CA2035769A1

CA2035769A1 - Prefabricated concrete blocks for building retaining walls

Info

Publication number: CA2035769A1
Application number: CA 2035769
Authority: CA
Inventors: J. Louis Brot
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-02-09
Filing date: 1991-02-06
Publication date: 1991-08-10
Also published as: DE69002609D1; ES2044515T3; FR2658217B1; FR2658217A1; EP0441083B1; EP0441083A1; DE69002609T2

Abstract

A B S T R A C T

A one-piece prefabricated concrete block for building retaining walls, the block being in the form of a six-faced parallelepiped having external keying shapes capable of enabling two adjacent blocks to co-operate with each other, the top face including, parallel to its front face, at least two, and preferably three, hollow female keying shapes which are open generally trapezium-shaped and situated at equal distances apart on the same block and between two blocks disposed one behind the other by interfitting said keying shapes on the rear face of one of the blocks and on the front face of the other block, with the bottom face including, parallel to the front face and in the same vertical plane as the two outermost keying shapes of the top face, two male keying shapes being capable of interfitting in any two of the female keying shapes of one or two blocks placed therebeneath.

Description

7 ~; 9 PREF~BRIC~TED CONCRETE BLOCKS FO~ ~U~LDING RETAINING W~LLS
DESCRIPTXON
The present invention relates to prefabricated c~ncre~e block3 for building retaining walls.
5The technical field of the invention is manufacturlng prefabrica~ed concrete blocks for public works.
BACKGROUND OF m E INVENTION
One of the main applications of the invention i~ building walls for retaining vertical or sloping embankments that are rectilinear or curvilinear in alignment and that ar~ associated with sound-absorption properties, the walls being intended to retain the option of having plants growing therein.
Various systems are known that enable retaining walls to be provided, either by using the technique of ~ coffer wall made up of blo~ks that are fairly heavy, or else by using the technique of modular blocks that can be interfitted in one another. However, systems that satisfy all of the above application constraints are ræ e.
In the first category, various patents have been filed, and reference is made, for example, to French patent number FR 78/09.686 filed by Entreprise Albert Peller et Cie which describes sound-insulating walls built up from transverse girders crossing longitudinal girders forming two continuous anchors, with the longi~udinal girders situated in front of -the wall being of trough-shaped section. The transverse and longitudinal girders surround rectangular wells that are filled with soil for plants.
In addition, patent FR 78/16.804 in the name of Sabla describes coffer walls which include transverse walls made up of: girders placed one abo~e the other; facade plates that slope outwards going up and which æ e placed in notches in the transverse girders; and transverse girders or bars which inter-connect the rear ends of the girders.
All of the walls described in these prior documents are built up ~rom prefabricated blocks that are relatively heavy and which require machinery to install them. In addition, the shapes of these prefabricated blocks are often complex, requiring expensi~e prefabrication molds to be made up.

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; ~' 2 ~,13 ~ rj t'jl ~13 In the second category, in which the presenk invention is included, ~here ara ~ens of patent applications which seek to satisfy at least som2 of the criticisms that can b~ made about the first category, by pn~posing blocks that are lighter in weight and can thus ~e manipulated and put into place by hand.
In addltion, tha relatively small d~mensions of these blocks can make it possible, depending on their shapes, for them to follow curved embankment profiles, whereas the longer blocks of the first cat~gory do not adapt to 311 of the curves that may be desired.
By way of example, reference may also be made to patent application No. FR 2 374 478 filed by Mr. Jean Famy on December 16, 1976 for "embankment retaining bl~cks", each constituted by a rectangular block having a triangular configuration of female keying shapes on each facs enabling facing blocks to be fixed together by inserting square section male ke~s between the blocks and sliding them along facing keying shapes. By having a set of various different parallel and perpendicular keying shapes, it is possiblè to follow a sloping embankment, and to make angles, but not to follow curves, nor to plant the embankment.
German patent application No. DE 3 118 487 filed Septembsr 5, 1981 by Mr. Juraschek Reinhard~describes vertical axis blocks comprising cylinders o~ ~ig-saw puzzle shaped sectlon having 'two male keying shapes on two opposite vertical faces and ~wo female keying shapes compatible with the male keying shapes on two other opposite vertical faces, with it also being possible to in~erconnect the blocks by pivot-forming elongate pieces disposed between two female keying shapes of two base bloc~s, thereby enabling a curve to be followed. However it is not possible to follow a steeply sloping embankment, nor to plant it.
French pa-tent application FR 2 570 411 filed September l9, 1984 by Mr. Pierre Chambreuil relates to "one-piece blocks for consolidating a double ~all". These blocks have a plane face, and the opposite face is constituted by male keying shapes and female keying shapes capable of co-operating and locking with cvrresponding parts o~ other blocks whlch are assembled -- .

