AU650772B2 - Revetments and units for use in constructing revetments - Google Patents

Description

AUSTRALIA

Patents Act COMPLETE SPECIFICATION

(ORIGINAL)

Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: 650 772 Priority Related Art: c

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Name of Applicant: Gordon Kendall Prestedge Actual Inventor(s): Gordon Kendall Prestedge Address for Service: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Invention Title: R-FVETMENTS AND UNITS FOR USE IN CONSTRUCTING REVETMENTS Our Ref 298890 POF Code: 1074/181717 The following statement is a full description of this invention, including the best method of performing it known to applicant 6006 6006 -2- THIS INVENTION relates to revetments.

According to the present invention there is provided a revetment including a plurality of groups of three revetment units one of which units is at a higher level than the other two, each unit comprising a head having a front face, a rear face and a peripheral edge, and a stem protruding from said rear face, the peripheral edge of said one unit resting on the stems of the two units below it at two contact zones with a portion of the peripheral edge of said one unit extending from one of said zones to the other, :said peripheral edge being shaped such that the portion of said edge of said one unit which extends from one of said *c zones to the other protrudes downwardly below a plane defined o* by an upper periphery of said stems and between the stems of said two units.

Preferably, the stem of each unit is stepped and has a relatively short larger diameter part adjacent said head and a relatively long small diameter part protruding from the larger diameter part, said edge of said one unit resting on said relatively short larger diameter parts of said two units.

SIn one form said peripheral edge of each unit is 'I /s smoothly curved throughout its circumferential extent.

-3- Preferably, said peripheral edge of each unit is circular and said stem of each unit is also circular in cross section.

In another form said peripheral edge of each unit is multi-facetted and comprises at least five faces.

Desirably said peripheral edge of each unit is composed of between five and eight faces and the cross sectional shape of the stem of each unit is identical to the cross sectional shape of the head of each unit.

It is preferred that said stem of each unit be centrally located with respect to the head of that unit and that said unit be symmetrical about the common longitudinal axis of each head and stem.

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o C C *li o• invention there is provided a revetment unit wh compr a head having a front face, a rear face and a- em protruding from said rear face, the ste in ng centrally located with respect to said and said unit being symmetrical about the com ongitudinal axis of said head and stem.

For a better understanding of the present invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings in which: 10 Figure 1 is a side elevation of a first form of revetment unit in accordance with the present invention, Figure 2 is a side view of a second form of revetment unit in accordance with the present invention, Figure 3 is a view taken in the direction of arrow III in 15 Figure 2, Figure 4 is a diagrammatic elevation showing a typical irevetment constructed from the units of Figures 2 and 3, and •Figure 5 is a front view of a slightly modified form of the revetment shown in Figure 4.

Referring firstly to Figure 1, the revetment unit illustrated is generally designated 10 and includes a head 12 and a stem 14. The head 12 is disc like and has a front face, a rear face and a peripheral edge. The stem 14 protrudes from relatively short larger diameter part 16 adjacent the head and th erfc f h ed1 ndi tpe o st rvd relatively long smaller diameter part 18 protruding from the larger diameter part 16. The part 18 tapers from the cylindrical portion 16 towards the free end thereof.

The revetment unit 20 of Figures 2 and 3 is similar to the revetment unit of Figure 1 and comprises a stem 22 and a head 24. The head 24 is again disc-like. The face 26 of the head is not flat as is the face of the head of Figure 1 but is somewhat conical in form having an apex designated 28. The other face of the disc is also slightly conical. The two parts .0 of the stem 22 are designated 32 and 34. The part 34 tapers. 1 S S *5 Turning now to Figures 4 and 5, these Figures show a number of revetment units 20 in use to stabilize a revetment which is. generally designated 36. Merely by way of example the wall is shown as being a sea wall, high water and low water levels being designated HW and IN respectively in Figure 4.

Reference numeral 38 designates the base on which the revetment 36 is built. The base 38 can be sand or rock.

A lower layer of rubble designated 40 is dumped on the base 38 to build-up the level. A first horizontal layer of revetment units, designated 20.1, is then placed on the layer of rubble.

