GB2465005A

GB2465005A - Spring biased flood defence

Info

Publication number: GB2465005A
Application number: GB0820154A
Authority: GB
Inventors: John Charles Macintosh Forrest; William Anthony Tustin
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-11-04
Filing date: 2008-11-04
Publication date: 2010-05-12
Anticipated expiration: 2028-11-04
Also published as: GB2465005B; GB0820154D0

Abstract

The invention relates to an apparatus 1 suitable for flood defence with a base means 6 mounted on a foundation 8. A slab unit 4 is rotatable relative to the base means 6 about an axis 5 between a lowered and a raised position. The slab unit 4 comprises at least a part of a barrier for water retention when in its raised position. Torsion springs (28 figure 5) engage both the slab unit 4 and the base means 6. The torsion springs (28 figure 5) have sufficient resilience to raise the slab unit 4 to the raised position, and are energized by the slab unit 4 being rotated to its lowered position. Locking bolts (44 figure 2) are used to lock the slab unit 4 in its lowered position with the torsion springs (28 figure 5) in an energized state. When the locking bolts are unlocked, the slab unit 4 is released from its lowered state, enabling the slab unit 4 to be rotated by the torsion springs.

Description

AN APPARATUS AND METHOD FOR FLOOD DEFENCE

The present invention relates to an apparatus and method for water retention for use mainly, but not exclusively, for flood defence.

Domestic and commercial properties built in low lying areas may be susceptible to flooding, particularly if they are built on a flood plain. Existing flood defences to protect such properties may comprise permanent bunds or walls of fixed height but these can prevent access across the line of defence and can be unsightly. Temporary defences immediately adjacent to domestic properties are usually provided in the form of sandbags and the sealing up of doors and windows. However, these defences confine the inhabitants to their homes during the period of the flood and are severely limited by the height of the sand bags and the strength of doorways and windows to resist water pressure. Other temporary defences, on a larger (non-domestic) scale, comprise a variety of systems such as flexible tubes filled with water, stone filled gabions, strutted and sheet materials covered with an impermeable membrane, and are sited alongside river banks to protect larger areas of flood sensitive land. All such temporary devices have the dual disadvantages of only protecting a small height of flood and being labour intensive to install and dismantle.

WO 2005/084108 discloses a flood defence apparatus having slab units rotatable about an axis between lowered and raised positions. The slab units are rotatable relative to a concrete foundation in the form of a channel and are substantially weight balanced about the axis. The slab units comprise part of a barrier for water retention when in their raised position and at least a third of the height of each slab unit comprising a downward part is positioned downwardly of the axis when the slab unit is in its raised position. The apparatus has sealing means for forming a seal between an angle mounted on the foundation and the downward part of the slab unit when the slab unit is in its raised position whereby hydrostatic pressure deployed from water being retained by the slab unit acts directly on the slab unit so as to compress the seal. Each slab unit can be rotated manually into its raised position without having to rely on driving means powered by electricity and/or hydraulics.

A problem with the above apparatus is that the weight-balanced slab unit is heavy. Also, the concrete foundation that forms part of the apparatus is costly to transport.

Another problem is that the concrete foundation has to have a deep portion to be able to receive at least a third of the height of each slab unit positioned downwardly of the axis when the slab unit is in its raised position, and which will preclude its usage in cases where underground services lie within the zone of swing of the slab unit.

A further problem lies in the geometry of the apparatus whereby the position of the axis for rotation at a position at least a third of the height of each slab unit relative in their raised position precludes the positioning of a row of slab units in any arrangement other than in a straight line.

An object of the present invention is to provide an apparatus and method for flood defence which alleviates at least one of the above-mentioned problems.

According to one aspect of the present invention there is provided an apparatus suitable for flood defence comprising: base means for mounting on a foundation; at least one slab unit rotatable relative to the base means about an axis between lowered and raised positions, the at least one slab unit comprising at least part of a barrier for water retention when in its raised position; resilient means engaging the at least one slab unit and the base means, the resilient means having sufficient resilience to substantially counterbalance the at least one slab unit so as to facilitate raising the at least one slab unit to the raised position, and energizable by the at least one slab unit being rotated to its lowered position; and locking means for locking at least one said slab unit in its lowered position with the resilient means in an energized state, and unlockable to release the at least one slab unit from its locked lowered state to enable the at least one slab unit to rotate under the influence of the resilient means.

Since the slab unit is not weight balanced it is much lighter and is easier to transport and handle.

