GB2390630A

GB2390630A - Drainage channel section

Info

Publication number: GB2390630A
Application number: GB0215979A
Authority: GB
Inventors: Peter Alexander Jennings; Walter Summerhill Mcintyre; Robert James King; David Charles Albone; Martin Fairley; Andrew William Young
Original assignee: Aco Technologies PLC
Current assignee: Aco Technologies PLC
Priority date: 2002-07-10
Filing date: 2002-07-10
Publication date: 2004-01-14
Anticipated expiration: 2022-07-10
Also published as: GB2390630B; EP1380691A3; ES2295512T3; EP1887137B1; DE60317611D1; ATE541093T1; EP1380691A2; EP1380691B1; PT1380691E; EP1887137A3; EP1887137A2; DK1887137T3; DE20321869U1; GB0215979D0; DE60317611T2; ES2384561T3; PT1887137E

Abstract

The drainage channel section 2, particularly for use in large areas such as distribution centres, car parks and airports, comprises a longitudinally extending pipe portion 6, a number of longitudinally spaced projections 22 communicating with the pipe portion and a longitudinal channel 24 supported by and communicating with the projections and which defines a longitudinal slot 26 into which water passes. The section is preferably moulded as a single unit with the projections each having a base which merges with the pipe portion and extends circumferentially around the pipe portion with each projection tapering towards the supporting channel. The pipe portion preferably has an ovoid cross-section and the longitudinal channel may be notched between at least some of the projections to allow reinforcement mesh or loose bars to be slid through the channel.

Description

Wide Channel Drainage System Background of the Invention

The present invention relates to channel drainage systems, and more specifically to high capacity channels typically referred to as wide channel drainage systems.

5 Technical Background

Robust drainage channels with a high hydraulic capacity are required for surface drainage in large areas such as distribution centres, car parks and airports.

One such drainage system is provided by Hodkin & Jones Sheffield Lid and is described

in GB-A-2 229 212. This provides an open channel member made of glass fibre 10 reinforced concrete, which is anchored into a concrete backfill surrounding the channel in use by means of a framework of reinforcing bars. This type of channel member is intended to be used with a separate lid. As described in GB-A-2 316 428 and GB -A-2 347 707 (Hodkin & Jones), the lid provides a number of projections that terminate in slots extending transverse to the direction of the channel in the surface. Water enters the 15 channel through these transverse slots. The hydraulic efficiency of wide, transverse slots in collecting water from the surface is not great. In storm situations the water may be carried over the slots.

A number of technical problems are encountered in the installation of such systems.

With the Hodkin & Jones system, these are created by the need to align the lids on the 20 channels and ensure that the top of the lid Is aligned with the finished surface level. GB -

A- 2 316 428 suggests that by forming the lid and the channel in a single unit, the problems of locating the lid relative to the channel in situ are avoided. However, apart from suggesting that the separate concrete lid and channel are bonded together, there is

no teaching of how such a single unit might be achieved.

This type of drainage channel Is intended for use in areas where there is a heavy surface loading from vehicles. It is therefore necessary to provide for reinforcement of the concrete slab covering the channel. In the system proposed by Hodkin & Jones Sheffield

s Ltd. the slab reinforcement is provided by a specially designed manufacturer supplied reinforcing bar network, which is shaped to cooperate with the projections in the lid.

This is a relatively expensive solution.

An alternative design of drainage system is described in GB-A- I 456 021 (Chatham De Leeuw Lid). This describes a pipe that has a series of tubes each arranged to project 10 upwards from the pipe to a point above the surface level and opening into the pipe for drainage flow. Material is then laid over the pipe, with the upper ends of the tubes projecting from the surface. The tubes are moulded with closed ends which are then cut to expose drainage holes. A commercial system of this general type is sold by Marshalls Mono Lid under the registered trade mark PORCUPIPE. As with the Hodkin & Jones 15 designs this provides discrete water entry points and provides limited hydraulic efficiency. However the small projecting tubes present relatively little interference with the necessary slab reinforcement.

It is acknowledged that line drainage is more efficient than point drainage arrangements.

