WO2010028959A1

WO2010028959A1 - Sealing of canals

Info

Publication number: WO2010028959A1
Application number: PCT/EP2009/061074
Authority: WO
Inventors: Michael ALTSCHÄFFL
Original assignee: Hagn Umwelt Gmbh
Priority date: 2008-09-12
Filing date: 2009-08-27
Publication date: 2010-03-18
Also published as: EP2321467A1; DE202008014492U1; DE102008047008A1; EP2321467B1; DE102008047008B4

Abstract

In order to make available a favourably-priced and reliable sealing of canals (12) or other watercourses in a water-bearing state, a canal working platform and a sealing method are proposed, in which the following steps are provided: arranging a working surface (26) above the water surface (22) of the canal (12) which is to be sealed, wherein the working surface (26) spans at least a portion of the water-bearing region of the canal (12); deployment of a first sealing web (32a) of a web-shaped sealing material (32) with at least one edge on the working surface (26); deployment of a second sealing web (32b) of the sealing material (32) on the working surface (26), wherein the second sealing web (32b) is deployed at least with one edge on the working surface (26) and is aligned to the first sealing web (32a); connecting at least one partial region of the adjoining edges of the first and of the second sealing web (32a,32b) on the working surface (26); moving the working surface (26) in relation to the sealing webs (32a,32b) which are connected together in longitudinal direction of the canal (12), wherein the connected sealing webs (32a,32b) are fixed in position in relation to the canal (12), and wherein the sealing webs (32) remain with their not yet connected edge regions on the canal working platform; and lowering of the free region of the sealing webs (32) which are connected together onto the canal base (16).

Description

Sealing of canals

RELATED APPLICATIONS

This application claims the benefit of the filing date of United States Provisional Patent Application 61/096,445, filed 12 September 2008, German Patent Application No. 10 2008 047 008.2, filed 12 September 2008, as well as German Utility Model Application No. 20 2008 014 492.2, filed 12 September 2008 the disclosures of which are hereby incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a device and a method for the sealing of canals and other watercourses in a water-bearing state. Particularly, the invention relates to a canal working platform for the sealing of canals and other watercourses in a water-bearing state, a canal sealing system for sealing a canal, a canal sealing method for sealing a canal, the use of a canal working platform and a canal section with a canal working platform.

:DW:sis BACKGROUND OF THE INVENTION

A sealing of canals, e.g. on the canal base or the lateral edgings, and of other watercourses, such as rivers for example, can be necessary both in new production and also in renovation. Canal or watercourse are also understood to mean other natural or artificial waters and also transport structures for conveying and structures for the holding or storage of other fluids, such as for example aqueducts or reservoirs. The term canal is, furthermore, to be understood to mean in particular also natural or artificial waters, such as for example a lake or a pool. In particular, water reservoirs are also to be understood by the term canal. Usually, the water is temporarily removed from the canal for sealing, so that the base surface and also the adjoining lateral inclines or walls can be sealed. However, it has been found that the draining of the canal is problematic, for example due to high costs and an additionally necessary period of time in which the canal can not be used. Furthermore, the draining of a canal also means, at the same time, an alteration of the weight forces acting as a whole on the ground, so that for example through lifting forces from the ground, intense stresses can in turn occur to the canal structure. In extreme cases, cracks and major damages can occur here to the canal structure. Furthermore, owing to a ground water level in situ in the environment, it can be necessary for the ground water to be lowered locally, because this acts as a lifting force on the canal or water flows into the canal through leaking walls or base surfaces. To lower the ground water, for example drawdown wells are provided in the surrounding area of the canal, which pump off the ground water, which also has an effect on the immediate environment in that also there the ground water conditions are altered, which can lead to settlement damage to structures in the environment. As a result of this, in the renovation of canals or other watercourses, it frequently occurs that the sealing or the renovation must take place in a water-bearing state, i.e. with a canal course filled with water, for which the term spread is prevalent, when an almost stagnant water is concerned and the water is retained; wherein the present invention, however, also relates to flowing, water-bearing canals in the sense of the above-mentioned understanding of the term canal, without a retention being required. To seal a canal in a waterbearing state, it is known for example to introduce bentonite mats, with which a lowering below the water level occurs owing to the increase in weight caused by the uptake of water. However, the overlapping joints of the individual bentonite mats are problematic, the tightness of which can not be controlled. Moreover, within the bentonite mat, which consists of a bentonite insert and is provided with two outer layers of non- woven material, a slipping of the bentonite insert occurs in particular at the lateral oblique banks of the canal cross- section. Furthermore, the failure of the seal can occur through damage to the non- woven materials, because the bentonite is washed out. To improve the tightness, it is known to provide bentonite mats with a sand layer or to use bentonite mats in which the bentonite is mixed with sand. However, these have the disadvantage that they are very narrow, so that a very large number of overlapping joints are produced. A further possibility for sealing in the bottom region consists in applying a submerged concrete, wherein it has, however, been found that a controlling of the actual thickness is only able to be carried out with great difficulty. An application of submerged concrete in the banks is technically not possible under water. Through the basically absent reinforcement, cracks occur in the bottom concrete on settling, combined with leaks of the canal bottom.