By providing an apparatus for flood defence which is to be mounted on a foundation that has already been prepared on site, the problems of transporting the foundation and possibly placing the foundation in difficult site conditions are avoided. Furthermore, the prepared foundation only needs a flat upper surface for the apparatus to be mounted on.

As each slab unit does not require at least a third of its height to be positioned downwardly of the axis when the slab unit is in its raised position, a deep portion is not required to receive the portion of the slab unit positioned downwardly of the axis. Also, this allows a flood defence comprising a line of raised slab units to have curvature as there is no significant portion of the slab units positioned downwardly of their axes. At least one slab unit may be provided with at least one tapered side.

A flood barrier of a substantial height can thus be quickly erected by use of the apparatus. The apparatus forms at least part of an active defence when the or each slab unit is in its raised position. In addition, the view from any property being protected by a flood barrier comprising the apparatus is only temporarily obstructed whilst the or each slab unit is in its raised position. The apparatus can be used for a range of applications for the protection of domestic, commercial, and public buildings, industrial sites and flood sensitive land whether from threat by river or sea and in both rural and built-up areas and provides a lack of unnecessary inconvenience to the owner of the property/land to be protected. The slab unit is preferably made from robust structural materials in unit sizes of lengths and widths to suit the parameters of the flood defence.

The apparatus provides a permanent demountable defence.

The resilient means may have sufficient resilience to raise the at least one slab unit to the raised position. The resilient means may be substantially aligned with the axis. The resilient means may comprise at least one torsion spring.

The slab unit may have a downward part positioned downwardly of the axis when the at least one slab unit is in its raised position. The apparatus may include sealing means for forming a seal between the base means and the downward part of the slab unit when the at least one slab unit is in its raised position whereby the released resilient means causes the downward part of the slab unit to compress the seal. Thus, the apparatus does not rely on hydrostatic water pressure to compress the seal and its base means does not need to have a sufficient depth to be able to receive at least a third of the height of each slab unit positioned downwardly of the axis when the slab unit is in its raised position. The sealing means may be mounted on footing means mounted on the foundation and supporting the apparatus.

The apparatus may include sealing means between a said slab unit and an adjacent abutment or slab unit. The sealing means between a said slab unit and an adjacent abutment or slab unit may form a continuous seal with the sealing means between the at least one slab unit and the base means or footing means when the at least one slab unit is in its raised position. The sealing means between a said slab unit and an adjacent abutment or slab unit may comprise at least one removable portion. Clamping means may be provided for clamping the removable portion between the slab unit and the adjacent abutment or slab unit.

The slab unit of the apparatus preferably forms at least part of a paved way when in its lowered position. The paved way may comprise a pavement or footpath for pedestrians and/or a road for vehicles. Thus, the apparatus provides a dual function of providing a paved way when the at least one slab unit is lowered and providing at least part of a barrier for water retention when the at least one slab unit is raised.

There may be at least one strut or prop for supporting at least one said slab unit in its raised position. The strut may be adjustable in length and may be used to tighten the slab unit against the seal between the slab unit and the base means when the slab unit is in its raised position.

The apparatus preferably includes a plurality of slab units rotatable about the axis.

According to another aspect of the present invention there is provided a method for flood defence comprising the steps of: rotating at least one slab unit about an axis relative to base means mounted on a foundation to a lowered position and to energize resilient means engaging the at least one slab unit and the base means; locking the at least one slab unit in its lowered position so that the resilient means is held in an energized state with sufficient resilience to substantially counterbalance the at least one slab unit so as to facilitate raising the at least one slab unit to a raised position where the at least one slab unit forms at least part of a barrier for water retention; and releasing the at least one slab unit from its locked lowered state so that the at least one slab unit rotates about the axis under the influence of the resilient means.

An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying schematic drawings, in which:-Figure 1 is a perspective rear view of the apparatus for flood defence according a typical embodiment of the invention; Figure 2 is a cross-sectional view of a module of the apparatus taken along lines 2-2 of Figure 1 with the module in its raised position; Figure 3 is a detail of Figure 2; Figure 4 is a rear view of the module in its raised position; Figure 5 is a perspective detail of Figure 1; Figure 6 is a cross-sectional view taken along lines 6-6 of Figure 5; Figure 7 is a sectional view of a vertical seal installed in the apparatus; Figure 8 is a plan view of a line of flood defence comprising the apparatus with the modules in their lowered position wherein some modules are modified; Figure 9 is a rear view of the apparatus of Figure 8 with the modules in their raised position; Figure 10 is a sectional view of a modified vertical seal between two modified modules of Figures 8 and 9; Figure 11 is an elevational view of the modified vertical seal taken along lines 11-11 of Figure 10; and Figure 12 is a perspective view of the modified vertical seal of Figures 10 and 11.

