GB2218141A - Retaining wall system and wall and joint units for same - Google Patents

Abstract

A wall unit for retaining wall is particularly useful for walls which change direction or are on irregular terrain. The unit includes a block portion (100) and a joint portion (112) which interengage with like portions on an adjacent unit. Due to the configuration of the engaging surfaces of the joint portion, a versatile unit is obtained. <IMAGE>

Description

RETAINING WALL SYSTEM AND WALL AND JOINT UNITS FOR SAME This invention relates to a retaining wall system and to wall and joint units for use in such a system. Retaining walls may serve as a noise barrier or baffle, or as a planter wall, or as a "Bund" wall. For brevity of description in this specification, the term "retaining wall system" is considered to include these possibilities.

There have been proposals for wall systerns for retaining soil or earth or other material, e.g. landfill. "wall systems have also been proposed for use in landscaping and terracing so that better use can be made of hilly sites, and are needed for embankments used in highway construction. One example of a retaining wall unit can be seen in U.S. Patent No. 4 524 551 issued June 1985.

Among desirable qualities of a retaining wall system are:1. it should employ a minimum number of different kinds of blocks or units; 2. it should be such that it can be constructed on a simple horizontal surfaced foundation pad; 3. it should be capable of resisting substantial lateral forces; 4. the geoinetry of each unit of the systetn should be such that it gives rise to substantial frictional resistance to shear forces or -forces which might give rise to movement lateral to the length oF the wall; 5. it should not require complex methods or equipment to anchor or tie the wall units back into the fill Inaterial; 6. each block or unit should be sturdy, simple, and easily manufactured; 7. the units should permit retaining walls at various (and varying) angles (including zero degrees) to the vertical to be readily constructed.

A retaining wall system which largely or wholly meets these requirements is generating considerable interest and is the subject of our U.l < .

Published Patent Application No. 2 185 512. A common problern, with this retaining wall system and with all others known to the Applicants, is to cope with a change of direction of the wall. One approach to this problem is shown in U.S. Patent No. 4 524 551 (SCHEIWILLER), see in particular Figures 21-26 and the associated description.

In most known systems, special wall units have had to be designed to enable a retaining wall to turn a 90 corner and different units have to be designed if the wall is to turn, for example, a 1200 corner or a 1350 corner. It is impractical for manufacturers or suppliers to stock a large variety of corner units, appropriate to each wall system, to cope with change of direction of the wall through an almost unlimited variety of possible angles. An additional difficulty is that known systems do not cope effectively with a change of rake of the wall off the vertical plane in two adjoining portions of the wall.

The present invention aims to solve or alleviate these problems.

According to the present invention, there is provided a wall unit for a retaining wall system including one portion for interengaging with other sirnilar wall units and a second portion which includes a joint interengageable with a like joint on an adjacent unit, the joint being constructed and arranged so that the unit can be located at an angle, in either a vertical or a horizontal plane and within selected ranges, to an adjacent like unit.

The invention also consists in a joint portion for attachment to a wall portion of a wall unit, in order to convert the wall unit to a unit usable to build a corner at which the retaining wall changes direction.

In a preferred embodiment the joint is based on the engagement of a specially shaped projection forming part of one wall unit with a recess on an adjacent unit.

The preferred shapes for the recess and the projection are complementary and chosen so as to permit an upper joint unit to tilt up in a vertical plane to about 220 for example relative to a lower similar unit without loss of interengagement between the units. The preferred shape defining the exterior surface of the projection is that produced by a rotation about a vertical axis of a circular arc. The arc is preferably centred on a point slightly spaced from the periphery at the upper end of the projection. The preferred shape defining the interior surface of the recess is also that generated by rotation of a circular arc about a vertical axis; in this case the arc is centred on a point diametrically opposite and slightly spaced from the mouth of the recess.

In a preferred embodiment of the invention the recess portion and the projecting portion of the joint are connected by an intermediate portion whose external surface is shaped as a frustum of a cone, the cone angle being within the range 1250 to 13 So, and preferably about 1300.

A preferred but not essential feature of the invention is that the nonjoint portion of the wall unit which engages with other like wall units is constructed according to the teaching in our aforesaid Patent Application No.

2 185 512. To avoid repetition and for the sake of brevity, the whole contents of the said Application are hereby incorporated in the present Application.

