AU731809B2 - Retaining wall block - Google Patents

Description

S F Ref: 398497

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name and Address of Applicant: Actual Inventor(s): Address for Service: Invention Title: ASSOCIATED PROVISIONAL [31] Application No(s) P03478 Keystone Retaining Wall Systems, Inc.

4444 West 78th Street Bloomington Minnesota 55311 UNITED STATES OF AMERICA Jim Rotondo Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Retaining Wall Block APPLICATION DETAILS [33] Country

AU

[32] Application Date 4 November 1996 The following statement is a full description of this invention, including the best method of performing it known to me/us:- .5815 RETAINING WALL BLOCK Technical Field The present invention relates to retaining wall blocks and in particular to a retaining wall block for use in mortarless, setback retaining walls.

Background of the Invention Retaining walls are commonly used in landscaping applications to support and secure embankments from sliding and slumping. Historically such retaining walls have been constructed from a variety of materials including natural stone, concrete, masonry, brick and timber.

Precast concrete blocks have gained widespread acceptance for the construction of retaining walls in the form of a mortarless structure built up of multiple rows or courses of blocks positioned on top of one another. Each block in such a structure ooooo includes means for securing blocks in adjacent courses.

The retaining wall blocks according to Australian Patent No 604072 (Forsberg) utilise a pin interlock system to secure adjacent rows to each other. Pins are secured in holes in the lower surface of each block, and extend downwardly to engage arcuate recesses located in the upper surface of adjacent blocks in the underlying course.

Construction of a wall from such blocks, however, requires accurate positioning of one block directly over adjacent lower blocks to ensure mating of the pin and recess, which 20 can prove tedious and tiring given the bulk and weight of most retaining wall blocks. The requirement to mould recesses can also increase the complexity and cost of the manufacturing process and the moulds used therein.

Many retaining walls are built such that each course of blocks is set back from an adjacent lower course, the weight of the off-set blocks acting to counter the pressure of the soil behind the wall, which tends to topple the wall over forward. The "setback" is commonly defined as the distance which the front face of blocks in one course of the wall are positioned behind the front face of the adjacent lower course. Flanges have been used toward the rear of the bottom face on retaining wall blocks disclosed in US Patent No 2,313,363 (Schmitt) and Australian Patent No 638554 (Block Systems Inc) to engage the [n:\lib11]00622:GJG rear face of adjacent lower blocks, thereby providing a setback equal to the flange width.

In walls constructed in this manner, the pressure of the soil acting on the upper block secures the flange against the lower blocks. Manufacture of such blocks, however, requires a relatively complicated moulding process requiring a flange cavity in the mould and means to ensure adequate compression of the flange during moulding for structural integrity. The flanges of such blocks are also prone to damage during transportation and during construction of a retaining wall.

Object of the Invention It is the object of the present invention to overcome or substantially ameliorate the above disadvantages.

Summary of the Invention There is disclosed herein a retaining wall block comprising: substantially parallel and planar top and bottom faces, a front face, a rear face, a pair of side faces, wherein each of said side faces defines an angle greater than 900 with said rear face, and a pair of holes provided in said bottom face nearby said rear face and substantially perpendicular to said bottom face, each said hole being adapted to securedly receive a pin, a free end of which projects from said hole beyond said bottom face and is Sadapted, in use, to abut against a rear face of a further said retaining wall block in an adjacent lower course of a retaining wall constructed from a plurality of said retaining wall blocks.

There is further disclosed herein a retaining wall block comprising: 25 substantially parallel and planar top and bottom faces, a front face, a rear face, a pair of side faces, wherein each of said side faces defines an angle greater than S900 with said rear face, [n:\lib11]00622:caa 3 a pair of holes provided in said bottom face nearby said rear face and substantially perpendicular to said bottom face, and a pair of pins each adapted to be securedly received in one of said pair of holes such that a free end of said pin projects from said hole beyond said bottom face, each said pin being adapted, in use, to abut against a rear face of a further said retaining wall block in an adjacent lower course of a retaining wall constructed from a plurality of said retaining wall blocks.

Preferably said block is constructed of high density concrete.

Preferably each said pin is manufactured from a resilient material.

Preferably each said pin is manufactured from plastic.

Preferably each said pin may be driven into a said hole by a mallet.

Preferably each said hole is tapered.

Preferably each said hole is located symmetrically with respect to a vertical centreline of said rear face.

Preferably each of said holes is located a substantially equal distance from said rear face.