SUMMARY OF THE INVENTION

There may be a need to provide a simple, favourably priced and, at the same time, reliable method with regard to tightness, and a device by which canals and other watercourses in a water-bearing state can be sealed.

This is achieved by a canal working platform, a canal sealing system and a canal sealing method according to one of the independent claims.

In an exemplary embodiment, a canal sealing method is provided for sealing a canal in waterbearing state, in which the following steps are provided. Firstly, a working surface is arranged above the water surface of the canal which is to be sealed, wherein the working surface spans at least a portion of the water-bearing region of the canal. (Note: The term above is also understood to mean an arrangement at the same height as the water level. In addition, this is also understood to mean an arrangement in which the water is displaced through a trough-like device and the working surface lies beneath the surrounding water level. Of course, the working surface can also be arranged somewhat below the water level when the connecting of the sealing webs is not impaired by water, i.e. is insensitive to water). Then a first web of a web-shaped sealing material is deployed with at least one edge on the working surface. Depending on the size of the working surface, the web can also lie with both edges on the working surface. A second web of the sealing material is then deployed on the working surface, wherein the second sealing web is deployed at least with one edge on the working surface and is aligned to the first sealing web, e.g. with the edge of the second sealing web to the edge of the first sealing web, with the connection also being possible over the surface, for example in the case of overlapping webs. Thereafter, the connection takes place of at least one partial region of the adjoining edges of the first and of the second sealing web on the working surface. Then a movement takes place of the working surface in relation to the sealing webs which are connected together in the longitudinal direction of the canal, wherein the connected sealing webs are fixed in place in relation to the canal, and wherein the sealing webs with their not yet connected edge regions remain on the canal working platform. Then a lowering takes place of the free region of the sealing webs, which are connected to each other, onto the canal base.

Following this, a sealing web can then be deployed again on the working surface, connected with the edge of the already connected sealing webs, and the working surface can be moved again, so that a further lowering is possible. Through this method, it is possible to gradually arrive at a continuous sealing plane which seals the canal wall with respect to the adjacent water, wherein the connecting process of the individual sealing segments on the working plane takes place securely and reliably. Through the deployment of the sealing webs on the working surface above the place of use on the base surface of the canal, it is possible with a minimal effort to align two sealing webs, which are to be connected together, so that the connection can take place free of tension. As the connecting is carried out on the working surface, known and proven connecting techniques can be used here, such as for example hot welding. Of course, the connecting of the sealing webs can also take place mechanically. The sealing webs can consequently be connected with each other reliably without great effort. Preferably the working surface spans at least the water-bearing region of the canal. As the working surface is moved in relation to the sealing webs which are connected to each other and not vice versa, a new alignment of the sealing surface in relation to the canal is not necessary after the moving of the working surface. The working surface is, as it were, drawn away under the sealing web. In order to bring the sealing webs which are connected together, or at least the region of the sealing webs which are connected together under water at its actual place of use, the sealing webs which are connected together are lowered onto the canal base; in so doing, at the same time an exact close fit of the sealing webs to the canal wall is also possible. As the movement of the working surface only takes place to such an extent that an edge region of the sealing webs always remains on the working platform, after the moving or lowering a further sealing web can be laid out on the working surface. When this further sealing web is aligned to the sealing webs which are already connected, the further sealing web can also be connected with the or one of the already connected sealing webs. This connection also takes place above the water surface. As the working platform is also stabilized in its position for this further connecting process, here also a secure and reliable connection is possible. Then the working steps which have already been described take place again, i.e. a moving of the working platform or working surface in relation to the sealing webs which are connected together in longitudinal direction of the canal, and subsequent lowering of the sealing web onto the canal base.

The sealing material is preferably plastic sealing webs (PSW), which consist for example of PE-HD. Plastic sealing webs are suitable due to their high flexibility with, at the same time, a high strength, and can in addition adapt themselves very well to the geometry of the canal. The plastic sealing web can be produced for example in thicknesses of 1.0 mm to 3.0 mm. The connection with a double seam which is welded thermally has proved to be particularly advantageous. Through the resulting cavity in the double seam, it is possible to check every weld seam for tightness. This offers a possibility for monitoring, not only during the sealing process, but furthermore also constitutes a possibility for monitoring the connection sites in installed state at one or more later times.

As a canal or a similar watercourse is a longitudinally directed structure, basically various directions of the laid-out sealing webs can be identified in relation to the direction of the canal. Firstly, the canal can be sealed by sealing webs being laid transversely to the canal direction and being connected to each other on their longitudinal edges. In addition, however, it is of course also possible that sealing webs, which can be stored according to material, thickness and weight e.g. on rolls with a web length of up to several hundred metres, are arranged and connected in longitudinal direction, i.e. in the direction of the canal parallel to each other. With this variant, a connecting at the ends of the sealing webs, i.e. at the joints of the narrow sides is then necessary, in order to achieve a continuous sealing of the canal. With transversely arranged sealing webs, on the other hand, only a connection of the sealing webs on their longitudinal edges is necessary. A further difference consists in that with transversely arranged sealing webs, the connecting seams can be checked for tightness with an embodiment for example as a double seam, with this also being possible without great effort at a later time, i.e. in the installed state. With longitudinally arranged sealing webs, on the other hand, the connecting seams also run in longitudinal direction, i.e. a connecting seam arranged in the centre does not project out of the water at any point, whereby a checking under water in the final state is only possible with great difficulty (using a diver), because with a double seam the tightness is checked by applying a pressure into the cavity which is produced by the double seam.

