of the subsurface support is emplaced in the ground is
preferably by a launching mechanism, such as that disclosed in the
U.S. Pat. No. 5,044,831.
[0011] In another embodiment of the present invention, the support
device is in the form of an improved soil nail including a
fiberglass body and a metal tip. The metal tip is preferably made
from a single piece of metal, such as a machined ingot of hardened
steel. The tip comprises a contacting portion or stinger that makes
contact with the ground when emplaced, and a proximal base portion
that is received within an opening in the distal end of the
fiberglass body thus allowing the tip to be attached to the
fiberglass body. The base portion may be attached by a compression
fit within the opening of the body and/or may be secured by an
appropriate bonding agent, such urethane glue. The size and
dimensions of the soil nail can be modified for the intended
purpose of use. One common size acceptable for use in many soil
stabilization efforts includes a fiberglass body of twenty feet in
length and a contacting portion of the metal tip extending
approximately six inches in length from the distal end of the
fiberglass body. For those applications in which a shorter body is
required, the same tip construction can be used, and the length of
the body can simply be shortened. Unlike most prior art soil nails,
the soil nail of the present invention has a tubular shaped body
without projections which allows the soil nail to be emplaced by
the soil nail launcher disclosed in the U.S. Pat. No. 5,044,831.
The use of a soil nail with a fiberglass body in conjunction with a
metal tip provides many advantages. The fiberglass body provides a
more cost effective solution than traditional soil nails that are
just made of metal. The fiberglass body also is highly resistant to
corrosion, even more so than many metal soil nails within corrosion
treated surfaces. The weight of the soil nail of the present
invention is also less than a metal soil nail, allowing it to
achieve greater velocity when emplaced by a soil nail launcher,
thus enhancing its ability to penetrate the ground. The strength of
the soil nail is not compromised because the fiberglass has
adequate strength, and has a greater elastic limit as compared to
many metal soil nails enabling the nail to handle even greater
tensile and shear loads. Although the soil nail has a relatively
smooth outer surface allowing it to be emplaced by a launcher, the
surface characteristics of the fiberglass provide excellent
adhesion with soil. Additionally, the stinger can be especially
designed to handle particular soil or rock formations without
having to modify the body of the soil nail. For example, in more
dense soil or rock formations, the stinger shape can be modified
prior to assembly with the body thus making the soil nail more
adaptable for many uses.
[0012] In another preferred embodiment of the present invention, a
self-centralizing soil nail is provided. This self-centralizing
feature enables the inner member or inner bar to be centralized
within the outer member. The inner member maintains a uniform
concentric relationship wherein the inner member is uniformly
spaced from the inner surface of the outer member. This feature is
achieved by crimping the outer member at selected locations along
the length of the outer member thereby narrowing the inner diameter
of the outer member, but maintaining an opening in the outer member
large enough for passage of the inner member. The outer member is
crimped so that the inner member is centered in the opening of the
outer member and, the space between the outer surface of the inner
member and the interior surface of the outer member is
substantially uniform. Placing the inner member in this centralized
relationship increases the capacity of the soil nail both in
tension and compression. If the soil nail is not centered and makes
contact with the interior surface of the outer member, the inner
member is subject to corrosion. Additionally, if the inner member
is spaced too closely to the interior surface of the outer member,
there may be small voids or spaces that do not completely fill with
cementious material and/or the cementious may have a very small
thickness which is more susceptible to being fractured. The
narrowing of the diameter of the outer member achieves natural
centering of the inner member without having to make an outer
member of a more complex construction.
[0013] In yet another embodiment of the present invention, this
self-centering feature can be achieved by use of one or more
self-centralizing elements that may be installed within the outer
member. These self-centralizing elements may be in the form of
inserts or spacers that have an outer diameter sized to
frictionally engage the inner diameter of the outer member. The
centralizing elements also have an inner diameter that is sized to
frictionally receive the inner member thereby holding the inner
member in place. The centralizing elements may be located at the
proximal and distal ends of the outer member, with one or more
centralizing elements also being placed intermediate between the
proximate and distal ends.
[0014] In yet another embodiment, the self-centralizing feature of
the present invention may be incorporated into a soil nail that is
installed by drilling the soil nail into the ground. This
self-drilling soil nail includes a drilling bit secured to the
distal end of the soil nail.
