COPING MEMBERS FOR LIQUID CONTAINERS

Abstract: A liquid retaining structure comprising a coping member (1) adapted to be tensioned adjacent its inner and outer faces, the coping member being further adapted for mounting adjacent the upper edge of a wall comprising a plurality of panels abutting in edge-to-edge relationship to form a substantially continuous wall.

Description: COPINGMEMBERSFORLIQUIDSCONTAINERS This invention relates to improvements in or relating to a method and apparatus for construction of liquid containers and particularly although, not exclusively related to swimming pools. Various types of pre-fahricated or semi pre-fabric- ated swimming pools are known. Apart from fibreglass pools, these generally comprise an asse-mbly of pre-cast concrete or shaped asbestos cement sheet wall panels arranged in edge to edge configuration about the perimeter of the pool. Atop the wall panels is mounted a coping comprising a plurality of pre-cast members, also arranged in edge to edge configuration and post-tensioned by a cable or like tensionin member about the outer periphery of the coping to form a rigid support beam for the structure. Although such structures are generally satisfactory for circular or oval shaped pools, the structures possess a number of disadvantages and limitations. Among these are that the structures are only suitable to withstand outwardly directed forces imposed by the contents of such pools but nevertheless these pools are generally designed to be constructed in a ground aperture for support by a surrounding earth bank or like infill. It has been proposed that structures of the abovementioned kind may be suitable as a free standing structure in above ground applications by employing buttresses at closely spaced intervals around the external perimeter of the structure but for reasons of cost and the need for structural integrity, the below ground application is usually recommended. None of the abovementioned types of structure permits construction of a pool suitable for either in ground or above ground application while simultaneously permitting pool constructions incorporating substantially straight walls, e.g. a rectangular pool, or a pool incorporating indented or convexly curved walls. Co-pending International Patent Application No. PCT/AU8Q/QQ_104 by the present applicant proposes an in¬ expensive method and apparatus for construction of below ground pools which are generally free from restriction on perimetral shape and the contents of that specification are incorporated herein by reference. The present invention generally comprises an improvement in the method and apparatus set forth in the specification of PCT/AU80/Q01Q4 and provides a liquid retaining structure generally free of perimetral shape restraints and which is suitable either for above ground and below ground applications. According to one aspect of the invention there is provided a coping member for a liquid retaining structure comprising a body adapted to be tensioned adjacent its inner and outer faces, said body being further adapted for mounting adjacent the upper edge of a wall of said liquid retaining structure. Preferably the Body comprises apertures extending through the body adjacent the inner and outer faces of the body to receivably locate tensioning members. Alternatively the body may comprise flanges adjacent its ends, said flanges adapted for tensionable connection, in use, to flanges of adjacent bodies. Suitably the body is formed from cast concrete and the hollow apertures are formed in the casting process. Alternatively the hollow apertures may be formed by hollow members cast into said body. Preferably the body includes means to retainably align in use adjacent bodies in desired end to end relationship. Suitably the body comprises one or more lugs, the lugs of one body are receivably located in corresponding apertures of an adjacent body to retainably align said adjacent bodies in desired end to end relationship. Preferably the Body comprises a decorative upper surface formed during the casting process. According to another aspect of the invention there • is provided a method of constructing a liquid retaining structure comprising aligning a plurality of wall panels in desired edge to edge relationship to form a substantially continuous wall; mounting a plurality of coping members as described above adjacent the top edge of said wall to form a substantially continuous coping; and, tensioning said coping members adjacent their inner and outer faces to form a substantially continuous pre-stressed, post-tensioned coping about the perimeter of • the structure. Preferably tensioning members are inserted through access apertures in an outer perimetral portion of a coping member, said access apertures communicating with the hollow apertures within the body of said coping member. Preferably said