Preferably each said hole is located between 10 mm and 50 mm from said rear face.

Preferably said block is provided with a further pair of holes such that an inner pair and an outer pair of holes is provided.

i Preferably said front face is roughly textured.

There is further disclosed herein a retaining wall comprising a plurality of courses of said retaining wall blocks, at least some of said blocks each straddling a pair of said blocks in an adjacent lower course and having a said pin securedly received in each 25 of said pair of holes with a free end of each said pin abutting against the rear face of a said straddled block in said adjacent lower course.

Brief Description of the Drawings A preferred form of the present invention will now be described by way of Sxample with reference to the accompanying drawings wherein: [n:\libII]00622:caa Figure 1 is a perspective view of a retaining wall block from below.

Figure 2 is an inverse plan view of the retaining wall block of Figure 1.

Figure 3 is a plan view of a section of retaining wall constructed from the retaining wall blocks of Figure 1.

Figure 4 is a side elevation view of a section of retaining wall constructed from the retaining wall blocks of Figure 1.

Figure 5 is a plan view of another section of retaining wall constructed from the retaining wall blocks of Figure 1.

Detailed Description of the Preferred Embodiments A retaining wall block 1 according to a preferred embodiment of the current invention includes planar top and bottom faces 2,3 which are substantially parallel and spaced apart a distance equal to the height of the block 1. A front face 4 extends between front edges of the top and bottom faces 2,3, whilst a rear face 5 extends between rear edges of the top and bottom faces 2,3. The front face 4 may be textured and shaped as i 15 required to enhance the aesthetic appeal of a wall to be constructed from the blocks 1. In the current embodiment the front face 4 is roughly textured and comprises a generally planar, roughly textured centre section 4a which is generally parallel with the rear face and two outer sections 4b, 4c each joining the front face centre section 4a and a side face 6,7. The side faces 6,7 each extend between corresponding side edges of the top and S 20 bottom faces 2,3 and join lateral edges of the front and rear faces 4,5. Here each of the front and rear faces 4,5 and side faces 6,7 extend substantially perpendicularly from the plane of each of the top and bottom faces 2,3. The intersection of the various faces may be sharp, flattened, rounded or bevelled.

The side faces 6,7 each define an angle greater than 900 with the rear face 5 so that a curved wall can be formed with the lateral edges of the front faces 4 of adjoining blocks 1 abutting.

Pin holes 8 are provided in the bottom face 3 nearby the rear face 5. The pin holes 8 are located at such a distance from the rear face 5 as to prevent tear-out failure of the material surrounding the hole 8. The holes 8 extend perpendicularly through the bottom [n:\libll]00622:GJG face 3 and into the block. The holes 8 are tapered in profile such that a resilient pin driven into any one of the holes 8 will deform as it is driven further in and lodge an end thereof securely in the hole 8 by frictional forces. The distance between the front of the hole 8 and the rear face 5 will determine the "setback" of a wall constructed from like sized blocks 1.

In the preferred embodiment, four holes 8 are provided in the bottom face 3 at a constant distance from the edge of the rear face 5. The holes 8 are positioned symmetrically about a centre line of the rear face 5, providing inner and outer holes 8a, 8b suitable for different wall profiles. Any number of further holes may be provided to lo cater for different setbacks and wall profiles as required. Care should be taken, however, to ensure holes are not spaced so close to jeopardise the structural integrity of the block 1.

A vertically extending notch 9 may be provided along the centre line of the rear face 5 to facilitate positioning of blocks 1 with respect to neighbouring blocks 1 in the adjacent ooooo S"lower course.

e• •15 The blocks 1 are formed in a simple mould with protrusions formed on the lower surface of the mould to correspond to the holes 8. The completed blocks 1 can readily be transported without significant risk of damage as no weak flanges are disposed on any of the faces.

Pins 10 for use with the block 1 are made of a resilient material such as plastic, and 20 should be sized such that they can be readily driven at least approximately 10 mm into the bottom surface 5 of the block 1 whilst leaving at least approximately 20 mm of the pin protruding therefrom. Ends of the pins 10 may be chamfered to facilitate location thereof in the holes 8.