In an advantageous embodiment each unit according to the invention has both a specially shaped projection and a specially shaped recess, and the vertical axes of the projection and the recess coincide. In such a unit, a generally vertically extending hole may be provided through each unit to allow grit, water, or other material which may collect in the recesses to be brushed into the hole or to run away through the hole.

In this specification, the words "horizontal" and "vertical" have been used in relation to a wall unit which is placed horizontally upon a horizontal surface. It will be appreciated that in some circumstances a wall or a portion thereof will extend either upwardly or downwardly. Accordingly these words are not used in a sense limiting the scope of the invention solely to walls or wall units which are horizontal or have blocks with vertical surfaces; on the contrary, it is an important advantage of the invention that angular adjustability is readily obtained, without significantly increasing the difficulty or cost of building a retaining wall.

In the preferred and illustrated embodiment of the invention, the projection extends downwardly and the recess is in an upper surface of the joint portion. It is within the scope of the present invention to adopt a reverse arrangement, that is, the recess may extend into a lower surface of the joint portion and the projection may extend upwardly.

The joint portion may be cast or moulded separately from the standard block portion and may be attached to or used with wall units other than those in accordance with our aforesaid Patent Application.

The invention will be better understood frorn the following description of illustrative embodiments, given by way of example only with reference to the accompanying drawings, in which: Figure 1 is a front view of one embodiment of joint wall unit in accordance with the invention, showing a wall unit block portion according to the aforesaid Patent Application (herein called a standard block portion) to which is attached a joint portion; Figure 2 is a plan view of the joint portion shown in Figure 1; Figure 3 is an end elevation of the joint portion shown in Figure 1; Figure 4 is a side elevation of the joint portion shown in Figure 1; Figure 5 is a cross-section on the lines V-V of Figure 2;; Figure 6 is a cross-section on the lines VI-VI showing construction lines (chain-dotted) whereby surfaces of the joint portion are defined according to the presently most preferred embodiment of the invention; Figure 7 is a perspective view showing a wall unit including a joint portion assembled together with the joint portion of another wall unit; and, Figure 8 illustrates a corner of a wall made using wall units according to the invention.

Figures 9 to 14 illustrate the presently-preferred embodiment of the invention; Figure 9 being a diagrammatic perspective view of a joint region of a retaining wall; Figure 10 being an end view of a wall unit block according to our Patent Application No. 2 185 512 but having recesses therein for reception of a joint unit according to this embodiment of the invention; Figure 11 is a side elevation of a joint unit according to this embodiment of the invention; Figure 12 is a vertical central cross-section of the joint unit shown in Figure 11; Figure 13 is an end elevation of the joint unit of Figure 11; and Figure 14 is a plan view of the joint unit of Figure 11.

In the drawings, like parts are denoted by like reference numerals.

For ease of manufacture, a joint unit in accordance with one embodiment of the present invention is made in two portions, namely a standard block portion 10 and a joint portion 12. In use, these are preferably connected together by adhesive. If desired, they may be connected together additionally by a mechanical inter-engagement such as a dowel pin and counterpart recess or in any other convenient way. In Figure 1 an adhesive join is indicated at 14.

The preferred standard block portion 10 is constructed according to the teaching in U.K. Published Patent Application 2 185 512. The joint portion 12 of the unit has a recess therein and a projecting portion 16. The construction of these parts is seen best from Figures 2-6.

Referring to Figures 2-6, the joint portion 12 is generally circular as seen in plan and has an extension 18 with a planar vertical surface 20 by which it is adhesively secured to the standard block 10. The recess 22 extends into the top surface 24 thereof, and this recess is symetrical about a vertical axis 26. An intermediate portion 28 connects the projecting portion 16 and the recessed part 12 of the unit 10. The external surface of the intermediate portion 28 has the shape of a frustrum of an inverted cone with a cone angle of approxirnately 1300; that is, the angle marked a in Figure 3 is substantially 250.

A different cone angle could be employed, e.g. the angle a could be from about 200 to about 260. The intermediate portion 28 is provided to faciliate some tilting in a vertical plane of one wall unit relative to another. The circular configuration (as seen in plan) of the recess 22 and the projecting portion 16 provide for a large number of possible relative positions between two connected adjacent wall units, so accommodating a wide variety of angles of change of direction of a wall as seen looking down on the wall. As seen in Figure 8, one observes that there is change of direction of substantially 900, but it will be appreciated that with the wall units according to the preferred embodiment of the present invention, this angle could take any value between 0 and about 1800.

