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BACKGROUND OF THE INVENTION
1. Field of the Invention
In my U.S. Pat. No. 4,707,962 I disclosed an anchoring system for so-called
"cascade" wall structures and the like consisting primarily of a pair of
anchor members of more or less "dumbbell-shaped" cross section each having
a web section terminating at both ends in an integrally-formed rib or
flange and a generally arcuate bridging member, the opposite ends of which
lock in behind a transversely-spaced pair of the anchor member flanges
while the webs and remaining flanges of the latter are embedded in the
soil forming the embankment or wall which must be confined. While this
system is far superior in most respects to other prior art systems for the
same purpose, it does have certain shortcomings which have proven to be
somewhat troublesome and limit its utility, especially in certain
applications.
To begin with, the anchor members are quite large, heavy and very difficult
for one person to handle. This fact alone creates alignment problems,
makes them difficult to stack and store, and they provide no versatility
in terms of the distance separating the flanges which is fixed despite the
fact that many applications exist in the field in where this spacing is
far from ideal.
The flush arrangement of the web and buried portion of the anchor with
respect to the top of the embankment creates compaction problems in that
heavy equipment cannot be used for backfilling and the contractor is
essentially forced to do it by hand. Also, being fabricated of concrete,
even reinforced concrete, the tension loads that the web is capable of
safely withstanding is somewhat limited.
Furthermore, inasmuch as the web comprises an integral part of the anchor
member, auxiliary rods and pipes must be used to align and maintain the
flanges in vertically-stacked relation where required.
2. Description of the Related Art
The most pertinent prior art known to me is found in my U.S. patent
mentioned above although I have another Pat. No. 4,050,254 which pertains
generally to the subject of tied-back retaining wall structures but ones
of considerably different construction.
Of the prior art cited in my earlier patent discussed above, I consider to
Knight the U.S. Pat. No. 1,847,655 and the German Pat. No. 812463 to be
worth noting in terms of the evolution of the art of modular retaining
wall structures and because they include certain specific features which
I, too, incorporate into my anchoring system. Knight, for example,
discloses a wall-forming module having oppositely-facing keyslots in its
ends which, upon being placed in opposed face-to-face relation with the
keyslot in another such module overlapping the latter, can be connected
together by means of a key to form an essentially water-tight joint. This
patent, however, includes no tie-back feature by means of which the
modules are anchored to the soil nor is one needed since the function of
the wall thus formed is not that of a retaining wall at all but rather a
piling to be driven into the ground and, therefore, it is already
supported both front and back and requires no additional anchoring.
In the German patent, on the other hand, a retaining wall structure is
shown in FIGS. 2 and 3 wherein opposed pairs of post-like members are
connected together by some sort of anchoring member h and adjacent pairs
of these posts are bridged by arcuate panels not unlike those of my
earlier patent to form a retaining wall. The posts are devoid of keyslots
and there is no suggestion that the anchoring members h could be wire mesh
nor is any way shown or suggested for connecting these anchoring elements
to the posts. Moreover, nothing in this patent suggests the novel feature
of using the mesh in vertically-disposed relation as the sole anchoring
member requiring no second post on the other end thereof.
SUMMARY OF THE INVENTION
I have now found that the aforementioned shortcomings of my patented
retaining wall system can be overcome by the simple, yet unobvious,
expedient of eliminating the integrally-formed concrete web altogether,
providing the anchor-forming endpieces which remain with
vertically-extending keyslots, and tying back these anchors into the
embankment individually or, alternatively, a pair of them to one another
in side-by-side spaced apart relation by means of either straight or
generally U-shaped lengths of wire mesh having at least one end formed and
enlarged to define a retaining member connectable to one of these anchors
by sliding same down into the keyslot. The resulting wire mesh web can be
fabricated of any length necessary to suit a particular application and it
has the additional advantage of being able to accommodate much greater
tension loads than a concrete one, even when reinforced with steel. This
means that much higher retaining walls can be constructed without the
stepped-back configuration required of my earlier anchoring system.
Another very important advantage is that the wire mesh web when in place
will be vertical, not horizontal as was the case with the Geomesh mats
imbedded in the embankment behind the anchoring elements of my earlier
patent. This means, of course, that a pair of anchor-forming endpieces can
be tied together in side-by-side spaced apart relation by using a
generally U-shaped length of wire mesh or the like moving from the face of
the embankment where one of the anchors is located back into the interior
thereof and out again to connect with the second anchor of the pair. When
used in a free-standing wall structure, a straight length of mesh will
connect a pair of anchors on opposite faces of the wall as was the case
with the integrally-formed concrete one; however, the important difference
is that the thickness of the wall can be varied at will by lengthening or
shortening the web.