[0015] In yet another preferred embodiment of the present
invention, a composite self-drilling soil nail is provided in which
the soil nail is installed by drilling. The soil nail is
self-installing by inclusion of a drill tip attached to the distal
end thereof. This soil nail more specifically comprises an outer
member or tubular member having a threaded outer surface with a
hollow opening or bore extending through the tubular member, and
the hollow bore also being threaded. Preferably, the outer member
is made of a material such as fiberglass. If it is necessary to
extend a length of the outer member, an outer coupler may be used
to join the distal end of one outer member with proximal end of an
abutting outer member. The outer coupler is a tubular member
itself, having internal threads which are threaded in an engagement
with the abutting ends of the outer members. A threaded inner
member is placed through the threaded bore of the outer tubular
member by threaded engagement between threads on the inner bore and
external threads on the outer surface of the inner member. As
mentioned, the drill tip is secured to the most distal end of the
soil nail enabling the soil nail to be self-drilled. The proximal
end of the soil nail receives a bearing plate sized to hold or bear
against the specific geological formation being held by the soil
nail. An outer nut is threaded over the outer member and in
engagement against the bearing plate. An inner nut is threaded over
the inner member that has an end protruding beyond the adjacent end
of the outer member, and the inner nut is tightened against the
outer nut. The use of the threaded inner member enhances the
strength of the soil nail, particularly when using fiberglass as
the outer member, and also when fiberglass sections are to be
joined for extending a length of the soil nail. The use of steel
couplers improves the strength of the joint between the outer
members; however, metallic couplers will corrode over time. The use
of the inner member provides more permanent tensile and compressive
capacity to the overall soil nail, and also helps to compensate for
weakening of the metallic coupler over time. If fiberglass couplers
are used, the joint between the outer tubular members is relatively
weak, but the inner bar again greatly enhances the bearing capacity
of the soil nail. The use of two holding nuts as opposed to a
single nut against the bearing plate further provides strength to
the system.
[0016] The primary problem with use of fiberglass is that
fiberglass has a very low shear resistance. Therefore, creating
threads on a fiberglass member will result in a very weak
connection at that threaded location, which clearly limits the
application of fiberglass soil nails when they must be threaded.
One solution provided by the present invention is the use of the
inner member which overcomes any deficiencies with respect to a
threaded fiberglass member.
[0017] In another aspect of the invention, various embodiments are
provided with surface irregularities or asperities that increase
the pull-out capacity of the soil nail. In one embodiment, the
surface asperities include protrusions formed on the outer surface
of the soil nail. In another embodiment, the surface asperities may
include indentations. These surface asperities may be used in
combinations. In another aspect, the surface asperities are created
by a galvanization process in which the outer tube or member is
subjected to a hot dip galvanizing process. The molten metal that
is to be applied to the outer member is stirred in order to suspend
particles in the molten metal. These particles are referred to as
dross. More specifically, dross is the mass of solid impurities
that may float on the surface of the molten metal, or may be a
heavier impurity that can sink to the bottom of the container
holding the molten material. These impurities are usually removed
by skimming the surface or screening the molten material before the
object is subjected to the hot dip galvanization. In the present
invention, these stirred particles within the molten metal provide
a beneficial purpose in the creation of a very rough layer of
material applied to the outer member. This roughness increases the
pull-out capacity, as well as to provide an increased capability
for the tube to bond to cementious material placed within the outer
member. Therefore, the particles that are normally skimmed from the
surface of the molten metal provide a very useful purpose with
respect to treating the surface of the outer members.
[0018] In yet another embodiment of the present invention, a system
is provided for repairing a roadway in which cracking and
deterioration of the roadway is caused by a slip plane in the
roadbed. The system includes a plurality of soil nails that extend
through the slip plane and therefore join the earth on the opposing
sides of the slip plane to stabilize the surrounding area. In this
configuration, the soil nails are installed at various angles to
extend substantially perpendicular to the slip plane. The soil
nails each include a protective outer member or tube, an inner
support member, and a stabilizing mixture preferably in the form of
grout, cement, resin, or combinations thereof. The upper ends of
the soil nails terminate below the paved surface of the road. A
wire mesh layer is placed over the upper ends of the soil nails and
covers preferably a significant portion of the earth lying above
the slip plane. The mesh is then held in place by galvanized plates
which are fitted over the protruding upper ends of the inner
support members. The galvanized plates are then secured to the
inner members by, for example, epoxy-coated nuts.