Referring to Figure 1 of the accompanying drawings, an apparatus 1 suitable for flood defence is positioned between two wall abutments 2. The apparatus 1 comprises a plurality of modules 3 and each module 3 comprises a preformed slab unit 4 rotatable about a horizontal axis 5 between lowered and raised positions. The slab unit 4 is rotatable relative to a corresponding base means 6 mounted on a flat upper surface 7 of a concrete foundation 8. Figure 1 shows three modules 3 with their slab units 4 mobilized in their raised positions and one module 3 with its slab unit 4' locked in its lowered position.

Referring to Figures 2 and 3, the base means 6 of each module 3 comprises a base frame having a pair of parallel channels 9, 10 supporting a pair of U-shaped channel sections 11 perpendicular to the channels 9, 10. One channel 9 is a front channel to be near the axis 5 and close to a water confronting side of the apparatus I activated for flood defence, and the other channel 10 is a rear channel distal from the axis 5. A continuous horizontal seal 12 is fixed to a vertical section 13 of the front channel 9. There is a raised pocket 14 in the bottom of each U-shaped channel section 11 and one end portion 15 of each U-shaped channel section 11 supports a catch or locking block 16 and the opposite end portion 17 of the U-shaped channel section 11 extends beyond the front channel 9. An axle 18 coaxial with the rotation axis 5 of the slab unit 4 passes through each opposite end portion 17 and corresponding pivot blocks 19 of the slab unit 4.

The pivot blocks 19 are fixed to decking 20 of the corresponding slab unit 4 and the pivot blocks 19 act as a fulcrum for rotation of the slab unit 4. The decking 20 comprises steel plating 21 covered by an asphalt layer 22 which forms the top surface of the slab unit 4 when the slab unit 4 is in its lowered position. Referring to Figure 4, each slab unit 4 has an edge frame 23 formed by channel sections 24, 25 and within which is a sub-assembly of sections 26, 27 acting to support the decking 20. Parallel with the width of the slab unit 4 are two separate pairs of opposed channel sections 26 running the full width of the slab unit 4 within the frame 23 and there is a said pivot block 19 mounted in between each pair 26 (see Figure 5). Parallel with the length of the slab unit 4 is a channel section 27 running the full length of slab unit 4 within the frame 22 except between each opposed pair of channel sections 26.

Referring to Figures 5 and 6, adjacent each opposed channel section 26 is a torsion spring 28. Each torsion spring 28 is fitted around the axle 18 and each end of the spring 28 comprises a straight portion 29, 30. One straight portion 29 is urged by the spring 28 towards the underside of the decking 20 and is held by an L-shaped angle iron 31 fixed to the decking underside and adjoining the opposed channel section 26. The other straight portion 30 is urged by the spring 28 towards the top of the front channel 9 and is held by a pocket 32 mounted on top of the front channel 9.

Referring to Figures 2 and 4, a prop or strut 33 capable of being extended a defined length is located in between each pair of opposed channel sections 26. The prop 33 comprises a tube 34 sliding snugly within a larger diameter tube 35. The smaller diameter tube 34 is hingably secured at one end to a prop housing 36 fixed to the underside of the decking 20 and in the stowed position the free end of the larger diameter tube 35 is held securely to the slab unit 4 by a clip (not shown). The prop 33 has securing means (not shown) for securing the prop 33 at the length required.

Alongside each prop 33 is a pair of clips 37 fixed to the decking underside 30 for holding a vertical seal 38. Referring to Figure 7, each vertical seal 38 comprises first and second plates 39, 40 in between which there is a seal member 41. Shafts 42 pass through the first plate 39 and the seal member 41 and are fixed to the second plate 40. Each shaft 42 has a hand-operated butterfly nut 43 on the opposite side of the first plate 39 to the seal member 41.

Figure 7 also illustrates the fixing arrangement of the channel sections 25 to the decking 20.

The channel sections 9, 10, 11, 24, 25, 26, 27 may be made of any suitable material such as steel or aluminium or plastic.

