Note: Descriptions are shown in the official language in which they were submitted.
CA 02426836 2003-04-25
~~TAININ~ WA~,~, I~A~E ~~ sA~~~~~s
Technical Field
The invention pertains to retaining walls and methods of
constructing retaining walls. In particular, it pertains to retaining walls
made of sandbags which support fill material without the use of geogrid.
hack round
Retaining walls are used in a wide variety of civil engineering and
landscaping applications, for example to support slopes and
embankments for highways, support noise barriers, etc. Retaining walls
are commonly made having a supporting face structure made of
interconnecting blocks with soil or other fill material placed and
compacted in back of the wall, and generally with sheets of geogrid laid
in the fill at various levels, extending back from the wall and attached to
it.
International patent application No. W~ OOI61 X80 published
~ctober 19, 2000 discloses a system of building retaining walls from
sandbags which uses interconnecting members to attach the sandbags in
adjacent courses to each other so as to stabilize and strengthen the
sandbag wall structure, permitting the construction of permanent
retaining wall structures (and, if desired, temporary ones) and ones that
may be higher and steeper than conventional sandbag retaining walls.
The interconnecting members are plates having projections on both sides
thereof that protrude into horizontally and vertically adjacent sandbags.
~ptionally, sheets of geogrid may be attached to the interconnecting
members to extend at selected courses into the fill material supported by
-1-
CA 02426836 2003-04-25
the sandbags in order to help stabilize the fill and anchor the sandbag
structure to the fill.
Geogrid is a costly product, and for some applications where
sandbag retaining walls with geogrid are effective, it would be desirable
to be able to construct the walls so as to have a high degree of stability
but without using geogrid.
Summary of Invention
The invention provides a retaining wall structure comprising a
plurality of courses of sandbags which form a wall face, supporting a
mass of fill material. In this specification, a "sandbag" means any bag,
or soft-walled container, holding any suitable fill material, including
sand, soil, mixtures thereof, and including fill mixed with seed for grass
or other plants. Interconnecting members are positioned between
adjacent courses of sandbags to connect sandbags of adjacent courses
together. Sandbags also extend from the wall face into the fill material,
preferably at spaced-apart positions along a course. Depending on the
height of the wall and the number of courses in it, sandbags may extend
from the wall face into the fill material at a plurality of courses of the
wall.
The invention also provides a method of constructing a retaining
wall as aforesaid. A plurality of sandbags is placed to form a first
course and interconnecting members are placed on it. It is to be
understood that the "first" course is not necessarily the bottommost
course, but can be any suitable course in a wall having a plurality of
courses. A second course of sandbags is placed above the first course,
with the interconnecting members connecting the two courses together.
Within the second course, sandbags is placed so as to extend into the fill
-2-
CA 02426836 2003-04-25
material supported by the wall. Interconnecting members are placed on
the extending sandbag so as to attach them t~ the other sandbags of the
second course. A third course of sandbags is then placed above the
second course, covering the interconnecting members on the second
course and on the extending sandbags.
Brief Description of Drawings
Figure 1 is a cross-sectional side view of a retaining wall
structure according to one embodiment of the invention.
Figure 2 is a cross-sectional plan view thereof.
Figure 3 is a cross-sectional plan view of a retaining wall
structure according to a second embodiment, showing a freestanding
wall .
Figure 4 is a cross-sectional side view of the wall of Figure 3.
Figure 5 is a perspective view showing the placement of
interconnecting members on sandbags in a course.
Figure 6 is a cross-sectional view through an interconnecting
member on the line 6-6 of Figure 5.
Detailed Description of the Preferred Embodiments
Referring to Figures 1 and 2, a retaining wall structure 10
according to the invention is constructed on ground 12 and comprises a
~0 plurality of courses 14 of sandbags 16, forming a wall face 18. Each
course 14 is preferably laid approximately horizontal, though it may
-3-
CA 02426836 2003-04-25
follow the contour of the ground as required. The face of the wall is
preferably sloped to enhance stability, though it may be vertical if
desired. Fill material 20 is compacted behind and supported by
sandbags 16.
The sandbags are preferably made of a geotextile material that is
durable and that permits water to flow into and through the bags, and
seedlings to grow out, while retaining fine soil particles within the bag.
The material of the bags should not be biodegradable, for durability of
the wall.
