Roadside water drainage apparatus

Abstract

A roadside water drainage apparatus, comprising at least one base unit (12), to be placed in the ground (11) to the side of a road, each base unit (12) comprising a generally horizontal rigid frame (14) having a horizontal upper face (16), a lower face (18), a length parallel to and a width perpendicular to the road, alongside which it is to be placed, the frame (14) comprising at least one aperture (20) passing through the frame and dimensioned to allow the passage of rainwater to pass vertically through the frame, wherein at least one of the apertures (20) comprises a porous block (22) and capable of reversibly absorbing a volume of rainwater into the pores of the block in an amount of at least 50% of the volume of the block.

Description

[0001] Roadside Water Drainage Apparatus

[0002] Technical Field

[0003] The present invention relates to a roadside water drainage apparatus comprising a base unit to be placed in the ground to the side of a road, for providing effective water drainage from rainfall.

[0004] Background and Prior Art

[0005] Rainfall onto roads can be a significant hazard to vehicles, and it is desirable to be able to swiftly remove rain water from the road, especially when rainfall rates are particularly high.

[0006] Traditionally, this is achieved by having drainage ditches by the side of the road, often filled with gravel, to provide a drainage channel for rainwater run-off from the road. Sometimes porous blocks are provided underneath the gravel, to provide a reversible water absorption capability, so that rainwater can be absorbed quickly and then desorbed or released slowly over time, allowing time for the water to drain away without flooding.

[0007] However, gravel can become clogged with debris, such as leaves, dirt and other environmental products present by a roadside, which can block its ability to cope with higher rates of rainfall.

[0008] Devices are known to be positioned by the roadside that can help with the management of rainwater run-off, although not their primary purpose.

[0009] WO2020 / 183153 A1 discloses an apparatus for installing a vehicle restraint comprising a base unit, the base unit comprising a plurality of apertures that are capable of handling the drainage of rainwater. Optionally the apertures may comprise a metal mesh to prevent the ingress of soil, leaves and the like which might otherwise partially or wholly block the aperture.

[0010] W02022 / 023702 A1 discloses a development of this apparatus wherein an additional base unit is provided which can support an item of street furniture. Although such designs are effective at handling the passage of rainwater, due to the action of the apertures, it has been found that under heavy rain conditions, these alone are not sufficient to handle the high quantities of rainwater and can become overwhelmed.

[0011] Improvements in this area would therefore be desirable.

[0012] Brief Description of the Invention

[0013] In a first aspect, the invention relates to a roadside water drainage apparatus, comprising at least one base unit, to be placed in the ground to the side of a road, each base unit comprising a generally horizontal rigid frame having a horizontal upper face, a lower face, a length parallel to and a width perpendicular to the road, alongside which it is to be placed, the frame comprising at least one aperture passing through the frame and dimensioned to allow the passage of rainwater to pass vertically through the frame, wherein at least one of the apertures comprises a porous block and capable of reversibly absorbing a volume of rainwater into the pores of the block in an amount of at least 50% of the volume of the block.

[0014] Such an apparatus is serviceable from ground level, and is very effective at handling high rates of rainwater run-off, due to the aperture and the porous blocks ability to channel, absorb and control the flow of rainwater.

[0015] The term “reversibly absorb” means the ability to absorb water, typically in from the upper surface, and for the absorbed water to subsequently desorb by leaving the porous block, typically by the action of gravity and capillary action from the lower surface.

[0016] In a preferred embodiment, the roadside water drainage apparatus comprises at least one item of roadside equipment, such as vehicle restraint systems, direction signs, road signs, warning signs, traffic cameras, traffic lights and signals, emergency telephones, supports for overhead gantries, safety fencing, acoustic damping fencing, and so on. Thus, the roadside water drainage apparatus is preferably also suitable for supporting roadside equipment, wherein the frame comprises a plurality of attachment positions at intervals for attachment thereto from above of an item of roadside equipment.

