Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02357328 2001-09-13
1-22691
TITLE OF THE INVENTION
RETAINING WALL BLOCKS AND RETAINING WALLS CONSTRUCTED
FROM SUCH BLOCKS
TECHNICAL FIELD
[0001] The invention relates to concrete retaining wall blocks and to
retaining
walls constructed from such blocks.
BACKGROUND OF 'THE INVENTION
[0002] Concrete blocks are frequently used for constructing retaining walls.
Rectangular blocks have been stacked to form a retaining wall and then back
filled
on one side to form a terrace. The backfill can exert a sufficient force on
the
retaining wall blocks to cause the stacked blocks to move out of their
original
position. In some cases, the blocks are stacked to form a stepped wall so that
the
front face of each row or tier of blocks is offset slightly behind the front
face of the
adjacent lower row of blocks. Further, a raised lip has sometimes been formed
along the upper edge of the block adjacent the front face to prevent the
stepped
blocks from sliding out ofposition, as shown in Arvai et al. U.S. patent
5,791,827.
In order to eliminate this problem, retaining wall blocks have sometimes been
formed with a groove extending along a bottom surface parallel to an exposed
face
of the block and a raised portion is formed on a top surface to extend
parallel to the
front face. The groove on a stacked block receives the raised portion on an
adjacent
lower block for maintaining alignment of the front faces of the stacked
blocks.
Such an arrangement is shown, for example, in Forlini U.S. patent 5,647,185.
Retaining wall blocks also may be formed with round knobs on the top surface
which fit into a groove on the bottom surface of a stacked block to permit
forming a
curved retaining wall, as shown in Wagenaar U.S. patent 5,337,527. Another
method for stabilizing a retaining wall constructed from concrete blocks is
through
the use of a geogrid tie back system in which the retaining wall is secured to
the
ground behind the retaining wall with ground anchors. The use of ground
anchors
for stabilizing retaining walls is shown, for example, in Kelly, Jr. U.S.
patent
5,402,609 and in Wagenaar U.S. patent 5,337,517.
BRIEF SUMMARY OF THE INVENTION
[0003] The invention is directed to retaining wall blocks and to retaining
walls
formed from such blocks. The retaining wall is constructed from tiers of cast
concrete blocks which are trapezoidal in plan and have rectangular front faces
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which are textured and, optionally, colored to simulate a desired type of
stone or
rock. The blocks are provided with at least one top projection or knob which
is
received by a bottom groove in a block in an adjacent upper tier for
interlocking the
tiers of blocks. Preferably, the bottom groove is omitted from the blocks in
the
lowermost tier.
[0004] The top projections are omitted from blocks used in the top row of
blocks
in the retaining wall. The top blocks may have an top surface portion which is
recessed below an upper edge of the front face of the blocks to allow
extending top
soil or other material over the top surface portion up to the front face. In
an
alternate embodiment, the upper surface of the top blocks is recessed below
upper
edges of the front and rear to define a trough extending between the sides
parallel to
the front face. The troughs in a row of top blocks form a drain ditch which
extends
along the top of the retaining wall.
[0005] Planter blocks also may be used in one or more tiers below the
uppermost
tier. Each planter block has a trough in its upper surface which extends
between the
sides of the block parallel to and adjacent the front face of the block. The
knobs on
the top of the planter block are spaced further behind the front face than the
bottom
recess, so that the front face of blocks in an adjacent upper tier are spaced
behind
the front face of the planter block and at least a portion of the trough is
exposed.
The trough may be filled with soil and plants.
[0006] In a further embodiment, the blocks are provided with finished front
and
rear faces for constructing a free standing wall.
[0007] Accordingly, it is an object of the invention to provide retaining wall
blocks and retaining walls constructed from such blocks.