The apparatus 1 is delivered to site as a modular unit with the slab unit 4 having its own props 33 and clipped on vertical seals 38. To initially install the apparatus 1, the slab unit 4 of each module 3 is placed in an upright raised position and the free ends of the props 33 are unclipped from each slab unit 4 and inserted into the raised pockets 14 in the bottom of the U-shaped channel sections 11 so that the slab units 4 are held in their raised position. The front and rear channels 9, 10 of each module 3 are bolted to the flat upper surface 7 of the concrete foundation 8 which has been prepared previously. The channels 9, 10 have predrilled holes 48 (see Figure 3) to enable them to be bolted to the foundation 8.

The props 33 are removed from the pockets 14 and the prop free ends are clipped back to the slab units 4. The slab unit 4 is rotated by hand to its lowered position causing the torsion springs 28 to become energized and the slab unit 4 is locked in place by a locking bolt 44 secured to each catch 16 and turned by a key (not shown). Holes 45 (see Figure 1) are provided in the slab unit 4 to provide access for the key.

In order to form an active flood defense, the slab units 4 of the modules 3 are unlocked and the torque of the energized springs 28 causes the slab units 4 to rotate to their vertical, raised positions. This causes the toe 46 (see Figure 3) of each slab unit 4 to impinge on the horizontal seal 12 on the front channel 9 of the base frame 6.

The free ends of the props 33 are again unclipped from each slab unit 4 and inserted into the corresponding raised pockets 14. The props 33 may be adjusted in length to ensure that all the raised slab units 4 are aligned and are secured at the length required. The props 33 thus act as structural components for resisting horizontal forces or hydrostatic pressure of a flood.

The vertical seals 38 are removed from their clips 37 and are inserted from above the raised slab units 4 into each gap formed between opposing edge frame side channel sections 25 of each adjacent slab unit 3 so that rear returns 47 (see Figure 7) on the opposing edge frame side channel sections 25 are sandwiched between the seal member 41 and the first plate 39. The vertical seals 38 are lowered until they are stopped by a toe plate (not shown) fitted at the bottom end of each edge frame side channel section 25. The bottom portion of the seal member 41 faces the horizontal seal 12 and the seal member 41 is pressed against the returns 47 by the hand operated butterfly nuts 43 being tightened to clamp the vertical seal 38 into position. This also causes the seal members 41 to press against the horizontal seal 12 in order to effectively plug the gap between the opposing edge frame side channel sections 25.

The gap between each wall abutment 2 (see Figure 1) and an adjacent slab unit 4 are sealed in the same way and when the last of the vertical seals 38 is fixed the defence is completed.

In a typical embodiment, the apparatus 1 is delivered to site as a box approximately 3 metres long, 2.5 metres wide and 0.35 metres thick.

Referring to Figure 8, a flood defence line 50 follows a river 51. The flood defence line 50 has a double bend and has a plurality of modules 3a-3f mounted on a foundation 52. From the left hand side of Figure 8, the first three modules 3a, 3b, 3c are angled away from each other and the third to sixth modules 3c, 3d, 3e, 3f are angled towards each other. For the third to sixth modules 3c, 3d, 3e, 3f the adjacent sides 53 of their slab units 54c, 54d, 54e, 54f are tapered so that when the slab units 4a, 4b, 54c, 54d, 54e, 54f are all positioned in their lowered position they are all laid flat and effectively adjoin each other. It is noted that the slab units 4a, 4b of modules 3a, 3b are rectangular, the slab units 54c, 54f of modules 3c, 3f have one tapered side 53 and the slab units 54d, 54e of modules 3d, 3e have two tapered sides 53.

When these tapered slabs units 54c, 54d, 54e, 54f are in their raised position as shown in Figure 9 there is a triangular gap 55 between the adjacent tapered slab units and this is sealed by a tapered vertical seal 56 illustrated in Figures 10, 11 and 12. In cross-section the tapered seal 56 has two end portions 56a, 56d and two inwardly folded portions 56c, 56e. One end tapered seal portion 56a is fixed to the inside of the C-shaped channel 57 forming the tapered side of one tapered slab unit and the other end tapered seal portion 56d is fixed to the inside of the C-shaped channel 58 of the adjacent tapered slab unit by a clamping system 59 using plates 37, 40, shafts 42 and butterfly nuts 43 as shown in Figure 7 where the shafts 42 pass through holes 60 in the rear return 61 of C-shaped channel 58.

Whilst particular embodiments have been described, it will be understood that various modifications may be made without departing from the scope of the invention. For example, the base means 6 of the apparatus 1 may just comprise the two U-shaped channel sections 11 and the channels 9, 10 or any other means of supporting the U-shaped channel sections 11 form footing means for the apparatus to be mounted on and the footing means are on, or form part of, the foundation surface.