[0017] A vehicle restraint system, or crash barrier, is normally a substantially horizontal steel member, attached to a plurality of vertical steel support posts which are positioned at intervals. Each support post must be stably anchored, in order to resist impact in the event of a vehicle crashing into the crash barrier. Details of such support posts and their anchoring techniques can be found in WO2020 / 183153 A1.

[0018] Alternatively, the roadside installation may be an item of street furniture, as described in W02022 / 023702 A1 .

[0019] In typical embodiments the base unit will comprise a substantially rectilinear shape. There are typically a plurality of base units, each base unit will normally be essentially identical. In practice, a plurality of such base units will be laid end to end to achieve the desired length of run of base units. The precise dimensions of the base units are not critical, but a typical embodiment of the invention may be 4 to 10 metres in length, about 500 to 1200 mm wide and 150 to 400 mm in height. The lower face may provide a horizontal surface, or it may comprise protrusions or undulations.

[0020] Preferably, the frame of each base unit is made from concrete, and may be reinforced as desired. This provides the frame with the strength to withstand the forces due to a vehicle, such as a car or lorry, passing over the apparatus if they leave the road for whatever reason. Alternatively the frame of each base unit may be made from rubber polymer.

[0021] It is desirable to allow the maximum possible rate of flow of rainwater without compromising the structural integrity of the frame of the base unit. Therefore, preferably at least 30%, preferably at least 40%, of the surface area of the horizontal upper face of the frame is comprised of apertures. Typically, the surface area of the horizontal upper face of the frame is comprised of less than 90%, more preferably less than 80% apertures. As the apparatus is to be positioned to the side of a road, it must be capable of withstanding the forces exerted onto its surface by a road vehicle, such as a car or lorry. Therefore, preferably the apertures have a maximum width, parallel with the width of the frame, that does not exceed 150mm. This ensures that any tyres of such vehicles remain supported by the frame.

[0022] The porous blocks provide a rainwater reservoir, so that rainwater can be quickly absorbed and held within the body of the porous block, and then slowly released over time by capillary action. This then smooths out the flow of rainwater that has fallen during a peak period to be drained away without causing local flooding. In a typical arrangement, the porous blocks extend from the upper face to the lower face of the frame.

[0023] Preferably the porous blocks are capable of reversibly absorbing a volume of rainwater into the pores of the block in an amount of at least 70% of the volume of the block, more preferably at least 80% and most preferably at least 90%.

[0024] The porous blocks are preferably made from mineral wool, preferably stone wool. Such materials can have an extremely high water carrying capacity due to their highly porous nature. Such materials can reversibly absorb a volume of rainwater into the pores of the block in an amount of around 95% of the volume of the block. Porous blocks of this kind are made from microscopically small mineral fibres that form a dense network with a large surface area, which also acts to filter out pollutants. For example, removal of 80 wt% of solid particles, 70 wt% of polycyclic aromatic hydrocarbons and petrochemical oils, and 50wt% of heavy metals, fertilisers and nitrates.

[0025] A highly preferred type of porous block is surrounded by a textile membrane, preferably a geotextile membrane. Suitable examples of such porous blocks can be found in WO 2015 / 069098 A1 , and can be obtained under the brand name Hydrorock™. Such membranes prevent the porous block from being clogged with debris, so little or no maintenance is required.

[0026] Preferably the porous blocks have an upper surface that is flush with the horizontal upper face of the frame. This presents a flat planar surface aligned with the surface of the ground next to the roadside, assisting the flow of rainwater run-off and providing a safe region in the event that a vehicle inadvertently leaves the road.

[0027] Preferably the porous blocks are insertable and removable from the apertures by vertical movement with respect to their respective aperture. The blocks may be held in place by a latch or cover, so that they are easily removed for maintenance and / or replacement as needed.

[0028] In general, the frame will comprise an array of apertures, comprising apertures spaced apart along the width of the frame, and preferably also spaced along the length of the frame.

[0029] Conveniently, the apertures have a rectangular cross-section when viewed from above, although they can be of any practical shape.

[0030] In a preferred embodiment, at least one aperture provides an open drain region, extending from the upper face to the lower face, that does not comprise a porous block. Such open drain regions can provide a faster rate of flow of rainwater, albeit at the cost of having to handle the water as it flows downwardly out of the aperture. The open drain region may constitute the whole or a part of an aperture.