In an alternative deployment of the sealing webs in longitudinal direction, for example unrolling supports can be arranged on the working platform, which are moved successively in longitudinal direction of the canal in order to thereby unroll the sealing webs from the unrolling supports. The connecting of the sealing webs, unrolled in parallel, can take place here by a connecting device extending over the entire width of the canal, which connects the edges continuously during unrolling. A further variant, in which a continuous movement of the working platform is possible, also consists in that the sealing webs are rolled out obliquely or diagonally in relation to the longitudinal direction of the canal.

In a further exemplary embodiment of the method provision is made that the free region of at least one sealing web is fixed on the canal base and the lowering takes place by a differential water level, wherein the water level in the region of the canal which is not yet sealed constitutes the lower current and the water level in the region which is already sealed constitutes the upper current, which is separated from the lower current by the seal reaching from the working platform to the canal bottom, and has a higher water level.

The advantage of lowering by the differential water level consists in that an additional device is not necessary for lowering the free region of the sealing webs. This is particularly advantageous when the sealing web has a lower density than water, as is the case for example with the plastic sealing webs which have already been mentioned, in which the density is less by 0.05 than that of water. Such a light sealing web would namely initially float on the surface of the water on moving away of the working plane. Through a differential water level of for example greater than approx. 0.01 m to approx. 1.0 m, the sealing web is forced, however, to descend, because it is in fact fixed to the canal base and the water accumulates, as it were, on the plastic sealing web. The differential water level can be achieved simply for example in that water is brought from the lower current region by pumping over into the upper current region. Of course, the differential water level can also be achieved by following water, controlled from above, in the canal, wherein the controlling here of the wake requires particular attention. For the case where a canal has to be renovated during full operation, such as for example in the case of a drinking water duct, it is possible using the described method to lay a kind of bypass around the site which is to be sealed at that time. For this, for example a lifting system can be provided, functioning without a separate pump, which already functions with a small differential water level. By adjusting the degree of efficiency of the lifting system accordingly, i.e. by adjusting the amount of water which is directed past in the bypass, the differential water level can then be influenced in a simple manner.

In a further exemplary embodiment of the method, provision is made that the working surface is supported on the canal base during the connecting process of the sealing webs.

It is thereby ensured that the working surface is held in a stable position during the connecting process. In particular, it is ensured through the support that the working surface does not have any vibrations or other movements, whereby a movement would be brought about in relation to the sealing webs, which in turn would have a direct negative influence on the quality, i.e. the tightness, of the connection site of the sealing webs.

In a further exemplary embodiment of the method, provision is made that the sealing webs are lowered into the water via a ramp-shaped trailer which forms a continuation of the working surface, wherein the working surface has a working plane which is held by the support structure and wherein the trailer is arranged on a first edge of the working plane and extends obliquely downwards away from the first edge of the working surface.

The trailer brings about a controlled lowering of the sealing web, so that a folding of the sealing webs during the settling process is prevented or reduced as far as possible. The ramp- shaped trailer is preferably fastened to the working surface or to a sub-construction of the working surface so as to be swivellable about a horizontal axis, so that the trailer can also be used in different depths of water. In order to increase the range of possible different depths of water, the trailer can also be constructed so as to be variable in its length, for example by a telescopic embodiment or an embodiment with elements which are able to be additionally fitted, which in the case of particularly great depths of water nevertheless produce an incline which does not drop too steeply. Thereby, a folding during lowering is avoided, which also has a positive effect on the region of the sealing web which is still situated on the working surface. A fold- free resting of the regions which are to be connected is fundamentally necessary for the further welding of the sealing webs.

In the case of small depths of water, instead of the trailer a chamfering of the region of the working platform can also be provided, from which the sealing webs are lowered into the water, in order to simplify the lowering.

In addition, a temporary lowering of the region of the working platform can also be provided, from which the sealing webs are lowered into the water, in order to facilitate the lowering of the sealing webs.

In a further exemplary embodiment of the method, provision is made that the working surface is adapted to the canal cross-section by means of side wings which are held swivellably on the working surface, and the deployed sealing webs together cover the entire canal cross-section and at least a portion of the lateral canal edges.

Through the side wings, which are held swivellably about a horizontal axis, the region between the working surface and the actual canal edge can be bridged, in order to make a working surface available on the entire width of the canal, i.e. not only the width of the water surface, but also in the region of the laterally adjoining bank inclines. It is thereby ensured that the connection of the sealing webs can be carried out reliably over the entire length of the connecting seam. At the same time, it is thereby also ensured that the canal is sealed in its entire cross-section, i.e. also up to the upper rims of the canal edges. The movable side wings permit an adaptation to changing cross-sections in the course of the canal. The side wings are therefore inclined more steeply in the case of narrow cross-sections and flatter in the case of wide cross-sections. The side wings are preferably embodied so as to be telescopic, in order to be able to be used for as broad a spectrum of different cross-sections as possible. In narrow passes, for example in bridge narrow passes, the side wings can be folded in or else can be dismantled without difficulty. The working platform can thereby be used on the entire length of the canal and a conversion or a dismantling and assembly of the working platform is not necessary.