To construct a straight section of wall 20 from the retaining wall blocks 1, as depicted in figures 3 and 4, the first course A of blocks 1A is arranged with the rear faces of each of the blocks 1A facing toward the soil embankment 21 to be supported and the lateral edges of the front faces 4A of adjacent blocks 1A abutting, the blocks 1A being arranged in a straight line. Two pins 10 are driven into two of the holes 8 of each of the blocks 1B to be used in the second course B of the wall section 20 by a mallet or similar means. For the straight section of wall 20, use of the outer holes 8b will typically be more [n:\libll]00622:GJG suitable to provide greater stability to the arrangement by placing the pins 10 at a greater distance apart.

Each block 1B of the second course B is placed on the first course A such that it straddles two adjacent blocks 1A of the first course A such that the rear face 5B of the block 1B overhangs the rear faces 5A of the adjacent first course blocks 1A. The block 1B is then slid forward until each of the pins 10 engages the rear face 5A of one of the adjacent first course blocks 1A. If required the block 1B is centred over the two adjacent first course blocks 1A utilising the notch 9B as a guide. The remainder of the second B and subsequent courses C, D etc are constructed in a similar manner.

Whilst constructing such a wall 20, the pins 10 may be used for attachment of a reinforcing geogrid 22 or similar tie-back means, utilised to further secure the wall 20 to the embankment 21. The geogrid 22 is a generally flat sheet of flexible and high strength plastic with a series of rows of slots which are adapted to fit over the free ends of the pins 10. The geogrid 22 extends rearwardly into the embankment 21 to help maintain the 15 positioning of the blocks 1. Other similar tie-back means may be constructed of materials such as metal, timber or hard rubber.

A curved section of wall 30 is constructed in much the same manner (see figure except that, depending on the curvature required, use of the inner holes 8a will typically be required to achieve the required setback.

*o *o o *b [n:\libll]00622:GJG

Claims (10)

1. A retaining wall block comprising: substantially parallel and planar top and bottom faces, a front face, a rear face, a pair of side faces, wherein each of said side faces defines an angle greater than 900 with said rear face, and a pair of holes provided in said bottom face nearby said rear face and extending substantially perpendicular to said bottom face, each said hole being adapted to securedly receive a pin, a free end of which projects from said hole beyond said bottom face and is adapted, in use, to abut against a rear face of a further said retaining wall block in an adjacent lower course of a retaining wall constructed from a plurality of said retaining wall blocks.

2. A retaining wall block comprising: substantially parallel and planar top and bottom faces, .ooooi a front face, a rear face, a pair of side faces, wherein each of said side faces defines an angle greater than 90' with said rear face, a pair of holes provided in said bottom face nearby said rear face and extending i substantially perpendicular to said bottom face, and a pair of pins each adapted to be securedly received in one of said pair of holes such that a free end of said pin projects from said hole beyond said bottom face, each said oo*o** pin being adapted, in use, to abut against a rear face of a further said retaining wall block 25 in an adjacent lower course of a retaining wall constructed from a plurality of said retaining wall blocks.

3. The retaining wall block of either of claims 1 and 2 wherein said block is constructed of high density concrete.

4. The retaining wall block of claim 2 wherein said pin is manufactured 3 om a resilient material. [n:\libII]00622:caa 8 The retaining wall block of claim 4 wherein each said pin is manufactured from plastic.

6. The retaining wall block of any one of claims 2, 4 or 5 wherein each said pin may be driven into a said hole by a mallet.

7. The retaining wall block of any one of claims 1 to 6 wherein each said hole is tapered.

8. The retaining wall block of any one of claims 1 to 7 wherein each said hole is located symmetrically with respect to a vertical centreline of said rear face.

9. The retaining wall block of any one of claims 1 to 8 wherein each of 1 o said holes is located a substantially equal distance from said rear face. The retaining wall block of any one of claims 1 to 9 wherein each said hole is located between 10 mm and 50 mm from said rear face.

11. The retaining wall block of any one of claims 1 to 10 wherein said block is provided with a further pair of holes such that an inner pair and an outer pair of holes is provided. .oo..i bc 12. A retaining wall comprising a plurality of courses of retaining wall blocks according to any one of claims 1 to 11, at least some of said blocks each straddling a pair of said blocks in an adjacent lower course and having a said pin securedly received each of said pair of holes with a free end of each said pin abutting against the rear face of a said straddled block in said adjacent lower course. .:oe.i

13. A retaining wall block substantially as hereinbefore described with o reference to the accompanying drawings. o*o. Dated 7 February, 2001 Keystone Retaining Wall Systems, Inc. Patent Attorneys for the Applicant/Nominated Person SPRUSON FERGUSON [n:\Iib11]00622:caa