Among the other advantages is the fact that by having the two paired
anchor-forming endpieces independent of one another, one can be buried and
recessed beneath the surface along with the wire mesh web connecting it to
its companion flange on the outside of the embankment thus permitting
heavy motorized equipment to be used to compact the fill material placed
thereabove without danger of its being damaged. Also, by recessing the
wire mesh web at the top of each endpiece, its retaining member can be
made to project beyond the keyslot at the lower end of the latter thus
providing a self-aligning coupling to a second endpiece underneath without
having to use special alignment rods or sleeves for this purpose. By
extending the vertically-extending web back through and beyond the
so-called "shear plane", instances of what is known as "slip circle
failure" can be avoided.
The other very obvious advantages have to do with the greater ease with
which the components of my latest system can be handled, shipped, stored
and otherwise manipulated.
Accordingly, it is the principal object of the present invention to provide
a novel and improved system for erecting retaining walls of one type or
another together with the unique method of using same.
A second objective is to provide a system of the type described wherein a
set of four interlocking components, two of which are identical, cooperate
with one another in assembled relation to produce a much more versatile
and effective way of building a retaining wall than that which has been
available heretofore.
Another object of the within-described invention is to provide a wall panel
for bridging the gap between adjacent anchor-forming endpieces that is
susceptible of various decorative and ornamental treatments while, at the
same time, retaining the structural integrity necessary as a component of
the assembly used to contain and retain the earthworks.
An additional objective of the invention herein disclosed and claimed is to
provide a simplified retaining wall erection system which requires no
skilled labor, little if any motorized equipment, and one that can be
erected easily and safely by one person.
Additional objects are to provide a combination of individual components
for use in erecting a retaining wall which are relatively lightweight yet
strong, easy to use, compact, safe, modular and highly decorative.
Other objects will be in part apparent and in part pointed out specifically
hereinafter in connection with the description of the drawings which
follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view, portions of which have been broken away to
conserve space, showing a spaced apart pair of the keyslotted
anchor-forming endpieces and a straight length of the wire mesh web
interconnecting the latter into assembled relation by means of the
enlargements formed on the ends thereof that define retaining ribs;
FIG. 2 is a perspective view similar to FIG. 1 but to a smaller scale,
again with portions broken away to conserve space, showing side-by-side
pair of the anchor-forming endpieces interconnected by a generally
U-shaped span of web-forming wire mesh;
FIG. 3 is a fragmentary section to a greatly enlarged scale taken along
line 3--3 of FIG. 1;
FIG. 4 is a fragmentary section taken along line 4--4 of FIG. 3;
FIG. 5 is a fragmentary vertical section showing a multi-tiered retaining
wall with no stepback and with the enlargements at the end of the wire
mesh webs being employed to align the anchor-forming endpieces vertically;
FIG. 6 is a further enlarged fragmentary sectional detail emphasizing the
vertical alignment feature mentioned above in connection with FIG. 5;
FIG. 7 is a still further enlarged fragmentary section similar to FIG. 4
but showing a modified retaining rib on an end of the wire mesh web;
FIG. 8 is a fragmentary horizontal section showing how the system is used
to confine both faces of a dirt-filled wall;
FIG. 9 is a fragmentary vertical section similar to FIG. 3 but to a much
smaller scale showing a truss-type wire web as an alternative to the
ladder-type shown in the other figures;
FIG. 10 is a front elevation showing the decorative face of one of the
steel-reinforced panels which are used to span the gap between adjacent
anchor-forming endpieces;
FIG. 11 is a section to an enlarged scale taken along line 11--11 of FIG.
10;
FIG. 12 is an exploded view showing one way in which these panels can be
held in vertically-aligned relation using alignment pins; and,
FIG. 13 illustrates the manner in which the panels are poured in two steps.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring next to the drawings for a detailed description of the retaining
wall forming system of the present invention and the method of using same,
it will be seen to comprise basically four elements of an assembly, two of
which are identical. Specifically, these elements comprise what will be
denominated here as "anchor-forming endpieces" or just "endpieces", a wire
mesh web and a wall panel, the three having been referred to in a general
way by reference numerals 10, 12 and 14, respectively. When a pair of the
anchor-forming endpieces 10 are interconnected as shown in FIG. 1 by the
wire mesh web 12, the resulting subassembly takes on the general shape of
a dumbbell in cross section. The anchoring elements of my earlier U.S.
Pat. No. 4,707,962 had this generally dumbbell-shaped cross section;
however, the web-forming portion was considerably thicker, heavier and,
most important, was formed integral with the flange-forming endpieces;
whereas, the I-beam shaped subassembly of my present system consists of
three separate interlocking pieces 10 and 12 which greatly facilitate the
handling thereof as well as increasing its versatility as will become
apparent as the description proceeds.