[0008] Other objects and advantages of the invention will become apparent from
the following detailed description of the invention and the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Fig. 1 is a perspective view as seen from the upper right front of a
basic
retaining wall block for constructing a retaining wall according to the
invention;
[0010] Fig. 2 is a top plan view of the retaining wall block of Fig. l;
[0011] Fig. 3 is a perspective view as seen from the upper right front of a
top
block for constructing a retaining wall according to one embodiment of the
invention;
[0012] Fig. 4 is a right side elevational view of the top block of Fig. 3;
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(0013] Fig. 5 is a perspective view as seen from the upper right front of an
end
top block for constructing a retaining wall according to a further embodiment
of the
invention;
[0014] Fig. 6 is a perspective view as seen from the upper right front of a
drain
ditch top block for constructing a retaining wall according to a further
embodiment
of the invention;
[0015] Fig. 7 is a right side elevational view of the top block of Fig. 6;
[0016] Fig. 8 is a perspective view as seen from the upper right front of a
planter
block for constructing a retaining wall according to a further embodiment of
the
invention;
[0017] Fig. 9 is a right side elevational view of the planter block of Fig. 8;
[0018] Fig. 10 is a cross sectional view through one embodiment of a seven
tier
retaining wall constructed with blocks according to the invention;
[0019] Fig. 11 is a cross sectional view through a further embodiment of a ten
tier retaining wall constructed with blocks according to the invention, with
four
tiers of planter blocks and topped with a drain ditch block;
[0020] Fig. 12 is a fragmentary perspective view of a stepped retaining wall
according to a further embodiment of the invention;
[0021 ] Fig. 13 is a fragmentary perspective view of a landscape area
including
two serpentine retaining walls according to the invention;
[0022] Fig. 14 is a perspective view of a top block for a free standing wall
according to the invention;
[0023) Fig. 15 is a perspective view of a half top block for a free standing
wall;
[0024] Fig. 16 is a perspective view of an intermediate tier block for a free
standing wall according to the invention;
[0025] Fig. 17 is a perspective view of a half intermediate tier block for a
free
standing wall;
[0026] Fig. 18 is a perspective view of a lowermost tier or base block for the
base of a free standing wall;
[0027] Fig. 19 is a perspective view of a half base block for a free standing
wall;
[0028] Fig. 20 is a top plan view of a free standing retaining wall wherein
the
blocks are illustrated as having the shape of a right trapezoid in plan.
DETAILED DESCRIPTION OF THE INVENTION
[0029] The invention is directed to concrete blocks for manufacturing
retaining
walls of various configurations and to retaining walls manufactured from such
blocks. Figs. 1 and 2 illustrate a basic block 10 for use in constructing a
retaining
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wall according to the invention. The block 10 is suitable for use in tiers of
a
retaining wall other than the uppermost or top tier. The block 10 has a
rectangular
front face 11 which is textured and, optionally, may be colored to represent
various
types of stone and rock. The block 10 has left and right sides 12 and 13, a
rear 14, a
top 15 and a bottom 16. Preferably, the block 10 is trapezoidal in plan with
the
front face 11 and the rear 14 substantially parallel. By making the length of
the rear
14 shorter than the length of the front face 11 and by angling at least one of
the
sides 12 and 13 slightly towards the center of the rear 14 of the block 10, a
curved
retaining wall may be constructed with the front faces 11 of adjoining blocks
10
abutting.
[0030] Optionally, a wire or rod 17 may be embedded in the block 10 to have a
portion 18 which extends across a recess 19 formed in the top 15. The rod
portion
18 is adapted to be engaged with a block lifting mechanism, such as a chain
connected to a fork lift or a backhoe. The rod portion 18 facilitates lifting
the block
10 with the top 15 and bottom 16 substantially horizontal for transporting the
block
10 and for constructing a retaining wall. Preferably, a rod 20 also is
embedded in
the block 10 to form a loop 21 which extends beyond the rear 14. The block 10
is
cast with its front face 11 down in a form (not shown). The loop 21
facilitates
lifting the block 10 from the form after it has cured. Either in addition to
or as an
alternative to the rod 17, grooves 22 and 23 may be formed in the sides 12 and
13
of the block 10 to facilitate lifting the block 10 while it is horizontal with
the tines
of a fork lift. The grooves 22 and 23 open to the rear 14 and stop short of
the front
face 11 so as to not be visible at the exposed face of a retaining wall
constructed
with the blocks 10.
[0031 In order to provide stability to a retaining wall constructed from the
blocks 10, at least one, and preferably two knobs 26 project from the block
top 15.
The knobs 26 are located a predetermined distance from the front face 11 and
preferably are symmetrically spaced from the sides 15 and 16. A recess 27 is
provided in the block bottom 16. When a plurality of the blocks 10 are stacked
to
form a retaining wall, each knob 26 on a lower block is received by a recess
27 in
an adjacent upper block 10. Preferably, the recess 27 is in the form of a
groove
which extends completely across the width of the block 10 parallel to the
front face
10. The use of two knobs 26 rather than a single rib extending the width of
the
block 10 facilitates the construction of curved retaining walls.
