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(11) | EP 1 520 942 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Suface drainage |
| (57) A drainage channel section 1 comprises a longitudinally extending pipe portion 2,
and a longitudinal slot 3 that lies, in use, in a surface to be drained and that is
adapted to be in liquid communication with the pipe portion 2. The drainage channel
section 1 comprises one or more transverse openings into which a material in which
the channel section is embedded in use can extend from either side of the channel
section 1 to form a structural bridge member. |
Field of the Invention
[0001] The present invention relates to surface drainage and in particular, linear surface drainage arrangements.
Background
[0002] There is an increasing demand for economic, efficient drainage systems for draining surface water (or other fluids) from large catchment areas. Examples include car parks, highways, airport pavements and distribution centres.
[0003] One known form of surface drainage system relies on a number of discreet, spaced inlets in the surface to be drained, which communicate with a common, underlying channel. Examples of such systems can be seen in published UK Patent Applications GB-A-2316428 and GB-A-1456021. A commercial system of this general type has also been sold by Marshalls Mono Ltd under the registered trade mark PORCUPIPE.
[0004] These drainage systems result in a reasonably robust installation, as the overlying slab of surface material is substantially continuous, only broken by the discreet, spaced inlets. However, the very nature of these systems, with their discreet, spaced inlets, limits the hydraulic efficiency of the system; the inlet area of the system is limited and, particularly in e.g. storm systems, water may be carried over the surface between the inlets.
[0005] Another known form of drainage system employs a substantially continuous linear slot in the drained surface to serve as the inlet. It is recognised that surface drainage systems employing linear slots are more efficient than those drainage arrangements possessing discrete inlets, as in general they provide a greater inlet area and minimise the volume of water (or other liquid) that can wash over the drained surface without being entrained by the inlet. US Patent US6000881 shows a linear drainage system of this type, as does GB-A-2311549. Both of the systems described in these documents employ a large underground channel which has at its upper side a narrower throat portion defined by two walls extending upwardly to the surface to be drained, where they terminate to form a continuous slot drain in the surface.
[0006] Whilst these continuous linear slot drainage systems offer improved hydraulic efficiency relative to the known drainage systems, these linear slot systems suffer from the drawback that slabs of the surrounding surface material (typically concrete) are cantilevered out over the underground channel at either side of the slot, and this may exert significant loads on the channel itself. The channel must therefore be extremely robust, either through its own construction or by reinforcement of the surrounding surface material, if the risk of damage to the channel by these high loads during and after installation is to be avoided.
[0007] The skilled person is therefore presented with the dilemma between the robustness of discrete inlet systems and the hydraulic efficiency of the linear drainage systems.
[0008] A solution to this dilemma is proposed in our copending European Patent Application EP03101666.0.
Summary of the Invention
[0009] In a first aspect, the present invention provides a drainage channel section comprising a longitudinally extending pipe portion, and a longitudinal slot that lies in use in a surface to be drained and that is in liquid communication with the pipe portion, wherein the drainage channel section comprises one or more transverse openings into which a material in which the channel section is embedded in use can extend from either side of the channel section to form a structural bridge member, at least one of the transverse openings extending through the pipe portion.
[0010] In a preferred embodiment of the invention, the pipe portion and slot portion are provided as separate components. In a further preferred embodiment, the transverse opening or at least one of the transverse openings is divided by a wall that is substantially incompressible in the lateral direction, into which a material in which the channel section is embedded in use can extend from either side of the channel section to form a structural prop member by way of face-to-face contact.
In a yet further embodiment, the longitudinal slot is wider than the pipe portion.
[0011] Preferred embodiments of the invention may employ features from one or a combination of two or more of the various aspects of the invention set out above.
Brief Description of the Drawing
[0013] The invention is described below, by way of example, with reference to the accompanying drawing in which:
Figure 1 illustrates a perspective view of a drainage channel section in accordance with an embodiment of the present invention;
Figure 2 illustrates a perspective view of a drainage channel section having a non-continuous structural bridge member;
Figure 3 illustrates a cross-section of the drainage channel section of Figure 1;
Figure 4 illustrates a cross-section of the drainage channel section of Figure 2;
Figure 5 illustrates a perspective view of a drainage channel section having an alternative top edge;
Figure 6 illustrates a cross-section of the drainage channel section of Figure 5;
Figure 7 illustrates a perspective view of a drainage channel section together with a sleeve;
Figure 8 illustrates a perspective view of the sleeve shown in Figure 7; and
Figure 9 illustrates a cross-section of the sleeve.
