U.S. patent number 5,791,826 [Application Number 08/718,236] was granted by the patent office on 1998-08-11 for embankment retaining wall system.
Invention is credited to Damian A. Moran.
United States Patent |
5,791,826 |
Moran |
August 11, 1998 |
Embankment retaining wall system
Abstract
In an assembly for constructing a multi-tiered retaining wall to
support a backfilled embankment, at least one generally planar
backfill retaining wall panel has opposed top and bottom edges, and
opposed parallel side edges. Each wall panel spans between pairs of
transversely spaced posts. Each post is in the form of a rigid
elongate column having an upper end, a lower end and opposed side
portions. An abutment forming a recessed area extends
longitudinally along each side portion of the column for receiving
the side edge of the wall panel. A pin element insertable into the
column retains the wall panel in place between pairs of columns in
the abutment prior to backfilling against a rear surface of the
wall panel. A seat at the upper end of the column supports a wall
panel of an adjacent higher tier. A saddle at the lower end of the
column provides for free-standing support of the column on a wall
panel on an adjacent lower tier prior to backfilling. A connector
extends from the column for connection to a wire mesh for anchoring
the column to the backfilled embankment. The column further
provides a wall panel of an upper tier with a predetermined
set-back into the embankment in relation to a wall panel in an
adjacent lower tier.
Inventors: |
Moran; Damian A. (DeWinton,
Alberta, CA) |
Family
ID: |
24885330 |
Appl.
No.: |
08/718,236 |
Filed: |
September 20, 1996 |
Current U.S.
Class: |
405/284; 405/285;
52/604 |
Current CPC
Class: |
E02D
29/0241 (20130101); E02D 2200/13 (20130101) |
Current International
Class: |
E02D
29/02 (20060101); E02D 005/00 () |
Field of
Search: |
;405/284-286
;52/604,169.1,169.3,169.4 ;D24/126,128,133,135 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Graysay; Tamara L.
Assistant Examiner: Mayo; Tara L.
Attorney, Agent or Firm: Malyszko; Thomas E.
Claims
I claim:
1. An assembly for constructing a multi-tiered retaining wall to
support a backfilled embankment comprising:
(a) at least one generally planar backfill retaining wall panel
having opposed top and bottom edges, and opposed parallel side
edges;
(b) at least two transversely spaced posts wherein said at least
one wall panel spans between pairs of said posts, each of said
posts comprising:
(i) a rigid elongate column having an upper end, a lower end and
opposed side portions;
(ii) an abutment portion extending longitudinally along each side
portion for receiving one of said side edges of said at least one
wall panel;
(iii) means for retaining said at least one wall panel in place
between a pair of said posts in said abutment portion prior to
backfilling against a rear surface of said at least one wall
panel;
(iv) a seat at said upper end of the column for supporting a wall
panel on an adjacent higher tier;
(v) a saddle at said lower end of the column for free-standing
support of said post on a wall panel on an adjacent lower tier
prior to said backfilling; and
(vi) means extending from said post for connection to a mesh for
anchoring said post to said backfilled embankment.
2. The assembly of claim 1 wherein each of said posts further
includes a set-back portion which provides a wall panel of an
adjacent upper tier with a predetermined set-back into said
embankment in relation to a wall panel in an adjacent lower
tier.
3. The assembly of claim 2 wherein said set-back portion comprises
said saddle offset forwardly of said abutment portion and said seat
offset a corresponding amount rearwardly of said abutment
portion.
4. The assembly of claim 2 wherein each of said at least two posts
is substantially T-shaped in cross-section having a laterally
extending flange with an outer face and an opposed inner face, and
a web extending rearwardly from said inner face of the flange.
5. The assembly of claim 4 wherein said abutment portion comprises
a recessed area formed at the juncture of said web and said flange
for receiving a complementary shaped side edge of said at least one
wall panel and for resisting movement of said complementary shaped
side edge away from said backfilled embankment.
6. The assembly of claim 4 wherein said retaining means comprises a
pin element insertable into an aperture in said web, said pin
element engaging a rear surface of said at least one wall panel
when said at least one wall panel is located in said abutment
portion.
