Retaining wall system
A retaining wall system (10) is defined which includes a plurality of tyres (11) arranged in a plurality of courses (14). The tyres can be offset within the wall and can be cut in various ways to advantageously improve the strength of the wall. In addition, reinforcing (25, 30, 32) formed from tyres or conveyor belts can be associated with the wall system to improve the structural stability of the wall.
Latest Ecoflex Australia Pty Limited Patents:
The present invention relates to retaining walls and methods for forming the same, more particularly, to retaining walls that utilise tyres and conveyor belts in their construction. When the term “retaining walls” is used in this specification, it includes walls used for retaining embankments, such as in civil engineering applications (eg. road construction, public works etc), but also includes breakwaters and groins, protecting walls, walls in tunnels and at piers, quays, etc.
BACKGROUND OF THE INVENTIONDiscarded tyres and conveyor belts from the automotive, mining and aviation industries represent a significant and growing environmental problem, due to difficulties with disposal, environmental breakdown and/or incineration.
Retaining walls formed from tyres are known in the art. For example, U.S. Pat. No. 5,480,255 discloses an impact absorbing barrier for highways, formed from whole tyres and half tyres, and in-filled with sand material. FR 2,682,700 discloses the use of tyres in a retaining wall where one side wall of the tyre has been removed.
U.S. Pat. No. 5,378,088 discloses a retaining wall formed from a plurality of segmented automobile tyres. Side wall segments disposed horizontally form a front row of the wall, and tread segments of the tyres are connected to the side wall segments and extend rearwardly therefrom to provide additional support to the front row. However, the method of forming the front row is both complex and time consuming, requiring excessing tyre cutting, the use of rods 17, additional rods 24 and a relatively complex assembly procedure. Furthermore, the tread segments 20 are provided solely to support the front wall and there is no disclosure of the segments providing any reinforcing stability to any fill material that might be arranged behind the front wall.
It would be advantageous if at least preferred embodiments of the present invention provided a retaining wall and a method for forming the same that improves upon, or at least provides a useful alternative to, the retaining walls formed from tyres that exist in the prior art.
SUMMARY OF THE INVENTIONIn a first aspect, the present invention provides a retaining wall for retaining an embankment or similar including a plurality of tyres arranged in a plurality of courses adjacent to the embankment and such that a central axis of each tyre is offset from vertical.
An advantage of such a construction is that a sloping embankment can be formed which then provides additional support to the retaining wall, and additional strength.
Typically, each tyre's central axis is offset from vertical at a batter angle ranging from 10° C. to 20° C. Use of this angle has been observed in practice to provide ease of construction of the retaining wall whilst still retaining the advantages of the inclination of the wall.
Adjacent courses can be separated by a fill material, optionally by a distance that is half a tyre in diameter. Alternatively, adjacent courses can abut. Each tyre can at least partially (but typically completely) be filled with a fill material, and further fill material can be used to fill gaps between the tyres, and between the tyres and the embankment.
Typical fill materials include concrete (for example at the lowest course of tyres and at intermittent courses (eg. every alternating course) in the tyre wall construction). Granular or particulate, optionally free draining materials, can also be employed, for example, such as cobble, sand and/or shredded tyre. The use of shredded tyre further assists in the disposal of additional discarded tyres and is thus environmentally advantageous.
Typically at least some, and in some cases all, of the tyres are each cut either:
-
- (a) in a plane between opposing side walls thereof, and can then be arranged in the walls so that both side walls generally face downwards; or alternatively (and/or additionally)
- (b) so as to remove a substantial proportion of one of the side walls, so that the tyres are arranged in the wall so that the remaining uncut side wall generally faces downwards.
With option (a), typically a section of the tyre remains uncut to provide a hinge for pivoting of the tyre portions thereabout, thereby increasing the strength of the wall (ie. with each tyre half being attached to another tyre half). Alternatively, in (b), the removed side wall can be arranged in the tyre to be adjacent to the remaining side wall when the tyre is located in the wall. This provides a more stable base in the tyre for the in-fill of material, and optionally allows for the positioning of a liner between the removed and remaining side walls, thereby covering the lower opening of the tyre when arranged in the wall, and making the tyre better capable of retaining fill therein.
