GB2158860A

GB2158860A - Retaining wall block

Info

Publication number: GB2158860A
Application number: GB08512410A
Authority: GB
Inventors: Angus Fraser Cowie
Original assignee: STONE G Ltd
Current assignee: STONE G Ltd
Priority date: 1984-05-16
Filing date: 1985-05-16
Publication date: 1985-11-20
Also published as: IE851226L; GB8412499D0; GB2158860B; GB8512410D0; IE56558B1

Abstract

A wall block for building a retaining wall has an upper ridge (22) and a lower matching groove (12) formed by intersecting pairs of parallel surface portions. At the rear of the wall, an upper surface portion (25) of the block extends rearwardly and downwardly to be engaged by the retained material, and the angle (A) is preferably less than 90 DEG . The block shape allows blocks to be "stacked" in a wall without a bonding medium between them. <IMAGE>

Description

SPECIFICATION Retaining wall block The invention relates to a wall block for use in a retaining wall.

Retaining walls, that is, walls built to support earth at a higher level on one side than on the other, can be built using conventional materials involving mortar to bond together adjacent bricks or like building elements. The invention is however concerned with the provision of a wall block which facilitates the construction of a retaining wall by eliminating the need to provide mortar between superimposed courses.

The invention accordingly provides a wall block for building a retaining wall, the block having opposed surfaces for use respectively as upper and lower surfaces in a retaining wall, the surfaces being so shaped as each to engage the other surface of a like or cooperating superimposed or subadjacent wall block so as to resist relative displacement of the blocks in at least one horizontal direction.

Usually the block will be of a standard length and will have a uniform cross-section. The blocks will be assembled to form the wall in superimposed courses with a suitable bond.

The invention also provides a wall block for use in a retaining wall, the block being so shaped that when received on a like or cooperating block in the retaining wall, the block exposes to material being retained by the wall a surface so orientated that the horizontal loading due to the material is transmitted with a vertical component to the underlying block.

The surface portion of the block exposed in this way can be a plane surface conveniently having an inclination downwardly into the retained material in the range of 5 to 45 .

The wall block of the invention in contrast to prior art wall blocks thus takes into account the angle of friction rearwardly of the wall.

Because of the geometric configuration of the block, this is especially true with lower heights of retained soils, and reduces as the angle of batter, that is, the angle inclination from the vertical is increased.

The invention also provides a wall block having on opposed sides thereof configurations arranged for co-operative engagement whereby one such block can be stacked upon a like block in predetermined relationship in a retaining wall.

The opposed configurations can comprise for example one or more mating ridge and groove configurations, which can extend along the length of an elongate block. The block can comprise a single ridge and a single opposed groove, which can be constituted by two pairs of parallel faces intersecting at an angle which ensures easy location of the blocks one upon another and also the effective transfer of the forces the wall must resist down to the foundation.

The pair of parallel faces at the rearward side of the block in use may be joined by a rear face at right angles to them, but preferably the rear face is inclined so as to provide an enlarged exposed portion of the upper of the parallel faces, to function as the load transmitting surface mentioned above.

The lower surface of the wall block of the invention is in any event preferably shaped so that a lowermost course of the blocks can rest on a generally level foundation in a stable position. The lowermost course can be bonded by mortar to the foundation; conveniently, the mortar can be confined within one or more grooves or recesses formed in the lower surfaces of the blocks. The next and all successive courses can simply be placed on the course below, in an appropriate pattern, without an intervening bonding agent. The wall is consequently of great utility where coastal erosion is to be resisted, as it can be constructed quickly, for example, between tides, without the need for protection until mortar has adequately set. The lower course can be otherwise secured firmly in place, as by mechanical connection to the foundation by retaining bolts received in drilled holes.

The cross-sectional shape of the wall block of the invention is conveniently chosen so that the retaining wall built up from it has a batter of a predetermined angle appropriate to the forces to be resisted. In general the higher the wall, the greater is the appropriate angle of batter. Although the angle will in most instances be in the range of 0 to 15 , a wall as high as 20 m. could have a batter of around 45".

The invention moreover provides a retaining wall comprising superimposed courses of wall blocks in which the blocks of each course are in direct engagement with those of the subadjacent and superimposed courses and are restrained against displacement by the shapes of the interengaging wall block surfaces. The wall blocks of such a wall are preferably of the kind defined above and such that wall blocks of only one shape or at least of only one cross-section are required.