access apertures are diametrically located • about the perimeter of the substantially continuous coping. According to yet a further aspect of the invention there is provided a liquid retaining structure comprising a plurality of wall panels arranged in desired edge to edge relationship to form a substantially continuous wall; a plurality of coping members as described above mounted adjacent the top edge of said wall to form a substantially continuous coping; and, tensioned members arranged within the hollow apertures of said bodies to form a substantially continuous pre-stressed, post-tensioned coping. Preferably the wall panels are comprised of cementitious material. Suitably the wall panels are comprised of pre-cast steel fibre reinforced concrete. Preferably the wall panels are mounted in channel ' _- ' - 4 - sectioned footings. Preferably the wall panels comprise reinforcing ribs. Suitably the reinforcing ribs are located adjacent to side edges of the wall panels and extend substantially perpendicularly therefrom. Preferably the reinforcing ribs include attachment means to permit, in use, attachment of adjacent wall panels. Preferably the wall panels include integral attach¬ ment means for the flexible lining membrane. Preferably the structure comprises a flexible lining membrane. Various aspects of the invention will now be described with reference to the accompanying drawings in which;- FIG. 1 illustrates a preferred coping member according to the invention. FIG. 2 illustrates a mould for manufacture of the coping member of FIG. 1. FIG. 3 illustrates one embodiment of a wall panel. FIG. 3A illustrates an alternative panel jointing member. FIG. 4 illustrates a mould for a wall panel of FIG.3. FIG- 5 illustrates section of a preferred embodiment of a wall of a liquid retaining structure according to the invention. FIG. 6 illustrates a plan view of a preferred embodiment of a liquid retaining structure according to the inventio . In FIG. 1, the coping member 1 may be formed from any suitable material but is preferably formed from cast -concrete or Fibresteel ( egd. Trade Mark) ' reinforced concrete. The upper surface 2 preferably includes an integrally cast decorative pattern 3 or it may be formed with a smooth or roughened surface to accept a decorative finish such as pebbles, tiles etc. One end of the member includes a lug 4 and the other end includes a complementary shaped recess (not shown) to facilitate location and alignmen of the coping members when fitted to a liquid retaining structure. Accurate end to end alignment may be achieved by means of locating pins Cnot shown) in apertures 4a in each en of coping members 1. The under surface of the member is formed as a shallow channel and includes recesses 5 and 6 to locate the upper edges of adjoining ribbed wall panels. Located adjacent the inner and outer edges of the coping member are hollow apertures 7 which extend longitudinally through the coping member 1. FIG. 2 illustrates a mould suitable for manufacturing the cast coping members of FIG. 1. In use the mould 8 is partially filled with cementitious material and insert 9 is pushed into the mould to form the underside of the coping member. The inner surface 10 of the mould includes an embossed or raised surface to provide a complementary decorative finish on the upper surface 2 of the coping member. " Lugs 11 and complementary recesses 12 are provided to locate the insert 9 relative to mould 8. Mould 8 includes apertures 13 through which pins 14 may be inserted to form apertures 7 in the coping members during casting. These are removed after the cementitious material has cured and prior to removal of the coping member from the mould. Alternatively lengths of tubing or like hollow sections may be situated within the mould and allowed to cure in situ to form apertures 7. FIG. 3 illustrates one embodiment of a wall panel 15 comprising ribs 16 extending perpendicularly from the outer face 16 of panel 15 and . which taper inwardly from top to bottom of the panel. The ribs include apertures 17 to permit alignment and attachment of adjacent wall panels and further attachment means for supporting braces if required. FIG. 3A illustrates an alternative means for jointing - 6 - of wall panels. The jointing member comprises an elongate member 40 of generally T-shaped cross-section with a rearwardly extending leg 41. At the base of member 40 is an upwardly opening channel 42. A locating pin 43 is receivably located in aperture 44 on the top of member 40. FIG. 4 illustrates a mould for casting the wall panels of FIG. 3, preferably from steel fibre reinforced concrete. The mould comprises two sections 18 and 19 to shape the front and rear faces respectively of the wall panel. The section 19 includes a perimetral flange 20, the depth of which about the horizontal portions corresponds to the rib thickness and the