[0019] Other features and advantages of the present invention will
become apparent by a review of the following figures, taken in
conjunction with the detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a cross-section of the subsurface support of the
present invention in a first embodiment, the support device being
emplaced in the ground and providing tensioning support to an
overlying above ground structure;
[0021] FIG. 2 is a cross-section illustrating an example launcher
that may be used to emplace the outer member of the support
device;
[0022] FIG. 3 is a partial cross-section illustrating a second
embodiment of the support device emplaced in the ground and
providing compression or bearing support to an overlying
structure;
[0023] FIG. 3A is an enlarged section of FIG. 3 illustrating one
way in which to provide holes or perforations in the subsurface
support;
[0024] FIG. 4 is a simplified elevation of a plurality of support
devices that may be used as passive soil nails or as tiebacks to
stabilize a sloping surface, the supports being emplaced in a
horizontal orientation;
[0025] FIG. 5 is an exploded fragmentary perspective view of a
third embodiment of the present invention in the form of an
improved soil nail;
[0026] FIG. 6 is a fragmentary side view of the soil nail of FIG.
5;
[0027] FIG. 7 is a cross section similar to FIG. 2 illustrating the
soil of the third embodiment being loaded in the launcher;
[0028] FIG. 8 shows an example installation of the soil nail of the
third embodiment to reinforce soil near a river or streambed
against scouring.
[0029] FIG. 9 illustrates yet another embodiment of a subsurface
support of the present invention in the form of a soil nail;
[0030] FIG. 10 is a cross-section taken along line 10-10 of FIG.
9;
[0031] FIG. 11 is a perspective view of a modification of the
embodiment of FIG. 9;
[0032] FIG. 12 is a perspective view of yet a further modification
of the embodiment of FIG. 9; and
[0033] FIG. 13 is a schematic diagram illustrating a method of
manufacturing the embodiment of FIG. 9;
[0034] FIG. 14 is a perspective view of yet another embodiment of
the present invention showing a soil nail with protruding
asperities;
[0035] FIG. 15 is a perspective view of another embodiment of the
subsurface support of the present invention;
[0036] FIG. 16 is a perspective view of the embodiment of FIG. 15
including additional crimps along the middle of the support;
[0037] FIG. 17 is a cross sectional view taken along line 17-17 of
FIG. 15;
[0038] FIG. 18 is a perspective view of another embodiment
including two outer members interconnected by a coupler thereby
extending the length of the support; and
[0039] FIG. 19 is a perspective view of another embodiment of the
present invention in which the centering feature includes an insert
or spacer mounted within an outer member;
[0040] FIG. 20 is a side view of another embodiment of the
subsurface support including a composite construction of steel and
fiberglass materials;
[0041] FIG. 21 is a schematic view of a roadway repair along a slip
plane using a plurality of subsurface supports; and
[0042] FIG. 22 is an elevation view showing further details of a
soil nail of FIG. 21 when installed to repair the roadway.
DETAILED DESCRIPTION
[0043] Referring to FIG. 1, the subsurface support 10 in a first
embodiment of the present invention is shown installed in the
ground G. The support device includes an outer member; preferably
in the form of a steel or iron tube 12 having a selected length and
diameter, and having an integral pointed tip 14. The tip 14 can be
conical in shape that facilitates emplacement of the outer tube as
by a launcher, as discussed below. After the outer tube is
emplaced, the stabilizing mixture is placed in the interior chamber
of the outer tube. Then, an inner support member that can be in the
form of an epoxy coated steel rod or bar is then placed within the
stabilizing mixture prior to hardening of the mixture. When the
stabilizing mixture cures, the inner support member 16 can provide
support to an overlying structure in compression, tension, and/or
shear. Depending upon the design requirements of the particular
structure to be built, a plurality of subsurface supports may be
emplaced at desired locations at the construction site, and each of
the support devices can be sized to provide the necessary
support.
[0044] FIG. 1 also illustrates one example of the manner in which
the support device 10 provides support. This one example
illustrates use of the subsurface support as an anchor in tension.
The subsurface support 10 includes a head or cap 20 that is
connected to the exposed upper end of the inner support member 16.
This head or cap can be attached by an integral threaded member 21
that is placed into a threaded well formed in the upper end of the
inner support member 16. The cap or head 20 then can be used for
attachment to the overlying structure. In the example of FIG. 1, a
ring 22 attaches to the cap 20, and a cable 24 connects to the
above ground structure (not shown). Thus, in FIG. 1, the support
device is used for providing tensioning support to the manmade
structure. If the device 10 was needed to provide support in
compression, the inner support member 16 could be directly
connected to the foundation or other base support of the overlying
manmade structure, as further discussed below with respect to FIG.
3.
