GB2419368A

GB2419368A - Retaining wall

Info

Publication number: GB2419368A
Application number: GB0423475A
Authority: GB
Inventors: Charles Philip Richardson; David John Hindle
Original assignee: NCD INTERNAT Ltd
Current assignee: NCD INTERNAT Ltd
Priority date: 2004-10-22
Filing date: 2004-10-22
Publication date: 2006-04-26
Anticipated expiration: 2024-10-22
Also published as: GB2419368B; GB0423475D0

Abstract

A retaining wall 102 is constructed from a porous structural support matrix 104 which extends through the majority of the wall. A retaining mesh 106 is attached to the support matrix and holds a filler material 108. The wall can be constructed in situ to create a gabion type of arrangement and the design is such that it can be constructed to form a variety of desired shapes (figs 3-6). Securing rods 112 maybe used to improve the stability of the wall.

Description

24 1 9368 Structural Reinforcement Device The present invention relates to

structural reinforcement devices, particularly, although not exclusively, to structural reinforcement devices for use in the earth retaining industry.

In many areas of construction it is important to prevent land slip occurring. Examples of such land slip include lo natural land slip, i.e. from a rock face or similar, or slip of a man made structure such as a road bridge foundation or the sides of a canal. In such instances it is known to provide earth retaining structural reinforcement.

Traditional forms of free standing or earth retaining structures such as masonry and brick have been in existence for thousands of years. More recently, mass and reinforced concrete have almost entirely replaced these materials for permanent installations but can involve expensive and time consuming construction.

For more cost effective and rapid support, one solution known in the art is a gabion wall. A gabion wall comprises a number of baskets which are filled with stones and stacked together to form a wall. The individual baskets are held together and held in place by a number of support rods which are inserted between the baskets and into the surface to which the gabion wall is adjacent.

Problems with this system include that each box must be hand filled with stone such that large stones are at the surface and smaller stones are in the centre of the basket to prevent leakage. Also, a reinforcement wall may be required to follow a contour in a landscape, i.e. the curve of a hill side. A gabion wall, although having the capacity to have its baskets individually stepped, will only form a curve to the extent that the size of the basket allows, unless bespoke baskets of irregular shape are made at undesirably high expense of money and time.

Further, gabion walls only offer a limited amount of structural support and are liable to twist and warp lo following constant pressure from an adjoining land slip feature.

It is an aim of aspects of the present invention to address the above mentioned problems and provide a solution which is easy to manufacture, easy to install, can easily be made to follow a variety of different contours and offer increased resistance to twist and warp.

According to a first aspect of the present invention there is provided a structural reinforcement device comprising a porous structural support matrix extending substantially through a majority of the device, a particulate filler material and retaining means operable to retain the particulate filler material within the device.

Preferably, the structural support matrix extends laterally to the periphery of the device. Preferably, the structural support matrix extends laterally to the side walls of the device. Preferably, the structural support matrix extends to the side walls of the device which are perpendicular to the direction of a force exerted by the substance which is being supported. Preferably, the structural support matrix extends substantially throughout the device.

Advantageously, the provision of a structural support matrix offers increased structural rigidity thereby increasing the resistance of the structure to twist and warp.

Preferably, the particulate filler material has an average lo particulate size less than the average pore size of the porous structural support matrix.

Preferably, the particulate filler material comprises stones. Examples of suitable particulate particulate filler materials include sand, gravel, slag aggregate or the like. Preferably, the particulate filler is graded from 5mm to lOOmm, more preferably from lOmm to 50mm.

Preferably, the porous structural support matrix comprises pores of less than about 500 cm2, more preferably less than about 300 cm2 and most preferably less than about 200 cm2. In a particularly preferred embodiment, the porous structural support matrix comprises pores which are about cm2.

However, it should be appreciated that the size of the pores in the porous structural support matrix are dictated by the size of the particulate filler material and their size and shape may be varied according to the application for which the structural reinforcement device is being used.

Preferably, the porous structural support matrix comprises at least one matrix layer. Preferably, the porous structural support matrix comprises a plurality of matrix layers. Preferably, the or each matrix layer has a substantially constant depth. Advantageously and preferably, the or each matrix layer may have different plan dimensions to other matrix layers. Preferably, the different plan dimensions of each matrix layer is dictated by the shape of the structural reinforcement device lo required.

Advantageously, by adding matrix layers of differing plan dimensions, the shape of the matrix can be made to follow different contours as required.

Preferably, the or each matrix layer comprises a crosslinked 3dimensional structure. Preferably, the or each matrix layer comprises a series of upper bars at an upper face thereof and a series of lower bars at a lower face thereof which upper and lower bars are preferably connected by a series of braces. Preferably, the series of upper and lower bars are substantially parallel with each other. Preferably, the braces extend away from the upper and/or lower bars at an appropriate angle, which is preferably approximately 45 . Preferably, the or each matrix layer is flexible.