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~.~33 ;~7 69 together ~n a con~lguration which is staygered in both direations of the plane constitut0d by the wall that is to be built. The wall is thus self-locking without mortar or cement, but it cannot be caused to slope or to curve, and is ~herefore unsuited for an embankment.
European patent application No. 0 215 994 filed September 26, 1985 by the Swis~ Rol~ Schelwiller descrlbes hollow centered square section coffer-forming blocks including female dove-tail keying shapes in the middles of their ~our vertical faces. They are then assem~led together by plane connecting blocks having male ends suitable for being received in the keying shapes of said coffer blocks. This system is capable of following a sloping embankment because of other intermediate parts and because of parallel and perpendicular keying shapes on their top and bottom faoes, but it is not suitable for following curves.
Numerous other patents could also be mentioned such as European patent No. 0 282 679 filed March 20, 1987 by the same Swiss and disclosing additional blocks for use with the above and enabling them to follow curves, and German patent application No. 3 740 646 filed December 1, 1987 by Mr. Willi Ruckstuhl describing a set of six ~o eight blocks that co-operate with one another b~ means o~ dove-tail keying shapes for the purpose of providing various vertical or sloping embankment wall profiles.
All of the above-outlined systems are either fairly simple to make and assemble, comprising few different blocks, in which case they are suitable for one type of utilization only, or else they are relatively complex both to make and to assemble, including numerous different blocks, enabling them to adapt to different configurations.
In addition, most of them are not suitable or being made by automatic machines for prefabricating concrete blocks. Such machines must be capable of unmolding pre~abricated blocks by sliding mold walls or accessories in two directions only. Few machines are capable of thus forming keying shapes in perpendicular directions on more than one face, and such .
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4 ~ 3~9 machines are very complex, thereby increasiny the C03t of the blocks they make.
The problem posed is thus to be able to make prefabrlcateA
one-piece concrete blocks sultable for building retaining S walls, with the blocks being of such a shape and having depressions in their aces that enable them to be made with conventional standard automatic machines. Said outside shape being common to all of the blocks while enabling vertical or sloping walls to be built, that enable such walls to be thickened by adding such interconnected blocks one behind the other while still following a curve or a rectilinear alignment, with the dimensions of these blocks being compatible with manual handling, and with their inside shapes being capable of being adapted to planting a sloping retaining wall and to absorbing noise radiation.
SUMMARY OF THE INVENTION
A solution to the problem posed is a one-piece pre-fabricated concrete block for building retaining walls, the block heing in the form of a six-faced parallelepiped having external keying shapes capable of enabling two adjacent blocks to co-operate with ~ach other, the top face of the block ~ncluding, parallel to its front face, at least two, and preferably three, holl~w female keying shapes which are open ; and generally trapezium-shaped and situated at equal distances apart on the same block and between two blocks disposed one behind the other by interfitting said keyi~g shapes on the rear face of ons of the blocks and on the front face of the other block, and with the bottom face of the vlock including, parallel to the front face and in the same vertical plane as the two outermost keying shapes of the top ~ace, two male keying shapes being capable of interfi-tting in any two of the female keying shapes of one or two blocks placed therebeneath.
The ob~ect of the present invention i9 achieved with a one-piece block as defined above including a single elongate keying shape on each of its side faces, in the form o~ a female dove-tail keying shape on one side and in the form of a male dove~tail keying shape on the other side, with engaged keying .