[0032] When a retaining wall constructed from the blocks 10 is to have a
substantially vertical face, the recesses 27 and the knobs 26 on the blocks 10
forming the wall will have the same spacing from the front face 11 of each
block.
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If the knobs 26 are spaced further from the front face 11 than the recesses
27, an
upper tier of blocks 10 forming a wall will be spaces to the rear of the
adjacent
lower tier of blocks 10. If desired, the front face 11 may be provided with a
slight
vertical slope. If the knobs 26 have the same space from an upper edge of the
front
face 11 as the recesses 27 from a lower edge of the front face 11, the face of
the
retaining will have the same slope as the front face of the blocks 10.
[0033] Figs. 3 and 4 show details of a top block 28 for forming the top of a
retaining wall according to one embodiment of the invention. 'the top block 28
has
a front face 29 which is preferably textured to simulate a desired type of
stone or
rock, and optionally may be colored. The front face 29, sides 30 and 31, a
rear 32
and a bottom 33 of the top block 28 may be the same as for the block 10. The
top
block 28 differs from the block 10 in that it has a generally flat top surface
portion
34 which is recessed below an upper edge 35 of the front face 29. Optionally,
a rod
36 may be embedded in the block to extend across a recess 37 in the top
surface
portion 34 for engagement by a lifting mechanism for lifting the block 29
while it is
substantially horizontal. Alternately, the recess 37 may be eliminated and the
rod
36 may be bent to form a loop extending above the surface 34 while remaining
below the upper edge 35. Also, an optional horizontal grooves 38 may be
provided
in the sides 30 and 31 to facilitate lifting the horizontal block 29 with the
tines of a
fork lift. When the top block 28 is located on the top of a retaining wall,
the rear
side of the retaining wall may be back filled and soil or mulch, for example,
may
extend over the top surface portion up to the upper edge 35 of the front face
29.
Thus, grass or other vegetation may be planted or mulch may be spread over the
top
of the retaining wall without a risk of it washing over the retaining wall in
a heavy
rain..
[0034] Referring to Fig. 5, an end top block 40 is shown according to a
further
embodiment of the invention. The end top block 40 is similar to the top block
28,
except that a right side 41 of the end top block 40 extends at right angles to
a front
face 42 of the block 40. Both the front face 42 and the right side 41 are
textured
and may be colored to simulate a desired rock or stone. The front face 42 has
an
upper edge 43 which connects with an upper edge 44 of the right side 41. The
block 40 has a top surface portion 45 which is recessed below both upper edges
43
and 44. A rod 46 is located in a recess in the top surface portion 45 near the
center
of gravity of the block 40 to facilitate lifting the block 40 in a generally
horizontal
attitude. The end top block 40 is designed to be used both at the end of an
upper
tier of a retaining wall and where the upper tier makes a 90° turn. In
a retaining
wall in which the tiers step down, the end top block 40 also may be used to
create
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an attractive end for each tier. It will be appreciated that a left side 47 of
the block
40 may be finished rather than the right side 41, or that both the left and
right sides
47 and 41 may be finished to match the front face 42. The block 40 includes a
recess or groove 48 in a bottom 49 for receiving one or more knobs 26 on a
lower
block. The recess 48 is spaced from and extends parallel to the front face 42.
The
recess 48 stops short of the finished side 41 and/or 47 so as to not be
visible from
the front or from the finished sides.
[0035] Some areas which have extreme dry and wet seasons and areas which
have poor soil percolation are prone to flooding from sudden heavy rains. When
a
retaining wall is back filled to its top, heavy rains can cause water to flood
over the
retaining wall and can cause erosion. Figs. 6 and 7 show a drain ditch top
block 50
which can be placed on the top of a retaining wall. The top block 50 is formed
to
create a drainage ditch which extends along the top of the retaining wall to
control
the flow of water over the retaining wall. The top block 50 is similar to the
top
block 28, in that it has a similar front face 51, left and right sides 52 and
53, rear
side 54, and bottom 55. The front face 51 has an upper edge 56. The top block
50
differs from the top block 28 in that it has an upper surface portion 57 which
is
recessed below both the upper edge 56 of the front face 51 and an upper edge
58 of
the rear 54 to form a trough which extends parallel to and between the front
face 51
and the rear 54.