Solutions of this type are proposed by Zum Industries, Inc in US-A- 6 000 881, which 20 shows a plastics channel section including a narrow throat drain. Protuberances are provided to secure the channel section Into the material in which it is embedded. Support rods and reinforcing rods can also be fixed to the section.

A similar metal system is produced by Elkington Gatic and is described further in GB-A-

2 311 549. It provides a slot drain comprising a polygonal channel portion and a throat 25 portion, the throat portion consisting of two walls extending upwardly from the channel

portion to create a slot drain.

In both these designs there is improved hydraulic efficiency relative to Hodkin & Jones or the Chatham De Leeuw point drainage systems. However the slabs of concrete at either side of the slot are cantilevered out over the channel section and this results in a 5 significant risk of loading damage in this area, especially in the case of plastics channel sections that are clearly not capable of bearing any significant load.

Solution of the Invention Accordingly, the present invention provides a drainage channel section produced of plastics material comprising a longitudinally extending pipe portion, a plurality of lo longitudinally spaced projections communicating with the pipe portion, a longitudinal channel supported by and communicating with the projections and defining a longitudinal slot that lies in a horizontal plane.

Supporting a slot drain on a series of projections provides a convenient means of enabling slab reinforcement to pass between the projections and ensures that a continuous 15 reinforcement is provided when the channel sections are embedded. This system therefore has the advantages of high hydraulic capacity and efficiency of the Zurn and Elkington Gatic systems without creating weakness in the load bearing slab. The system is easy to install without the alignment problems of Hodkin & Jones two part channels.

The channel may also be notched between at least some projections to allow a reinforcing 20 mesh to be slid through the channel. This enables the slab covering the channel section to have two dimensional reinforcement. Where the channel is continuous reinforcing rods are preferably installed through arched openings defined between the projections.

Brief Description of the Drawings

In order that the invention may be well understood, some embodiments thereof will now

be described, by way of example only, with reference to me accompanying diagrammatic drawings, in which: Figure I shows a perspective view of a channel section in accordance with the invention; 5 Figure 2 shows a perspective view of a channel section provided with means for creating a lateral connection; Figure 3 shows a perspective view of a detail of a longitudinal slot channel and supporting projections of the channel section of Figure 1 or 2; Figure 4 shows an end view detail of the slot channel and projections of Figure I 10 or 2; Figure 5 shows a top plan view of the slot channel and projections of Figure 3; Figure 6 shows a side view of the slot channel and projections of Figure I or 2; Figure 7 shows a section through the slot channel and projections shown in Figure 6; 15 Figure 8 shows a perspective view of a second embodiment of a channel section; and Figure 9 shows a perspective view of a second embodiment of a channel section provided with means for creating a lateral connection.

Description of a Preferred Embodiment

20 A high capacity drainage system is intended to be constructed from interconnected plastics channel sections 2 which are laid out in an appropriate configuration before being

embedded in concrete. The channel sections serve as a liner in use. The load is borne by a reinforced top slab incorporated during installation of the system.

Each channel section 2 can either be blow moulded or rotationally moulded from medium density polyethylene (MDPE). Two basic designs of channel section are offered 5 as illustrated in Figures 1 and 2. These may be provided in differing cross sectional sizes depending on the capacity required. The channel sections are preferably constructed having a mean ovoid size of 900mm deep by 600mm wide. A smaller system may be provided with a size of 600mm x 400mm. The basic channel section is illustrated in Figure 1 and is preferably a two metre standard length. Figure 2 shows a one metre back lo inlet channel section variant which has a spigot 4 with three knock-outs enabling connections with a 150mm, 225mm and 300mm diameter plastics, clay and concrete pipes. Each channel section 2 comprises a generally ovoid pipe portion 6 having open female and male end faces 8, 10 so that the sections 2 can be slotted together.