Description of an Embodiment
[0014] Figures 1 and 3 show a plastics drainage channel section 1 in accordance with an embodiment of the present invention. The drainage channel could of course be made from any suitable rigid or resilient material such as steel for instance.
[0015] The channel section comprises a generally triangular pipe portion 2 having open end faces, although the pipe portion may be provided with a different shape. At their upper ends, the side walls of the pipe portion are spaced from one another to define an elongate, open slot 3 to be located in a horizontal surface plane in use. Water entering the slot passes into the pipe portion 2.
[0016] A series of tubular cross-members 4 extend through the pipe portion across its width to form a series of passages that extend from one side of the channel section to the other. When installed, concrete bridges extend through these passages to support the concrete surface slab over the channel section.
[0017] A filter member (not shown) can be mounted within the slot 3, supported by the tubular cross-members 4. The filter may take the form of a mesh material. This filter serves to prevent large solid objects entering the inlet former. It is designed to be removable through the slot at the upper end of the former for cleaning.
[0018] The channel section may be moulded from medium density polyethylene (MDPE). It may be provided in differing cross sectional sizes depending on the capacity required. The channel section is preferably constructed having a mean size of 900mm deep by 600mm wide. A smaller system may be provided with a size of 600mm x 400mm.
[0019] The channel section is preferably a two metre standard length, although it may be convenient to also provide shorter or longer lengths (e.g. 1 metre lengths). However, if the site where the system is to be located has sufficient handling capabilities, longer lengths of channel section may be used.
[0020] In this example, the channel section is formed in one piece. By moulding the channel section in one piece, complete with tubular cross-members 4, the component count for a drainage installation is minimised. This approach can also create a stiffer integrated monolithic structure. Alignment problems during installation are also avoided.
[0021] However, the invention also encompasses a fabricated two (or more) part construction. For instance, an upper portion of the channel section that forms the slot inlet 3 may be formed separately from the lower pipe portion 2.
[0022] Figures 2 and 4 illustrates an alternative embodiment in which the tubular cross-members 4 are interrupted by a vertical plate 5, creating two opposed, blind lateral openings having face to face contact, one opening to either side of the former.
Figures 5 and 6 show a channel section having a rolled edge 6, 6' which may be used when the section is for use with asphalt and/or block surfacing materials.
[0023] It is intended that a series of these sections be interconnected to form a high capacity drainage system. Any suitable form of connection between the open end faces of adjacent sections may be employed. Preferably a water seal (not shown) is fitted between end faces of adjacent channel sections to form a seal. This seal may be made of rubber, neoprene or ethylene propylene diene monomer (EPDM) which is highly resistant to water. The seal is preferably a donut section with a hollow centre to allow give good compressibility to absorb tolerance variations on length.
[0024] As shown in Figures 7 to 9 an alternative connector between the open end faces of adjacent sections can be provided by a sleeve 7 which bears against the outer surface of the sections. The sleeve, which may be capable of forming a water seal, can be positioned over the join between adjacent sections. In use, the sleeve can be moveable along the outer surface of the channel section, such that when two section ends abut each other, the sleeve can be moved along one section until it is positioned over the join.
[0025] Alternatively, the sleeve could be located at one end of a first section such that a second section is pushed into the sleeve until it abuts the first section, leaving the sleeve positioned over the join.
[0026] Preferably the channel section is provided with a foot (not shown) which can engage the ground, this would ease installation. The foot may be formed separately from the section and bear against its outer surface in much the same way as the alternative connector. The foot may have a flanged construction which spreads out laterally with respect to the channel section. The foot provides support to the section while being positioned in the surface to be drained during installation. Also the foot provides support against up-thrust as the wet concrete is introduced to secure the section in place.
[0027] In one embodiment the alternative connector is adapted to provide the functionality of the sleeve and the foot in one integral component. Additionally, as the alternative connector bears against the outer surface of the channel section, it may be used in combination with the donut sectioned seal.
[0028] A drainage system employing the channel sections described above can be installed in the following manner. First a trench is dug in the ground of the area to be drained. Multiple channel sections are laid into the trench, butted one against the other and secured together, preferably with the use of the sleeve mentioned above. The channel sections are held in position in the trench (e.g. using straps and the foot integral with the sleeve) and then embedded in concrete (or other surfacing material). The channel sections serve as a liner in use. The load is borne by a reinforced top slab incorporated during installation of the system, including the concrete bridges that extend through the channel sections.