7. The assembly of claim 6 wherein said pin element engages said
rear surface of said at least one wall panel above the centre of
gravity of said at least one wall panel to resist the tipping over
of said at least one wall panel toward said embankment prior to
said backfilling.
8. The assembly of claim 4 wherein said seat comprises a planar top
surface of said web for engaging a correspondingly shaped bottom
edge of said adjacent upper wall panel.
9. The assembly of claim 8 wherein said seat includes means for
resisting movement of said bottom edge of the adjacent upper wall
panel away from said backfilled embankment.
10. The assembly of claim 9 wherein said movement resisting means
comprises a portion of said inner face of the flange extending
above said top surface of the web for engaging a front surface of
said adjacent upper wall panel.
11. The assembly of claim 10 wherein said inner face of the flange
extending above said top surface of the web is offset rearwardly
from said inner face of the flange extending along the length of
said web to provide a set-back to the adjacent upper wall panel
supported by said seat.
12. The assembly of claim 4 wherein said saddle each of said at
least two posts is of a shape corresponding to said top edge of the
wall panel on said adjacent lower tier to provide a snug fit
thereon.
13. The assembly of claim 12 wherein said saddle forms an inverted
u-shaped slot, wherein one leg of said u-shaped slot extends from
said web to form a heel element for engaging a rear surface of said
lower tier panel, and an opposed leg of said u-shaped slot extends
from said flange to form a toe element for engaging an opposed
front surface of said lower tier panel.
14. The assembly of claim 13 wherein said toe element is offset
forwardly of said inner face of the flange to provide a set-back to
said at least one wall panel engaging the abutment portion of each
of said at least two posts in relation to said lower tier panel
engaged by said saddle.
15. In a multi-tiered soil retaining wall for a backfill embankment
having at least one wall panel spanning between a pair of spaced
posts, said at least one wall panel having opposed top and bottom
edges and opposed generally parallel side edges, the improvement
wherein each of said posts comprises:
a rigid elongate column having an upper end, a lower end and
opposed side portions;
an abutment portion extending longitudinally along each side
portion for receiving one of said side edges of said at least one
wall panel;
means for retaining said at least one wall panel in said abutment
portion;
a seat at said upper end of the column for supporting a wall panel
on an adjacent higher tier;
a saddle at said lower end of the column for free-standing support
of said column and any wall panel retained in said column's
abutment portion on a wall panel on an adjacent lower tier prior to
backfilling; and
means for connecting said column to a mesh for anchoring said
column to said backfilled embankment.
16. The retaining wall of claim 15 wherein each of said posts
further comprises a set-back portion which provides a wall panel of
an adjacent upper tier with a predetermined set-back into said
embankment in relation to a wall panel in an adjacent lower
tier.
17. The retaining wall of claim 16 wherein said set-back portion
comprises said saddle offset forwardly of said abutment portion and
said seat offset a corresponding amount rearwardly of said
abutment.
18. The post of claim 16 wherein said column is generally T-shaped
in cross-section having a laterally extending flange with an outer
face and an opposed inner face, and a web extending rearwardly from
said inner face of the flange.
19. The retaining wall of claim 18 wherein said abutment portion
comprises a recessed area formed at the juncture of said web and
said flange for receiving a complementary shaped side edge of said
at least one wall panel and for resisting movement of said
complementary shaped side edge away from said backfilled
embankment.
20. The retaining wall of claim 18 wherein said retaining means
comprises a pin element insertable into an aperture in said web,
said pin element engaging a rear surface of said at least one wall
panel when said at least one wall panel is located in said abutment
portion.
21. The retaining wall of claim 20 wherein said pin element engages
said rear surface of said at least one wall panel above the centre
of gravity of said at least one wall panel to resist the tipping
over of said at least one wall panel toward said embankment prior
to said backfilling.
22. The retaining wall of claim 18 wherein said seat comprises a
planar top surface of said web for engaging a correspondingly
shaped bottom edge of a wall panel of an adjacent upper tier.