[0036] When a plurality of top blocks 50 are located in a row along the top of
a
retaining wall, the recessed top portions 57 form a drainage ditch extending
along
the top of the retaining wall. It should be appreciated that the drainage
ditch may
extend along either the entire length of top of the retaining wall or along
only a
portion of the top of the retaining wall. The drainage ditch may continue to
one or
both ends of the retaining wall, or it may connect at one or more points along
the
retaining wall to a storm sewer or to a drain ditch which carries surface
water away
from the retaining wall.
[0037] Referring to Figs. 8 and 9, a planter block 60 is shown according to a
further embodiment of the invention for use in constructing retaining walls.
The
planter block 60 has a front face 61 which is preferably textured to imitate
the
appearance of a desired type of stone or rock, left and right sides 62 and 63,
a rear
64, a top 65 and a bottom 66. The front face 61 has an upper edge 67. A trough
68
is formed in the top 65 of the block 60 to extend adjacent to, parallel to and
substantially below the upper edge 67. The trough 68 extends between the sides
62
and 63. The bottom 66 of the block 60 has a recess 69, and at least one and
preferably two knobs 70 project from the top 65 to the rear of the trough 68.
As
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clearly shown in Fig. 9, the knobs 70 have a greater spacing from the front
face 61
than the recess 69.
[0038] When a row of the planter blocks 60 is stacked in a retaining wall tier
above a tier formed from the blocks 10. the front face 61 of the block 60 will
be
positioned above and adjacent the front face 11 of the block 10. When a row of
the
blocks 10 are stacked above a retaining wall tier formed from the planter
blocks 60,
the front faces 11 of the blocks 10 will be stepped behind the front faces 61
of the
blocks 60 sufficiently to expose at least a portion of the trough 68. The
trough 68 is
then tilled with soil for planting, for example, flowers, small bushes or
vines which
will grow over the retaining wall. The step back in the face of the retaining
wall at
a tier formed from the planter blocks 60 also provides increased stability to
the
retaining wall, permitting construction of the retaining wall to a greater
height.
[0039] For stability, retaining walls are constructed with the blocks
staggered in
adjacent tiers, in a manner similar to constructing a brick wall. Thus the
seam
between two abutting blocks in a wall is located below and above the center of
blocks in adjacent upper and lower tiers, respectively. Although not
illustrated, it
will be appreciated that half width blocks may be provided for each of the
blocks
10, 28, 40, 50 and 60 to finish the end of a retaining wall.
[0040] Fig. 10 is a cross section through an exemplary retaining wall 73
constructed with tiers of the basic blocks 10 and topped with a tier of top
blocks 28.
Optionally, the wall 73 may be supported on a poured concrete footer 74.
Alternately, the wall 73 may be constructed on a footing of a suitable packed
and
leveled granular bearing material. Base blocks 10' may be used in the
lowermost
tier which are identical to the blocks 10, except that they do not have a
bottom
recess 27. It will be apparent that the recess 27 is not needed in the
lowermost tier
of blocks. Also, for higher retaining walls the omission of the recess 27
gives a
greater flat bearing surface for supporting the retaining wall. Preferably, a
geotextile wrapped perforated drain 75 is installed behind the base of the
blocks 10'
in the lowermost tier. After the lowermost tier of the blocks 10' is
installed, tiers of
the blocks 10 set in place, with the seams between the blocks in each tier
staggered
from the seams in the adjacent tiers. As the tiers of blocks 10 are installed,
the area
between the blocks 10', 10 and the existing soil 76 is filled with a free
draining
aggregate 77 and the aggregate 77 is tamped. Finally, the uppermost tier of
the wall
73 is formed with a row of top blocks 28 and, optionally, top soil 78 is
spread over
the surface up to the upper edge 35 of the front face of the top blocks 28 to
complete the retaining wall 73. In some installations, mulch, gravel or paving
may
extend over the top blocks 28 up to the upper edge 35.
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[0041] Fig. 11 illustrates an exemplary retaining ten tier retaining wall 80.
The
illustrated retaining wall 80 constructed from a lower tier of blocks 10',
alternating
tiers of planter blocks 10 and basic blocks 10, and topped with a drain ditch
top
block 50. Because of the planter blocks 60, the retaining wall 80 will have a
general slope rather than the substantially vertical retaining wall 73 of Fig.
10. The
illustrated retaining wall 80 has four tiers formed from planter blocks 60.