[0045] Referring now to FIG. 2, a launching device 40 is shown as a
preferred method in which to emplace the outer member of the device
10. The launcher 40 illustrated in FIG. 2 corresponds to the
launcher illustrated in the U.S. Pat. No. 5,044,831, this reference
being incorporated herein in its entirety. The launcher 40 is shown
in its loaded condition with an outer member/tube 12 loaded in the
launcher and ready for firing. The outer tube 12 with the pointed
end 14 is capable of penetrating the ground upon sufficient impact
force. The launcher 40 comprises a barrel 42 communicating with a
breach 44. The breach 44 defines an upper chamber 45. The distal or
forward end of the outer tube 12 is received within an annular
shaped sabot 46, preferably made of a plastics material, which is
slidably received within the barrel 42 adjacent the chamber 45. The
trailing or proximal end of the outer tube 12 extends through the
chamber 44 and projects rearwards from the launcher 40 through an
aperture formed in the cap or upper surface 50 of the breach 44. An
annual shaped breach seal 52 seals the outer tube 12 with respect
to the upper surface 50. A gas inlet tube 54 communicates with the
chamber 45 for the admission of compressed gas. A baffle 56 of a
larger diameter than the barrel 40 forms an axial projection of the
barrel extending into contact with the surface of the ground G. On
firing the launcher, compressed gas is forced into the chamber 45
that causes outer tube 12 to be fired into the ground. The baffle
56 includes a locating ring 58 that forms a snug fit around the
sabot 46 such that the launcher remains in alignment with the outer
tube that is emplaced in the ground. Accordingly, the outer tube
when emplaced remains in coaxial alignment with the barrel 42. As
also shown in FIG. 2, the breach seal 52 and sabot 46 may be held
in position prior to firing by a plurality of resilient members 60
which exert a separating force between the seal and the sabot.
[0046] Although a launcher of a particular construction is
illustrated in FIG. 2, it shall be understood that other launcher
types and methods can be used to emplace the outer tube within the
ground. For example, a launcher that makes use of an explosive
charge may be used. Alternatively, a vibratory means may also be
used along with some force that helps to ease the outer tube into
the ground. As stated above, it is preferable to avoid excavation
for emplacement of the outer tube as such excavation is equipment
and manpower intensive, and environmentally unfriendly.
[0047] FIG. 3 illustrates a second embodiment 10' of the present
invention. The support device 10' is the same as shown with respect
to the subsurface support of the first embodiment, with the
exception of a plurality of perforations/openings 30 which may be
formed in the outer tube 12. FIG. 3 also illustrates the device 10'
used to support an overlying structure S in compression. More
specifically, the device 10' has its upper end 28 embedded within a
concrete foundation F of a structure S. The foundation is shown as
extending a distance below ground level G. As also shown in FIG. 3,
the plurality of perforations/openings 30 which may be formed in
the outer tube allow the stabilizing material 18 to flow out from
the openings 30, thus forming external stabilizing structures 32.
In compression or tension, these external stabilizing features 32
help to strengthen the connection of the device 10' to the
surrounding soil. When filling the interior chamber of the outer
tube with the stabilizing mixture 18, such filling may take place
under pressure so that a desired quantity of the stabilizing
mixture 18 exits the perforation/openings 30, thereby forming the
external stabilizing features 32. In order to completely fill the
interior chamber of the outer tube, it may be preferable to
commence filling of the chamber from the lower most portion of the
chamber. A line (not shown) carrying the stabilizing mixture under
pressure can be inserted in the chamber and extend to the lower
most end of the support device, and then as the stabilizing mixture
fills the chamber, the line may be raised as necessary. Those
skilled in the art can envision other ways in which the stabilizing
mixture can fill the chamber of the outer tube.
[0048] Now referring to FIG. 3A, an enlarged section of the support
device 10' is shown specifically illustrating one manner in which
holes or perforations may be made in the outer tube 12. In FIG. 3A,
the openings 30 are formed by creating moon shaped cutouts thereby
leaving a chad or tab 34. The chad or tab 34 would be pushed away
from the exterior surface of the outer tube 12 as the pressurized
stabilizing mixture exited the interior chamber of the outer tube.
Alternatively, holes could be drilled or punched in the outer tube
12 in order to create an opening by which the stabilizing mixture
could flow through. Those skilled in the art can envision other
ways in which openings may be formed through the outer tube 12 in
order to facilitate flow of stabilizing mixture through the outer
tube to create the external stabilizing features 32.
