IES67878B2

IES67878B2 - A drainage installation for roads

Info

Publication number: IES67878B2
Authority: IE
Inventors: David Twomey
Original assignee: David Twomey
Priority date: 1995-04-06
Filing date: 1995-04-06
Publication date: 1996-05-01
Also published as: GB9520590D0; IES950251A2; EP0819197A1; GB2299605B; ATE175457T1; WO1996031657A1; EP0819197B1; DE69601306T2; AU5286996A; DE69601306D1; GB2299605A

Abstract

A kerb drain comprises a longitudinal kerb section 1 moulded from concrete and having a top surface 2, a rear wall 5, and a front wall. The front wall is formed, in a lower portion thereof, with a rabbet 6, in which is located an enclosed drainage channel 7 which runs longitudinally of the kerb. The channel is a conduit having in a front wall thereof a plurality of apertures 12 through which water may enter a hollow interior of the conduit. The kerb drain, is located between a roadway and a pavement or verge, in which the roadway has an upper porous layer which is water permeable and an underlayer which is substantially impervious to water. The front wall of the conduit containing the apertures is located adjacent to the porous layer such that surface water percolating through the porous layer flows through the apertures and into the hollow interior of the conduit. The kerb drains are connected at intervals to junction boxes, which contain a sump, and from which accumulated water may be diverted to a main drainage system.

Description

A DRAINAGE INSTALLATION FOR ROADS Field of the Invention The invention relates to a drainage installation for roads, and in particular to a kerb drain and gulley system. The invention also relates to a method of draining road surfaces. The term roads as used throughout the specification is intended to include roadways, highways, carriageways, bridges, runways and the like.

Background to the Invention It is known to provide drainage installations for roads, which include a roadway, a pavement or verge extending along one or both sides of the road, and having a surface which is elevated relative to the surface of the road, a kerb which extends upwardly from the road surface to the pavement or verge, and an open water gulley, typically of channel shape, extending longitudinally between the road surface and the kerb, at a level below the road surface. Such drainage installations suffer from the disadvantage that because the channel is open at the top pedestrians stepping off the pavement onto the road are in danger of tripping over the channel. Cyclists are also at risk because of the danger of bicycle wheels catching in the open channel. Also, the open nature of the channels can lead to frequent blockage of the channel by debris from the road surface. 367878 - 2 It is known to have enclosed drainage channels in or associated with a roadway kerb. For example, it is known to provide a drainage channel formed by a plurality of pre-cast concrete sections laid end to end along the roadway. Typically, the concrete sections are in the form of blocks having a drainage channel moulded in the center of the block end a cover portion containing a water inlet communicating between the top of the road surface and the channel whereby water may flow from the road surface into the drainage channel. The known pre-cast concrete kerb blocks containing an integral drainage channel are difficult and expensive to mould. Also, they are not suitable for draining road surfaces containing a top layer of porous asphalt.

In modern roadway construction, the roadway comprises a road base containing layers of hard core or the like. Above, the road base is laid a dense layer of bitumen macadam, which is largely water impervious. The top surface of the roadway is comprised of a layer of porous asphalt laid over the dense layer. With this arrangement rain water percolates through the upper porous asphalt surface of the roadway through to the underlying dense bitumen macadam layer. It is necessary to provide means to remove the percolating water from between the two layers.

Object of the Invention It is an object of the invention to provide a drainage installation for a road which is capable of removing water from a roadway at a level below the surface of the roadway. It is also an object of the invention to provide a kerb drain for a roadway which is simple to manufacture and install, and which is suitable for removing water either from the top surface or a sub-surface of a roadway. - 3 Summary of the Invention According to the invention a kerb drain comprises a longitudinal 5 kerb section moulded from concrete or other suitable material, the kerb having a top surface, a rear wall, and a front wall, wherein the front wall is formed, in a lower wall portion thereof, with a rabbet, in which is located an enclosed drainage channel which runs longitudinally of the kerb. Preferably, the channel comprises a conduit having in a front wall thereof a plurality of apertures through which water may enter a hollow interior of the conduit.