[0029] Typically the concrete will be poured in at least two stages to avoid excessive up-thrust due to the buoyancy of the channel produced by the wet concrete during the first pour.
[0030] To increase the robustness of the concrete slab and bridges, reinforcement may be positioned around the channel and loose bars and/or fabric is passed through the lateral passages prior to the concrete being poured.
[0031] A blanking rod (not shown) may be placed in the slot inlet to prevent ingress of wet concrete into the channel during installation. Preferably, the blanking rod substantially fills the slot inlet in order to reinforce the inlet during installation. As the concrete or the like surrounds the inlet during installation of the system, the concrete applies lateral forces on the outer walls of the inlet which act to close or minimize its width. Providing the blanking rod is made from a sufficiently robust material(s), it can fill the inlet to provide support to the inner walls in resisting the lateral forces which are applied to the outer walls. As the concrete sets the rod can be moved away from the inlet since the lateral forces applied by the concrete will no longer act to minimize or close the slot.
[0032] 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.
[0033] In airport installations, where it is imperative that there should be no loose components or fragments of pavements and/or drainage products that could be drawn into aircraft engines on the surface, a galvanised or stainless steel slotted rail can be applied above the plastic slot. This rail can be fitted like a saddle over the slot and secured using suitable fixings to maintain mechanical alignment. Such a rail is better able to withstand the demands placed on the surface where aircraft towing tractors can achieve wheel loads in excess of 30 tonnes or where jet-blast may aggravate the paved surface.
1. A drainage channel section comprising a longitudinally extending pipe portion, and
a longitudinal slot that lies, in use, in a surface to be drained and that is in liquid
communication with the pipe portion, in use, wherein the drainage channel section
comprises one or more transverse openings into which a material in which the channel
section is embedded in use can extend from either side of the channel section to form
a structural bridge member, the transverse opening or at least one of the transverse
openings extending through the pipe portion.
2. A drainage channel section as claimed in Claim 1, wherein the channel section is formed
as one piece.
3. A drainage channel section as claimed in Claim 1, wherein the channel section is formed
as at least two parts.
4. A drainage channel section as claimed in Claim 3, wherein the pipe portion and the
longitudinal slot are formed as separate parts.
5. A drainage channel section as claimed in any one of the preceding claims, wherein
the transverse opening or at least one of the transverse openings is divided by a
wall that is substantially incompressible in the lateral direction.
6. A drainage channel section as claimed in Claim 5, wherein the wall is arranged substantially
centrally in the channel section.
7. A drainage channel section as claimed in any one of the preceding claims, wherein
the longitudinal slot is wider than the pipe portion.
8. A drainage channel section as claimed in any one of the preceding claims, wherein
the pipe portion is substantially triangular in cross-section.
9. A drainage channel section as claimed in any one of the preceding claims, wherein
a filter is arranged in the slot, in use.
10. A drainage channel section as claimed in any one of the preceding claims, wherein
a heel guard grating is arranged in the slot, in use.
11. A drainage channel section as claimed in any one of the preceding claims, wherein
a slotted rail is arranged in the slot, in use.
12. A drainage channel section as claimed in Claim 9, wherein the filter is removable.
13. A drainage channel section as claimed in any one of the preceding claims, wherein
the channel section is made of medium density polyethylene.
14. A drainage channel section as claimed in any one of the preceding claims, wherein
the longitudinal slot has a rolled edge.
15. A drainage channel section as claimed in any one of the preceding claims, wherein
the channel section has a locating foot arranged thereon.
16. A drainage channel section substantially as herein described with reference to any
one of the embodiments shown in the accompanying drawings.
17. A channel system comprising at least two drainage channel sections as claimed in any
one of the preceding claims.
18. A channel system as claimed in Claim 16, wherein a seal is arranged between the drainage
channel sections.
19. A channel system as claimed in Claim 18, wherein the seal is made of rubber, neoprene
or ethylene propylene diene monomer.
20. A channel system as claimed in Claim 18 or 19, wherein the seal is donut-shaped.
21. A channel system as claimed in any one of Claims 17 to 20, wherein the at least two
drainage channel sections are joined together by means of a connecting sleeve.
22. A channel system as claimed in Claim 21, wherein the connecting sleeve is slidable
along the at least two drainage channel sections.
23. A channel system as claimed in Claim 21 or 22, wherein the connecting sleeve has a
locating foot located thereon.
24. A channel system substantially as described herein with reference to any one of the
embodiments shown in the accompanying drawings.