The
troughs in the planter blocks 60 are filled with top soil 81 and plants 82,
such as
flowers, vines or small bushes. A geotextile fabric wrapped perforated drain
83 is
positioned behind the base of the lowermost tier of blocks 10' and is
surrounded by
stone. An area between the retaining wall 80 and the existing soil 85 is
filled with a
compacted, free draining aggregate 84. Topsoil 86 or other desired surface
material
may be placed above the existing soil 85 to extend up to the upper rear edge
58 of
the top block 50. It should be appreciated that a retaining wall may be
constructed
with one or more tiers of planter blocks 60 separated by one or more tiers of
blocks
10 to provide a desired appearance and slope.
[0042] Fig. 12 is a fragmentary illustration of a stepped retaining wall 88
arrangement formed from base blocks 10', blocks 10, top blocks 28, and end
blocks
40'. The end blocks 40' are identical to the end blocks 40, except that both
left and
right sides of the end blocks 40' are finished and of the same height as the
front
face. The retaining wall 88 has a lowermost tier of base blocks 10'. In the
portion
of the retaining wall 88 nearest the lower center of Fig. 12, the retaining
wall is only
two tiers high, with the upper tier formed from a top block 28. Where the wall
is
three or more tiers high, blocks 10 form the intermediate tiers, and top
blocks 28
form the upper tier. An end block 40 is used at the end of each tier. In the
illustrated wall 88, the end blocks 40 are rotated 90° so that the
longer front face 42'
extends perpendicular to the front face of the wall 88. The area immediately
adjacent the top blocks 28 and the end blocks 40' is shown covered with mulch
89,
and bushes 90 are planted behind the mulch 89. In the illustrated wall 88, a
sidewalk 87 is poured up to the lowermost tier of blocks 10'.
[0043] As indicated above in the description of the basic wall blocks 10, the
blocks 10 are generally trapezoidal in plan. This allows forming curved
retaining
walls with the front faces of adjacent blocks 10 abutting . Fig. 13
illustrates an
exemplary landscape area 91 formed from a serpentine lower retaining wall 92
and
a serpentine upper retaining wall 93. The serpentine lower retaining wall 92
is
formed from a tier of top blocks 28 and, where the wall 92 has two tiers, a
lower
tier formed from blocks 10'. The number of tiers in the lower wall 92 is
selected to
provide a horizontal upper edge to the lower wall 92. If necessary, a portion
of the
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lowermost tier of blocks may be partially buried. A portion of the illustrated
lower
wall 92 is one tier high and a portion is two tiers high to compensate for
elevational
changes in the surrounding terrain. The illustrated upper wall 93 is two tiers
high.
For aesthetics, the upper wall 93 has a different serpentine arrangement from
the
lower wall. Areas between the walls 92 and 93 and the area above the upper
wall
93 are landscaped with mulch and bushes.
[0044) It should be appreciated that the above described retaining wall blocks
may be modified for constructing a free standing wall which is finished on
both
sides. Fig. 14 shows a top block 95 having a finished front face 96 and a
finished
rear face 97, and Fig. 15 shows a half width top block 95'. The top of the top
blocks 95, 95' may be recessed, as shown, to permit growing landscape plants
on
top of the wall, or it may be flat (not shown). Fig 16 shows a basic or
intermediate
tier block 98 having a finished front face 99 and a finished rear face 100,
and Fig.
17 shows a half width intermediate tier block 98'. Fig. 18 shows a bottom tier
block
101 having a finished front face 102 and a finished rear face 103, and Fig. 19
shows
a half width bottom tier block 101'. The blocks 95, 98 and 101 may be formed
to
be rectangular in plan if a straight wall is to be constructed, or trapezoidal
in cross
section if curved walls are to be constructed. Curved and straight walls are
created
by selecting the orientation of the blocks. If alternate blocks are reversed
so that the
shorter finished face of adjacent blocks are on opposite sides of the wall,
the wall
will be straight. If the shorter finished faces of two adjacent blocks abut,
the wall
will curve. The blocks 95, 98 and 103 also may be formed to have a shape in
plan
of a right trapezoid, wherein one end is perpendicular to the sides, as shown
in the
top plan view of a section of a free standing wall 104 in Fig. 20 formed from
blocks
105.
(0045] It will be appreciated that various modifications and changes may be
made to the above described preferred embodiments of retaining wall blocks and
retaining walls constructed from such blocks without departing from the scope
of
the following claims.
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