Instead of the side wings, of course other elements can also be provided, in order to bridge the distance from the actual working platform to the canal edge in the case of changes in cross- section; for example, projections can also be pushed out telescopically from the working plane, in particular parallel to the plane of the platform, in order to reach up to the bank edge. The laying out of the sealing webs can then also take place over the bank region which is not covered by water up to the adjoining pushed-out part of the working platform onto the working platform itself.

In addition, a canal working platform is provided according to the invention for the sealing of canals and other watercourses in a water-bearing state, which comprises a support structure and a working surface which has a working plane which is held by the support structure, wherein the working surface is able to be arranged above the water level and is constructed to span at least a portion of the water-bearing region of the canal, wherein the working surface is constructed such that web-shaped sealing material is able to be deployed for sealing the canal and is able to be connected together on the working surface.

It is pointed out that the term 'above' is also understood to mean an arrangement at the same height as the water level; furthermore, this is also understood to mean an arrangement in which the water is displaced by a trough-like device and the working surface lies beneath the surrounding water level. Through the canal working platform which is described above, the condition is created that a web-shaped sealing material can be deployed in situ above the water level and can be aligned, wherein the working surface is preferably constructed so as to be flat, but may also have a structured and/or contoured surface in order to optimize the factional resistance between working surface and sealing web, to thus simplify the handling of the webs. For example, the surface can be provided with the same material as that of the sealing webs. Preferably, the working surface spans at least the water-bearing region of the canal. In addition, the working surface is preferably designed to be so large that at least two webs of the sealing material which is used can be laid out adjacent to each other, in order to be connected together in this position on the working surface. The working surface comprises substantially the working planes held by the support structure and possibly further extensions of the working plane, explained in further detail below, wherein the latter does not necessarily have to be even. It is also pointed out that the working plane itself can in turn be divided. The term working surface preferably refers to the region which is necessary in order to be able to lay out at least a part of the webs which are to be connected so that a problem- free connection can take place. For this, provision can also be made to make available a standing area for the operators and a higher possibility for laying out, compared with this, so that the connecting or the operating of the connecting tools or machines is possible more easily for the skilled workers and/or operators.

In an exemplary embodiment, the working surface is able to be stabilized temporarily in position.

The basic conditions for producing a reliable connection of the sealing webs are thereby improved.

The working surface is preferably constructed so as to be movable in relation to the waterbearing canal.

The mobility in relation to the water-bearing canal makes it possible that the sealing webs can remain in their position in relation to the canal once they are connected together, so that a laborious handling of sealing webs which are connected together is dispensed with. Through the mobility of the working surface, the working surface can be drawn away, as it were, under the sealing webs, in order to then bring the sealing webs, which are connected together, to their place of use on the canal base.

In an exemplary embodiment, on a first edge of the working plane a ramp-shaped trailer is arranged which forms a continuation of the working surface and extends obliquely downwards away from the working surface.

The trailer, which preferably extends from the working surface to the base of the canal, forms a bridge between the two planes which are spaced apart from each other, i.e. between the working surface and the usage surface on the canal base, whereby a controlled lowering of the sealing surface which is produced above the water surface becomes possible, in order to lay this flat onto the canal base and the lateral inclines.

The trailer is preferably held swivellably on the working surface.

Thereby, different depths of water can be bridged with the trailer, with trailers having different lengths also preferably being able to be used, so that with a greater depth of water the ramp angle does not run too steeply. For a particularly good adaptability of the canal working platform, the trailer can also be constructed so as to be telescopic or able to be extended by the fitting of module elements.

In a further exemplary embodiment, provision is made that at least on a second edge of the working plane, which runs transversely to the first edge, a side wing is arranged which is held detachably on the canal working platform and forms a lateral continuation of the working plane.

The side wings allow the working surface to be adapted to the respective canal cross-section or cross-section of the watercourse. The articulated mounting of the side wings additionally permits an adaptation to different lateral bank angles of the canal walls, which also means a better adaptability of the canal working platform to different depths of water. Thus it is possible, for example, to align the working surface in a particular relation to the water level which is present and to bridge the different distances, resulting thereby, to the edges with the laterally arranged side wings.

In a further exemplary embodiment, provision is made that the support structure is constructed so as to be floating.

This can take place for example by means of a steel frame which has one or more pontoons. A floating platform offers the advantage that it can be brought in situ via the canal itself. Moreover, the platform is independent of the local depth of water. A fixed connection, e.g. with the canal wall or with the canal base is only necessary for stabilizing the position. Of course, the canal working platform can also be deposited on the base of the canal or else can be embodied travelling on the bottom of the canal, for example with wheels or with a caterpillar track, which presents itself in particular in the case of small and constant depths of water over the length of the canal. In the case of a floating platform, the moving of the platform in relation to the canal takes place for example by means of steel cables and caterpillars or wheel loaders, which travel in the case of flat canal cross-sections in the canal itself or for example can also move laterally to the canal on a dam top path. A further variant is the moving of the pontoon by pusher craft.