Referring now to Figures 5 and 6, an important feature of the invention is the choice of shape of the external surface of the projection 16 and the internal surface of the recess 22. Both surfaces are de-fined by rotating a circular arc through 3600 around the vertical axis 26. A circular arc 34, which defines the wall of the recess 22 instead of being centred on the axis 26, is centred on a point 32 diametrically opposite to the postion of the arc at its start point prior to rotation and which is slightly spaced from the mouth of the recess. The exterior surface of the projection 16 is defined by the rotation of an arc 36, 3600 around the axis 26, this arc 36 being an arc of a circle centred on a point 38 diametrically opposite. That is, the point 38 is located adjacent to the upper end of the projection and slightly spaced outwardly from it.In the presently most preferred version of the invention, the radial distance R1 From the point 32 to the arcuate wall 34 of the recess 22 is 146 units, and the width WR measured in a horizontal plane of the mouth of the recess 22 is 140 units.

The radial distance R2 from the arcuate interior wall 36 of the projection to the point 38 is 142 units, and the width WP of the projection at its widest (top) point is 138 units. The height H1 of the projection is preferably 82 units and the depth H2 of the recess is preferably 111 units. The height of the intervening portion H3 is 14 to 15 units. Of course the invention is not regarded as limited to these particular values; they are merely values which have proved successful in testing. A vertical cylindrical hole 40 of diameter (D) about 46 units is provided through the projection 16 to merge into the recess 22. This hole allows exit of detritus and rainwater which might otherwise collect in the recess 22. It is advantageoijs that R1 should be from 102 to 106.60/0, and preferably from 103 to 105.6'my of R2. It is also advantageous that H2 should be from 132 to 139% of, and preferably from 134.4% to 136.4% of H1. The height of the intervening portion H3 is desirably from 16.5 to 18.9% of H1.

Referring now to Figure 7, two adjacent wall units are shown in mutual interengagement. The lower one has a joint portion 12a and a standard block portion 10a and this is located substantially at 900 to an upper wall unit which has a joint portion 12b and a standard block portion 10b. The portion 10b is shown dotted so as to avoid confusion. The arrow 60 illustrates that the blocks are readily assembled together in the building of a corner portion oF a retaining wall to form a hinge joint, by inserting the projection 16b generally vertically downwards into the recess 22a of the lower block, and, thereafter, if necessary, tilting of one wall unit relative to the other in a vertical plane is possible as indicated by arrow 62, end a wide possibility of adjustment in a horizontal plane can be achieved as indicated by arrow 64.

Referring now to Figures 9-14, the illustrated wall unit 100 (Figure 10) is generally in accordance with the disclosure in our said Application No.

2 185 512. It has cylindrical recesses 102, 104 therein, each capable of receiving a spigot shortly to be described. The recesses may, but need not, extend through the block so forming cylindrical holes. The preferred joint unit in accordance with the invention has a recessed body portion 112 and a downwardly projecting portion 116. The recess 122 in the body portion 112 is constructed and shaped in the same way as is described in connection with the recess 22 of Figures 5 and 6. The projecting portion 116 is constructed and shaped similarly to the projecting portion 16 described in connection with Figures 5 and 6.

A cylindrical spigot 140 (which may be solid or hollow but is preferably solid) extends in a radial direction outwardly from the body portion. Its diameter and length are chosen so that it fits reasonably closely in either of the recesses 102, 104 in the wall unit 100. The ratio of the outside diaineter of the spigot 140 to the internal diarneter of the recess 102 (or 104) is preferably from 1.03:1 to 1.055:1, and more preferably about 1.042:1. The spigot 140 may be located about half-way up the height of the block portion 112. The length of the spigot may be frorn about 75 to 100 per cent of the diameter of the body portion 112.The portion 112 is joined to the projecting portion 116 by an intervening portion 128 whose shape and arrangement essentially corresponds to that shown at 28 in Figures 1-4.

In use, the spigot 140 can be fixed within a chosen recess (102 or 104) by adhesive or by wedging or by simple push fit. The lengths of those portions of the spigots which are inserted into the recesses can be chosen as desired in accordance with the configuration of the retaining wall and the characteristics of the terrain where the wall is to change direction. This ability to adjust the distance between the hinge axis and the centre line of a standard wall unit block is an important feature of the invention and is indicated by the arrow B in Figure 9. As a consequence, the system according to Figures 9-14 is able to cope with a wide variety of circumstances.