[0049] FIG. 4 illustrates use of the subsurface support of the
invention to stabilize a sloping surface. In the figure, three
support devices 10 are illustrated and are spaced from one another
in a desired arrangement to best support the sloping surface. The
support devices are disposed in a horizontal orientation, but it
shall be understood that the support devices may be placed at any
angle or orientation depending upon the surrounding terrain. The
support devices in FIG. 4 would be representative of use of the
supports as either passive soil nails or tiebacks.
[0050] Additionally, the subsurface support of the present
invention can be used in combination at a particular jobsite to
support an overlying structure and to stabilize surrounding soil.
In this case, one or more support devices can be structurally
connected to an overlying structure such as shown in the figures,
and one or more additional support devices can be used as soil
nails to stabilize the surrounding soil or rock formation. Even in
tunnel construction, the support device of the present invention
can be used to stabilize the soil or rock formation surrounding the
tunnel. In a tunnel, a support device can be emplaced in any
orientation to include stabilizing the ceiling/upper surface of the
tunnel.
[0051] FIGS. 5 and 6 illustrate yet another preferred embodiment of
the present invention, namely, an improved soil nail 70 of dual
material construction. As shown, the nail 70 includes a contacting
portion or stinger 72 that attaches to a fiberglass body 74. The
soil nail extends symmetrically along a longitudinal axis A-A. The
stinger 72 comprises a conical distal tip 76, and a plurality of
axially aligned flanges 78 that extend proximally from the tip 76.
Spaced between the flanges 78 are neck sections 80 defining
portions of the stinger with smaller diameters. A transition flange
82 interconnects the most proximally located neck section 80 to an
intermediate extension 84. A shoulder 86 defines the interface with
the distal end of the body 74. A base portion 88 extends from the
shoulder 86, and is inserted within the opening 90 formed in the
distal end of the body 74. Preferably, the distal end 92 of the
body 74 has a flat surface thus providing a complementary flat
mating surface with the contacting face 94 of the shoulder 86. As
shown, the stinger components are generally smaller in diameter
than the diameter of the body 74. Further, the flanges 78 generally
have a similar diameter as compared to the large end of the conical
distal tip 76. The conical tip 76 and flanges 78 may further
include peripheral edges 79 that extend generally parallel to the
longitudinal axis A-A of the soil nail. The base portion 88
preferably extends approximately one foot within the opening 90 if
the exposed part of the stinger has a length of approximately six
inches. If a longer stinger is used, then preferably the base
portion extends further into the opening 90 in order to provide
adequate support. The base portion may be secured by a compression
fitting in opening 90 and/or an appropriate bonding agent can be
used.
[0052] Referring to FIG. 7, the soil nail 70 is shown as mounted
within the soil nail launcher 40 of FIG. 2. The soil nail 70 is
emplaced in the same manner as the outer tube 12 described in the
first embodiment; however, it being understood that the soil nail
70 is a subsurface support that can also be completely buried
within the soil without exposing an upper end thereof.
[0053] FIG. 8 shows an example use of the soil nails 70. This
figure specifically shows a number of soil nails 70 installed in
and around the bed of a body of water, such as a stream or river R
to thereby stabilize the soil around the bed. The soil nails 70
have been placed adjacent some abutments A that may be used to
stabilize an overhead structure such as a bridge (not shown).
Scouring and other types of erosion can be remedied with use of
soil nails in this manner. It shall be understood that the soil
nail of the present invention can be used in many other
applications, and FIG. 8 is simply one example.
[0054] FIG. 9 illustrates yet another soil nail embodiment of the
present invention. The soil nail 100 of FIG. 9 includes a plurality
of surface asperities that improve the pull out capacity of the
soil nail. Once a soil nail is in place, it is advantageous for the
soil nail to remain in place without slippage or pull out. With
respect to the embodiment shown in FIG. 3, pull out capacity is
improved after the cementious material exits the location of the
external stabilizing features. However, there is also a need to
provide a soil nail with improved pull out capacity wherein such
features are not activated in a later processing step, but rather,
are formed integrally with the soil nail prior to placement. In the
embodiment of FIG. 9, the body 102 of the soil nail 100 includes a
plurality of dimples or indentations 110 formed in a linear
pattern. Referring also to FIG. 10, these indentations 110
preferably do not pass through the entire thickness of the wall of
the soil nail thereby maintaining better structural integrity of
the soil nail whereas a plurality of holes made in the same linear
fashion might otherwise decrease the overall strength of the soil
nail such that it may break apart upon being fired from a launcher
into the ground, or may prematurely deteriorate in the soil. The
surface asperities caused by the indentations enhance the pullout
capacity of the soil nail without materially weakening the
construction of the soil nail. FIG. 9 also illustrates an optional
stinger 104 attached to the distal end 106 of the soil nail.