For a better understanding of the invention reference may be made to the following illustrative description and the accompanying drawings, in which: Figure 1 is a partial sectional side view of a retaining wall built with wall blocks in accordance with the invention; and Figures 2 and 3 are like views of retaining walls built from respective different forms of wall block in accordance with the invention.

The retaining wall shown in Figure 1 comprises like wall blocks 1 placed one upon the other. Only three of the wall blocks 1 are shown, but it will be understood that a larger number will normally be used in practice, depending on the required height of the re taining wall. The wall blocks 1 are of constant cross-section, and of an appropriate length in the direction perpendicular to the Figure, for example in the range of 10 cm to 1 m. The wall blocks are laid in courses in an appropriate bonding pattern.

The cross-sectional shape, or end shape, of each wall block 1 will be seen to be defined in part by a first pair 10,11 and a second pair 20,21 of parallel faces which intersect to define like internal and external angles. The block 1 is thus formed with a longitudinally extending recess or groove 12 at the lower surface and with a matching longitudinally extending projection or ridge 22 at its upper surface. In Figure 1, the angles between the faces defining this ridge and this groove are 130 but considerable variation is possible within the scope of the invention. At the upper limit, the angle can approach 180*, but some inclination between the intersecting edges of the cross-sectional shape must be present.

As shown, the lowermost wall block 1 rests on the substantially horizontal surface of a foundation 2 suitably of concrete. The undersurface of the wall block then defines with the foundation 2 a cavity 3 of triangular crosssection, the dimensions of the triangle depending on the angle of the groove 1 2 and the lengths of the sides of the cross-sectional shape formed by the faces 10 and 20. The lowermost wall block 1 is secured to the foundation 2 by mortar or cement received within the cavity 3. Alternatively, the foundation 2 can include a ridge of triangular crosssection cast in situ and shaped for reception in the cavity 3.

At the end of the wall block 1 shown to the right of Figure 1, the faces 20,21 are joined by a plane transverse face 24, which together with the exposed end portion 25 of the face 21, is engaged in use by the soil to be retained by the wall. The face 24 may be perpendicular to the faces 20,21 but preferably, as shown, it has a rearward inclination to such perpendicularity in the upward direction so that the angle A between the face and the portion 25 is less than a right angle, for example, 78 , the angle between the faces 20 and 24 being then correspondingly greater than a right angle, at 102". This configuration provides a greater area for the portion 25 than would be obtained with the face 24 perpendicular to the faces 20,21, and this is advantageous as this portion serves for transforming the horizontal loading of the block by the retained material into a vertical component which the wall can readily withstand.

As shown to the left of Figure 1, the wall block 1 has four adjoining planar faces 4,5,6 and 7 extending between the faces 10,11.

The number, width and angular relationships of these faces 4,5,6 and 7 is chosen to provide a decorative configuration of the exposed face of the wall and can be selected accordingly. The illustrated wall block 1 will be seen to be such that horizontal grooves are formed along the exposed face of the wall by the faces 4,7 of adjoining blocks.

Each of the upper wall blocks 1 is received on the block immediately below it with its lower surface groove 1 2 received in mating relationship on the upper surface ridge 22 of the lower block. Relative displacement of the wall blocks 1 transversely of their length is opposed by this mating engagement so the wall has adequate strength up to a predetermined height. No mortar between the blocks is required to achieve satisfactory performance.

The widths of the faces 10,20 and the angle between them, are such that the plane containing the apices of the ridges 22 and grooves 1 2 is not at right angles to the surface of the foundation 2, but is inclined to it at an angle B of some 82". The retaining wall consequently has a batter of some 8 .

It will be evident that the shape of the wall block can be considerably varied within the scope of the invention. Thus, referring to the block 1 of Figure 1 and taking the width of the rear face 24 as L, the averaged widths of the faces 20 and 21 can be in the range of 0.90 to 3.0 L, for example 1.33 L, and the width of the faces 10 and 11 can be in the range of 0.3 to 1.0 L, for example 0.734 L.

The widths of the faces 4,5,6 and 7 at the decorative face of the block can be respectively in the range of 0.1 to 0.6 L, for example 0.5 L; 0 to 0.44 L for example 0.267 L; 0.3,to 0.6 L, for example 0.567 L; and 0 to 0.4 L, for example 0.267 L.