[0031] Advantageously, the open drain region comprises a filter for allowing the passage of rainwater but preventing the passage of leaves, gravel and the like, and the filter is preferably removable from the open drain region. This effectively collects debris at surface level, and provides for ease of cleaning. For example, the filter may be a removeable filter basket that snugly fits into the open drain region.

[0032] It is also advantageous to position one or more open drain regions along the length of the frame that will be adjacent to the road. In this arrangement, the open drain regions can handle the passage of leaves, gravel and the like that may flow onto the apparatus from the road surface during rainfall, preventing such debris from blocking the apertures that contain porous blocks.

[0033] As discussed, the apparatus is typically positioned in the ground with its length parallel to and adjacent to a road. Ideally the horizontal upper face is flush with the surface of the ground, so that water can easily flow onto the surface of the apparatus, and that vehicles such as cars and lorries that leave the road can pass safely over the apparatus.

[0034] Preferably, additional porous blocks are provided beneath the frame, in contact with the lower face of the frame. These additional blocks provide additional water carrying capacity, so that the apparatus can tolerate higher rates of rainfall. As many porous blocks as are needed according to the predicted rainfall can be deployed.

[0035] Optionally, a sand layer is provided beneath the frame, and if present, beneath the additional blocks provided beneath the frame, as this helps to wick the water out of the porous blocks and provides an additional porous drainage layer. Additionally, a geotextile membrane is preferably provided beneath the layer of sand, in order to prevent the sand from migrating away from the layer and losing its integrity.

[0036] Optionally a gravel layer is provided beneath the sand layer, and, if present, beneath the textile membrane. This can provide a further drainage capability.

[0037] Since the apparatus is intended to be positioned by the roadside, there may be piped or cabled services already in place. Therefore, it is preferred that at least one channel is provided beneath the lower face of the frame, along the length of the apparatus, and for carrying cabled or piped services. In this way the apparatus can carry the piped or cabled services without disruption. Preferably the at least one channel is located beneath an aperture, so it can be easily accessed by removal of a porous block.

[0038] The invention will now be illustrated, by way of example, and with reference to the following figures, in which:

[0039] Figure 1 is a front sectional view through a first roadside water drainage apparatus according to the present invention.

[0040] Figure 2 is a plan view of the roadside water drainage apparatus shown in figure 1.

[0041] Figure 3 is a rear sectional view through a second roadside water drainage apparatus according to the present invention. Figure 4 is a plan view of the roadside water drainage apparatus shown in figure 3.

[0042] Turning to the figures, figures 1 and 2 show a first roadside water drainage apparatus 10 comprising a base unit 12 placed in the ground 11 alongside a road and comprising a generally horizontal rigid frame 14, having a horizontal upper face 16, a lower face 18. Additional base units will typically be provided, placed end-to-end, however only one is shown in the figures. The base unit 12 is rectangular, with its long side parallel to the road 13 alongside which it is placed. The frame 14 is made from reinforced concrete, although other materials may be used, and measures 700mm wide, 4000mm long and 200mm thick.

[0043] The frame 14 comprises a plurality of apertures 20 that are rectangular in dimension when viewed from above, with a width of 100mm and are sufficiently large to allow large quantities of rainwater to pass vertically through the frame 14. However, if a vehicle inadvertently leaves the road 13 and passes over the frame 14, the width of the apertures 20 is such that the tyres of the vehicle will be supported by the concrete frame 14.

[0044] Each aperture 20 comprises a porous block 22 that is made from a stone wool and is wrapped in a geotextile membrane, which in this case is a D25 HDX porous block available from Hydrorock. The porous blocks 22 have an upper surface 24 that is flush with the horizontal upper face 16 of the frame 14 and a lower surface 25 that is flush with the horizontal lower face 18. Each porous block 22 can be inserted and removed from its respective aperture 20 by vertical movement of the porous block 22 relative to the frame 14.