Preferably, each of the plurality of matrix layers is positioned with the series of upper and lower bars substantially perpendicular to those in an adjacent matrix layer.

Preferably, the structural reinforcement device is adapted to be secured to a surface, preferably by securing rods.

Preferably, the retaining means comprises a mesh which may be wrapped around the exterior of the structural reinforcement device. Preferably, the mesh comprises a metallic mesh structure but may alternatively or additionally comprise a plastic geotextile or similar material.

Preferably, the retaining means comprises at least one substantially planar sheet. Preferably, the retaining means comprises at least two substantially planar sheets which may be secured together by securing clips.

According to a second aspect of the present invention there is provided a method of providing structural reinforcement to a surface comprising the steps of: 20placing a structural support matrix adjacent to the surface to be reinforced; adding retaining means around the sides of the structural support matrix; adding a particulate filler material to the structural support matrix to thereby make a structural reinforcement device.

Preferably, the method comprises the additional step of constructing a structural support matrix from at least one matrix layer. Preferably, the structural support matrix is constructed by placing each matrix layer at an angle, preferably at substantially 90 to the matrix layer adjacent thereto.

Preferably, the method further comprises securing the structural reinforcement device to a surface. Preferably, the structural reinforcement device is secured to a surface by placing securing rods through the structural support matrix into a surface.

lo According to a third aspect of the present invention there is provided a method of producing a free standing structure comprising the steps of: placing a structural support matrix in a desired location; adding retaining means around the sides of the structural support matrix; adding a particulate filler material to the structural support matrix to thereby make a free standing structure.

Preferably, the method further comprises the step of adding securing rods though the structural support matrix to offer increased internal stability to the free standing structure.

Advantageously, a free standing structure made in accordance with the above method may be used as a crash barrier, for example, on a highway. Advantageously, the impact of a crash of a vehicle into the free standing structure will be absorbed by the free standing structure thus decreasing the risk of the vehicle rebounding into other vehicles. Alternatively and advantageously, a free standing structure made in accordance with the above method may provide a visual barrier, a barrier for security purposes, a noise barrier, a blast resistant barrier or a flood barrier.

According to a fourth aspect of the present invention there is provided a structural reinforcement kit comprising: a structural support matrix; retaining means; Preferably, the kit comprises at least one matrix layer.

More preferably the kit comprises a plurality of matrix layers.

Preferably, the kit comprises at least one securing rod.

More preferably, the kit comprises a plurality of securing rods.

Preferably, the retaining means comprises at least one substantially planar sheet. Preferably, the retaining means comprises at least two substantially planar sheets, which two substantially planar sheets may be secured together by securing clips.

Preferably, the kit further comprises at least one securing clip operable to secure the at least two substantially planar sheets of retaining means together.

Preferably, the kit comprises a plurality of securing clips.

Preferably, the kit further comprises a particulate filler material.

The invention extends to a structural support matrix for use in any of the above aspects.

All of the features disclosed herein may be combined with any of the above aspects in any combination.

For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawings in which: Figure 1 is a sectional side view of a first embodiment of a structural reinforcement device; Figure 2 is a plan view of a matrix layer of a structural reinforcement device; Figure 2b is a sectional view along plane A-A' of a matrix layer of a structural reinforcement device; Figure 2c is a sectional view along plane B-B' of a matrix layer of a structural reinforcement device; Figure 3 is a sectional side view of a second embodiment of a structural reinforcement device; Figure 4 is a sectional side view of a third embodiment of a structural reinforcement device; Figure 5 is a sectional side view of a fourth embodiment of a structural reinforcement device; and Figure 6 is a sectional side view of a fifth embodiment of a structural reinforcement device; A structural reinforcement device 102 is shown in figure 1 being generally cuboidal in shape. The device 102 has an internal structural support matrix 104, external retaining lo means 106 in the form of a mesh around four side walls of the matrix 104. The device 102 is shown part-filled with a particulate filler material 108. In normal use, the device would be full of particulate filler material 108.

A lower face of the matrix 104 is not covered with mesh 106 because the lower face abuts a ground surface 110, so there is little risk of the particulate filler material leaking. However, mesh 106 may be added to the bottom face of the device 102 if required.

In some instances, it may not be necessary to add mesh 106 to a rear face of the matrix 104. An example of such an instance would be where the rear face of the device abuts a surface to be reinforced, such as a wall. In such an instance there is little risk of particulate filler material leaking.

The device 102 is secured to the surface 110 by securing rods 112 which penetrate through the matrix 104 and the filler material 108 into the surface 110.

In the device 102, the matrix 104 has five matrix layers 114. It should be appreciated that the number of matrix layers 114 used may vary within almost infinite parameters dependent upon the size of the device required. For example a larger device may require more layers, while a smaller device may require fewer layers.