23. The retaining wall of claim 22 wherein said seat includes means
for resisting movement of said bottom edge of the adjacent upper
wall panel away from said backfill embankment.
24. The retaining wall of claim 23 wherein said movement resisting
means comprises a portion of said inner face of the flange
extending above said top surface of the web for engaging a front
surface of said adjacent upper wall panel.
25. The retaining wall of claim 24 wherein said inner face of the
flange extending above said top surface of the web is offset
rearwardly from said inner face of the flange extending along the
length of said web to provide a set-back to the adjacent upper wall
panel supported by said seat.
26. The retaining wall of claim 18 wherein said saddle is of a
shape corresponding to said top edge of the wall panel on said
adjacent lower tier to provide a snug fit thereon.
27. The retaining wall of claim 26 wherein said saddle forms an
inverted u-shaped slot, wherein one leg of said u-shaped slot
extends from said web to form a heel element for engaging a rear
surface of said lower tier panel, and an opposed leg of said
u-shaped slot extends from said flange to form a toe element for
engaging an opposed front surface of said lower tier panel.
28. The retaining wall of claim 27 wherein said toe element is
offset forwardly of said inner face of the flange to provide a
set-back to said at least one wall panel engaging the abutment
portion of said column in relation to said lower tier panel engaged
by said saddle.
29. A post for use with at least one wall panel spanning between
pairs of said posts to construct a retaining wall for supporting an
embankment, said post comprising:
a rigid elongate column having an upper end, a lower end and
opposed side portions;
an abutment portion extending longitudinally along each side
portion for receiving a side
edge of said at least one wall panel;
a seat at said upper end of the column;
a saddle at said lower end of the column for free-standing support
of said column on a wall panel; and
means for connecting said column to a mesh for anchoring said
column to said embankment.
30. The post of claim 29 further comprising a set-back portion for
providing a wall panel with a predetermined set-back into said
embankment.
31. The post of claim 30 wherein said set-back portion comprises
said saddle offset forwardly of said abutment portion and said seat
offset a corresponding amount rearwardly of said abutment.
32. The post of claim 29 wherein said column is generally T-shaped
in cross-section having a laterally extending flange with an outer
face and an opposed inner face, and a web extending rearwardly from
said inner face of the flange.
33. The post of claim 32 wherein said abutment portion comprises a
recessed area formed at the juncture of said web and said
flange.
34. The post of claim 32 wherein said seat comprises a planar top
surface of said web.
35. The post of claim 34 wherein said seat includes means for
resisting movement of a wall panel away from said embankment.
36. The post of claim 35 wherein said movement resisting means
comprises a portion of said inner face of the flange extending
above said top surface of the web.
37. The post of claim 36 wherein said inner face of the flange
extending above said top surface of the web is offset rearwardly
from said inner face of the flange extending along the length of
said web.
38. The post of claim 32 wherein said saddle forms an inverted
u-shaped slot having two opposed legs extending from said lower end
of the column.
39. The post of claim 38 wherein said opposed legs are offset
forwardly of said seat to provide a wall panel with a predetermined
set-back into said embankment.
40. The post of claim 29 further including a means for retaining
said at least one wall panel in said abutment portion.
Description
FIELD OF THE INVENTION
The present. invention relates to retaining wall systems, and in
particular gabiontype retaining walls.
BACKGROUND OF THE INVENTION
Various methods of constructing retaining walls have been proposed
for erecting and supporting embankments of earth, for example
beside elevated highway overpasses and intersections. One such
method, sometimes referred to as gabion-type embankments or
construction, employs modular structural units of suitable gravel
partly or fully enclosed in prefabricated wire meshes or the like,
each of which may be integrally cast to a front segment or panel.
These cells of gravel are arranged side-by-side in tiers one atop
another as required. The wall's gravel mass functions to hold back
the soil embankment, and the front panels form an outer shell of
the wall. A disadvantage of such construction is that each
successive tier must be individually leveled and aligned prior to
installing the next tier. This is time consuming and inefficient,
and hence costly. The individual cells are also difficult to handle
because they are bulky and heavy, further hampering alignment and
leveling procedures.