Optionally, at least some or all of the tyres are provided with drain holes (eg. drilled therethrough).
In an alternative construction, the retaining wall can be formed from solid tyres (or a mixture of solid and hollow tyres). Suitable solid tyres include discarded forklift tyres and solid tyres from the mining industry. The advantage of using solid tyres is that excessive fill does not need to be employed, and the deformation that can occur with hollow tyre retaining walls is substantially overcome.
Alternatively, the deformation where hollow tyres are employed can also be ameliorated or eliminated by strengthening the tyre tread wall and side wall(s) (eg. by lining the inside of the tread wall with further cut tyre tread—cut to suitable lengths). For example, two additional tread sections can be positioned inside the tyre to abut the inner face of the tyre tread section (with one section being located inside the other). In addition, extra tyre rings (ie. cut tyre side walls) can be positioned within the hollow tyre prior to filling (for example up to four additional rings can be employed at the base of a hollow tyre). Such arrangements have been found to strengthen hollow tyres in the retaining wall and to prevent deformation, and to also help in disposing of even more waste (second hand) tyres.
In a second aspect of the present invention there is provided a retaining wall for retaining an embankment or similar that is formed from a plurality of tyres wherein at least some of the tyres are each cut:
-
- (a) in a plane between opposing side walls thereof to define two portions, and such that a section of the tyre remains uncut to provide a hinge for pivoting of the tyre portions thereabout, and so that the tyres can be arranged in the wall such that both side walls generally face downwards; and/or
- (b) to remove a substantial proportion of one of the side walls wherein the removed side wall is arranged in the tyre to be adjacent to the remaining side wall, and the tyres are arranged in the wall so that the remaining uncut side wall generally faces downwards.
Such an arrangement makes for the easy in-filling of each course of tyres when the wall is being constructed (ie. there is little or no upper side wall to deflect fill material being arranged in the tyres). Also, the judicious cutting in this manner can provide a wall that is even stronger than one formed from a number of individual “intact” tyres.
In a third aspect, the present invention provides a retaining wall for retaining an embankment or similar including a reinforcing section extending rearwardly into the wall from an outer portion thereof, the reinforcing section being part of the retaining wall and being formed from:
-
- (a) portions/sections cut from one or more tyres; and/or
- (b) conveyor belt portions/sections.
The reinforcing section can be used with retaining walls formed with conventional facing materials (eg. concrete or stone). In this case the reinforcing can replace existing reinforcing materials (such as geofabric materials). The reinforcing section can also be used very simply in an earthen batter retaining wall (ie. having no particular facing material other than the earth itself). However, most preferably the reinforcing section is used with a face formed from a plurality of tyres in a plurality of courses (as described below).
Such reinforcing provides a structurally stable retaining wall (and is quite different in function to and simpler than, for example, the arrangement defined in U.S. Pat. No. 5,378,088).
When the wall facing material is formed from tyres and when at least some of the tyres in the wall section have an intact tread, such tyres additionally define an enclosure into which fill material can be arranged. This means that there is no need for the employment of rods or pylons (which are otherwise required in the arrangement shown in U.S. Pat. No. 5,378,088).
Further, because the reinforcing can be constructed essentially from tyres or conveyor belts and fill material, it is simpler and economically more expedient than existing arrangements.
Typically, the reinforcing section is attached to the wall facing structure and may either be formed from a plurality of tread sections, or from a plurality of side wall sections, and optionally (or alternatively) from a plurality of conveyor belt sections. Both the tread sections and side wall sections can be cut from additional tyres, and the conveyor sections can be cut from a single conveyor belt. The sections can then be joined together to define the reinforcing section.
Preferably the sections are joined to define a grid formation, which thereby replaces the existing geogrids used in the prior art. It should be appreciated that prior art geogrids are typically formed from woven and non-woven textiles, optionally reinforced with polymer; or from polymeric fibres. Such geogrids and reinforcing materials tend to be very expensive, whereas the use of tyres and conveyor belts is both environmentally and economically advantageous and, again, is a simpler option.
In the grid formation, individual sections can be attached or linked to and/or threaded through adjacent sections to define the grid formation.