In an exemplary embodiment support elements are provided by which the working surface is able to be fixed temporarily in its position in the canal.

These supports can be mechanical stilts or hydraulic stilts for example, by which the platform can be raised or lowered vertically, in order to be able to thereby balance out different water levels. The capability of being temporarily fixed is necessary in order to keep the canal working platform or the working surface stable in position for the welding of the sealing components. By holding stable in position, influences from swell, for example with a floating platform, or else movement of the platform by equipment or personnel, are prevented.

In addition, a canal sealing system for sealing the canal in a water-bearing state is provided according to the invention, in which a canal working platform according to one of the previously described embodiments and a pumping station are provided, by which water is able to be pumped from one side of the canal working platform to the other and a differential water level is able to be produced.

By the provision of a pumping station, a controlled lowering of the sealing components, i.e. of the sealing webs which are connected together, is possible, because a differential water level can be set which exerts the desired effect on the sealing material, i.e. a weight force, and presses this down towards the canal base. The differential water level can also be achieved by a controlled inflow of water in the upper current. The pumping station can also be called upon to support the regulation of the inflowing water, pumping excessive inflowing water in the manner of a bypass past the sealing working site, i.e. in a downstream direction.

In a further exemplary embodiment of the canal sealing system provision is made that a device for connecting the sealing webs is provided on the working surface.

This is preferably a fixedly installed device which is connected with the support structure of the platform. The connecting device, for example a hot-welding system, and the construction of the platform are thereby able to be stabilized more simply in their position with respect to each other. In addition, the sealing material can also be fixed more simply for the connecting process, which is essential for a precise connecting seam. The system is thereby able to make available as high a number of cycles as possible, i.e. as high a number as possible of sealing webs connected together, without the reliability and security of the connection sites being thereby impaired. The provision of the connecting device in fixed relation to the working surface permits, for example, a semi-automatic sealing method, because only the sealing webs have to be introduced and aligned. The connecting of the sealing webs itself can then take place automatically.

In order to rule out interruptions due to weather, by heavy rainfall for example and high temperatures through direct solar radiation, the canal sealing system is preferably equipped with an additional roofing of the working surface. In order to be able to better regulate and monitor the conditions for the connecting process, provision is made to equip the working surface with a housing, for example in the case of external temperatures of around freezing point, in which for example a hot-welding would not lead to the desired results. A component of the system is preferably also a device for the preparation of the sealing webs. When, for example, the sealing webs are arranged on rolls, these can be stored in an unrolling support, in order to thus be unrolled therefrom. For example, the unrolling support, which may be movable or displaceable in the direction of the canal, i.e. laterally in relation to the unrolling direction, can be arranged on one side of the canal, and the sealing web can be drawn over with an unrolling device to the other side of the canal, for example with a cable winch or with a cable fastened to a wheel loader. The sealing web can then be deposited onto the working platform and the side wings and the bank region and can be aligned to the sealing web which is already lying on the working platform. Of course, several unrolling devices, i.e. several unrolling supports can also be arranged adjacent to each other on the bank.

The method described above and the device necessary for this or respectively the necessary canal sealing system were described in relation to a sealing web, for example a plastic sealing web. Of course, depending on the material and the substrate beneath the sealing web, a protective layer can also be introduced. This protective layer can already be situated on the sealing web or can be introduced as a separate protective layer. For example, a protective non- woven material can be used as a protective layer which, like the sealing web, is available on rolls. To deploy the sealing web and the protective non-woven material, for example unrolling supports can be used, having several suspension devices arranged in parallel, so that the sealing web and the protective non- woven material can also be unrolled together or one over another. When the sealing web has a different width than the protective plane, i.e. the protective non-woven material, a protective non-woven material can also be deployed initially, which is connected with an adjacent protective non-woven material web, so that the sealing webs can be applied onto this protective non- woven material surface and can be connected with each other. The respective longitudinal joints of the protective non- woven material are connected thermally or mechanically, for example, so that in the lowering process a protection of the lowered sealing web is ensured over the entire surface.

For the case where an additional protection of the sealing web on the side facing the water is necessary, it is of course also possible with the system and method according to the invention to deploy such a further protective layer on the sealing webs, which are already connected together, on the platform, to connect it with a further protective layer arranged adjacent thereto and to lower the layers together, i.e. the non-woven material layer, the sealing webs and the additional protective layer.

The invention also relates to the use of a canal working platform according to one of the described variant embodiments and to the use of a canal sealing system according to one of the described variant embodiments.

The invention also comprises a canal section with a canal working platform according to one of the described embodiments.

An exemplary embodiment of the invention is described in further detail below with the aid of the enclosed drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

Fig.l : shows a cross-section through a canal with the canal sealing system according to the invention; Fig. 2: shows a longitudinal section through the canal and the canal sealing system according to Fig. 1; and Fig. 3: shows a cross-section through the canal according to Fig. 1 in sealed state.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

In Fig. 1 a canal 12 is shown, the cross-section of which has a first lateral chamfer 14, a substantially flat base surface 16 and a second lateral incline 18. The two lateral inclines 14, 18 continue at their highest point respectively into approximately horizontally adjoining terrain 20. The canal 12 is shown in a water-bearing state, i.e. with a water level 22.