depth on its vertical portions enables spacing of mould section 18 to the desired wall thickness of the wall panel. Depending flanges 21 on either end permit attachment of the mould sections by bolting, clamping or like means. Locating lugs 22 are provided on the inner face of section 18 to locate a liner retainer strip, the purpose of which is described in co-pending Application No. PCT/AU80/00104, to permit its integral casting within the wall panel. Apertures 23 are provided in mould section 19 to accept removable pins 24 to form the apertures 17 in the wall panel. In use the mould is assembled on its side as shown on a flat surface and cementitious material is poured into the mould aperture. The upper exposed surface " of the cementitious material is then trowelled or screeded off to a flat surface forming one of the outer faces of the reinforcing ribs 16 of the finished wall panel. , The construction of a liquid retaining structure will now be described with reference to FIGS. 5 and 6. In FIG. 5, reinforced concrete footing channels 24 are arranged on a ground surface to define the perimeter of the desired shape of the liquid retaining structure. The footing channels preferably include an inwardly facing step 25 to support the lower edge of the wall panels against "kick-out" from internal pressure during the filling of the structure with liquid. If required, the floor of the • structure may be formed as a hollow depression 26 and may be lined with sand or concrete 27. Wall panels 15 are then arranged in side by side relationship, their adjacent flange connected by bolts 28 or the like, with their lower edges in the footing channel to define a substantially continuous wal surface. Coping members 1 are then arranged atop the wall with the upper edge of the wall surface located in recess 5 and the upper part of rib 16 located in recess 6. The copin members are aligned by means of pins located in apertures 4a ' and with adjacent edges abutting such that lug 4 is located in the complementary aperture (not shown) in an adjacent coping member. If required the abutting surfaces between the top of the wall panels and the recesses 5 and 6 may be sealed with a cementitious grout as well as the abutting ends of adjacent coping members. With all coping members in place a substantially continuous coping is formed atop the substantially continuous wall. Tensioning members such as cables may then be arranged within apertures 7 and tensioned - to form an essentially rigid beam like continuous coping about the upper edge of the structure. A flexible membrane liner 29 may then be arranged within the interior of the structure and attached to the upper part of the wall via liner retaining member 30 as generally described in my co-pending application. In an alternative construction, planar sheets of a suitable material such as cast steel fibre reinforced concrete, asbestos cement sheeting, plywood sheeting, plastic sheeting or the like are located with abutting ends by means of member 40 illustrated in FIG 3A. The channel 42 locates the lower edges of the sheets or wall panels and avoids the necessity for separate footing channels. Locating pins 43. accurately locate the upper end of member 40 in a further . aperture (not shown) in recess 6. The wall sheets or panels -=g\J E O PI - 8 - are thus locked in place in lower channel 42 and upper channel or recess 5 in the coping member. The T-shaped cross section of the member 40 thus provides a rigid support for the abutting joint between adjacent wall panels and also enables attachment of braces to the rearwardly extending leg 41 if required, FIG. 6 illustrates a typical tensioning arrangement for a rectangular swimming pool structure. The coping members for this structure comprise a plurality of essentially identical rectangular coping members 1, plain corner members 31 and 31a and terminal corner members 32 and 32a. The tensioning cables are inserted in a pair of apertures 33 which communicate with the apertures 7 in the rectangular members 1. The cables pass through curved apertures in corner member 31a (which suitably includes a skimmer box 34) . The cables pass then to corner member 32a where they emerge from apertures 35. Post tensioning cable anchors are then fitted to the ends of the cables at the openings to apertures 35.and the other ends of the cables are suitably tensioned adjacent apertures 33. Cable anchors are then attached to the tensioned ends of the cables prior to disengagement of the tensioning means. Additional tensioning cables are then inserted through apertures 36 until they emerge at apertures 37. These cables are then anchored and tensioned in a similar manner as described above. The resultant pre-stressed, post-tensioned coping around the upper edge of the pool effectively comprises a rigid continuous beam which is capable of supporting great load, either