Note: Descriptions are shown in the official language in which they were submitted.
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FIELD OF TH~ PRESENT INVENTION
The present invention relates to retaining wall blocks
and more particularly to pre-cast slabs which can be divided into
a plurality of blocks of different sizes, depending on the needs
during the construction of the retaining wall.
10DESCRIPTION OF PRIOR ART
The construction of retaining walls with pre-cast
interlocking concrete blocks is well known. For example, see
Canadian Industrial Design 44,696 (Thomas), U.S. Patent 468,838
(Steiger), Canadian Patent 941,626 (Risi), U.S. Patents 3,488,964
(Kubo), 4,193,718 (Wahrendorf et al) and 4,372,091 (Toffolon,
Brown).
However, when constructing retaining walls using such
blocks, it is necessary to have a plurality of different blocks
in order to achieve an aesthetically pleasing result. To this
end, full-length blocks and half-length blocks are required. The
half-length blocks are used in making the ends of the walls
and/or corners. Furthermore, in the case of retaining walls
having more than a nominal height, it is preferable to provide
blocks having different widths in order to provide a greater mass
in the lower portion of the wall to increase the stability of the
wall.
30Finally, headers are required to provide a more
aesthetically pleasing top or finishing row of blocks.
This requirement for a plurality of different blocks,
each having a different configuration requires a plurality of
different moulds which increases the cost of producing such
blocks, thus increasing the cost of a retaining wall built with
such blocks. In addition, careful planning is required when
ordering the various types of blocks necessary to construct a
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ogiven retaining wall. Indeed, if a given block is not provided
in sufficient quantity, costly delays may be incurred.
.
OBJECTS OF THE PRESENT INVENTION
It is a general object of the present invention to
provide a retaining wall construction system which will
substantially lessen the disadvantages of the prior art by
providing a pre-cast slab comprising a plurality of elements 10 which can be divided into a plurality of blocks having the
required configuration during the construction of a given
retaining wall.
Another object of the present invention is to provide
such a pre-cast slab which can be divided in blocks of different
widths and lengths.
¦ An object of the present invention to provide such a
pre-cast slab for the construction of retaining walls that will
20 not require mortar or any other binder to form a solid and sturdy
wall.
J Yet another object of the present invention is to
provide a pre-cast slab for the construction of retaining walls
25 which allows but does not require the addition of tie backs or
other similar horizontal retention means.
Another object of the present invention is to provide
i a pre-cast slab for the construction of retaining walls which is
30 inexpensive to manufacture, simple to use and effective in its
operation.
Briefly, in accordance with the present invention, a
pre-cast slab for use in the construction of retaining walls
35 comprises an upper face and a lower face, at least said upper
face comprising a plurality of grooves defining at least two (2)
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elements allowing, but not necessitating, breakage of said
elements into separate blocks along said dummy grooves, each said
element having generally the same length and the same width and
- comprising:
- an upper face on which are disposed a plurality of
retaining pins extending axially of said element;
- a lower face having recess means extending axially of
said element, having a configuration so as to matingly
interlock when such elements are broken into blocks
which are disposed in horizontal courses one upon the
other;
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wherein at least one (l) of said elements comprises further
groove~ defining at least two substantially equal sub-
~ elements in said element.
.
~i 20 Such recess means may comprise a trapezoidal groove
throughout substantially the length of said element and such pins
may be shaped like a truncated cone.
These and other objects and advantages of the present
invention will no doubt become apparent to those of ordinary
skill in the art after having read the following detailed
~ description of a preferred embodiment of the invention.
t3 30
DESCRIPTION OF DRAWINGS
For the purpose of clarifying the nature of the present
, invention, an embodiment of the invention is illustrated in the
hereinbelow-described figures of the accompanying drawings and
is described in detail hereinafter.