~3 ~7~9 shapes accepting a degree of angular rotation of one block relative to an adJacent block.
In a preferred embcdiment, said one-piece block includes two key~ng shapes on lts rear face in the form of male dove talls, and two keying shapes on its fron~ face in the form of female dove-tails.
Another ob~ect of the present inventlon is also achieved with one-piece blocks as defined above further including a central cavity which is open to its top and bottom faces, and with other blocks for which said cavity is closed at lts top face and open at its bottom face and also at its front face by means of at least one slot communicating with a fe~ale keying shape in said front face.
The result is novel one-piece prefabricated concrete blocks for building retaining walls which satisfy the entire problem posed and which enable any shape of wall to be built.
Existing systems such as those described above are not suitable, as can be seen *rom that description, for making an assembly of arbitrary shape unless intermediate parts are added thereto, whereas blocks of the present invention all have the same outside leading dimensions. Similarly, when existing systems enable various different shapes to be obtained, they are unsuitable for automatic manufacture by standard machines, whereas blocks of the present invention are suitable for being manufactured in that way because of their semi-open profile parallel elongate ke~ing shapes on each pair of opposite faces.
These blocks can thus be used for building any type of retaining wall by being assembled on top of one another, side by side, and one behind another. The walls may be vertical or sloping and they may follow varying angles, having convex or concave front curves and rear reinforcement. For sloping walls, some of the blocks can be planted, and it is always possible for some o the blocks to be noise-absorbing.
In addition, these blocks can be small in size, weighing about 20 kg, thereby making them suitable or being manipulated by hand. They do not require intermediate blocks or pieces for mutual enga~ement and fixing. They can thus be put into place quickly and simply.

, ' ' , ' . ' , '' ;3 ~ r~ ~; 9 BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment of the invention is dessribed by way of example with reference to the accompanying drawings. Other embodiments are possible within th~ claims ~hat specify tha scope and the extent of the invention, and in particular the shapes of the inter-block keying shapes may be different. In the drawlngs:
Figure 1 is a perspective view of two one-piece blocks ready to be stacked one on top of the other;
Figures 2A, 2B, 2C, and 2D are plan elevation and section views of a standard block;
Figures 3A, 3B, 3C, and 3D are four views similar to Figures 2A to 2D of a soundproofing block;
Figure 4 is a vertical section through a retaining wall;
and Figure 5 is a horizontal section through a retaining wall.
DETAILED DESCRIPTION
Figure 1 is a perspective view of ~wo one-piece blocks ready to be stacked one on the other along a common vertical axis XX' to constitute a column. One of the blocks, 1, is called a standard block and the other block, 2, is called a soundproofing block. The standard block 1 is shown in detail in Figure 2, and the soundproofing block 2 is shown in detail in Figure 3.
These blocks are in the form of rectangular blocks having six faces that are parallel in pairs, with the outsides of the faces including, in conventional manner, elongate keying shapes suitable for enabling two adjacent blocks to co-operate.
However, the layout and the functions of these keying shapes are specific to the present invention and are not taught by any existing block.
Keying shapes 8 and 9 of the front and rear faces 14 and 15 may be o any shape enabling them to co-operate so as to prevent the blocks coming apart, even in traction, and so as to bring block~ into alignment one behind the other. They may include tenons or dove-tails of conventional profile. There may be one or more per face. For reasons of appearance, it is preferable to put the female shapes 8 on the front face.
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Keying shape-~ 10 and 11 on the side faces 15 ~ay be on the same type as the keying shapes on the Pront and rear Paces, providing the same functions of bringing the blocks into alignment and preventiny them from being pulled apart, but sideways in this case. However, although ad~acent blocks in the depth direction are generally required to follow a plane perpendicular to the Pront face, ad~acent blocks in the width direction may have to follow a curve which is convex or concave,, and to make this possible each side face should have one keying shape only, with a male shape on one side and a female shape on the other, and with the shapes ha~ing sufficient cle æance to enable adjacent blocks to plvot somewhat relative to each other, as described with rePerence to Figure 5.
Keying shapes 6 and 7 in the top and bottom faces 17 and 18 respectively are diPferent in shape and nature Prom the preceding shapes. The blocks can be preven~ed from moving relative to each other merely by the effect of gravity and their weight, so there is no need to have retaining shapes as in the horizontal plane. It is therefore preferable both Por simplifying manufacture during unmolding and for simplifying centering during stacking for the blocks to be of the type having hollow generally trapezium type section shapes 6 (or "notches") on the top face 17 with the long base on the outside, and pro~ecting shapes 7 (or "teeth") on the bottom face 18 with the short base on the outside and optionally rounded. In addition, since the blocks must be capable of following the slope of a sloping embankment, the female shapes 6 should be at least -two in number and preferably three, for co-operating with only two male shapes capable of engaging in two female shapes when an upper block overlaps two adjacent lower blocks, as described with rePerence to Figure ~
The one-piece blccks are preferably in the Porm of rectangular parallelipipeds which are long in the depth direction of the wall they are used to build.
Figure 2 comprises four plane views oP a standard block l as shown in perspective in Flgure l. View 2D is a front view ~ ~ 3 ~ ~ 6 9 of the block, i.e. it shows the front face 14 thereof. The keying shapes 18 constitute vertical lines, and in order to interrupt these lines for reasons of appearance, particularly if the blocks are not exactly in alignment vertically, they may be in~errupted horizontally at at least one end by means of a grcove 13 lntersecting these vertical lines. In the present case this is shown at the top end only, but it could be done in addi~ion or instead at the bottom end.
View 2B is a section on plane CC of view 2D. It clearly shows how the notches 6 in the top face are spaced apart at a uniform pitch d on the same block as shown, and also between one block and an adjacent block placed in front of it or behind it by mutual engagement of their keying shapes 8 and 9. Four notches 6 are shown in the present case, however ~hey could be only three of them, or there could be re of them. Two teeth 7 suffice on the bottom ace and these are placed in the same vertical plane as the end notches 6 in the ~op face. In addition, it is preferable for the standard "base" block to have a central cavity 4 which is open to its top and bottom faces, thereby both lightening the blocks and also imparting properties thereto suitable for growing plants or for absorbing sounds, as can be seen in Figure 4. The cavity 4 may be rectangular in section.
Views 2A and 2C are a bottom view and a top view respectively, i.e. they show faces 18 and 17. The keying shapes 8 and 9 of the front and rear faces can clearly be seen, as can the shapes 10 and ll of the side faces. The outside surfaces 20 and 21 of the side keying shapes 10 and 11 act as pivot pieces to enable one block-to rotate somewhat relative to an adjacent block. They therefore need to have a shape of the spherical type or of the type of a cone circumscribing a sphere, and/or they need to provide adequate clearance, whereas the keying shapes 8 and 9 may ~e of any other shape.
It will also be observed in these vie~s that the central cavity 4 passes right through the blocks and that all the other lines parallel to the front and rear faces represent the keying shapes 6 and 7 of the top and bottom faces.