Also, a reinforcing section can be provided for each course and is typically arranged to extend generally horizontally or to be inclined downwardly into the wall.
Each plurality of courses typically defines a “row”. Accordingly, in an alternative construction, a plurality of rows of tyres can be arranged adjacent to the embankment.
In a fourth aspect, the present invention also provides a method for forming a retaining wall for retaining an embankment or similar including the steps of:
-
- (a) forming a base for the retaining wall adjacent to the embankment and that slopes downwardly to the embankment from surrounding ground; and
- (b) arranging a plurality of tyres in a plurality of courses adjacent to the embankment and along the base.
As above, the batter angle of the so-formed wall typically ranges from 10° C. to 20° C. offset from the vertical.
Typically, a course of tyres is laid and each tyre is then at least partially (preferably completely) in-filled with the fill material prior to laying the next course.
In addition, each course of tyres can be arranged to be offset (along the line of the course) from adjacent course(s).
In a fifth aspect, the present invention provides a method for forming a retaining wall from a plurality of tyres including the step of cutting at least some of the tyres:
-
- (a) in a plane between opposing side walls thereof, wherein a section of the tyre remains uncut to provide a hinge for pivoting of the tyre portions thereabout, and then arranging those tyres in the walls so that both side walls generally face downwards; and/or
- (b) to remove a substantial portion of one of the side walls, with the removed side wall being arranged in the tyre to be adjacent to the remaining side wall, and then arranging those tyres in the wall so that the remaining uncut side wall generally faces downwards.
Such a method is employed with hollow tyres (not solid tyres).
In a sixth aspect, the present invention provides a method for forming a retaining wall for retaining an embankment or similar including the step of positioning in the wall a reinforcing section that is formed from portions/sections cut from one or more tyres or from one or more conveyor belts.
Thus, the method can be used to form any type of retaining wall that requires a reinforcing section, and the advantage is that typical geogrid or geofabric materials used as reinforcing sections can be replaced by sections formed from tyres or conveyor belts.
Preferably a face of the wall is defined by arranging a plurality of elements in a plurality of courses adjacent to the embankment to define the wall face. Such elements can be construction elements used in conventional reinforcing wall faces, such as concrete blocks, stone blocks etc. Alternatively, the construction elements can be formed from a plurality of tyres (optionally cut in accordance with the teachings of the present invention).
Typically, the reinforcing section is attached prior to or after the arranging of at least one course of construction elements in a face of the wall.
Also, instead of only using tyres in the reinforcing section (for example discarded tyres) conveyor belts can be employed (especially discarded conveyor belts). For example, nylon woven conveyor belts from the mining industries (being conveyor belts that do not have any steel or metal content) can be employed. Such conveyor belts have a high tensile strength and therefore provide desirable strength characteristics when used as reinforcing in retaining walls.
BRIEF DESCRIPTION OF THE DRAWINGSNotwithstanding any other forms which fall within the scope of the present invention, preferred forms of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:
FIGS. 14 to 16 show components of reinforcing, prior to being attached in the manner shown in perspective in
FIGS. 21 to 25 show various tyre side wall reinforcing arrangements;
FIGS. 28 to 30 show further alternative means of attaching tyre treads to whole tyres; and
A preferred embodiment of a retaining wall 10 according to the current invention for retaining an embankment 100 or similar, comprises a plurality of tyres 11 each having a cavity 12 defined therein at least partially filled with a fill material 13. (Alternatively tyres 11 can be solid tyres from forklifts, mining vehicles etc. In this latter case use of less fill material and a more stable wall can result). In the preferred embodiment, each cavity 12 is substantially filled with the fill material 13. The tyres 11 are arranged in a plurality of courses 14 adjacent to the embankment 100. Further fill material 15 substantially fills gaps between each of the tyres 11 and between the tyres 11 and the embankment 100.
The embankment 100 is typically excavated away from ground line 102 to define a wall at an angle to the vertical of approximately 10° to 20°, with the retaining wall 10 similarly having a batter angle of 10° to 20°. In the preferred embodiments depicted, the retaining wall 10 has a batter angle of approximately 14° (eg. the central axis of each tyre in the wall is inclined at 14° with respect to vertical). Taller walls will typically require a larger batter angle for stability, whilst smaller walls can employ smaller batter angles so as to reduce the space occupied by the retaining wall 10. As well as for retaining typical embankments as used in landscaping and the like, retaining walls of the current invention may be used with other embankments including those used as noise barriers or waterway walls (sea walls) etc.