[0045] The three apertures 20 that are adjacent to the road 13 do not contain a porous block, and instead comprise an open drain region 26 that comprises a filter material 28 flush with the lower surface 18. The filter material 28 forms part of a removable basket that snugly fits and can be lifted out of the open drain region, cleaned and replaced as desired.

[0046] Additional porous blocks 30, 32 are positioned beneath the frame 14 in contact with the lower face 18., which in this case are a D135HD (300mm x 400mm in cross section) and a BD175HD (400mm x 400mm in cross section) blocks available from Hydrorock. However, channels 34, 36 are provided to carry any cabled or piped services located beneath an aperture 20. This enables the cabled or piped services to be easily accessed by removal of the respective porous block 22. One of the porous blocks 30 also comprises a flow channel 37, to further assist in the flow and drainage of rain water.

[0047] A 50mm sand layer 40 is provided beneath the additional blocks 30, 32 which helps to wick away any stored water held therein by capillary action. Beneath the sand layer is a geotextile membrane 42, which acts to prevent the sand layer from travelling downwards into the gravel layer 44 positioned beneath.

[0048] During rainfall, rainwater will run-off the surface of the road 13 and onto the surface of the base unit 12. Any water containing debris will first pass over and be captured by the filter material 28 that forms part of the removable basket. The remaining rainwater will be absorbed into the body of the porous blocks 22 and flow through the open drain region 26. Rainwater will then continually absorb into the porous blocks 22 from the top 24, whilst it percolates through the porous blocks and desorbs out from the lower surface 25 thereof. Thus, peak loads of rainwater are smoothed out, so that the water flowing through the apparatus can be managed without causing local flooding.

[0049] Over a 4m length of road, alongside of which is one of the apparatus shown in figures 1 and 2, a typical dual carriageway road would be 7.3m wide, presenting 29.2m2of surface area. During a rainfall event of 50mm / m2 over 1 hour this would result in 1460 litres of water (1.46m3). The available water storage capacity of the apparatus is 1204 litres, which will be able to handle this quantity of rainfall because it is spread out over 1 hour, releasing absorbed rainwater into the sand and gravel beds below.

[0050] If additional capacity is required, additional porous blocks can be deployed to the side of the apparatus.

[0051] Figures 3 and 4 show a second apparatus 50 according to the present invention comprising a base unit 52 placed in the ground 51 alongside a road and comprising a generally horizontal rigid frame 54, having a horizontal upper face 56, a lower face 58. The base unit 52 is rectangular, with its long side parallel to the road 53 alongside which it is placed. The frame 54 is made from reinforced concrete, although other materials may be used. The frame 54 is made from reinforced concrete and measures 1000mm wide, 4000mm long and 200mm thick. Also provided on the frame 54 is a roadside equipment attachment position 90.

[0052] The frame 54 comprises a single aperture 60 that is rectangular in dimension with a width of 600mm a length of 3200 mm and 200 mm.

[0053] The aperture 60 comprises three porous blocks 62 that are made from a stone wool and are wrapped in a geotextile membrane, which in this case is 2x D115 HD porous blocks (width 500mm, length 1200mm, depth 200mm) and 1x D95 HD (width 500mm, length 1000mm, depth 200mm) available from Hydrorock. The porous blocks 62 have an upper surface 64 that is flush with the horizontal upper face 56 of the frame 54 and a lower surface 65 that is flush with the lower face 58 of the frame 54. Each porous block 62 can be removed from its respective aperture 60 by simply lifting the porous block 62 upwards relative to the frame 54.

[0054] Also provided within the aperture 60 in the 100mm space not containing a porous block adjacent to the road 53 is an open drain region 66 that comprises a filter material 68 flush with the lower surface 58. The filter material 68 forms part of a removable basket that snugly fits and can be lifted out of the open drain region, cleaned and replaced as desired.

[0055] Additional porous blocks 70, 71, 72 are positioned beneath the frame 54 in contact with the lower face 18., which in this case are a D135HD (300mm x 400mm in cross section) and a BD175HD (400mm x 400mm in cross section) blocks available from Hydrorock. However, channels 74, 75, 76 are provided to carry any cabled or piped services located beneath the aperture 60. This enables the cabled or piped services to be easily accessed by removal of the porous block 62. One of the porous blocks 71 also comprises a flow channel 77, to further assist in the flow and drainage of rain water.