5 Laterally extending flanges 12 are provided at either side of a socket at the female end face 8. These flanges define a level base 14 and are provided with holes 16 so that the channel sections can be levelled by means of coarsely screwed feet passing through holes 16 to rest on a base of a trench during installation. Ribs 20 are formed around the pipe portion 6 on its external surface in order to provide greater structural rigidity to the 20 channel section 2 and to grip the surrounding concrete when the channel section 2 is embedded. Along the upper surface of the pipe portion 6, there are provided a series of hollow projections 22 that support a longitudinal slot channel 24 that terminates in an open slot 26 adapted to be located in a horizontal surface plane in use such that water entering the 2s slot 26 passes down through the projections 22 into the pipe portion 6.

Each projection 22 has a base 30 which merges into a wall of the pipe portion 6 as best illustrated in Figure 3. The base 30 extends circumferentially around the ovoid pipe portion. In a vertical section transverse to the longitudinal direction of the channel section, the hollow projection 22 extends from its base 30 it tapers towards the narrower 5 longitudinal channel 24. The channel 24 has side walls 32 that merge with side walls 34 of each projection.

The base of the channel 24 is effectively defined by openings into the hollow projections 22 and intermediate arch sections 38 bridging the gaps between adjacent projections.

This configuration directs water flow into the hollow interior of the projections 22.

10 Each projection 22 has two parallel transverse faces 40 that each taper from the base 30 of the projection towards the channel 24. These transverse faces 40 merge with the arch sections 38 so that in between each pair of projections 22 there is effectively defined an arched opening 42 as best seen in Figures 6 and 7.

An identical, but shorter slot channel 24 supported on fewer projections 22 is provided on IS the Figure 2 channel section.

The slot 26 can also support a metal edge structure, particularly for airport applications for added security.

Where the system is intended to be used in a car park with asphalt or block pavior wearing courses, a heel guard grating structure may be mounted on the slot.

20 A triple lipped water seal (not shown) may be fitted to the male end 10 of the channel section 2 to form a seal when the male end 10 is fitted into a socket defined at the corresponding female end 8. The seal may be made of rubber or ethylene propylene diene monomer (EPDM) which is highly resistant to water. The seal is "barbed" with three lips to aid easy insertion into the female section. The resulting hydrostatic pressure

formed on the back face of the seal when the channel section fills with water then increases sealing efficiency. Alternative sealing means may be used.

By moulding the channel section 2 in one piece complete with projections 22 and slot channel 24, this minimises component count and loose items on site as well as creating a 5 stiffer integrated monolithic structure. Alignment problems during installation are also avoided. Installation The wide channel system is generally installed by the method outlined below, although variations can be made by contractors to suit their particular circumstances.

10 The trenches are dug and channel restraining straps are laid in the trench with free ends left extending over either side. These straps are plastics webbing straps that are fitted with buckles to allow them to be fastened over the channel sections. A layer of base concrete is then laid in the trench to secure the straps. The channel sections 2 are assembled end to end to provide the required drainage channel configuration and 15 arranged in the trench. The channel sections can easily be cut between adjacent ribs 20 to accommodate odd lengths. Cutting the channel is easily achieved using a conventional carpenter's saw. The ribs 20 can be used as a guide to make the cut so that a clear spigot is left on which to locate the seal that is normally provided at the male end 10. The standard male end outer spigot at end 10 is effectively replicated in the channel section 20 wall 44 between the ribs 20, so that when a channel section 2 is shortened in length by cutting between the ribs, the standard water seal will fit over the cut spigot to exactly replicate the standard male end, thereby ensuring a reliable fit every time.

Adjustment screws passing through the holes 16 can be used to level the assembly against the base of the trenches. A coarse screw is provided for this purpose. This allows 25 appropriate adjustments to be made so that the slot 26 is located exactly at the right 1.

height and in the required plane relative to the finished surface. The straps are then passed through the arched openings 42 to hold the channel in position in order to prevent flotation during the final concrete pour. Reinforcing mesh is then positioned around the channel and loose bars passed through the openings 42 so that the concrete slab formed 5 over the channel section is continuously reinforced. A blanking rod is placed in the channel 24 to prevent ingress of wet concrete into the channel and into the hollow interior of the channel section 2 during installation.

Variations A second embodiment of the channel sections 2 of Figures 1 and 2 is shown in Figures 8 lo and 9.Like reference numerals are used to designate like parts.