At selected, longitudinally-spaced positions along selected,
vertically-spaced courses, sandbags are placed in courses 14 so as to
extend from the wall face into the fill material 20. Within a given
course, such extending sandbags 22 may be positioned, for example,
between every second and third sandbags, or at such other spacing as is
appropriate for effective stabilization of the wall face in a particular
application. Likewise, the extending sandbags 22 may be positioned at
selected levels during the construction of the wall, for example at every
third course (as illustrated in Figure 1), or as required for a particular
application. Sandbags 16 are preferably generally rectangular in shape
(in plan view) having a length significantly greater than their width. In
such case, the sandbags employed as extending sandbags 22 may be the
same size sandbags as those used to form the courses 14, simply being
positioned so that their long side extends back from the wall face when
they are used as extending sandbags. Alternately, for use as extending
sandbags, sandbags may be selected that have a length that is greater
than the length of the sandbags that form the wall face. In either case, it
will be apparent that extending sandbags must extend a distance into the
fill material that is effective to anchor the wall face and stabilize the fill
material.
_q._
CA 02426836 2003-04-25
Interconnecting members 24 are used m the construction of the
retaining wall 10. Generally, the interconnecting members may be of
the types described in International Patent Publication No. WO
OOI61880 dated October 19, 2000. Referring particularly to Figures 5
S and 6, interconnecting member 24 preferably comprises a plate 26,
generally rectangular and planar, with a plurality of projections 28
extending vertically from both sides of the plate. Projections 28 are
sufficiently strong and pointed to protrude into the sandbags.
Interconnecting member 24 is preferably made of plastics or aluminum
other non-corrodible material. Preferred dimensions of the
interconnecting member are about 286 millimeters in length, 100
millimeters in width and 42 millimeters in height (including the
projections).
Interconnecting members 24 are used m the construction of the
retaining wall by placing them on top of sandbags 16 in a given course
so that projections 28 on the lower side protrude into the sandbags.
When a second course of sandbags is placed on top of the first course
and the interconnecting members 24, the projections on the upper side
of the plate protrude into the sandbags in the second course, and the
weight of such sandbags presses the interconnecting members so that the
projections 28 on their lower side protrude fully into the sandbags in the
first course. The projections 28 can be configured to fully penetrate the
sandbags, or, preferably, to simply indent them. In either case, the
projections are considered to "protrude" into the sandbags.
Interconnecting members 24 are of a size and configuration such
that, when plate 26 is placed covering a portion of two abutting
sandbags within a course, some of projections 28 on the lower side of
the plate will protrude into each of the two abutting bags, connecting
them together, and when a sandbag is placed on top of such plate, i.e. in
-5-
CA 02426836 2003-04-25
laying a vertically adjacent course, projections 28 on the upper side of
such plate will protrude into that sandbag, attaching the upper sandbag
to the two lower sandbags. Thus, the interconnecting members attach
both horizontally and vertically adjacent sandbags at the same time.
The interconnecting members 24 are likewise used to attach the
extending sandbags 22 to the other sandbags 16 forming a course, as
best seen in Figure 2, by placing interconnecting members so as to
extend over sandbag 22 and each of the two sandbags 16 that it abuts
within a course. Then, a further course of sandbags is placed on top of
said course, covering said interconnecting members 24 and effectively
anchoring said extending sandbags 22 to the laterally adjacent sandbags
16 and to the sandbag 16 in the vertically adjacent upper course.
Optionally, a further sandbag 30 may be attached to an extending
sandbag 22 in order to increase the anchoring of the wall. Re:Eerring to
Figures 1 and 2, such sandbag 30 is positioned generally parallel to the
wall face 18 at the free end of an extending sandbag 22. An
interconnecting member 24 is placed to extend between sandbags 22 and
30, and a further sandbag 16 is placed on top of the interconnecting
member to secure the attachment of the interconnecting member to the
two sandbags 22, 30.
The invention may also be used in the construction of freestanding
walls. Referring to Figures 3 and 4, wall 40 comprises wall faces 42,
44 which support fill material 46 therebetween. The wall faces may be
sloped (as illustrated in Figure 4) or vertical if desired. Each wall face
comprises generally horizontal courses of sandbags 16 attached together
with interconnecting members 24 in the manner described above. At
selected longitudinal intervals along the wall, an extending sandbag 22 is
placed extending from one wall face to the other wall face and attached
-6-
CA 02426836 2003-04-25
to each wall face by means of the interconnecting members 24, again as
described above. Extending sandbags 22 are placed at such positions
longitudinally along a course, and in multiple courses, as may be
required to support both wall faces of a wall having a given length,
height and width.
As will be apparent to those skilled in the art in tlhe light of the
foregoing disclosure, many alterations and modifications are possible in
the practice of this invention without departing from the scope thereof.
Accordingly, the scope of the invention is to be construed in accordance
with the substance defined by the following claims.