An improvement to such wall construction is disclosed in U.S. Pat.
No. 4,914,887 to Meheen which employs pillar-like columns for
engaging individual wall panels. Each column has a vertical
key-slot for receiving an enlarged rib at the end of a wire mesh.
The mesh retains the column to the embankment. These ribs also
vertically interconnect the columns, and a system of pins
interconnect the wall panels to form a wall. However, this
arrangement suffers from several disadvantages which limit its
applicability. First, there is no apparent way of inclining or
setting-back the wall toward the embankment if required for
structural integrity of the embankment or merely for aesthetic
reasons. Second, a conventional mesh cannot be attached to the
columns, only one specifically configured to engage the vertical
key-slot. Third, there is no disclosed manner of staggering the
columns laterally in the plane of the wall, rather the columns must
be stacked one atop another. Hence, setting a column above a wall
panel to construct a retaining wall does not appear possible in
this system. Fourth, there is no means for positive column support
of adjacent wall panels prior to backfilling, nor can the wall
panels be supported atop the columns.
What is desired therefore is an embankment retaining wall system
which combines the structural concepts of gabions with precast wall
panel units in a manner designed for a singular, continuous and
uniform method of construction, and which overcomes the limitations
and disadvantages of these other prior art systems. Preferably the
system should reduce or minimize the amount of leveling and
alignment work necessary to construct the retaining wall. The
system should also provide for a controlled and predetermined
set-back of the retaining wall to avoid the time delays and
possible errors of having to establish such set-backs manually in
the field. Further, the posts or columns of the system should not
be limited to vertical alignment with, and support on, other posts
exclusively. Rather, the posts should be capable of support atop
the wall panels of the system to provide a greater flexibility of
arrangement and installation. The posts should also be capable of
supporting themselves as well as adjacent wall panels in a
free-standing manner prior to introducing a mesh or backfilling.
Yet further, the posts of the system should be capable of simple
on-site connection to a conventional gabion type mesh for ease of
use and to further reduce manufacturing and installation costs.
SUMMARY OF THE INVENTION
In one aspect the present invention provides an assembly for
constructing a multitiered retaining wall to support a backfilled
embankment comprising:
at least one generally planar backfill retaining wall panel having
opposed top and bottom edges, and opposed parallel side edges;
at least two transversely spaced posts wherein said wall panels
span between pairs of said posts, each of said posts
comprising:
a rigid elongate column having an upper end, a lower end and
opposed side portions;
an abutment means extending longitudinally along each side portion
for receiving said side edge of the wall panel;
means for retaining said wall panel in place between a pair of said
posts in said abutment means prior to backfilling against a rear
surface of said wall panel;
a seat means at said upper end of the column for supporting a wall
panel on an adjacent higher tier;
a saddle means at said lower end of the column for free-standing
support of said post on a wall panel on an adjacent lower tier
prior to said backfilling; and
means extending from said post for connection to a mesh for
anchoring said post to said backfilled embankment.
In another aspect the invention provides a post for use with at
least one wall panel spanning between pairs of said posts for
constructing a multi-tiered retaining wall to support a backfilled
embankment, said wall panel having opposed top and bottom edges and
opposed generally parallel side edges, said post comprising:
a rigid elongate column having an upper end, a lower end and
opposed side portions;
an abutment means extending longitudinally along each side portion
for receiving said side edge of the wall panel;
means for retaining said wall panel in said abutment means prior to
backfilling against a rear surface of said wall panel;
a seat means at said upper end of the column for supporting a wall
panel on an adjacent higher tier;
a saddle means at said lower end of the column for free-standing
support of said column and any wall panel retained in said column's
abutment means on a wall panel on an adjacent lower tier prior to
said backfilling; and
means for connecting said column to a mesh for anchoring said
column to said backfilled embankment.