Endpieces 10, in the particular form shown, have the same general
cross-section as the flange-forming elements on opposite ends of the
anchor members of my earlier system except for the fact that the portions
16 thereof on the inner face that separate the generally concave seats 18
which receive the rounded panel ends are each provided with a
vertically-extending keyslot 20. These keyslots together with the
aforementioned seats comprise the main functional surfaces of the
endpieces 10, the remaining exposed surfaces being shaped primarily for
decorative reasons. In simple terms, these endpieces comprise short,
keyslotted precast concrete pillars of sufficient breadth to anchor the
web 12 when attached thereto and buried beneath the ground. As such, their
function remains the same as it was in my earlier patented system. These
anchor-forming endpieces in the particular form shown comprise a one piece
pillar, however, two or more such endpieces can, if desired, be stacked
one atop another with all being bridged and interconnected by a single
length of webbing.
The prime area of novelty in my improved system forming the subject matter
hereof lies in the wire mesh web, the formation of the enlarged retaining
rib indicated in a general way by reference numeral 22 on the ends
thereof, and the manner of connecting these enlarged ribbed ends into the
keyslots in the anchor-forming endpieces. As can be seen most clearly in
FIG. 4, one form of retaining rib 22 comprises welding a pair of vertical
rods 24 to opposite sides of the horizontally-disposed strands 26 of steel
wire mesh which, together with the vertically-extending strands 28 located
at intervals intermediate the ribbed ends thereof define the so-called
"ladder-type" wire mesh web seen in FIGS. 1-7, inclusive.
An alternative form of an enlarged end portion defining a retaining member
for insertion into the keyslot in place of the rib 22 shown in FIG. 4 is
shown in FIG. 7 and it has been broadly designated by reference numeral
22M. Instead of a vertically-extending rib encompassing the full height of
the web 12, it will be seen to comprise an integrally-formed loop 30 in
the ends of the horizontally-disposed wires 26M of the web through the
vertically-aligned openings 32 in which is passed a wire or rod 34 which
cooperates with the loop encircling same to produce a series of
vertically-spaced enlargements. The crosswise dimension of both rib 22 and
enlargement 22M is, of course, greater than the width of the entrance 36
of the keyslot 20. For applications where maximum strength is required,
the FIG. 4 ribbed version is somewhat preferable to the alternative
looped-wire version shown in FIG. 7 because the latter has less bearing
surface in contact with the keyslot than the ribbed one. On the other
hand, the looped-wire version is easier and less labor-intensive to
fabricate.
A brief look at FIG. 10 will reveal an alternative form of web 12M in which
instead of the horizontally-disposed wires 26 being interconnected by
vertically-oriented ones to define a ladder-like construction, a zig-zag
wire pattern 38 interconnects the horizontal ones to produce a truss-like
web.
Of considerably more importance than the pattern of the wire mesh web or,
for that matter, the particular form of the enlargement on the ends
thereof that locks it into the keyslot 20, is the manner in which the
subassembly is used which consists of a pair of these endpieces and the
web interconnecting same, which subassembly has been broadly identified in
the drawings by reference numeral 40. Particular reference will now be
made to FIGS. 1-3, 5, 6 and 8 for a detailed description of the manner of
using this subassembly which in most respects differs significantly from
the way the anchor members of my earlier system were used.
Commencing with FIGS. 1 and 2, the simplest form of the subassembly 40 is
the one in which a straight section of wire mesh web is used to
interconnect the pair of anchor-forming endpieces 10. In the particular
form shown in these two figures, it will be noted that the lefthand end of
the web is recessed within the keyslot in the endpiece, whereas, the top
of the web is flush with the top of the righthand endpiece. In a setup
like this one, the lefthand endpiece is left exposed on the face of the
embankment 42 in the manner shown in FIG. 5 while the righthand one is
buried beneath the surface of the latter. With the righthand endpiece and
the top of the web buried beneath the surface of the embankment, heavy
motorized backfilling equipment (not shown) can be used to compact the
fill material working back and forth over the top of the latter. By way of
contrast, in the wall structure shown in FIG. 8 where both of the
endpieces are exposed, the web is recessed beneath the top surface of each
one while, at the same time, permitting compaction to be carried out
therebetween. In both the embodiments of FIG. 1 and FIG. 8, of course, the
length of the web 12 can be varied to suit the particular retaining
problem found to exist at the site. In FIG. 5, for example, the web, be it
straight as in FIGS. 1 and 8, or U-shaped as in FIGS. 2 and 5, can be
extended well behind the failure plane represented by the dashed line. In
my earlier system, the anchoring elements themselves were only of a given
length and any extension of the system to encompass a failure plane like
the one shown in FIG. 5 necessitated the use of Geomesh laid flat between
courses as each tier was put in place one atop the other.