A plan view of a matrix layer 114 is shown in figure 2a.

The matrix layer 114 has a plurality of longitudinally extending upper and lower bars 116 at upper and lower faces thereof respectively and a plurality of braces 118 connecting the upper and lower bars 116. The production lo of a matrix layer 114 is described in French patent application number FR 2 833 882 Al. However, it will be appreciated by a person skilled in the art that similar products formed from metal and/or plastic may provide a suitable alternative.

Figure 2b shows a sectional view from one end of the matrix layer 114 along the plane A - A' shown in figure 2a. The upper and lower bars 116 are laterally spaced, with the braces 118 connecting the upper and lower bars 116. The braces 118 hold the bars 116 in a concertina arrangement. Each brace 118 extends from an upper bar 116 to a point on the lower bar 116 that is laterally spaced in both horizontal directions from a point on the upper bar 116 from which it extends.

Figure 2c shows a sectional side view of the matrix layer 114 along the plane B - B' shown in figure 2a. The bars 116 extend along the length of the matrix layer 114 with the braces 118 connecting the bars 116.

As shown in figure 1, each successive matrix layer 114 is arranged at substantially 90 about a generally vertical axis to the preceding matrix layer 114. Hence, in figure 1, the bottom most layer 114 is shown side on, the second bottom matrix layer 114 end on etc. The retaining means 106 is made from wire mesh. The holes in the wire mesh are of an appropriate size to retain the filler material 108 within the device 102.

The filler material 108 is aggregate (small stones) between lOmm and 5Omm grading.

Advantageously, the device 102 allows the free drainage of water therethrough to prevent a build up of pore water pressure, although one or more side walls of the matrix may be covered with a liquid impermeable membrane to act as a flood protection barrier.

Usually, the device 102 would be erected on site rather than being prefabricated elsewhere. The device 102 is made by laying down the successive matrix layers 114 on top of each other and at 90 to each other. When the matrix 104 is of a sufficient size, it is wrapped in mesh 106 and then filled with aggregate 108. In instances where the surface area of the matrix 104 is larger than a sheet of mesh 106, then successive sheets of mesh may be secured together along their edges using clips known in the art. Securing rods 112 are then driven through the matrix 104 and into the surface 110. A further mesh 106 is then added to the top face of the device 102. If a device 102 of a greater height is required, then instead of adding a mesh 106 to the top face, after driving the securing rods 112 into the surface 110, a second matrix 104 is built on top of the first, wrapped in mesh 106, filled with aggregate 108 and securing rods 112 driven through this second matrix 104 into the first matrix 104.

This process may be repeated until the device 102 is of sufficient height for the desired application. The upper face of the device 102 may or may not then be covered with mesh 106 depending on the application.

Figures 3, 4, 5 and 6 show structural reinforcement devices in different shapes for use in different situations.

Figure 3 shows a sectional view of a buttressed free standing device 302. The structural support matrix 304 is formed of matrix layers 114 which are progressively wider in section toward the bottom of the device. When the matrix 304 is formed, it is wrapped with mesh 106 and filled with aggregate 108 in the same manner as the device 102. The device 302 is vertically secured throughout by securing rods 112, and is secured to a surface 310 (the ground) by securing rods 112.

Figure 4 shows a sectional view of a buttressed support device 402. The device 402 is made in a similar manner to the device 302 but has one side abutting a wall to which the device is offering lateral support.

Figure 5 shows a support device 502 offering support to an embankment. In this example, each matrix layer 114 is laterally stepped to form the device 502 which parallelogram shaped in section. Securing rods 112 are inserted down through the device 502 into the embankment side.

Figure 6 shows a support device 602 offering support to a curved embankment. The matrix layers 114 are stepped in a manner to follow the contour of the side of the embankment.

A support device made in accordance with the present invention offers increased resistance to twisting and warping by having a structural support matrix throughout the device. Further, because the matrix is formed of a lo modular system of matrix layers which can be of different sizes and can be stepped with regard to each other, then the shape of the device can be easily manipulated to correspond to a wide variety of shapes. Aggregate is a very cheap product available as waste from many construction industries and so devices made in accordance with the present invention are very cheap. Also, when the matrix is formed and the mesh added, the aggregate can be simply poured in, again increasing the ease of manufacture of a device made in accordance with the present invention.

A further advantage found with the present device is that it allows earth to settle at a greater angle of repose than if no support were employed. For example, in an artificial embankment the natural angle of repose of the earth would be approximately 45 , but by employing a support device in accordance with the present invention, an angle of repose significantly greater than 45 can be achieved. This has the advantage that a smaller surface is needed to achieve the height of an embankment.