Therefore, as discussed above with respect to the embodiment shown
in FIGS. 5 and 6, the stinger may be used to further improve the
pullout capacity of the soil nail.
[0055] Although the indentations 110 are shown as extending
uninterrupted between the proximal end 108 and the distal end 106,
it is also contemplated that the indentations could be provided in
a discontinuous pattern, a continuous pattern, or combinations
thereof Additionally, while the indentations are shown as being
provided in a linear orientation, it is also contemplated that the
indentations could be provided in a non-linear or random
fashion.
[0056] FIG. 11 illustrates a modification to the embodiment of FIG.
9 wherein a combination of surface asperities or features is
provided to improve the pull out capacity of the soil nail. In FIG.
11, the soil nail 120 has at least one linear set of indentations
124, as well as being deformed along a linear line L following the
path of the indentations 124. The deformed shape of the bar, as
well as the indentations each improves the pull out capacity of the
soil nail.
[0057] FIG. 12 shows yet another modification to the embodiment of
FIG. 9. This soil nail is also deformed along a linear line
following a path of the indentations 124, but further includes a
plurality of threaded portions 126 spaced along the length of the
soil nail. The threads also increase the pull out capacity of the
soil nail, and are features that can be formed prior to a placement
of the soil nail.
[0058] FIG. 13 illustrates a method by which a linear set of
indentations may be formed on opposite sides of the soil nail 100
in accordance with the embodiment of FIG. 9. As shown, an upper
sprocket 112 has a plurality of teeth 114 formed on the outer
surface thereof, similar to a sprocket for a bicycle. A lower
sprocket 116 with teeth 118 are also provided, and disposed on an
opposite side of the soil nail. In order to form the indentations,
the bar is orientated so that it passes between the sprockets, and
the sprockets then rotate about their respective central axes to
form the indentations on the outer surface of the soil nail.
[0059] With respect to a method of making the soil nail shown in
FIG. 12, a first step may include creating the various sets of
threads 126 on the outer surface of the soil nail. In the next
step, the indentations 124 can be formed in the manner shown in
FIG. 13. Additionally, it is contemplated that the amount of force
or pressure provided by one or both of the sprockets 112 and 116
could be increased such that the body of the soil nail is deformed
along the path of the indentations.
[0060] FIG. 14 illustrates yet another embodiment of the present
invention. In this embodiment, the soil nail 130 has a plurality of
small asperities formed on the outer surface of the nail. The
asperities in this preferred embodiment are shown as small
protrusions 132. The protrusions are relatively small in comparison
to the tabs 34 shown in the embodiment of FIG. 3A. The protrusions
132 help in increasing the pullout capacity of the soil nail. One
method to create the protrusions 132 is to weld small pieces of
material to the soil nail. The protrusions 132 can be used with a
soil nail that is launched from launcher 40 without concern that
the protrusions will create excessive interference which otherwise
might deform or break the nail upon being launched. The protrusions
can be provided in a geometrically spaced pattern or randomly on
the outer surface of the soil nail. One acceptable general size for
the protrusions may include those that protrude approximately
one-eighth to one-half inch away from the outer surface of the soil
nail. Spacing between each of the protrusions may be approximately
4-6 inches.
[0061] It is also contemplated that the protrusions 132 could also
be combined with the other asperities shown in FIGS. 9-12. Thus, a
composite group of asperities could be provided on a soil nail to
optimize pull out capacity. A desired combination of the asperities
can be tailored to match optimum pullout capacity based on the type
of soil and rock formations present.
[0062] With respect to launching the soil nails illustrated in
FIGS. 9-12 and 14, the launcher 40 illustrated in FIG. 2 can be
used without requiring modification.
[0063] Referring now to FIGS. 15 and 16, in another embodiment of
the present invention, a subsurface support 200 is illustrated. In
this embodiment, the support 200 includes an outer member or tube
202 and an inner member, such as a length of rebar 204 that is
placed within the outer member 202. The outer member 202 has a
plurality of locations at which the hollowed bore or opening 205 of
the outer member 202 is made smaller by crimping the outer member.
In FIG. 15, there are two crimped locations, namely, one crimped
area 208 at the distal end 206 of the outer member, and another
crimped area 212 located at the proximal end 210 of the outer
member 202.
[0064] In FIG. 16, there are three additional crimped areas 214
located between the proximal and distal ends of the outer tube 202.