[0056] A 50mm sand layer 80 is provided beneath the additional blocks 74, 75, 76 which helps to wick away any stored water held therein by capillary action. Beneath the sand layer is a geotextile membrane 82, which acts to prevent the sand layer from travelling downwards into the gravel layer 84 positioned beneath.

Claims

Claims1. A roadside water drainage apparatus, comprising at least one base unit, to be placed in the ground to the side of a road, each base unit comprising a generally horizontal rigid frame having a horizontal upper face, a lower face, a length parallel to and a width perpendicular to the road, alongside which it is to be placed, the frame comprising at least one aperture passing through the frame and dimensioned to allow the passage of rainwater to pass vertically through the frame, wherein at least one of the apertures comprises a porous block and capable of reversibly absorbing a volume of rainwater into the pores of the block in an amount of at least 50% of the volume of the block.

2. An apparatus according to claim 1 , which is also suitable for supporting roadside equipment, wherein each frame comprises at least one attachment position at intervals for attachment thereto from above of an item of roadside equipment.

3. An apparatus according to any one of the preceding claims, wherein each frame is made from concrete.

4. An apparatus according to any one of the preceding claims, wherein at least 30%, preferably at least 40%, of the surface area of the horizontal upper face of the frame is comprised of apertures.

5. An apparatus according to any one of the preceding claims, wherein the apertures has a maximum width, parallel with the width of the frame, that does not exceed 150mm.

6. An apparatus according to any one of the preceding claims wherein the porous blocks comprise mineral wool, preferably stone wool.

7. An apparatus according to any one of the preceding claims, wherein the porous blocks are surrounded by a textile membrane, preferably a geotextile membrane.

8. An apparatus according to any one of the claims, wherein the porous block has an upper surface that is flush with the horizontal upper face of the frame.

9. An apparatus according to any one of the preceding claims, wherein the porous blocks are insertable and removable from their respective aperture by vertical movement thereof.

10. An apparatus according to any one of the preceding claims, wherein the frame comprises an array of apertures, comprising apertures spaced apart along the width of the frame.

11. An apparatus according to claim 10, wherein the array of apertures comprises apertures also spaced along the length of the frame.

12. An apparatus according to any one of the preceding claims, wherein the apertures have a rectangular cross-section when viewed from above.

13. An apparatus according to any one of the preceding claims, wherein at least one aperture provides an open drain region, extending from the upper face to the lower face, that does not comprise a porous block.

14. An apparatus according to claim 13, wherein the open drain region comprises a filter for allowing the passage of rainwater but preventing the passage of leaves, gravel and the like.

15. An apparatus according to claim 14, wherein the filter is removeable from the open drain region.

16. An apparatus according to any one of claims 13 to 15, wherein one or more open drain regions are provided along the length of the frame that is adjacent to the road.

17. An apparatus according to any one of the preceding claims, positioned in the ground with its length parallel to and adjacent to a road.

18. An apparatus according to claim 17, wherein the horizontal upper face is flush with the surface of the ground.

19. An apparatus according to claim 17 or claim 18, wherein additional porous blocks are provided beneath the frame, in contact with the lower face of the frame.

20. An apparatus according to any one of claims 17 to 19, wherein a sand layer is provided beneath the frame, and if present, beneath the additional blocks provided beneath the frame.

21. An apparatus according to claim 20, wherein a textile membrane, preferably a geotextile membrane, is provided beneath the layer of sand.

22. An apparatus according to claim 20 or 21 , wherein a gravel layer is provided beneath the sand layer, and, if present, beneath the textile membrane.

23. An apparatus according to any one of claims 19 to 22, wherein at least one channel is provided beneath the lower face of the frame, along the length of the apparatus, and for carrying cabled or piped services.

24. An apparatus according to claim 23, wherein the at least one channel is located beneath an aperture.

Images