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Claims

Claims 1. A structural reinforcement device comprising a porous structural

support matrix extending substantially through a majority of the device, a particulate filler material and retaining means operable to retain the particulate filler material within the device.
2. A structural reinforcement device as claimed in claim 1, wherein the structural support matrix extends laterally to the periphery of the device.
3. A structural reinforcement device as claimed in either of claim 1 or claim 2, wherein the structural support matrix extends to side walls of the device.
4. A structural reinforcement device as claimed in any preceding claim, wherein the structural support matrix extends substantially throughout the device.
5. A structural reinforcement device as claimed in any preceding claim, wherein the particulate filler material has an average particulate size less than the average pore size of the porous structural support matrix.
6. A structural reinforcement device as claimed in any preceding claim, wherein the particulate filler material comprises stones.
7. A structural reinforcement device as claimed in any preceding claim, wherein the particulate filler is graded from 5 mm to 100 mm.
8. A structural reinforcement device as claimed in any preceding claims, wherein the porous structural support matrix comprises pores of less than about 500 cm2.
9. A structural reinforcement device as claimed in any preceding claim, wherein the porous structural support matrix comprises at least one matrix layer.
10. A structural reinforcement device as claimed in any preceding claim, wherein the porous structural support matrix comprises a plurality of matrix layers.
11. A structural reinforcement device as claimed in claims 9 or 10, wherein the or each matrix layer has different plan dimensions to other matrix layers.
12. A structural reinforcement device as claimed in claim 11, wherein the different plan dimension of each matrix layer is dictated by the shape of the structural reinforcement device required.
13. A structural reinforcement device as claimed in any of claims 9 to 12, wherein the or each matrix layer comprises a crosslinked 3-dimensional structure.
14. A structural reinforcement device as claimed in any of claims 9 to 13, wherein the or each matrix layer comprises a series of upper bars at an upper face thereof and a series of lower bars at a lower face thereof which upper and lower bars are connected by a series of braces.
15. A structural reinforcement device as claimed in claims 9 to 14, wherein the or each matrix layer is flexible.
16. A structural reinforcement device as claimed in any preceding claim, wherein the structural reinforcement device is adapted to be secured to a surface.
17. A structural reinforcement device as claimed in any preceding claim, wherein the retaining means comprises a mesh wrapped around the exterior of the structural reinforcement device.
18. A structural reinforcement device as claimed in any preceding claim, wherein the retaining means comprises at least one substantially planar sheet.
19. A method of providing structural reinforcement to a surface comprising the steps of: placing a structural support matrix adjacent to the surface to be reinforced; adding retaining means around the sides of the structural support matrix) adding a particulate filler material to the structural support matrix to thereby make a structural reinforcement device.
20. A method of providing structural reinforcement to a surface as claimed in 19, wherein the method comprises the additional step of constructing a structural support matrix from at least one matrix layer.
21. A method of providing structural reinforcement to a surface as claimed in claim 20, wherein the structural support matrix is constructed by placing each matrix layer at an angle to the matrix layer adjacent thereto.
22. A method of providing structural reinforcement to a surface as claimed in any of claims 19 to 21, wherein the method further comprises securing the structural reinforcement device to a surface.
23. A method of producing a free standing structure comprising the steps of: placing a structural support matrix in a desired location; adding retaining means around the sides of the structural support matrix) adding a particulate filler material to the structural support matrix to thereby make a free standing structure.
24. A method of producing a free standing structure as claimed in claim 23, wherein the method further comprises the step of adding securing rods through the structural support matrix to offer increased internal stability to the free standing structure.
25. A structural reinforcement kit comprising: a structural support matrix; retaining means.
26. A structural reinforcement kit as claimed in claim 25, wherein the kit comprises at least one matrix layer.
27. A structural reinforcement kit as claimed in either of claim 25 or claim 26, wherein the kit comprises at least one securing rod.
28. A structural reinforcement kit as claimed in any of claims 25 to 27, wherein the retaining means comprises at least one substantially planar sheet.
29. A structural reinforcement kit as claimed in any of claims 25 to 28, wherein the retaining means comprises at least two substantially planar sheets, which two substantially planar sheets may be secured together by securing clips.
30. A structural reinforcement kit as claimed in claim 29, wherein the kit further comprises at least one securing clip operable to secure the at least two substantially planar sheets of retaining means together.
31. A structural reinforcement kit as claimed in claim 30, wherein the kit comprises a plurality of securing clips.
32. A structural reinforcement kit as claimed in any of claims 25 to 31, wherein the kit further comprises a particulate filler material.
33. A structural reinforcement device substantially as hereinbefore described and with reference to the accompanying drawings.
34. A method of providing structural reinforcement to a surface substantially as hereinbefore described and with reference to the accompanying drawings.
35. A method of producing a free standing structure substantially as hereinbefore described and with reference to the accompanying drawings.
36. A structural reinforcement kit substantially as hereinbefore described and with reference to the accompanying drawings.