DESCRIPTION OF THE DRAWINGS
Embodiments of the invention will now be described, by way of
example only, with reference to the accompanying drawings,
wherein:
FIG. 1 is an elevated frontal view above and below grade of a
multi-tierd retaining wall constructed according to a preferred
embodiment of the present invention;
FIG. 2 is a cross-sectional plan view taken on line 2--2 of FIG.
1;
FIG. 3 is a cross-sectional side view taken on line 3--3 of FIG.
1;
FIG. 4 is an enlarged view of a portion of the wall assembly of
FIG.3;
FIG. 5 is an isolated frontal view in elevation of a panel of
FIGS.1-4;
FIG. 6 is a cross-sectional plan view of the panel of FIG.5;
FIG. 7 is an isolated frontal view in elevation of a post of FIGS.
1-4;
FIG. 8 is a side view of the post of FIG.7 showing a portion of a
gabion-type wire mesh connected thereto;
FIG. 9 is a cross-sectional plan view taken on line 9--9 of FIG.8;
and
FIG. 10 is a cross-sectional plan view taken on line 10--10 of
FIG.8.
DESCRIPTION OF PREFERRED EMBODIMENTS
Reference is first made to FIGS. 1 to 3 which show a portion of a
multi-tiered retaining wall (generally indicated by reference
numeral 20) for supporting an embankment 22 typically backfilled
with earth, such as gravel, soil or the like, according to a
preferred embodiment of the present invention. The backfill should
allow for proper drainage to avoid excessive expansion and
contraction in the backfilled area and resultant damage to the
retaining wall 20. The bottom of the exposed embankment, or bottom
grade, is indicated by 23a and the top of the embankment or top
grade is shown as 23b. The retaining wall 20 is constructed of wall
panels 24 supported by posts 26 which are in turn anchored into the
embankment by a wire mesh 28 commonly used in the construction of
gabion-type retaining walls. The retaining wall of FIG. 1 has four
tiers or courses 30 of wall panel and post assemblies or cells
above the bottom grade 23a, each assembly formed by a panel 24
flanked on either side by a post 26. One tier of the retaining wall
20 (indicated by 32) is typically buried below the bottom grade 23a
to prevent the bottom of the wall 20 from kicking out, as is
conventional in retaining wall construction.
Referring now to FIGS.5 and 6 as well, each wall panel 24 for
retaining the backfill of the embankment 22 has a generally planar,
rectangular shape with a front surface 34, a rear surface 36 for
contacting the backfill, opposed top and bottom edges 38 and 40,
and opposed parallel side edges 42. In the preferred embodiment the
panel is symmetrical about the x and y axis, and so the top and
bottom edges may be reversed without consequence, as can the side
edges for ease of installation. However, it will be appreciated
that in certain circumstances, such as when the front surface 34
has architectural details for example, it may be necessary to
retain a specified orientation. The concrete wall panel is
reinforced with stainless steel mesh 44 or other reinforcement as
required for structural integrity of the wall panel and the
retaining wall overall. In the preferred embodiment the panel has a
width (ie. the length of the top or bottom edges 38, 40) of about 5
feet (aprox. 1.52 m), a height (ie. the length of the side edge 42)
of about 2 feet (aprox. 0.6 m) and a thickness (ie. the width of
side edge 42) of about 4 inches (aprox. 102 mm). Different
dimensions and materials may of course be used as required, as long
as such changes are accounted for in the post design, discussed
next.
Referring now to FIGS.4-8, each post 26 in the retaining wall 20 is
structurally similar, except for the posts 26a in the underground
tier 32 which are modified slightly for ground contact as noted
later. In the preferred embodiment, the post 26 is also symmetrical
about the y-axis (see FIG.7) for ease of construction and
installation, hence like reference numbers will be used for like
features on either side of the post. It is noted that references to
"top", "bottom", and the like are used for ease of reference and
refer to an element's general orientation when part of the
retaining wall 20. In particular, "front", "back" and like
references tend to indicate if a feature is facing or oriented
close to the visible, outer area of the retaining wall or to the
embankment side of the wall, respectively.
