GB2222624A

GB2222624A - Drainage channel support system

Info

Publication number: GB2222624A
Application number: GB8820964A
Authority: GB
Inventors: Peter Charles Mazzotti
Original assignee: CIDAR Ltd
Current assignee: CIDAR Ltd
Priority date: 1988-09-07
Filing date: 1988-09-07
Publication date: 1990-03-14
Anticipated expiration: 2008-09-07
Also published as: GB8820964D0; GB2222624B

Abstract

A surface drainage channel comprises a generally circular corss-section elongate former 10 having upstanding edges 11 extending parallel to the longitudinal axis of the former for receiving a grating 12 wherein the said grating is arranged to be supported in use at least principally by a reinforcing bar 13 which lies below the surface of the constructed site and passes through the upstanding edges and/or by its own surface plate extending beyond the upstanding edges to be supported by the material of the constructed site at each side of the former beyond the upstanding edges. Suitably the grating has slotted feet to receive the reinforcing bars 50 enabling the grating to be removed to facilitate access to the former in use. Any loading on top of the grating is taken essentially by the bar 13 so that no loading or virtually no loading is carried by the edges 11. <IMAGE>

Description

SURFACE DRAINAGE AND THE LIKE The invention relates to surface drainage and the like.

The invention relates particularly to surface drainage of constructed sites such as walk-ways, car parks and the like around and in the vacinity of buildings but could be used for internal drainage as well as provide ducting for electrical cables for example.

At present surface drainage is provided for example by using shaped fibre or resin concrete blocks which are let into the surface and covered by a drainage grate. The region is first shuttered to form a channel for the blocks and then the blocks are placed in the formed channels and concreted in position. The operation of laying such drainage is laborious requiring a separate shuttering step which naturally delays the overall operation by say 12 to 24 hours at least while the concrete cures to form the channel. Also, the blocks are heavy and not easy to lift or store and are prone to damage if mishandled or dropped during handling.

According to the present invention a surface drainage system for a constructed site comprises a generally circular cross-section elongate former having upstanding edges extending parallel to the longitudinal axis of the former for receiving a grating, in which the grating is arranged to be supported in use essentially by a reinforcing bar which lies below the surface of the constructed site and passes through the upstanding edges and/or by its own surface plate extending beyond the upstanding edges to be supported by the material of the constructed site at each side of the former beyond the upstanding edges.

Two surface drainage systems according to the invention will now be described by way of example with reference to the accompanying drawings in which: Fig 1 is an end section of one system; Fig 2 is an end section of another system; and Fig 3 shows a side section view of part of the system of Fig 1.

Referring to the drawings, in Fig 1 a generally circular extruded plastics pipe 10 has upstanding edges 11 into which fits a grate 12. A reinforcing bar 13 extends through holes in the edges 11 and the grate 12 has corresponding slots 15 which fit over the bar 13, as shown in Fig 3. Any loading on top of the grate is taken essentially by the bar 13 so that no loading or virtually no loading is carried by the edges 11.

In use, for a site under construction for a walkway, say in a shopping precinct or garage forecourt, the plastics pipe is laid in position and held by the reinforcing bars at the correct height. The grates 12 are then fitted and the concrete is then laid surrounding the pipe and to the required surface height, that is with the top surfaces of the upstanding edges flush with the top surface of the concrete. The grates 14 may be fitted from above in position, with the slots 15 fitting onto the bars 13 after the concrete has cured.

Thus, it will be appreciated that the surface drainage is provided in the one concrete laying operation and no special shuttering step, as presently necessary, for making provision for the surface drainage is required. During the concrete laying operation it will be appreciated that in effect the pipe 10 acts as a concrete former while being formed of suitable water carrying material and shaped to accommodate the grate 12.

In Fig 2, the system is generally the same, except that the upper surface plate forming part of the grate 120 extends laterally beyond the upstanding edges 110. A reinforcing bar 130 is provided as before, but in some applications this can be omitted.

The loading on the grate 120 is taken by the bar 130, if present, and at the underside of the grate adjacent its lateral extensions. Thus, as in Fig 1, loading on the grate 120 bears little if at all on the pipe 100 itself.

The described grates are generally of conventional form except suitably shaped to fit between the upstanding edges 11 and 110 and in the Fig 2 arrangement extends as appropriate laterally to beyond the edges 110. The grate is normally slotted to fit the bars 13 and 130 but in some cases it is arranged with holes to receive the bars 13 and 130, in which case the grate is permanently fixed into position.

Importantly, the systems provided by the invention are arranged so that the drainage path itself is formed and easy to construct where drainage is required. The grates allow water or in some cases effluent to enter the pipes but are designed to fit in such a way that the load on the grates is not transferred to the pipe itself. In general, in the prior art it was not appreciated that such a facility was possible so that the blocks containing water passages themselves were thought necessary to be formed with sufficient strength to take any loading directly applied to the drainage system itself or applied according to the prior art designs to the blocks by the grates.

It will be noted that the bars 13 and 130 are used to hold the pipes 10 and 110 in position during construction of the site, that is during laying of the concrete for the site surface. The bars may be shaped or fitted with ferrules or the like to hold the edges 11 and 110 at a chosen or predetermined distance apart both during laying of the concrete and after construction.

The pipes 10 and 100 are formed by any suitable method for example by extrusion and can be cut to length as required. As long lengths of pipe can be made in a factory and then cut for transport and storage, and finally easily cut to exact required lengths on site. The pipes are thus relatively cheap to make and being light, considerable handling and labour costs are possible.

Where a fall is required for the flow of material in the former but where the finished surface is generally level, pipes of different internal diameter can be provided and used in series.

Thus, the smallest diameter pipes are used at one end and the fall provided by adding in suitable steps larger and larger diameter pipes progressively in series. A specially designed sloped or stepped interface unit can be provided and placed between the pipes of different internal diameter if desired.

In the described systems the pipes are formed of plastics material, however other materials may be used. The requirement is only that the pipes or formers have sufficient intrinsic strength to act as concrete formers and be shaped with upstanding edges. Materials which are waterproof and also in some cases generally resistant to the material flowing into them, and in some cases this may be chemical waste making selection of the precise material used possibly more demanding.

The described system may be used for surface drainage in elevated positions such as on the roof of a building or in a gulley at intermediate heights of a building for example. The system may also be used for internal drainage at intermediate floors of a building and provides where required trunking or ducts for carrying electrical power and signalling cables or provides ducts to accommodate central heating systems.

Claims

1. A surface drainage system for a constructed site comprising a generally circular cross-section elongate former having upstanding edges extending parallel to the longitudinal axis of the former for receiving a grating, in which the grating is arranged to be supported in use at least principally by a reinforcing bar which lies below the surface of the constructed site and passes through the upstanding edges and/or by its own surface plate extending beyond the upstanding edges to be supported by the material of the constructed site at each side of the former beyond the upstanding edges.

2. A system according to claim 1, in which the former comprises one or more lengths of extended plastics pipe.

3. A system according to claim 1 or 2, in which the grating has slotted feet to receive the reinforcing bars enabling the grating to be removed to fascilitate access to the former in use.

4. Drainage systems substantially as herein-described with reference to any one or more of Figs 1 to 3 of the accompanying drawings.