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Figure 3 comprlses four plane views of a so-called "sound proofing" block 2.
View 3D is a front view of this block and is identical to a standard block 1 except in that it also has two slots 12 formed ln the ~ottoms of the female keying shapes 8 and communicating with the central cavity. mese slots open out to the bottom end of the block, but they stop halfway up it.
There need be only one such slot 12.
View 3B is a section view DD on view 3D, and the same keying shapes 6, 7, 13, 8, and 9 can be seen as for the standard block o~ Figure 2B. However, the central cavity 5 is closed adjacent to the top face 17. It is fully open towards the bottom face 18 and partially open towards the front face 14 through the slots 12.
Views 3A and 3C are a bottom view and a top view respectively of the soundproofing block, showing its side keying shapes 10 and 11, and its front and rear keying shapes 8 and 9 as for the standard block l. The sound absorbing cavities 5 can be seen inside the block. These c~vities are shown in the present case as constituting two volumes, however there could be a single volume or there could be more than two.
The dimensions of these volumes 5, the dimensions of the slots 12, and the number of standard blocks 1 stacked beneath to make up a vertical cavity all depend on the sound frequencies that are to be absorbed. In some circumstances, soundproofing blocks 2 may be used on their own. However, it is preferable, given their use in embankment retaining walls essentially adjacent to roads, said cavity 5 and keying shape 12 optionally associated with the cavities 4 of one-piece blocks 1 placed therebeneath constitute a so-called "Helmholtz" cell for absorbing sounds in the frequency range 50 Hz to 500 Hz.
In a particular preferred embodiment, the Helmholtz cell is obtained by inserting sheaths of suitable synthetic material into each of said cavities 4, 5.
Figure 4 is a vertical section view on BB of Figure 5 through a wall retaining an embankment 23 and built up of one-piece blocks 1 and 2 as described above.