The post 26 forms a rigid elongate concrete column with appropriate
internal reinforcement some of which is indicated by 45 in FIGS.9
and 10. Unlike the wall panel 24, the post can not be twisted
upside down or back to front upon installation for reasons which
will be apparent below. The post 26 has an upper end 46, a lower
end 48, and is substantially T-shaped in cross-section (as best
seen in FIGS.9 and 10). A front portion of the post forms a
laterally extending flange 56 having an outer face 58 and an
opposed inner face 60. The outer face 58 may be beveled (as shown)
or altered otherwise for artistic or architectural purposes. A back
portion of the T-shaped post forms a web or stem 62 which extends
rearwardly from the inner face 60 of the flange 56. In the
preferred embodiment the web 62 is generally perpendicular to the
flange 56, and the juncture of the web 62 and the flange 56 along a
side portion of the post forms a substantially right-angled recess
64 for receiving the complementary shaped side edge 42 of the wall
panel 24. Upon assembly of the retaining wall the panel's side edge
42 is proximate to or abuts the web 62, and an adjoining portion of
the panel's front surface 34 abuts the flange's inner face 60. The
panel 24 is retained in this abutting relationship prior to
backfilling by a conventional pin 65 (indicated in FIG. 4 inserted
into web aperture 66 located away from the flange's inner face 60
by at least the thickness of the panel. The aperture 66 should also
be located toward the upper end 46 of the post as shown, namely
above the centre of gravity of the panel, to resist any tendency
for the panel to tip or pivot backwards toward the embankment prior
to backfilling behind the retained panel.
The lower end 48 of the post 26 forms a saddle (as best seen in
FIGS. 4 and 8) for supporting the post on the wall panel of an
adjacent lower tier (indicated by 24b in FIG.4) prior to
backfilling behind the post. The saddle is an inverted u-shaped
slot 68 having a shape corresponding to a panel's top edge 38 for a
snug fit thereon. The slot 68 is formed at the back by a heel 70
projecting from the web 62 and at the front by a toe 72 which is an
extension of the flange 56. When inserted on the lower panel 24b,
the heel 70 engages the panel's rear surface 36 and the toe 72
engages the panel's front surface 34. The heel and toe are of
suitable width's and lengths to support the post on lower panel 24b
in a free-standing manner, namely without the aid of further
supports (eg. cables, lumber, etc.), even when a panel is mounted
to the post via pin and aperture 66. Good results have been
achieved in the preferred embodiment with a heel height of about 2
inches (aprox. 51 mm) measured from the ceiling 74 of the slot 68
and a toe height of 3 inches (aprox. 76 mm) from the ceiling. The
width of both the heel 70 and toe 72 generally match that of the
flange 56 (about 6 inches, or 152 mm), although all of these
dimensions may vary as required.
The upper end 46 of the post has a seat 76 for supporting a wall
panel of an adjacent higher tier (indicated by 24c in FIG.4). The
seat 76 is formed by a relatively flat top surface 78 of the web 62
for engaging the correspondingly shaped bottom edge 40 of the
higher panel 24c. The seat 76 also has an upper toe 80 extending
from the flange 56. The upper toe 80 engages the front surface 34
of the higher panel 24c to resist sliding movement or kicking out
of the bottom edge of the higher panel 24c away from the backfilled
embankment.
The post 26 also incorporates a means of setting back successive
courses 30 of the retaining wall toward or into the embankment 22,
best seen in FIGS.3 and 4. A set-back distance of "X" (indicated in
FIG.4) per course is achieved by offsetting the saddle 68 from the
panel engaging recess 64 by a comparable amount, namely the lower
toe 72 of saddle slot 68 is located forward of the inner face 60 of
recess 64 by a distance of "X". Hence, when the wall panel 24 is
mounted in recess 64 of post 26, the panel is automatically setback
a distance "X" from the adjoining lower wall panel 24b.
Consequently, the seat 76 of the post should also be offset a
distance "X" rearwardly from the recess 64. In essence, the upper
toe 80 is located back of the inner face 60 by a comparable
distance "X" to match the set-back imposed by the saddle of the
post on the adjacent upper tier (shown in ghost outline in FIG.4).