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Figure 1 is a top perspective view of a concrete slab
made in accordance with the present
invention;
Figure 2 is a bottom view of the concrete slab of
Figure l;
Figure 3 is a top perspective view of the concrete
slab of figure 1 which has been broken into
four (4) separate blocks;
Figure 4 is a side elevation view of a retaining wall
constructed with blocks which were broken off
concrete slabs similar to the one shown in
Figure l;
Figure 5 is a perspective view of another concr te
slab from which header blocks may be broken
off;
Figure 6 is a partial perspective view of a retaining
wall constructed with blocks broken off
concrete slabs similar to those shown in
Figures 1 and 5.
DESCRIPTION OF A PREFERRED EMBODIMENT
In figures 1 and 2, a concrete slab is shown and is
generally referred to as numeral 5.
The slab 5 is pre-cast, that is cast before arrival at
the building site. If made of concrete, the slab may have
embedded therein suitable reinforcing elements (not shown) to
give additional strength to the resulting blocks when such is
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~ required. These reinforcing elements may comprise a steel grid or
s the like (not shown). since the method of obtaining those pre-cast
slabs or blocks is well-known in the art, same will not be
described any further.
' Each of said slab 5 has a generally rectangular top face lo,
i a bottom face 15 and side faces 20, 21, 22, and 23. The top face
of slab 5 comprises grooves 31, 32, and 33 while the bottom face 15
comprises grooves 34, 35, and 36 which are located in overlying
0relationship with respect to grooves 31, 32, and 33 respectively.
, . . .
~ Grooves 31/34 and 32/35 define three elements 60, 61, and 62
3 while grooves 33/36 divide element 62 in two further elements 62A
and 62B.
A plurality of protrusions 50 extend upwardly from the upper
~ face 10. Each protrusion has the shape of a shallow cylinder or
'~, preferably of a truncated cone and are placed in line near the
longitudinal axis of the upper face 10 of each element.
Each of these elements may form a separate block by breaking
the slab along the groove6 separating it from its neighbouring
element.
25A block may also comprise two elements, for example elements
60 and 61 form a wide block when elements 62A and 62B are broken
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off slab 5. Another example is illustrated in figure 4 where a
block 60 was broken off three slabs 5. The three wide blocks 61/62
form the three lowermost rows, the three broken off blocks 60 form
the next three rows while header block 71 was broken off header
slab 70 or is a block 61 from which the pins 50 have been removed
by a chisel or the like.
When an element is broken off to form a separate block, the
portion of the grooves remaining on the severed block forms a
chamfer which provides a mortar joint look when courses of severed
blocks are placed one over the other to form the retaining wall.
~ The under face 15 of each of the elements 60, 61, 62A, and 62B
i is provided with a longitudinal trapezoidal slot 55, which is
~ 15 capable of engagingly receiving the upper protrusions 50, when the
7 blocks are piled one on top of the other (in staggered or aligned
relationship) during the erection of a retaining wall.
For each particular element such as element 60, the
20 ~protrusions 50 are preferably slightly rearwardly offset with
respect to the corresponding slot 55 so that upon the erection of
the retaining wall, each row of same will be automatically set back
a predetermined distance D from the row underneath. Typically,
this distance D from the center of the protrusion 50 in upper face
10 to the center of the corresponding slot 55, in underface 15 is
such that an inclination of the retaining wall to the vertical of
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about 5 to 15 is provided. However, D may be adjusted to provide
any other desired inclination. In addition, the width of the slot
55 should slightly exceed the width or diameter of the protrusions
50 to allow ade~uate fitting.
It should be noted that the slots 55 extend along the
longitudinal axis of each element but end at a certain distance
from the side faces of each element. Element 62, as explained
above, can be divided into two half elements 62A and 62B along the
dummy grooves 33l36. Therefore the slot in each half element 62A
and 62B similarly does not extend the way to the end walls.
Alternatively, however, the slots 55 may, if desired, extend
the full length of each block element as do the slots 31 and 32,
for example. Additionally, the grooves 33/36 may, if desired, end
at a certain distance from the groove 32 in a manner similar to
slots 55 as seen in figure 2, ie. the grooves 33/36 may be blocked
off adjacent grooves 32 and 35.