Within the canal cross-section a canal working platform 24 is arranged, which has a support structure which it not shown, and a working surface 26 held by the support structure. The working surface 26 extends over a majority of the water level 22. The platform can be constructed for example as a floating platform, for example a steel structure provided with at least one pontoon, on which the working surface 26 is formed.

Support elements 28 are provided on the canal working platform 24, by which the working surface 26 is able to be fixed temporarily in its position in the canal 12. In other words, in the phase shown in Fig. 1 the working surface 26 is held so as to be stable in position by means of the support elements 28. The support elements 28 are hydraulic stilts, for example, which are positioned on the base surface 16 of the canal 12 and introduce the weight forces of the working surface 26 into the canal base 16.

In addition, side wings 30 are arranged on the canal working platform 24 on the lateral edges, which side wings are held detachably on the working platform and form a lateral continuation of the working surface 26. As the side wings 30 are held swivellably on the platform, the working surface resulting as a whole from the side wings 30 and the working surface 26 can be adapted to different canal cross-sections. Moreover, the working surface 26 also serves, particularly in the region of the platform, as a base surface for example for a pumping station and for any units and lifting equipment which may be necessary.

The working surface 26 is constructed to be flat such that a web-shaped sealing material, i.e. sealing webs 32, is able to be deployed for sealing the canal 12 on the working surface 26. In the exemplary embodiment shown, a protective non-woven material 23 is also laid beneath the sealing web 32, as a protection of the sealing web 32 from damage, which is also designated as geotextile, which is provided between the canal bottom and the sealing web. To be introduced, this geotextile, i.e. the non-woven material web 34, is rolled out before the unrolling of the sealing web 32 on the working platform 24. Of course, the thickness of the geotextile is to be adapted to the roughness of the substrate.

In the exemplary embodiment, the sealing web is a plastic sealing web (PSW) of PE-HD, with this being produced for example in thicknesses of between 1 and 3 mm. To connect sealing webs of this material, a so-called double seam is used, wherein the material is thermally welded. As a cavity is produced in the case of a double seam, each weld seam can be checked for tightness, which constitutes additional security. When the plastic sealing webs are laid transversely to the flow direction or respectively perpendicularly to the canal axis, each weld seam can also be checked for its tightness in the final state, because the start and end of the weld seam lie respectively above the water level 22.

To apply the two web materials 32,34, a device 36 is provided on one of the bank regions 20, which receives the web materials 32,34, which are available on rolls, in the manner of an unrolling support, wherein in the drawing only one roll 38 is shown. To apply the web materials 32,34, the roll 38 is suspended into the device 36 and is drawn away from there over the canal cross-section, for example by means of a cable winch, which presents itself in particular for larger canal cross-sections. The web can then be aligned on the working platform 26. As can be seen in Fig. 2, the working platform 24 has a sufficiently large working plane as part of the working surface 26, so that a first sealing web 32a can lie with an edge region or else even completely on the working platform 24, wherein adjacent to the laid-out web 32a in addition sufficient space is available to lay out a second sealing web 32b.

After the laying out or deployment of the second sealing web 32b on the platform, it is connected with the first adjoining sealing web 32a, which is possible without difficulty on the working plane 26, because this is in fact situated above the water level 22. When the two sealing webs 32a, 32b are connected together, the canal working platform 24 is moved in relation to the sealing webs 32a, 32b, which are connected together, in longitudinal direction of the canal 12, i.e. towards the left in Fig. 2. The working platform 24 is thus drawn away towards the left under the sealing webs 32. As the sealing webs 32 are fastened at their free end, i.e. at their right end in Fig. 2, on the base surface 16 of the canal 12, for example by the application of a load or of a mechanical connection by means of screws or clamping strips on the base surface of the canal, the sealing webs 32 remain fixed in their position with respect to the canal 12 upon movement of the platform. For fixing to the base surface, the sealing web 32 is forced to sink locally at the start of the sealing process by a superimposed load, for example by sand bags, plates or similar. The sealing web 32 is then fastened to the existent bottom 16 of the canal 12 and is connected tightly. This can take place for example by the use of divers who fasten the sealing web by means of submerged concrete, flat iron bars or injection anchors or studs. The tight connection ensures that no water can flow under the sealing web 32 and can detach it from the base 16 of the canal 12 or else from side walls 14, 18. The tight connection is also particularly important in order to separate an upper current 50 from a lower current 48, which will be described in further detail. In the region of bridge structures or inlets and similar, a tight connection likewise takes place of the sealing web 32 with the canal base 16 or with the lateral inclines 14,18.

The sealing webs 32 remain on the canal working platform 24 with their edge regions which are not yet connected, i.e. with their left edge regions in Fig. 2. After the moving of the working platform 24, the sealing webs 32 can be lowered onto the canal base 16. For this, on the canal working platform 24 on one edge a ramp-shaped trailer 40 is arranged, which forms a continuation of the working surface 26 and extends away from the working surface 26 obliquely downwards to the canal base 16. The trailer 40 is preferably held swivellably on the working surface 26, in order to be able to bridge different depths of water.