Depending upon the length of the outer member, it may be
advantageous to provide one or more intermediate crimped areas
which ensure the inner member maintains a uniform concentric spaced
relationship with respect to the outer member.
[0065] Referring to FIG. 17, this cross-section illustrates the
outer member 202 being crimped. As shown, the outer tube maintains
its normal diameter or shape at spaced locations along the outer
periphery of the outer tube; while a plurality of crimped sections
228 make the opening or bore 205 smaller at that location.
[0066] Referring to FIG. 18, another configuration is shown with
respect to the subsurface support 200 in which the length of the
support is extended by use of two outer members interconnected by a
coupler. A proximal end of a first outer member is attached to a
distal end of an adjacent or abutting outer member and these
members are connected to one another by a threaded coupler 220. One
way in which the coupler 220 may connect the abutting ends of the
outer members is by a threaded connection in which the outer
peripheral surfaces of the abutting ends may have an external
thread, and the coupler may have an internal thread. As also shown,
the inner member 204 extends continuously through the bores of both
of the outer members 202. This figure also illustrates the use of a
self-drilling bit 226 that can be used for emplacement of the
subsurface support in which the subsurface support is drilled into
the ground and the self-drilling bit 226 remains within the ground
when the subsurface support is drilled to a desired depth.
[0067] With respect to installation of the subsurface support 200,
there are a number of methods by which these subsurface supports
can be emplaced. One contemplated method is to launch the
subsurface support 200 in which there is a single outer member 202.
The distal end, since it is crimped, has a smaller cross-sectional
area that enhances its ability to be launched into the ground
without requiring a separate tip piece. In order that the opening
at the distal end does not become clogged with soil or rock, a
removable cap (not shown) can be placed over the opening.
Alternatively, a hole may be drilled, and the outer member is
placed in the hole. As mentioned, the support 200 may also have a
self drilling capability in which the support is attached to a
drilling tool and the self-drilling bit 226 facilitates
drilling.
[0068] Once the outer member is emplaced, it is filled with
cementious material by use of, for example, a pressurized grout
tube placed within the opening 205. After filling the opening 205,
the inner member 204 is inserted through the opening 205 and
through the length of the outer member. As shown in the figures,
the distal end of the inner member 216 may protrude beyond the
distal end 206 of the outer member. Similarly, the proximal end 218
of the inner member 202 may extend beyond the proximal end of 210
of the outer member 202. As shown in the cross-section of FIG. 17,
the inner bar or member 204 maintains a uniform spacing between the
outer surface of the inner member and the interior surface of the
outer member. By maintaining the spaced relationship between the
inner and the outer member, the inner member does not rest against
or otherwise lie in a position that is too close to the inner
surface of the outer member. Accordingly, the grout will fill the
space between the inner and outer members to provide additional
strength for the soil nail support. Particularly in installations
where the soil nail may be placed in a more horizontal location,
without providing some means to maintain uniform spacing between
the inner and outer member, the inner member will have a tendency
to lie against the outer member therefore minimizing the
effectiveness of the inner member.
[0069] Referring to FIG. 19 in yet another embodiment of the
present invention, in lieu of providing crimps to narrow the
diameter of the outer member an insert or spacer 230 is used to
offset or space the inner member from the outer member.
[0070] In FIG. 19 the insert 230 is shown as being placed within
the inner bore 205 of the outer member 202. The insert includes an
outer peripheral portion 232 that is placed in frictional
engagement with the inner surface of the outer member, an inner
concentric portion 234 with an opening 236 that receives the inner
member 204, and a plurality of radial supporting projections 238
that interconnect the inner concentric portion 234 with the outer
peripheral portion 232. The radial supporting projections 238
enable grout to pass through the spacer 230 when the outer member
is being filled. The size of the opening 236 is adapted to receive
the inner member 204 and the inner member will maintain a uniform
spaced relationship with the interior surface of the outer
member.
[0071] The insert 230 can be used at various locations along the
length of the outer member to include intermediate between the
proximal and distal ends, as well as placed at the proximal and
distal ends.
[0072] Referring to FIG. 20, a composite self-drilling soil nail
300 is illustrated in another embodiment. The soil nail includes a
threaded outer member 302 and a threaded inner member 304 which is
received through the bore or opening of the threaded outer 7228
member. The bore of the outer member may be smooth or may also be
threaded to receive the inner member. A bearing plate 306 is placed
over one end of the soil nail, and the bearing plate has a central
opening which is large enough to receive the outer member. The
bearing plate is shaped and sized for holding the particular
geological feature being stabilized. An outer securing nut 308 is
threaded over the outer tubular member 302 and is tightened against
the abutting surface of the bearing plate 306. An inner securing
nut 310 is then threaded over the threaded inner member, and
tightly against the abutting surface of the outer securing nut 308.