Thus, each tyre 11 is typically arranged such that a central axis thereof is offset from vertical at an angle approximately equal to the batter angle. With this incline of the tyres 11 to match the batter angle, the stability of the wall 10 is enhanced by reducing the reliance on friction between the courses 14 of tyres 11 for shear stability. In prior art retaining wall designs where shear stability has not been considered to be of prime concern, the tyres 11 have been laid flat with each subsequent course 14 set back from the adjacent lower course 14 to provide the batter angle of the wall 10.
The tyres 11 are typically arranged such that the tyres 11 of a given course 14 are offset from those of the adjacent lower course 14 in a typical brickwork fashion. In the preferred embodiments depicted, adjacent courses 14 are separated by the further filler material 15, here giving a separation between courses 14 of approximately half a tyre 11 diameter. Alternatively, the tyres 11 of adjacent courses 14 may abut, with the further filler material 15 filling gaps between surfaces of the adjacent tyres 11 which do not abut.
The tyres 11 are also typically separated from the embankment 100 by the further filler material 15. Alternatively the tyres 11 may abut the embankment 100 with the further filler material 15 filling gaps where the surface of the tyres 11 do not abut the embankment 100.
For larger retaining walls as depicted in
The foundation 101 for the retaining wall 10 is here excavated below the ground line 102 to help secure the lowermost course 14a in place. To further secure the lowermost course 14a, the tyres 11 thereof are filled with concrete as the fill material 13 (tyres shown as shaded). A stabilised sand base may be employed for the foundation 101. Alternatively, the foundation can be a concrete base (optionally reinforced). For construction with a waterway wall, where the tyres 10 will act as the interface with the water, every second course of tyres 11 is typically filled with concrete to increase the mass of the wall and thereby reduce any possible instability resulting from wave action.
The fill material 13 typically comprises a free draining material in at least some of the courses 14. Here the free draining fill material 13 is granular and is used in all but the lowermost course 14a. Cobble has been found to be a suitable fill material 13, whilst the use of other free draining materials, including shredded tyres is also desirable. Use of shredded tyres further increases the recyclability of the discarded tyres, but they are typically not used where the wall construction relies on its mass for stability.
The further fill material 15, used to fill gaps between tyres 11 and between the tyres 11 and embankment 100 is also here a free draining granular material such as cobble. To further assist in drainage, drain holes 17 may be provided in the tyres 11, and a socked perforated sub-surface drain 18 or similar may be laid between the lowermost course 14a and the embankment 100.
To increase the stability of the retaining wall 10, the tyres 11 may be secured to each other and, if so desired, to the embankment 100 or foundation 101 with the use of nylon rope or similar. Reinforcing grids may also be used to secure one or more of the courses 14 of tyres 11 to the embankment 100. Such reinforcing grids typically extend at least approximately 0.7 m into the embankment 100, depending on the wall 10 design, to ensure stability and allow the construction of taller retaining walls 10. The embankment 100 may be compacted to more securely hold the reinforcing grid in place.
To reduce any fire hazard which the use of rubber tyres may pose, the retaining wall 10 as a whole, or each of the tyres 11 individually, may be covered with a fire retardant material or coating. Such a material which may be used is geofabric which is also typically used as a liner 21 between the embankment 100 and the retaining wall 10.
Referring to FIGS. 5 to 7 (where like reference numerals will be used to denote similar or like parts) cross sectional views of various alternative retaining walls are respectively shown.
FIGS. 5 to 7 also show associated desirable slopes of the wall 10 (1 in 8) and the embankment 24 (1 in 4).
In the embodiment of
In construction of the wall 10 each tyre has respective reinforcing attached thereto as each course is successively layed (with the attachment of reinforcing being typically by the various attachment mechanisms as described below). During construction of the reinforcing section, controlled select fill 26 is positioned on top of each reinforcing section and is compacted (typically in 200 mm layers to 98 percent of its maximum modified density).