~ , lo ~3~9 The blocks 1 and 2 perform the same function of constituting the ~ront face of the wall by being stacked on one another, either vertically above one another as ln the sPcond and third rows up, or else tapering rearwards by one step d between two notches 6 as between the fourth and fifth rows, by two steps d between grooves 6 as between the third and fourth rows, or by four steps d between two notches 6 ~5 be~ween ~he first and second rows. Varying different slopes can be achieved in this way.
It is possible to plant rows such as the first row and the fifth row, where the offset is large.
In some of the rows, the blocks may b stacked to form sound absorbing cells as with the second and third rows.
In a particular embodiment, the front blocks 1 and 2 may have a front surface that is purely decorative and unsuitable for engaging with another surface, in which case these blocks are used solely for making the visible face of the retaining wall.
As many blo ks 22 as may be desired for reinforcing the wall may be placed behind the front blocks, either in a pyramid configuration as shown in the figure or else in a skew configuration if bottom support surfaces are not necessary, or else using rows going depthwise into the embankment only e~ery 3, 4, or more vertical columns.
Figure 5 is a horizontal section view on line AA of Figure 4 through a wall retaining an embankment 23 and constituted by one-piece blocXs 1 for the front face of the wall and by blocks 22 for reinforcing said wall from behind.
The side faces of the blocks 22 are plane and such bl~cks are used only for providing reinforcing depth to the front surface of the wall.
Given the way they fit into the front surface of the wall, it is important for the rear blocks to avoid having too many constraints on their degrees of freedom, and for the worlc to be stable, it suffices for them to have connections in the depth direction and the vertical stacking direction only.

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In addition, when the wall i5 ¢urved convexly as shown in the figure, the blocks 22 come closer together the deeper they are in the embankment. As ~hey get ¢loser together, when their OOrner8 touch, one o the two touchlng blocks i5 eliminated and S the reinforcement is continued using the other one only, if necsssary. The maximum angle of curvature depends vn the profiles of the ke~ing shapes and on the dimensions of the blocks, but it may vary up to four degrees, for example.
The hollow blocks 1 and 22 may also be filled with material in order to constitute a gravity wall.

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Claims

1/ A one-piece prefabricated concrete block for building retaining walls, the block being in the form of a six-faced parallelepiped having external keying shapes capable of enabling two adjacent blocks to co-operate with each other, wherin the top face of the block includes, parallel to its front face, at least two, and preferably three, hollow female keying shapes which are open generally trapezium-shaped and situated at equal distances apart on the same block and between two blocks disposed one behind the other by interfitting said keying shapes on the rear face of one of the blocks and on the front face of the other block, with the bottom face including, parallel to the front face and in the same vertical plane as the two outermost keying shapes of the top face, two male keying shapes being capable of interfitting in any two of the female keying shapes of one or two blocks placed therebeneath.

2/ A one-piece prefabricated concrete block according to claim 1, including two keying shapes on its rear face in the form of male dove-tails, and two keying shapes on its front face in the form of female dove-tails.

3/ A one-piece prefabricated concrete block according to claim 1, including a single keying shape on each of its side faces, with the shape on one side being in the form of a female dove-tail and with the shape on the other side being in the form of a male dove-tail, which shapes tolerates a degree of angular rotation of one of the blocks relative to an adjacent block.

4/ A one-piece prefabricated concrete block according to claim 1, including a central cavity open to its top and bottom faces.

5/ A one-piece prefabricated concrete block according to claim 1, including at least one central cavity which is closed towards the top face and open towards the bottom face and which is also open to the front face via at least one slot communicating with a female keying shape in said face.

6/ A one-piece prefabricated concrete block according to claim 5, wherein said cavity and the slot optionally in association with the cavities of other one-piece blocks placed therebeneath constitute a "Helmholtz" cell capable of absorbing sound at frequencies lying in the range 50 Hz to 500 Hz.

7/ A one-piece prefabricated concrete block according to claim 6, wherein the "Helmholtz" cell is obtained by installing sheaths of suitable synthetic material in said cavity.

8/ A one-piece prefabricated concrete block according to claim 1, wherein the keying shapes of the front face are interrupted horizontally at at least one end by a vertical line-breaking groove.

9/ A one-piece prefabricated concrete block according to claim 1, wherein its front face has a surface which is purely decorative in appearance with said block being for use solely in constituting the visible surface of said retaining wall.

10/ A one-piece prefabricated concrete block according to claim 1, wherein its side faces are plane with the block being used solely for constituting reinforcing thickenings for the front surface of said wall.