In Figure 2, a second form of wall block 100 is shown, with two pairs of parallel faces 110,111 and 120,121 forming a groove 112 and a ridge 1 22. The common angle of the groove 11 2 and ridge 1 22 is the same as in the block 1. The width of the faces 1 20 and 121 is reduced however, as compared with that of the corresponding faces of block 1, so that the batter of the wall is increased to an angle B' of about 12". The widths of the faces 120,121 are such that the angle A' between the rear face 124 and the face 121 is 75 .

Also, the sides of the cross-sectional shape forming the exposed face of the block are differently configured.

The wall block 200 shown in Figure 3 is so shaped that the retaining wall has zero angle of batter, so that a wall built of the blocks on a horizontal foundation is vertical. The shape of the wall block 200 generally resembles those of the blocks of Figures 1 and 2, but the exposed surface is defined by three faces 204,205,206 of which the centre face 205 is vertical, whilst the adjoining faces form horizontal grooves in the face of the wall of more strictly triangular configuration than those of the walls of Figures 1 and 2.

A wall block in accordance with the invention can be constituted of any suitable material, preferably concrete with a density in the range of 1,600 kg/m3 to 2,600 kg/m3.

It will be evident that the invention can be embodied in a variety of ways, to provide a retaining wall which can be assembled on the lowermost course without the use of mortar or concrete and which provides adequate strength properties, a selected batter, and an exposed face with an attractive decorative configuration.

Claims

1. A wall block for building a retaining wall, the block having opposed surfaces for use respectively as upper and lower surfaces in the retaining wall, the surfaces each being so shaped to engage the other surface of a like or co-operating superimposed or subadjacent block so as to resist relative displacement of the blocks in at least one horizontal direction.

2. A wall block for use in a retaining wall, the block being so shaped that when received on a like or co-operating block in the retaining wall, the block exposes to material being retained by the wall a surface portion so orientated that the horizontal loading due to the material is transmitted with a vertical component to the underlying block.

3. A wall block as claimed in claim 2 wherein the surface portion extends downwardly from the block in use at an angle in the range of 5" to 45 to the horizontal.

4. A wall block as claimed in claim 3 wherein the surface portion extends downwardly at an angle of 20 to the horizontal.

5. A wall block as claimed in claim 2, 3 or 4 having opposed upper and lower surfaces in use such that the block is retained in a predetermined relationship with a like block on or under which it is placed.

6. A wall block as claimed in claim 5 wherein the surface portion is part of a flat upper surface of the block of which another part is engaged by the undersurface of an overlying block.

7. A wall block for building a retaining wall, the block having on opposed sides thereof surfaces arranged for co-operative engagement, whereby the block can be stacked upon a like block in predetermined relationship in the wall without a bonding medium between the blocks.

8. A wall block as claimed in claim 1, 5, 6 or 7 wherein the opposed surfaces comprise ridge and groove configurations.

9. A wall block as claimed in claim 8 wherein the block is elongate and the ridge and groove configurations extend lengthwise of the block.

10. A wall block as claimed in claim 8 or 9 wherein the ridge configuration is formed by intersecting upper surfaces and the groove configuration is formed by intersecting lower surfaces parallel to the upper surfaces.

11. A wall block as claimed in claim 10 wherein the upper and lower surfaces intersect at an angle of 130 .

12. A wall block as claimed in claim 10 or 11 wherein the upper and lower surfaces at the side of the block engaged by the retained material in use are joined by a surface making an angle less than 90 with the adjacent upper surface.

1 3. A wall block as claimed in claim 1 2 wherein the angle is 78 .

14. A wall block as claimed in any one of claims 1 and 5 to 1 3 wherein the opposed surfaces are such that a wall built of the blocks has an angle of batter in the range of 0 to 45'.

1 5. A wall block as claimed in claim 14 wherein the angle of batter is in the range of 5" to 15 .

1 6. A wall block as claimed in any preceding claim wherein the exposed face of the block in use is formed by front surfaces in a decorative configuration.

1 7. A wall block as claimed in claim 1 6 wherein the front surfaces define horizontal grooves between adjacent courses of the blocks in the retaining wall.

1 8. A wall block substantially as herein described with reference to Figure 1, Figure 2 or Figure 3 of the accompanying drawings.

1 9. A retaining wall comprising blocks as claimed in any preceding claim.

20. A retaining wall comprising superimposed courses of wall blocks, the blocks of each course being in direct engagement with those of the subadjacent and superimposed courses and being restrained against displacement by the shapes of the engaging block surfaces.