Turning to
Turning to
The arrangements shown in FIGS. 5 to 7 provide an enhancement over the retaining wall arrangements of FIGS. 1 to 4, and also make better use of discarded tyres and conveyor belts generally.
Referring now to
Once a course of tyres has been placed, the fill of the retaining wall is brought up to an appropriate level and the reinforcing grid is then laid onto that fill, before being covered with further fill to lay the next reinforcing grid and so on (ie. the grid can be attached to the tyre in situ by appropriate techniques—described below). Alternatively, the reinforcing grid can be pre-attached to the course of tyres, such that when the course is laid, the grid is simultaneously laid.
The reinforcing grid as shown in
Referring now to
In
Referring now to
In
The grid-like reinforcing can also be formed from tyre side walls 30′ (or combinations of tread lengths with tyre side walls).
The arrangement of the liner in this manner functions to provide an enclosed receptacle for receiving fill material therein. Typically, the liner is a non-perishable, nylon, free draining and optionally uv-resistant material.
FIGS. 21 to 25 show various tyre side wall reinforcing type grids. In
In
Various other configurations of the grid-like reinforcing formed from the plurality of tyre side walls are possible. As with the arrangement of
Referring to
Referring to
Referring to
However, rather than employing reinforcing formed from cut tyres, conveyor belt strips 80 can be employed.
Typically conveyor belt strips that are 200 to 300 millimetres wide, and that are discarded by the mining industries are employed. Such strips are typically formed from a high tensile strength, nylon woven conveyor belt, and typically strips that do not have any metal content (e.g., steel which would otherwise corrode within the wall) are employed.
As can be seen in
The conveyor belt strip is typically connected to the beading using a proprietary conveyor belt connection (e.g., a 20KN working cap).
The conveyor belt strips can also include cross strips 80′, so that a grid formation (as previously described) is formed.
Typically the conveyor belts are attached to the tyres, although in some circumstances, the conveyor belt strips can simply lie adjacent to the tyre wall without being attached thereto.
One advantage with conveyor belt strips is that they generally come in very long lengths, and therefore there is no need to join lengths of strip together to form an elongate section extending into the wall. This is also advantageous when a grid like criss-crossing formation in the reinforcing is employed. The conveyor strips can also be threaded, and linked etc. as defined above.
As shown in
As with the tyre section reinforcing, the conveyor belt strips can be anchored at their remote end, and in fact all of the arrangements and modes of attachment described above for the tyre sections can be equally employed with the conveyor belt sections (and thus will not be described again).
Engineering analysis has indicated that retaining walls in accordance with the present invention compare favourably with current typical retaining walls such as timber crib, concrete crib or segmental brickwork walls, whilst generally being less expensive, lighter in weight and providing a solution to the problem of discarded tyre and conveyor belt disposal.
Whilst the invention has been described with reference to a number of preferred embodiments, it should be appreciated that the invention can be embodied in many other forms.
Claims
1-72. (canceled)
73: A retaining wall for retaining an embankment or similar structure including a plurality of tyres arranged in a plurality of courses adjacent to the embankment and such that a central axis of each tyre in an outer face of the retaining wall is inclined to both vertical and horizontal, wherein at least some of the tyres are each cut to remove a substantial proportion of one of the side walls and are arranged in the wall so that the remaining uncut side wall generally faces downwards.
74: A retaining wall as claimed in claim 73, wherein each tyre's central axis is inclined to vertical at a batter angle ranging from 10° to 20°.
75: A retaining wall as claimed in claim 73, wherein adjacent courses are separated by a fill material or abut.
76: A retaining wall as claimed in claim 74, wherein adjacent courses are separated by a fill material or abut.
77: A retaining wall as claimed in claim 75, wherein adjacent courses are separated by a fill material by a distance that is half a tyre's diameter.
78: A retaining wall as claimed in claim 76, wherein adjacent courses are separated by a fill material by a distance that is half a tyre's diameter.
79: A retaining wall as claimed in claim 73, wherein each tyre is at least partially filled with a fill material, and further fill material fills gaps between the tyres, and between the tyres and the embankment.