The trailer 40 makes possible a controlled lowering of the sealing webs 32 down from the working surface 26 to the canal base 16 and prevents a folding of the sealing components during lowering process, whereby also a folding in the region which is to be connected is avoided, which is still situated on the working surface. The lack of folds in this region is necessary for the further connecting process.

For the lowering of the sealing webs 32, a pumping station is provided, which is not illustrated, by which water is able to be pumped from one side of the canal working platform 24 to the other side, in order to produce a difference 42 of the two adjoining water levels 44 and 46. As the sealing web 32 is fixed to the canal base 16, the sealing web 32 divides the water in the canal 12 into the already mentioned lower current 48 and respectively upper current 50. When water is now pumped from the lower current 48 into the upper current 50, the water level 46 rises in the upper current 50. Owing to the different water level in the two regions, the water situated in the upper current 50 presses the sealing web 32 and the non- woven material web 34 situated therebeneath downwards onto the canal base 16, although the sealing web 32 is lighter than water. The water situated under the sealing components is pressed away in the course of this by the superimposed load in the direction of the lower current. Depending on the materials used and cross-sections, the differential water level 42 can be between 1 cm and 1 m, for example.

As the working platform 26 is moved just so far that an edge of the sealing web 32 still remains on the working surface 26, a further sealing web can be laid out on the working platform 24 and can be aligned to the edge of the other sealing web and connected therewith. The working platform can then be moved away again under the sealing webs, wherein also in this further step an edge of the sealing web 32 remains on the working surface 26, in order to lay out a sealing web 32 again. After the lowering of the sealing web 32, it assumes its final position by clinging to the profile of the canal 12. The plastic sealing web which has already been mentioned is particularly suited to this, due to its elasticity. By the gradual moving of the working platform, it is possible to make available a continuous sealing layer for sealing the canal, even though the latter is water-bearing.

For additional security, linear or surface loads can be applied on the sealing web 32 which rests in the region of the canal base 16. Thereby, for example in the case of damage occurring in the course of time, it can be prevented that the sealing web 32 detaches itself from the bottom and ascends, which can lead to damage for example in the case of barrages situated below, or even power plants. An application of a linear load presents itself in particular for the region in which the lateral bank inclines 14, 18 continue into the canal base 16, i.e. in the intersecting region.

In Fig. 3 in the diagrammatic illustration of the finished, i.e. sealed state, it is shown that the sealing web 32 is fixed and held in so-called embedding trenches 52 on the lateral embankments of the canal 12. To protect the sealing web 32 from damage, for example by vandalism, floating refuse etc., a wire-mesh fence 54 is laid beginning from the embedding trench 52 up to approximately 1 to 2 m below the water level 22. In order to fix the wire-mesh fence 54, round steel is included in the lower region and the wire-mesh fence 54 is thereby weighted down. Moreover, the wire-mesh fence 54 also serves as an exit for persons or wild animals out of the canal. A further variant embodiment for fastening the sealing components consists in that these are fastened by means of flat iron bars by pegging on or by means of anchors.

In countries with extreme climatic conditions, for example high or low temperatures and thereby a possible formation of ice or intense heating of the sealing web, in the exposed regions up to approximately 1 m below the water level a protective system can be applied, consisting of a surface stabilization blanket, wire-mesh fence and a 2 to 3 cm thick sprayed concrete layer.

The sealing which is described is suitable both for the renovation of an existing canal or watercourse and also for the sealing of a canal which is to be newly constructed, in which finished parts must be flooded directly following the introduction into a pit, in order to prevent a lifting due to lifting forces in the adjoining ground. An essential advantage of the described method consists in that the canal does not have to be emptied for sealing. When a plastic sealing web is used as a sealing web, the existent water is also not contaminated by the introduction of the sealing web, because this behaves in a neutral manner. In addition, the high laying performance results in a short construction period and takes place as far as possible independently of the weather, particularly when an additional roofing is provided on the working platform. Furthermore, the sealing according to the invention is distinguished by the testability of the weld seams. It is also to be emphasized that owing to the relatively thin sealing material as a whole a smaller material transport volume is necessary, which means a saving of resources and a reduced impact on the environment. With sufficiently large cross- sections of the canal, the material transport can take place for example via the canal itself by ships or floating pontoons which are drawn along the bank region. Furthermore, generally the sealing web can be laid with a protective layer situated therebeneath directly onto the base surface of the canal, without a clearing of sediment being necessary here. A further advantage of the sealing according to the invention consists in that the cross-section of the canal is not constricted, so that the canal, in the sealed state, has the same water throughput with the same depth of water, so that for example a re-calculation of the setting parameters of weir systems etc. regulating the canal is not necessary.

In addition, it is to be pointed out that 'comprising' does not exclude any other elements or steps and 'an' or 'a' does not exclude a plurality. Furthermore, it is pointed out that features or steps which have been described with reference to one of the above example embodiments can also be used in combination with other features or steps of other example embodiments described above. Reference numbers in the claims are not to be regarded as a restriction.