Suitably, the conduit is of rectangular cross section, open at both ends. The conduit may be fabricated from steel or other suitable material, and is keyed into the rabbet.

The invention also provides a drainage installation for roadways and the like comprising a road surface, a pavement or verge extending along one or both sides of the roadway, and a kerb located between the roadway and the pavement or verge, wherein the roadway comprises an upper porous layer which is water permeable and an underlayer which is substantially impervious to water, and the kerb is a kerb as described above and wherein the front wall of the conduit containing the apertures is located adjacent to the porous layer such that surface water percolating through the porous layer flows through the opertures and into the hollow interior of the conduit.

The kerb drains are connected at intervals to junction boxes, which contain a sump, and from which accumulated water may be diverted to a main drainage system. - 4 Brief Description of the Drawings Some embodiments of the inventions are hereinafter described with 5 reference to the accompanying drawings wherein: Figure 1 is an isometric view of a drainage kerb of the invention; Figure 2 is a front view of the drainage kerb of Figure 1; Figure 3 is a section through the line A-A of Figure 2, to a smaller scale, and also showing a section through the adjoining roadway; Figure 4 is a side view of a first embodiment of a junction box of 15 invention; Figure 5 is a front view of the junction box of Figure 4; Figure 6 is a plan view of the junction box of Figure 4; Figure 7 is a side view of a second embodiment of junction box of the invention; Figure 8 is a front view of the junction box of Figure 7; Figure 9 is a plan view of the junction box of Figure 7; Figure 10 is a plan view of a cover for the junction box of Figure 4 or Figure 7; Figure 11 is a front view of the cover unit of Figure 10 and Figure 12 is a side view, to an enlarged scale, of a locking device of the cover of Figure 10. - 5 Detailed Description of the Preferred Embodiments Referring to Figures 1 and to 3 of the drawings, a kerb drain of 5 the invention comprises a kerb 1 moulded from concrete or other suitable material. The kerb drain 1 is a longitudinal section comprising a top surface 2, a bevelled upper front wall portion 3, a lower wall portion 4 and a rear wall 5.

The lower wall portion 4 is formed with a longitudinal rabbet 6, which is in the form of a step-shaped rectangular channel. The rabbet 6 extends for the full length of the kerb 1 and extends inwardly of the kerb to a depth which is approximately half the width of the kerb 1.

For example, if the kerb, when viewed from the end, has a width of 130 mm, the rabbet 6 has a width of 60 mm.

The rabbet 6 is adapted to receive an enclosed drainage channel in the form of a conduit 7.

In the embodiment shown, the conduit 7 is substantially rectangular, in cross-section, and comprises a top wall 8, a bottom wall 9, a rear wall 10 and a front wall 11. The front wall 11 is formed with a plurality of slots 12 at spaced intervals along the length of the wall. The slots 12 form apertures through the wall through which water may flow into a hollow interior of the conduit 7.

The conduit 7 is keyed into the rabbet 6 by means of ties 13 which are fixed to and project from the rear wall 10 of the conduit 7 and extend into the concrete of the kerb 1. Suitably, the ties 13 are in the shape of fish tails. When inserted in the rabbet 6, the front wall of the conduit 7 is flush with the front wall portion 4 of the kerb 7.

In this embodiment the conduit 7 is fabricated from galvanised mild steel from which it is pressed, and slotted to form the slots 12.

For example, the conduit 7 may be made from 4-6 mm mild steel. Alternatively, channel 7 can be made from metal alloy, cast-iron, plastics, concrete or other suitable material. In the embodiment shown the conduit 7 is of a rectangular cross-section, but it could be of square, circular or other cross-section. - 6 The ties 13 are welded to the rear wall 10 of the conduit 7 at spaced intervals. To manufacture the kerb 1, the conduit 7 is placed into a mould having the shape of the kerb 1. Concrete, for example 25 newtons, air-entrained concrete, is poured into the mould in well known manner and allowed to cure. In this way, the kerb 1 is cast with the conduit 7 located in situ.