80: A retaining wall as claimed in claim 79, wherein the fill material includes concrete at the lowest course of tyres, or a granular or particulate, free draining material.
81: A retaining wall as claimed in claim 80, wherein the granular particulate material is selected from a group consisting of cobble, sand and/or shredded tyre.
82: A retaining wall for retaining an embankment or similar structure including a plurality of tyres arranged in a plurality of courses adjacent to the embankment and such that a central axis of each tyre in an outer face of the retaining wall is inclined to both vertical and horizontal, wherein at least some of the tyres are each cut in a plane between opposing side walls thereof and are arranged in the wall so that both sides walls generally face downwards.
83: A retaining wall as claimed in claim 82, wherein each tyre's central axis is inclined to vertical at a batter angle ranging from 10° to 20°.
84: A retaining wall as claimed in claim 82, wherein adjacent courses are separated by a fill material or abut.
85: A retaining wall as claimed in claim 83, wherein adjacent courses are separated by a fill material or abut.
86: A retaining wall as claimed in claim 84, wherein adjacent courses are separated by a fill material by a distance that is half a tyre's diameter.
87: A retaining wall as claimed in claim 85, wherein adjacent courses are separated by a fill material by a distance that is half a tyre's diameter.
88: A retaining wall as claimed in claim 82, wherein each tyre is at least partially filled with a fill material, and further fill material fills gaps between the tyres, and between the tyres and the embankment.
89: A retaining wall as claimed in claim 88, wherein the fill material includes concrete at the lowest course of tyres; or a granular or particulate, free draining material.
90: A retaining wall as claimed in claim 88, wherein the granular particulate material is selected from a group consisting of cobble, sand and/or shredded tyre.
91: A retaining wall for retaining an embankment or similar structure including a plurality of courses adjacent to the embankment, wherein at least some of the tyres are each cut to remove a substantial portion of a first side wall, and whereby each such tyre is positioned in the wall with a second remaining side wall facing downwards, with a liner being arranged adjacent to the second side wall, and with the removed first side wall being positioned on top of the liner and adjacent to the second side wall.
92: A retaining wall as claimed in claim 91, wherein a central axis of each tyre in an outer face of the retaining wall is inclined to both vertical and horizontal.
93: A retaining wall as claimed in claim 92, wherein each tyre's central axis is inclined to vertical at a batter angle ranging from 10° to 20°.
94: A retaining wall as claimed in claim 91, wherein adjacent courses:
- are separated by a fill material; or
- abut.
95: A retaining wall as claimed in claim 92, wherein adjacent courses:
- are separated by a fill material; or
- abut.
96: A retaining wall as claimed in claim 93, wherein adjacent courses:
- are separated by a fill material; or
- abut.
97: A retaining wall as claimed in claim 91, wherein adjacent courses are separated by a fill material by a distance that is half a tyre's diameter.
98: A retaining wall as claimed in claim 92, wherein adjacent courses are separated by a fill material by a distance that is half a tyre's diameter.
99: A retaining wall as claimed in claim 93, wherein adjacent courses are separated by a fill material by a distance that is half a tyre's diameter.
100: A retaining wall as claimed in claim 91, wherein each tyre is at least partially filled with a fill material, and further fill material fills gaps between the tyres, and between the tyres and the embankment.
101: A retaining wall as claimed in claim 92, wherein each tyre is at least partially filled with a fill material, and further fill material fills gaps between the tyres, and between the tyres and the embankment.
102: A retaining wall as claimed in claim 93, wherein each tyre is at least partially filled with a fill material, and further fill material fills gaps between the tyres, and between the tyres and the embankment.
103: A retaining wall as claimed in claim 100, wherein the fill material includes:
- concrete at the lowest course of tyres; or
- a granular or particulate, free draining material.
104: A retaining wall as claimed in claim 103, wherein the granular particulate material is selected from a group consisting of cobble, sand and/or shredded tyre.
Type: Application
Filed: Sep 30, 2004
Publication Date: Feb 24, 2005
Applicant: Ecoflex Australia Pty Limited (Newcastle)
Inventors: Garry Callinan (Merewether), Glen Cashman (Charlestown)
Application Number: 10/955,731