Another important feature of this embodiment of the invention is that the spigot can be placed- in the recess at any rotary orientation relative to the wall unit block. That is, as indicated by the arrow A in Figure 9, the direction of the axis 126 (Figure 12) an be adjusted relative to the block 100 which means that a hinge joint at a change of direction of the retaining wall can be formed to have an axis which is non-vertical, and, moreover, which can be located at a wide variety of angles to the vertical. A further feature of adjustability in the system is that one joint unit 112 can be located in a variety of relative rotational positions about a vertical axis relative to the joint unit above or below. This is indicated by the arrow C in Figure 9.

The variety of adjustment possible means that joint units, and blocks incorporating such units, in accordance with this embodiment of the invention are versatile and enable retaining walls to change direction in the horizontal plane as well as enabling the wall (if desired) to follow sloping terrain. Also, the angle of the wall facing the vertical (the angle of batter) can be altered at the same time as accomodating these changes of direction.

A desirable feature of the invention which provides a wide possibility of mutual adjustment, and hence greatly increases the versatility of the joint units, is that the recess is chosen to be deeper than the projection and the internal surface of the recess and the external surface of the projection are specially shaped so as to be complementary but not to be congruent. Contact between these surfaces over a substantial area is maintained, even when an upper block is tilted in a vertical plane at an angle up to about 220 relative to the lower block. To the best of Applicant's knowledge and belief, no prior wall unit joint, either in commercial use or proposed, has been able to achieve such adjustability, while at the same time being easily built by relatively unskilled persons and without needing numerous different angle blocks.

Claims (13)

1. A wall unit for a retaining wall system including one portion for interengaging with other sirnilar wall units and a second portion which includes a joint interengagable with like joints of adjacent units, the joint being constructed and arranged so that the unit can be located at an angle to an adjacent like unit within a selected range.

2. A wall unit according to claim 1 in which the engagement of a specially shaped projection forming part of one wall unit with a recess on an adjacent unit forms the said joint.

3. A wall unit according to claim 2 in which the recess and the projection are complementary and their shapes are chosen so as to permit an upper joint unit to tilt up to 220 in a vertical plane relative to a lower similar unit without loss of interengagement between the units.

4. A wall unit according to claim 2 or 3 in which the exterior surface of the projection is that produced by a rotation about a vertical axis oe a circular arc, said arc being centred on a point slightly spaced from the periphery at the upper end of the projection; and in which the shape defining the interior surface of the recess is also that generated by rotation of a circular arc about a vertical axis; said latter arc being centred on a point diametrically opposite and slightly spaced from the mouth of the recess.

5. A wall unit according to claim 4 in which the recess portion and the projecting portion of the joint are connected by an intermediate portion whose external surface is shaped as a frustrum of a cone.

6. A wall unit according to claim 5, in which the cone angle is within the range 128-136 .

7. A joint for a retaining wall for use where the wall changes direction, the joint being designed for use in conjunction with a wall unit and comprising a body portion having a recess therein and a projection extending therefrom the recess and projection being complementary and shaped so that when the projection of one joint is engaged in the recess of a like joint, the two joints are relatively movable through 3600 about a vertical axis and through up to about 220 about a horizontal axis.

8. A unit for a retaining wall comprising a block portion and a joint portion, the joint portion having an elongate spigot extending therefrom and the block portion having a complementary recess therein, the spigot and recess being complementary so that the spigot of one unit can be inserted to a variable extent into the recess of a like unit to connect the two units.

9. A unit for a retaining wall comprising a block portion and a joint portion, the joint portion having a substantially cylindrical spigot extending therefrom and the block portion having a substantially cylindrical recess therein, the spigot and recess being complementary and relatively rotatable about the spigot longitudinal axis whereby two like units can be connected in a variety of relative angular positions.

10. A unit for a retaining wall system substantially as herein described with reference to and as illustrated in the accompanying drawings.

11. A retaining wall system including wall units according to any one of claims 1-6 and 8 and 9.

12. A retaining wall system including a joint according to clairn 7.

13. Any novel combination or sub-combination disclosed and/or illustrated herein.