In this variant, the channel 24 is notched at a centre point of each arch section 38 to provide a small gap 46 through which reinforced mesh fabric can be placed down over the channel section to rest within the arched openings 42. The notches 46 allow the mesh to slide through whilst still leaving a continuous slot 26 in the surface to be drained: This 15 may require placing a blanking rod in the channel 24 during the final pour to prevent concrete flowing into the channel 24 through the notches 46. If the notches are sufficiently fine so that they can effectively close again once the mesh has been pushed through, this may not be necessary.

This second embodiment of the channel section 2 can also be used with loose rod 20 reinforcements as with the first embodiment. However these may be pushed down through the gaps 46 instead of being slid through the arched openings transverse the longitudinal direction of the channel section 2.

In airport installations, it is imperative that there should be no loose components or fragments of pavements and/or drainage products that could be drawn into aircraft 25 engines on the surface. Therefore, a steel safety edge is applied above the plastic slot 26.

This safety edge is loose fitted like a saddle over the slot (which may be notched as described above) once the reinforcement has been put in place. The steel safety edge comprises two sections of hot or cold rolled steel angle iron placed back to back with suitable spacers welded in place to maintain the slot geometry. Heavy duty concrete s anchors are provided at approximately 500 metres centres on the sides of the angle iron not facing the slot 26 and below the surface. The steel safety edge fabrication may be hot dipped galvanised for corrosion protection. When the final concrete pour is made the concrete anchors are buried deep into the concrete haunch to ensure the assembly stays in place at all times. Such a steel edge is better able to withstand the demands placed on the 10 surface where aircraft towing tractors can achieve wheel loads in excess of 30 tonnes or where jet-blast may aggravate the paved surface.

Other fittings or gratings may also be supported on top of the slot as required.

Claims

1. A drainage channel section produced of plastics material comprising a longitudinally extending pipe portion, a plurality of longitudinally spaced projections communicating with the pipe portion, a longitudinal channel 5 supported by and communicating with the projections and defining a longitudinal slot that lies in a horizontal plane.

2. A drainage channel section as claimed in claim 1, which is moulded as a single unit.

3. A drainage channel section as claimed in claim 1 or 2, wherein the hollow lo projections each have a base which merges with the pipe portion and extends circumferentially around the pipe portion, each projection tapering towards the supported channel.

4. A drainage channel section as claimed in any one of the preceding claims, wherein the pipe portion has an ovoid cross section.

5 5. A drainage channel section as claimed in any one of the preceding claims, wherein the longitudinal channel is notched between at least some projections to allow a reinforcing mesh or loose bars to be slid through the channel.

6. A drainage channel section as claimed in any one of the preceding claims, wherein the pipe portion has an ovoid cross section.

Document # #22 t 7953 v7 - PATENT SPEC

Amendments to the claims have been filed as follows

7. A drainage channel section substant1a11y as herein described with reference to the accompanying drawings.

Document # t.2217953 v6 - PATENT SPEC

6. A drainage channel section substantially as herein described with reference to the accompanying drawings.

Amendments to the claims have been filed as follows 1. A drainage channel section produced of plastics material comprising a longitudinally extending pipe portion, a plurality of longitudinally spaced hollow projections communicating with the pipe portion, a longitudinal channel 5 supported by and communicating with the projections and defining a longitudinal slot that lies in use in a surface to be drained.

2. A drainage channel section as claimed in claim 1, wherein the longitudinal channel is notched between at least some projections to allow a reinforcing mesh or loose bars to be slid through the channel.

lo 3. A drainage channel section produced of plastics material comprising a longitudinally extending pipe portion, a plurality of longitudinally spaced hollow proj ections communicating with the pipe portion, a plurality of longitudinally extending channel sections supported by and communicating with the projections in order to define when installed in a surface to be drained a continuous 15 longitudinal slot that lies in a surface to be drained.

4. A drainage channel section as claimed in any one of the preceding claims, which is moulded as a single unit.

5. A drainage channel section as claimed in any one of the preceding claims, wherein the hollow projections each have a base which merges with the pipe 20 portion and extends circumferentially around the pipe portion, each projection tapering towards the supported channel.