Before leaving FIGS. 1 and 8 it should, perhaps, be pointed out that the
system shown therein differs significantly from my previously patented
system and also from that disclosed in German Pat. No. 812 463 in that the
Geomesh itself is the only anchoring element required and it need not,
therefore, be used as a bridging element between a pair of anchor posts as
both of these patents show. In other words, the Geomesh anchors of FIGS. 1
and 8 could be split vertically at some point between the ends thereof
such that one section anchored one post and the remaining section the
other or, alternatively, the mesh sections could overlap one another
without being connected together in any way. From a practical standpoint,
of course, a single length of mesh of the proper length simplifies
installation even though the bridged connection between posts is
unnecessary.
Directing the attention to FIGS. 2 and 5, an alternative form of the
subassembly 40 is shown in which both of the endpieces 10 lie in
transversely-spaced exposed relation on the surface of the embankment
while the web 12 is U-shaped to interconnect the two after passing into
the embankment and back out again. Here again, the web can be recessed for
compaction purposes, be made as long as necessary and, as seen in FIGS. 5
and 6, be used to form the interlock vertically aligning the tiers of
endpieces thus eliminating the need for separate alignment pins and
sleeves for this purpose.
FIG. 5 also shows a tiered retaining wall with no setbacks being required
in the manner of a stepped so-called "cascade wall". Depending to some
degree upon the particular soil conditions encountered, tiered walls
containing three stacked three foot high tiers can be constructed without
having to set back any of the tiers. This becomes possible because the web
of each successively lower tier in the stack can be made longer as shown
to resist the relatively greater loads imposed thereon from above. The
U-shaped configuration seen in FIGS. 2 and 5 is preferred over one which
is "squared off" primarily because of the simplicity of manufacture
although there is little to recommend one over the other functionally and
both can easily be made to nest.
With specific reference to FIG. 6, a bit more should, perhaps, be said
concerning the interlocking feature of the webs 12. As shown, the wires or
rods 26 or, alternatively, the single one 32 that goes down through the
looped-wire ends 30 in the modification 22M of FIG. 7 are preferably both
left flush with the top horizontally-disposed strand 26 of the mesh while
allowed to project at least an inch or so below the lowermost horizontal
strand thereof. By so doing, this projecting portion 44 will enter the
unobstructed upper end of the keyslot in the endpiece therebeneath thus
forming an alignment connection therebetween. In the lowercost of several
tiers, this projection 44 will merely stick down into the ground below the
bottom of the endpiece. In that rare circumstance where this projection
would cause a problem, it can either be cut off or the web turned upside
down in which the bottom strand of the mesh would be at the top and
recessed while the top strand at the bottom would be flush with the bottom
of the endpiece. For maximum versatility, therefore, the length of the
rib-forming wires 24 or the centerwire 32 should roughly correspond to the
overall height of the endpieces while the vertical distance separating the
top and bottom strands of the web should be less than the overall height
of the endpiece by the length of the projection 44.
Directing the attention briefly to FIGS. 10-13, inclusive, certain features
of the bridging panel 14 which comprises the fourth element of the
assembly will be described in detail along with the method by which it is
fabricated. It, like the ones in my earlier system is precast out of
concrete. The most obvious difference, of course, is that the earlier one
was curved while the one illustrated herein is flat. Both have the exposed
side edges 46 curved to seat within the complementary curved concave seats
18 of the endpieces as shown most clearly in FIG. 8.
Steel reinforcing rods 48 and 50 are embedded in the concrete and may take
the form shown in FIGS. 10, 11 and 13, some (48) extending horizontally
while others (50) extend vertically. The vertically extending ones,
particularly those at opposite ends of the panel can be used
advantageously as alignment pins by letting them project as shown either
above or below the adjacent panel surface from which they emerge. Suitable
sockets 52 must, of course, be provided in the mating surface of the
companion panel in the stack. An alternative construction might be one
shown in FIG. 12 in which the vertically-extending rod 50M is
foreshortened to leave sockets at both ends as shown in FIG. 12 in which
case a separate alignment pin 54 would be used. No attempt has been made
to describe how these sockets 52 might be formed since such procedures are
well within the skill of the ordinary artisan and for this reason form no
part of the present invention. As a matter of fact, by welding short
sleeves (not shown) to one or both ends of the vertically-extending rebar
pieces at opposite ends of the panel, formation of the sockets 52 takes
care of itself.
Finally, with reference to FIG. 13, one method of forming the panels in
order to provide a decorative face thereon will be described briefly.
First, a shallow pan-type mold 56 consisting of a pallet 56P and an
open-bottomed frame 56F is partially filled with wet zero-slump concrete
and before it sets, the rebar (48, 50) is laid in place atop the layer
just formed and a second layer poured on top. Next, a lid 58 containing
suitable decoration 60 which is to appear on the face of the panel is
pressed down atop the second layer, vibrated and left in place until the
assembly hardens. Finally, the lid is raised and the finished panel
removed from the pallet along with the mold which is then stripped
therefrom.
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