Claims

C l a i m s

1. Canal sealing system for the sealing of canals (12) and other watercourses in a waterbearing state, with: a canal working platform comprising

- a support structure and

- a working surface (26) which has a working plane which is held by the support structure; wherein the working surface (26) is able to be arranged above the water level (22) and is constructed to span at least a portion of the water-bearing region of the canal (12); wherein the working surface (26) is constructed such that web-shaped sealing material (32) is able to be deployed for sealing the canal (12) and is able to be connected together on the working surface (26); and a differential water level (42) being able to be generated between water on one side of the canal working platform and water on the other side of the canal working platform.

2. Canal sealing system according to Claim 1, wherein a pumping device is provided by which water is able to be pumped from one side of the canal working platform to the other and the differential water level (42) is able to be produced.

3. Canal sealing system according to Claim 1 or 2, characterized in that the working surface (26) is able to be stabilized temporarily in position.

4. Canal sealing system according to one of the Claims 1 to 3, characterized in that the working surface (26) is constructed so as to be movable in relation to the water-bearing canal (12).

5. Canal sealing system according to one of Claims 1 to 4, characterized in that on a first edge of the working plane a ramp-shaped trailer (40) is arranged, which forms a continuation of the working surface (26) and extends obliquely downwards away from the working surface (26).

6. Canal sealing system according to Claim 5, characterized in that the trailer (40) is held swivellably on the working surface (26).

7. Canal sealing system according to one of the preceding claims, characterized in that at least on a second edge of the working plane, which runs transversely to the first edge, a side wing (30) is arranged, which is held detachably on the canal working platform and forms a lateral continuation of the working plane.

8. Canal sealing system according to Claim 7, characterized in that the at least one side wing (30) is held swivellably on the working plane and is able to be adapted to different canal cross-sections.

9. Canal sealing system according to one of the preceding claims, characterized in that the support structure is constructed so as to be floating.

10. Canal sealing system according to one of the preceding claims, characterized in that support elements (28) are provided, by which the working surface (26) is able to be fixed temporarily in its position in the canal (12).

11. Canal sealing system according to one of the claims 1 to 10, characterized in that a device for connecting the sealing webs is provided on the working surface (26).

12. Canal sealing method for sealing a canal in a water-bearing state, comprising the following steps:

- arranging a working surface (26) above the water surface (22) of the canal (12) which is to be sealed, wherein the working surface (26) spans at least a portion of the waterbearing region of the canal (12);

- deployment of a first sealing web (32a) of a web-shaped sealing material (32) with at least one edge on the working surface (26);

- deployment of a second sealing web (32b) of the sealing material (32) on the working surface (26), wherein the second sealing web (32b) is deployed at least with one edge on the working surface (26) and is aligned to the first sealing web (32a);

- connecting at least a partial region of the adjoining edges of the first and of the second sealing web (32a,32b) on the working surface (26);

- moving the working surface (26) in relation to the sealing webs (32a,32b) which are connected together in longitudinal direction of the canal (12), wherein the connected sealing webs (32a,32b) are able to be fixed in position in relation to the canal (12), and wherein the sealing webs (32a,32b) remain with their edge regions which have not yet been connected on the canal working platform;

- lowering of the free region of the sealing webs (32a,32b) which are connected together onto the canal base (16); wherein the free region at least of a sealing web (32) is fixed on the canal base and the lowering takes place by a differential water level (42), wherein the water level (44) in the not yet sealed region of the canal (12) constitutes the lower current (48) and the water level (46) in the already sealed region constitutes the upper current (50), which is separated from the lower current (48) by the seal (32) extending from the working platform to the canal base (16) and has a higher water level (46).

13. Canal sealing method according to Claim 12, characterized in that the differential water level (42) is generated by adjusting the amount of water which is directed past in a bypass acting as a lifting device.

14. Canal sealing method according to Claim 12 or 13, characterized in that the differential water level (42) is produced by the pumping of water out of the lower current (48) into the upper current (50).

15. Canal sealing method according to one of Claims 12 to 14, characterized in that the working surface (26) is supported on the canal base (16) during the connecting process of the sealing webs (32a,32b).

16. Canal sealing method according to one of Claims 12 to 15, characterized in that the sealing webs (32) are lowered into the water via a ramp-shaped trailer (40) which forms a continuation of the working surface (26), wherein the working surface (26) has a working plane which is held by the support structure and wherein the trailer (40) is arranged on a first edge of the working plane and extends obliquely downwards away from the first edge of the working surface (26).

17. Canal sealing method according to one of Claims 12 to 16, characterized in that the working surface (26) is adapted to the canal cross-section by means of side wings (30) held swivellably on the working plane, and the deployed sealing webs (32) together cover the entire canal cross-section and at least a portion of the lateral canal edges (14,18).

18. Canal sealing method according to one of Claims 12 to 17, characterized in that plastic sealing webs are used as sealing material (32).

19. Use of a canal sealing system according to one of Claims 1 to 11 for the sealing of a canal (12).

20. Canal section with a canal sealing system according to one of Claims 1 to 11.