As it will be appreciated, one of the elements, for example
element 61 is provided with only two protrusions 50. By so doing,
the block placed in the row above the element 61 can be placed
perpendicularly to the longitudinal axis of element 61 without
interfering with the interlocking of the other blocks, for example
when forming a corner. Furthermore, element 61 may be used as a
header block by simply removing the two protrusions.
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- Alternatively, however, the element 61 may, if desired, have
. the same numbered protrusions 50 as shown for element 60, the four
protrusions being disposed the same as for element 60.
SThe manner of constructing a retaining wall with the use of
slabs made in accordance with the present invention is described
hereinafter.
For the particular embodiment illustrated in the enclosed
10figures, each or a group of said elements 61, 62, or 63 may
sonstitute a distinct block for the construction of the retaining
` wall. Thus, if a two-element block is necessary (usually for one
or more of the lower courses), the pre-cast slab S is broken along
the dummy grooves 31/34 or 32/35. If only one-element blocks are
; lS required, said pre-cast slab 5 is broken along both dummy grooves
;i 31/34 and 32/35. Finally, when half-element blocks are required
(at the ends or when making a corner), the slab 5 is broken along
grooves 32/35 and then again along grooves 33/36. The breakage of
the slab along the dummy grooves will create a rough surface 90 in
q~ .20 the plane perpendicular to said dummy grooves lines which will
provide a cut stone look.
Horizontal retention means 80 can be attached on the element
60 as shown in figures 1 and 4. These retention means 80 may be
~ 25 made of any appropriate material and are adapted to be attached to
jconnection pins 75 placed on the top face of element 60 and act as
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tie backs when buried into the soil as shown in figure 4. However,
it is to be understood that any other type of retention means can
be used for the same purpose.
Pre-cast slabs made in accordance with the present invention
are useful for building retaining walls of up to 1.35 meter under
normal soil conditions in the case such blocks are 813mm x 610mm x
76mm. For higher walls or abnormal soil conditions, an engineer
should be consulted.
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As with any retaining walls structure, it is important
that the wall rest on an appropriate foundation and that adequate
drainage be provided behind the wall.
The first step consists in excavating a trench in which
q the foundation material and one or more rows of blocks will be
placed. For example, the following trench characteristics may
be use in most normal situations:
WALL HEIGHT TRENCH DIMENSION NUMBER OF ROWS
D W OF BURIED BLOCKS
up to 750mm 225mm x 550mm
;ll 15 750 to 1350mm 300mm x 750mm 2
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The trench and the excavated embankment are then
preferably covered with an appropriate geotextile to prevent the
~, smaller particles of soil from infiltrating and blocking the
drainage system.
Crushed stone (20mm or 0-20mm) is placed in the trench
` and compacted to act as a foundation for the retaining wall. A
drain is then placed in the rear portion of the trench and
J 25 connected to an existing drainage system.
:..
In order to increase the stability of the wall, it is
preferable that the lowermost course be made of a block
comprising two elements. However, for wall heights of up to
750mm, this is not an absolute requirement for most normal soil
conditions. The blocks should be staggered as any normal brick
work to increase the strength of the wall.
.,
3 The subsequent courses of the retaining wall may be
' 35 single-element blocks.
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SI~B CUTTING CHART
TY~ES OF ELEMENTS ALONG DUMMY GROOVE
lxlW + lx2W 31/34 32/35
- 5 3xlW 31/34 and 32/35
2xlW + 2 half element 31/34 32/35 and 33/36
The corners are constructed using half-element blocks 62A or
62B (see figure 6) obtained by breaking element 62 along grooves
33/36.
After the last row of blocks 60, 61, or 62 has been erected,
a top block on header 71 is placed on said last row. However,
alternatively, the elements 60 or 61 can also be used as a header
by removing the protrusions 55 with a chisel.
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While specific embodiments of this invention have been
illustrated in the accompanying drawings and described hereinabove,
it will be evident to those skilled in art that changes and
modifications may be made therein without departing from the
essence of this invention, as set forth in the appended claims.
' For example, in the preferred embodiment, the concrete slab was
designed to be divided into four (4) elements. However, it has to
be understood that said slab may comprise 3, 5 ~ 6 or more sub-
. elements depending on the needs.
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