It will be appreciated that providing the saddle 68 and the seat 76
with non-matching set-backs may produce undesirable results, such
as interference by the seat 76 with insertion of the upper panel
24c therein, or the formation of a gap between the panel 24c and
the seat 76 requiring insertion of shims or the like. In the
preferred embodiment the set-back "X" is less than the thickness of
the wall panel side edge 42 so that wall panels of adjacent tiers
overlap and engage one another as shown. Such overlapping
facilitates weight transfer through the retaining wall to its
foundation. Although the set-back "X" may be greater than the panel
width, this is not preferred due to loss of such favourable weight
transfer and possible seepage through the resultant gap between
vertically adjacent wall panels.
It is noted that the posts 26 employed in the underground tier 32
of the retaining wall do not engage a lower tier of wall panels,
but rather sit on a foundation of compacted gravel, concrete or
other suitable material. Consequently, the saddle feature is not
required, and in fact is detrimental to the post's stability on a
hard foundation where the protruding heel 70 and lower toe 72 can
not be shoved into the substrate. Hence, the heel 70 and toe 72 are
omitted or otherwise removed to provide the posts of the
underground tier with a generally flat bottom to promote stability
prior to backfilling.
Referring to FIGS.9 and 10, a mesh-like connector 82 is embedded in
the post 26 and extends about 6 to 7 inches or more (aprox. 152 mm
to 178 mm) away from the web 62. Wire or other suitable binder
(such as high strength synthetic materials, tack welding, etc.) is
used to connect the wire mesh 28 to the post 26. Two sets of mesh
28 are attached to each post, except for those along the vertical
periphery of the retaining wall. The mesh 28 is arranged in a
conventional manner as shown in FIGS.2 and 3 to form generally
rectangular shaped, enclosures, the size or volume of which
preferably decrease in successive tiers toward the top of the
embankment in pyramid-like fashion. The mesh 28 from adjacent posts
is preferably overlapped at the back of the enclosures and may be
bound if desired. The backfilled enclosures therefore anchor the
attached posts 26 to the embankment, as is appreciated by those
skilled in this field.
It can now be appreciated how the retaining wall system of the
present invention is formed, how it functions and some of the
resulting benefits. Specific dimensions and distances are used for
illustrative purposes only. Before arranging the first underground
tier 32 of the retaining wall, a trench 90 (see FIG.3) is excavated
to reach stable compactable soil, and is then partly filled with
crushed gravel or other suitable material and compacted to a
desired Proctor reading, typically at least 95%. The surface of the
compacted gravel base 92 should be at a depth equivalent to the
height of the first course of the wall, namely about 2 feet (aprox.
0.6 m) below the desired bottom grade 23a. The width of the trench
in this example is about 6 feet (aprox. 1.8 m) to accommodate the
enclosure formed by the mesh 28. The length of the trench will
depend on the length of wall desired.
The underground tier 32 is then arranged sequentially, preferably
in 50 foot (15 m) lengths. First and second posts 26a are set
generally vertically near the front of the trench and spaced apart
5 feet (aprox. 1.5 m), the length of the wall panels 24. A wall
panel 24 is then inserted between these two posts so that each
panel edge 42 abuts the recess 64 of each post. A pin is then
inserted into the aperture 66 of each post's web 62 to retain the
panel in place. The pin should only engage the inserted panel and
not protrude from the other side of the aperture 66 to avoid
interference with insertion of the next adjacent panel A third post
26a is then set another 5 feet away from the second post and
another panel is inserted in the resultant space therebetween, and
pins are inserted in apertures 66 for support. The above procedure
is repeated until the first 50 feet of the underground course is
set. The meshes 28 are also attached to the posts at this time and
arranged to form the previously discussed enclosures. Prior to
backfilling this underground course of wall, it is important that
the posts and wall panels be aligned and leveled as precisely as
possible to ensure the proper placement of subsequent courses of
the wall. Good results have been achieved with the following
backfilling procedure: suitable backfill material is placed in the
trench 90 on both sides of the posts and panels (namely at the
front adjacent to the panels' front panel faces 34 and the posts'
outer faces 58, and at the rear into the mesh enclosure 28) to
about 1/3 to 1/2 the height of the posts; the level and alignment
of the underground course is then checked and ad d as required; and
subsequently the trench is filled completely in front of the posts
and panels, followed by a complete fill of the mesh area 28 and the
surrounding trench area behind the posts and panels. Hence the
underground course 32 is virtually completely buried, except for
some exposure of the top edges of the panels so that they may
receive the next course. A good part of the time and cost of
constructing the entire retaining wall 20 is spent preparing this
underground course 32 to ensure its proper alignment and level, in
which case the construction of subsequent courses proceeds
relatively quickly and easily.