inwardly or outwardly directed, without substantial deflection. It will be appreciated that the connection of the coping members by a tensioned force adjacent the inner and outer faces 38 and 39 of the coping members will not permit deflection of the beam like coping without stretching of the tensioning cables. In an alternative embodiment of the invention the tensioning means may comprise either integrally moulded flanges or reinforced flange members cast into the ' coping members adjacent at each end adjacent the inner and outer faces. A tensioned connection may be achieved between adjacent members by bolts or the like. It will be further appreciated that the present invention permits construction of liquid retaining structures with little or no restriction on perimetral shape. Structures with convex and/or concave perimetral walls may be readily constructed from suitably shaped coping members. For example in a liquid retaining structure of circular plan, the coping members may be essentially identical curved members with curved cable apertures 7 adjacent their inner and outer edges. Termination points for the tensioning cable are readily achieved by, for example, shaping the cable apertures 7 to extend through the outer side walls of one or more of the coping members. A particular advantage of the present invention is the ability to construct liquid retaining structures with straight walls without the need for buttresses to support the wall against deflection. For certain applications, however, such as very high walled free standing structures, additional structural integrity may be achieved by incorporating further tensioning cables around the outer perimeter of the wall. These additional cables may be conveniently supported in apertures in the connecting ribs 16 of the wall panels or support members 40. Although not generally considered essential for most applications, braces (as shown in FIG. 5) may be employed at widely spaced intervals for additional support. It will be readily apparent to a skilled addressee that many modifications and variations may be made to the present invention without departing from the spirit and scope thereof.

Claims: CLAIMS : 1. A coping member for a liquid retaining structure comprising a body adapted to be tensioned adjacent its inner and outer faces, said body being further adapted for mounting adjacent the upper edge of a wall of said liquid retaining structure. 2. A coping member as claimed in claim 1 wherein said body comprises apertures extending through the body adjacent the inner and outer faces of the body to receivably locate tensioning members. 3. A coping member as claimed in claim 1 wherein said body comprises flanges adjacent its ends, said flanges adapted for tensionable connection, in use, to flanges of adjacent bodies. 4. A coping member as claimed in any one of claims 1-3 wherein said body includes means to retainably align in use adjacent bodies in desired end to end relationship. 5. A method of constructing a liquid retaining structure comprising aligning a plurality of wall panels in desired edge to edge relationship to form a substantially continuous wall; mounting a plurality of coping members as claimed in any one of claims 1-4 adjacent the top edge of said wall to form a substantially continuous coping; and, tensioning said coping members adjacent their inner and outer faces to form a substantially continuous pre- stressed, post-tensioned coping about the perimeter of the structure. 6. A method as claimed in claim 6 wherein tensioning members are inserted through access apertures in an outer perimetral portion of a coping member, said access apertures communicating with hollow apertures within the body of said . coping member. 7. A method as claimed in claim 5 or claim 6 wherein said access apertures are diametrically located about the perimeter of the substantially continuous coping. 8. A liquid retaining structure comprising a plurality of wall panels arranged in desired edge to edge relationship to form a substantially continuous wall; a plurality of coping members as claimed in any one of claims 1-4 mounted adjacent the top edge of said wall to form a substantially continuous coping; and, tensioned members arranged within the hollow apertures of said bodies to form a substantially continuous pre-stressed post-tensioned coping. 9. A coping member for a liquid retaining structure substantially as hereinbefore described with reference to FIGS. 1, 2, 5 and 6. 10. Amethod of constructing a liquid retaining structure substantially as hereinbefore described with reference to the accompanying drawings. 11. A liquid retaining structure substantially as hereinbefore described with reference to FIGS. 5 and 6.

Inventors: DURACK MICHAEL JAMES
Applicants: DURACK M J, DURACK MICHAEL JAMES
Application year: 1982
Main classification: E04H3
IPC codes: E04H4