The edge of each slab unit may be modified to allow the vertical seals to be inserted from the side when the slab units are in their raised position as opposed to being inserted from above the raised slab units.

Instead of asphalt 22, other forms of covering for the slab unit decking may be used such as Astroturf RTM or recycled plastic.

A module may have a plurality of slab units rotatable about a single base comprising base means. The apparatus may comprise one or more modules.

Claims

CLAIMS: 1. An apparatus suitable for flood defence comprising: base means for mounting on a foundation; at least one slab unit rotatable relative to the base means about an axis between lowered and raised positions, the at least one slab unit comprising at least part of a barrier for water retention when in its raised position; resilient means engaging the at least one slab unit and the base means, the resilient means having sufficient resilience to substantially counterbalance the at least one slab unit so as to facilitate raising the at least one slab unit to the raised position, and energizable by the at least one slab unit being rotated to its lowered position; and locking means for locking at least one said slab unit in its lowered Q position with the resilient means in an energized state, and unlockable to release the at least one slab unit from its locked lowered state to enable the at least one slab unit to rotate under the influence of the resilient means. C)
2. The apparatus as claimed in claim 1, wherein the resilient means has sufficient resilience to raise the at least one slab unit to the raised position.
3. The apparatus as claimed in claim 1 or 2, wherein the resilient means is substantially aligned with the axis.
4. The apparatus as claimed in claim 1, 2 or 3, wherein the resilient means comprises at least one torsion spring.
5. The apparatus as claimed in any preceding claim, wherein at least one said slab unit has a downward part positioned downwardly of the axis when the slab unit is in its raised position.
6. The apparatus as claimed in claim 5, including sealing means for forming a seal between the base means and the downward part of the slab unit when the at least one slab unit is in its raised position whereby the released resilient means causes the downward part of the slab unit to compress the seal.
7. The apparatus as claimed in claim 6, wherein the apparatus includes footing means mountable on the foundation and the sealing means is mounted on the footing means.
8. The apparatus as claimed in any preceding claim, including sealing means between a said slab unit and an adjacent abutment or slab unit. a)

Q
9. The apparatus as claimed in claims 6 and 8, wherein the sealing means between a said slab unit and an adjacent abutment or slab unit forms a continuous seal with the sealing means between the at least one slab unit and CO the base means when the at least one slab unit is in its raised position.
10. The apparatus as claimed in claims 7 and 8, wherein the sealing means between a said slab unit and an adjacent abutment or slab unit forms a continuous seal with the sealing means between the at least one slab unit and the footing means when the at least one slab unit is in its raised position.
11. The apparatus as claimed in claim 8, 9 or 10, wherein the sealing means between a said slab unit and an adjacent abutment or slab unit comprises at least one removable portion.
12. The apparatus as claimed in claim 11, including clamping means for clamping the removable portion between said slab unit and the adjacent abutment or slab unit.
13. The apparatus as claimed in any preceding claim, wherein the slab unit forms at least part of a paved way when in its lowered position.
14. The apparatus as claimed in any preceding claim, including a plurality of said slab units rotatable about said axis.
15. The apparatus as claimed in any preceding claim, including at least one strut for supporting at least one said slab unit in its raised position.
16. The apparatus as claimed in claim 15, wherein the strut is adjustable in length to enable the slab unit to be tightened against the seal between the slab 0) unit and the base means when the slab unit is in its raised position.
17. The apparatus as claimed in any preceding claim, wherein at least one said slab unit has at least one edge tapering inwardly towards the top of the CO slab unit when the slab unit is in its raised position.
18. A method for flood defence comprising the steps of: rotating at least one slab unit about an axis relative to base means mounted on a foundation to a lowered position and to energize resilient means engaging the at least one slab unit and the base means; locking the at least one slab unit in its lowered position so that the resilient means is held in an energized state with sufficient resilience to substantially counterbalance the at least one slab unit so as to facilitate raising the at least one slab unit to a raised position where the at least one slab unit forms at least part of a barrier for water retention; and releasing the at least one slab unit from its locked lowered state so that the at least one slab unit rotates about the axis under the influence of the resilient means.
19. The method as claimed in claim 18, wherein the step of locking the at least one slab unit in its lowered position holds the resilient means in an energized state with sufficient resilience to raise the at least one slab unit to a raised position. a) C)