The positioning of the kerb 1 relative to a roadway 14 and a pavement or verge 15 is illustrated with reference to Figure 3.

As shown in Figure 3, the roadway 14 comprises an upper porous surface layer 16 of asphalt, which is laid on an underlying dense layer 17 which is substantially impervious to water. The dense layer 17 is supported on a road base 18 formed from hard core or the like. The pavement or verge 15 extends along one or both sides of the roadway 14, and has a surface which is elevated relative to the surface of the road. The kerb 1 extends upwardly from the road surface 14 and abuts the edge of the pavement 15.

As shown in Figure 3, the rear wall 5 of the kerb 1 abuts the pavement 15, and the upper wall portion 3 and the lower wall portion 4 face the roadway. The conduit 7 is located substantially below the road surface. The upper portion of the front wall 11 of the conduit 7, which contains the slots 12, is located adjacent to the porous surface layer 16 of the roadway. A lower, closed, portion of the wall 11 is located adjacent to the intermediate dense layer 17 of the roadway. Thus, water such as rainwater falling on the upper surface of the roadway 14, percolates downwardly through the porous layer 16 and flows through the slots 12 into the hollow interior of the conduit 7.

The number, spacing and size of the slots 12 is of importance.

Thus, it is of importance that the slots 12 communicate with the porous asphalt layer 16 and also communicate with the joint between the layer 16 and the intermediate dense layer 17 so that all water percolating through the upper porous layer 16 is collected in the conduit 7. If desired, an upper portion of the slotted part of the wall 11 may be positioned above the surface of the roadway 14 to facilitate collection of surface water. - 7 It is important that the width of the slots 12 is less than the average diameter of the stone chips which are used in forming the porous asphalt surface layer 16. In a typical arrangement, the chips used in forming the surface layer 16 have a minimum size of 20 mm. The slots 12 are 10 mm in width and 52 mm in height. The slots are spaced apart at 10 mm intervals. Thus, should the stone chips forming the upper surface layer 16 of the roadway become loose, they cannot enter through the slots 12. The unslotted portion of the wall 11, which portion typically has a height of 84 mm, is of importance to prevent chips or particles from the layers 16, 17 from entering into the interior of the conduit 7.

The kerbs 1 are laid end to end along the side of the roadway. To facilitate laying of the kerbs 1 the conduit 7 projects a short distance, typically 6 mm, from each end of the concrete kerb 1 as shown in Figure 1. Thus, when the kerbs 1 are laid end to end the projecting portions 19 of the conduit 7 act as spacers to create a gap between adjoining kerbs 1. These gaps are filled with grout to seal the joint between the kerb sections. To facilitate laying of the kerbs 1, a seating plate 20 is attached to one end of the bottom wall 9 of the conduit 7 and projects laterally therefrom. The seating plate 20 facilitates levelling of adjoining kerbs 1.

A drainage installation for collecting surface water from the conduit 7 and directing the accumulated water into a main drainage system will now be described with reference to Figures 4 to 6 of the accompanying drawings.

As described above, a plurality of kerbs 1 of the invention are laid end to end along the roadway. Junction boxes 21 are connected to the kerb 1 at intervals, which may vary from about 10 meter intervals to 30 meter intervals depending on the expected water flow.

As shown in Figure 4, the junction box 21, has, in an upper corner thereof, an inlet section 22 which, in cross-section, is of substantially the same shape as the kerb 1. - 8 The junction box 21 is buried in the ground to a depth such that inlet section 22 abuts adjoining kerbs 1. The inlet section 22 suitably is made from metal. The remainder of the junction box may be moulded from concrete, plastics or the like. It could also be fabricated from glass reinforced plastics.

The inlet section 22 includes an inlet 23 which corresponds in size and shape to the conduit 7 and connects with the conduit 7. Thus, water from the conduit 7 flows into the inlet 23 and from there into the interior of the junction box 21. The junction box 21 has a hollow interior 24 including a lower sump 25.