A self-drilling tip 312 is secured to a distal end of the soil nail
300. The soil nail may be extended in length by providing more than
one section or length of the outer member 302. Accordingly, two
outer members may be placed end to end and connected by a threaded
outer tube coupler 314.
[0073] In another aspect of the present invention, surface
asperities may be formed on a soil nail by a galvanization process.
The outer support member is dipped in a molten metal, such as zinc.
Prior to dipping, the galvanizer tank is stirred to mix the dross.
Therefore, it is preferable that none of the dross should be
skimmed or removed from the galvanizer tank. The molten metal along
with the dross adheres to the surfaces of the member being dipped.
Upon drying, the galvanized layer has a very rough texture. This
rough texture increases the pull-out capacity of the soil nail,
also increases the bond capability between the interior surface of
the bore and grout or other cementious material placed within the
outer member. Thus, the suspended dross particles which are
normally removed from the molten material in a galvanization
process provide a very useful purpose in creating a soil nail
having an outer member with surface asperities. Additionally, it is
contemplated that the inner member can also be subjected to this
type of galvanization process in order to increase surface
asperities on the inner member that also improves bond between the
grout in the bore of the outer member and the inner member.
[0074] FIG. 21 illustrates a plurality of soil nails 360 that are
used to repair a roadway in which a slip plane P exists in the
roadbed area below the road surface R. Without disrupting the slip
plane, continual cracking of the roadway will occur as the slip
plane continues to shift over time. Therefore, numerous attempts to
simply repair the road surface will be unsuccessful as the problem
lies in the earth beneath the road surface. As shown, a plurality
of the soil nails 360 are use in combination and extend
substantially perpendicular to the slip plane P thereby stabilizing
the soil on both sides of the slip plane and interrupting the
capability of the slip plane to naturally shift over time.
[0075] Referring also to FIG. 22, the construction of each of the
soil nails 360 include the use of an outer member 362, and inner
member 364 that is placed within the outer member 362, in which
grout, resin or other cementious material is used to hold the inner
member 364 within the outer member 362. For the area excavated
above the slip plane P, a wire mesh material 368 is placed. The
mesh provides further support for the soil nails, as well as to
further disrupt the ability of the slip plane to shift. The mesh
368 is secured to each of the soil nails by, for example, an
epoxy-coated nut 370 that is tightened against the galvanized plate
366. The galvanized plate 366 is also sized to provide necessary
support to prevent shifting of the soil. Finally, the roadway R may
be repaired in which the soil nails are entirely located below the
roadway R.
[0076] With the method and apparatus of the present invention, a
subsurface support is provided which can be emplaced with a minimum
of effort. In one advantage of the present invention, the
subsurface support provides an alternative to other anchoring means
because the outer tube provides protection to the inner support
member from corrosion or other undesirable environmental factors.
Depending upon the geological conditions, the outer tube can be
emplaced with a launching device that is adapted to account for
varying geological formations. For example, ground formations with
little rock allows emplacement of the outer tube with a minimum of
force while placement of the outer tube into an actual rock
formation would require a greater force provided by the launching
mechanism. In any case, the particular launching device chosen may
have the capability of emplacing the outer tube to the appropriate
depth and through various rock and soil conditions. In another
advantage of the present invention, an improved soil nail is
provided in a two-piece construction. This construction is cost
effective yet provides at least the same performance as compared to
a soil nail made of a single piece of material. While surface
asperities are illustrated with respect to the embodiments shown in
FIGS. 9-14, the other subsurface supports of the invention may also
include such surface asperities to improve pull out capacities.
[0077] In some of the preferred embodiments, means is provided to
maintain a uniform spaced relationship between the inner member and
the outer member to maximize the strengthening effect of the inner
member for both applications in tension and compression. These
means include crimped features formed directly on the outer member
or the use of inserts placed within the outer member.
[0078] The outer members may be placed in series to extend the
length of the support in which a threaded coupling is used to join
abutting outer members. A self-drilling bit may be used for direct
installation of the outer tube without having to conduct a separate
drilling step.
[0079] While the method and the apparatus of the present invention
have been provided in various preferred embodiments, it shall be
understood that various other changes and modifications may be made
within the spirit and scope of the present invention.
* * * * *