The peripheries of the heads 24 touch one another (see particularly Figure The parts 32 and 34 overly the layer of rubble 40 with the heads 24 adjacent the seaward face of the layer of rubble and resting on the base 38. Further rubble is then dumped on the stems of the layer of units 20.1 and then a second layer of units 20.2 is placed on the layer 20.1. The heads 24 of the units 20.2 drop down behind the heads 24 of the lower layer of units 20.1. In the form shown in Figure 4 the heads 24 rest on the stem parts 32 of the lower layer of units 20.1. In the form shown in Figure 5 the stem parts 32 are omitted and each stem consists entirely of the part 34.

The units 20.2 are thus restrained from seaward and sideways movement by the lower layer 20.1. Rubble behind the units prevents their rearward movement. Further layers of 10 rubble and further layers of units 20.3 and 20.4 build the revetment to the desired level. A cast in-situ capping 42 0 supported on the heads 24 of the layer of revetment units 20.4, and compacted backfill 44, complete the wall. Before the backfill is dumped and compacted, a filter layer 46 is placed 1. 15 on the rubble 0* Using the revetment units described it is possible to build a wall which has a relatively steep front face. It can therefore be used as a jetty for mooring boats. It is also capable of withstanding wave action as the individual units interlock with one another and each resists zi,ooruent of the neighbouring revetment units under wa,4p action, Whilst revetment units which have disc-like heac' which are circular in elevation, and stems which are circular in cross-section are preferred, such a configuration is not essential. It is preferred because, as another unit is lowered onto those already in place, it readily rolls into the nesting configuration illustrated in Figure 5. Multi-facetted heads and stems are also possible, the greater the number of facets the greater the ease with which the unit moves into place.

Heads and stems with five or more facets are possible, heads and stems with eight facets being preferred if for any reason it is desired to diverge from a circular section. It is also possible for the edge of the head to be smoothly curved but not circular eg oval. The shape must not, however, diverge too far 10 from circular.

o o Whilst the revetment units can be of metal, which has the requisite rigidity, the preferred material is concrete, the heads and stems being cast as integral units.

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Claims (6)

1. A revetment including a plurality ur groups of three revetment units one of which units is at a higher level than the other two, each unit includes a head having a front face, a rear face and a peripheral edge, and a stem protruding from said rear face, .he peripheral edge of said one unit resting on the stems of the two units below it at two contact zones with a portion of the peripheral edge of said one unit extending from one of said zones to the other, said peripheral edge being shaped such that the portion of said edge of said one unit which extends from one of said zones to the other protrudes downwardly below a plane defined by an upper periphery of said stems and between the stems of said two units.

2. A revetment according to claim 1 in which the stem of each unit is stepped and has a relatively short f. larger diameter part adjacent said head and a relatively long small diameter part protruding from the larger diameter part, said edge of said one unit resting on said ielatively short .6c. larger diameter parts of said two units. 0.. 00 64 3. A revetment according to claim 1 or 2 in which said peripheral edge of each unit is smoothly curved throughout its circumferential extent. A revetment according to claim 3, in which said V 0 S S S. S S peripheral edge of each unit is circular. A revetment according to claim 4, in which said stem of each unit is circular in cross section.

6. A revetment according to claim 1 or 2, in which said peripheral edge of each unit is multi-facetted and comprises at least five faces.

7. A revetment according to claim 6 in which said peripheral edge of each unit is composed of between five and eight faces.

8. A revetment according to claim 7 in which the cross sectional shape of the stem of each unit is identical to the cross sectional shape of the head of each unit.

9. A revetment according to any preceding claim in which said stem of each unit is centrally located with respect to the head of that unit and said unit is symmetrical about the common longitudinal axis of each head and stem. A revetment substantially as hereinbefore described with reference to Figures 4 and 5 of the accompanying drawings. DATED: 28 April 1994 PHILLIPS ORMONDE FITZPATRICK 9 a Attorneys for: ,GORDON KENDAL PRESTEDGE ABSTRACT Revetments are constructed using a plurality of revetment units (20.1, 20.2 etc) which are arranged on river bed (88) or the like. Each revetment unit comprises a stem (22) and a disc- like head The stem (22) is stepped so that it has a relatively short larger diameter part (32) and a relatively long smaller diameter part The heads (24) of units (20.2, 20.3, 20.4) in each upper course lie behind the heads (24) of the units in the course below and rest on the larger diameter parts The heads and stems are preferably circular in cross-section but can be multi-facetted. S 00 *0 SS em o0 0 C* S