The junction box 21 is provided with an outlet 26, a lower portion of which is positioned just below the level of the inlet 23. The outlet 26 is adapted to receive a connector pipe (not shown) which is connected to the main drainage system.

In use, water collected in the slotted conduit 7 flows along the conduits 7 until it reaches one of the junction boxes 21. The water from the conduit 7 enters the inlet 23 and flows into the sump 25.

When the water rises in the sump 25 to the level of the outlet 26 it flows out through the outlet 26 into the connector pipe to the main drainage system.

Silt or other debris which succeeds in entering the conduit 7 is collected at the bottom of the sump 25 from which it may be removed periodically.

The junction box 21 is formed with a cover 27. Suitably, the cover 27 is fabricated from 4 mm galvanised mild steel. The cover has a flat top portion 28 which is aligned with the surface of the pavement 15. A front portion 29 of the cover 27 is bent to a profile which corresponds with the front profile of the kerb 1.

The cover 27 is shown in more detail in Figures 10 to 12. As shown in Figure 10, the top 28 is provided with two locks 30. The construction of the lock 30 is illustrated in Figure 12. Each lock 30 comprises a rotatable bolt 31 which is journalled in upper and lower bearings 32 contained in a frame 33 welded to the underside of the top 28 of the cover 27. - 9 The bolt 31 has a bolt head 34 by means of which the bolt 31 may be rotated by a suitable key or wrench, for example an alien key. The bolt head 34 is recessed within the top 28.

The bolt has, at its lower end, a foot 35 which projects at right angles from the bolt. When the bolt is in the closed position the foot 35 engages in a slot 36 formed in the side wall at the junction box 21. To open the lock the bolt 31 is rotated to disengage the foot 35 from the slot 36, whereupon the cover 27 may be lifted off the junction box 21.

When the cover 27 is removed access may be gained to the hollow interior 24 of the junction box 21. This facilitates removal of accumulated debris in the sump 25. It also permits the conduits 7 to be cleaned by means of rods, in a well known manner. The rods may be inserted into the inlet 23 and from there into the adjoining conduits 7, to remove silt or other debris which may have accumulated in the conduits 7.

The junction box illustrated in Figures 7 to 9 is substantially the same in construction as that of Figures 4 to 6, and like numerals denote like parts. The main difference is that in the embodiment of Figures 4 to 6, the outlet 26 is located in the rear wall of the junction box, whereas in the embodiment of Figures 7 to 9, the outlet 26 is located in the front wall of the junction box.

The dimensions shown on the drawings are for illustrative purposes only and are not intended to be limiting.

Claims

1. A kerb drain comprising a longitudinal kerb section moulded from concrete or other suitable material, the kerb having a top surface, a 5 rear wall, and a front wall, wherein the front wall is formed, in a lower wall portion thereof, with a rabbet, in which is located an enclosed drainage channel which runs longitudinally of the kerb.

2. A kerb drain as claimed in claim 1, wherein the channel comprises 10 a conduit having in a front wall thereof a plurality of apertures through which water may enter a hollow interior of the conduit.

3. A kerb drain as claimed in claim 2, wherein the conduit is of rectangular cross section, open at both ends, and is fabricated from 15 steel or other suitable material, and is keyed into the rabbet.

4. A drainage installation for roadways and the like comprising a road surface, a pavement or verge extending along one or both sides of the roadway, and a kerb located between the roadway and the pavement or 20 verge, wherein the roadway comprises an upper porous layer which is water permeable and an underlayer which is substantially impervious to water, and the kerb is a kerb drain as claimed in any of the preceding claims, and wherein the front wall of the conduit containing the apertures is located adjacent to the porous layer such that surface 25 water percolating through the porous layer flows through the apertures and into the hollow interior of the conduit.

5. A kerb drain and/or a drainage installation substantially as hereinbefore described with reference to, and as illustrated in, the 30 accompanying drawings.