With the underground course of the wall completed, arrangement of
the first "above grade" tier 30 of the wall may proceed. The first
two posts 26 are set about 5 feet apart on the top edges 38 of the
"buried" panels. The saddles 68 of these posts ensure that the
posts are self-supporting (ie. free-standing) on the lower panels.
A wall panel 24 is then inserted between both posts in a snug fit
and retained in place by inserting pins into post apertures 66 as
before. The mesh 28 may then be connected to the posts and arranged
to form the desired enclosure. This cell or assembly of the
retaining wall remains free-standing while the remainder of the
first tier 30 is arranged in sequence. The mesh enclosures 28
should be backfilled before proceeding with the next higher tier so
as to avoid damage to the mesh. Since there may be some play in the
vertical alignment of the posts prior to backfilling, their
alignment should be checked and adjusted, if need be, upon
backfilling behind the posts in question. The above procedure is
repeated for subsequent higher tiers (four in all in the embodiment
shown) until the top of the embankment is reached and capped with
the top grade 23b. It is noted that the posts in the FIG. 1
embodiment are supported at about the mid-point of the adjacent
lower wall panel. Although such arrangement my be altered, it is
desireable because it provides for a substantially balanced force
distribution to the posts of the lower tier.
Other advantages of the present invention may now be better
appreciated. First, the features of the above system provide for
automatic elevation and alignment of the above ground tiers 30 once
the underground course 32 is set properly, which minimizes the
amount of on-site leveling and alignment work to be done, thus
saving construction time and money. Second, the posts and panels
are self-supporting during arrangement of the retaining wall, and
so time and materials are not wasted in propping each of these
element prior backfilling. In particular, each post is
self-supporting without the aid or introduction of the wire mesh or
other external anchoring features such as pins or rods. Hence, the
wall tiers are completed quickly and efficiently compared to prior
art retaining wall construction methods. Third, the posts 26 of the
present invention are relatively light weight for ease of handling.
Depending on specific configurations, the posts may weigh as little
as 30 lbs. (aprox. 13.5 kg), allowing for easy manipulation by
workers during construction. Although light weight, the posts are
capable of carrying significant loads. Fourth, the posts provide
the retaining wall with a pre-determined or "controlled" setback.
Workers therefore need not waste time in the field checking whether
each individual wall panel has the required set-back. The required
set-back is achieved automatically as long as the posts are set
properly, thus eliminating the possible errors inherent with
establishing such set-backs manually in the field. Fifth, the
present system lends itself to a wide variety of arrangements of
the posts and panels in a single wall construction since posts of
successive tiers are not restricted to alignment one atop another.
For example, the posts on a second tier of a retaining wall may sit
at the centre of the lower first tier wall panels, whereas the
posts of the fourth tier may be shifted over for placement to one
side of the lower third tier wall panels.
The above description is intended in an illustrative rather than a
restrictive sense and variations to the specific configurations
described may be apparent to skilled persons in adapting the
present invention to specific applications. Such variations are
intended to form part of the present invention insofar as they are
within the spirit and scope of the claims below. For instance, some
wall panels may be manufactured integrally with one or two posts,
although this is not preferred because of potential handling and
installation difficulties.
* * * * *