EP0286068B1 - Sealing barrier against seepage - Google Patents

Description

The invention relates to a seepage barrier wall, which is composed of a plurality of partial walls let into the ground between a hazardous area and a hazardous area, each consisting of dense surface elements and connecting profiles for connection to adjacent partial walls, wherein interacting pairs of connecting profiles have several C-profile parts, in the T-profile parts of the respectively opposite connecting profile engage with the formation of chambers with sealing means, several chambers being provided one behind the other in the passage gap of the connecting profiles, of which at least the outer chamber facing the hazardous area is provided with sealing means.

In sheet piling, it is known to provide each sheet pile edge with a C-shaped profile part, one leg of which is T-shaped in cross-section and engages in the C-profile part of the respective opposite connecting profile. While efforts are often made to make the passage gap remaining between the two connecting profiles as narrow as possible and free of expansion (DE-PS 624 960), it is also known that the engaging T-profile part within the C-profile parts to expand adjacent space like a chamber and to provide it with sealants (US Pat. No. 3,302,412). It is also known to provide integrally with the main bodies profiles on the edges of partial walls, which are formed on the one side in cross-section in a dovetail-like substantially T-shape and on the other side essentially C-shaped, each having an edge with T -shaped cross-section engages in an edge with a C-shaped cross-section (EP-PS 0 129 275). Since the profiles are formed in one piece with the main part, the material properties in the profile area are determined by the material properties in the area of the actual walls and can therefore no longer be optimally adapted to the conditions in the profile area. However, the seal has the particular disadvantage that leakage flows only have to cover very short distances between the composite profile paths, so that the tightness is not guaranteed, although a sealant is provided within the profile. The tightness can also not be increased in that several such seals are provided side by side, since then the profiles would protrude very far from the wall parts and the sealing effect can not be increased without additional measures. Experience has shown, however, that such sealants are not absolutely reliable and can therefore only be used if leakage has to be kept below a certain limit, but not if no leakage is allowed to take place at all. For such a case, it is known (DE-OS 34 30 789, Fig. 18) to construct the surface element of the partial wall double-walled from a dense film and a filter fleece, the intermediate space being designed as a drainage layer which is formed with a connection profile formed in the assembled connection profiles Chamber is connected, which is emptied by means of a pump, so that the drainage layer functions as a hydraulic trap for seepage liquids and further penetration of the seepage barrier wall is prevented. This is due to the fact that the liquid level in the drainage layer is lower than in the endangered area adjacent to the drainage barrier wall, so that the liquid accumulating in the drainage layer cannot be pressed into the endangered area by hydrostatic pressure. However, if the partial walls are long, it is hardly possible to meet the condition everywhere and always that the liquid level in the drainage layer is lower than in the endangered area. This solution is also practically unusable because large amounts of water containing pollutants accumulate from the drainage layer that cannot be easily removed. These problems are not remedied by the fact that the chamber formed in the connecting profile can also be provided with a sampler, since this can only determine what is known anyway, namely that the water obtained contains pollutants.

Therefore, the invention is based on the prior art mentioned at the outset (US Pat. No. 3,302,412) which seeks to achieve the tightness of the seepage barrier wall without the need for constant liquid drainage. Your task is to improve the known septic barrier so that the occurrence a leak is noticed without the risk of the contaminants continuing to penetrate into the endangered area.

The solution according to the invention consists in that at least three chambers arranged one behind the other in the passage gap of the connecting profiles are provided, the middle one of which is accessible for control.

The chamber provided with the sealing means is comparable to the conventional connecting joints provided with sealing means, irrespective of whether they comprise only one or more chambers. As long as no leakage occurs or as long as no contaminants are contained in a possible leakage, the sealing wall according to the invention functions like a conventional one. The decisive difference is that, firstly, any pollutant leakage - be it liquid or gaseous - can be determined immediately, secondly, this leakage cannot yet penetrate to the endangered area because it is stopped by the controllable chamber and, if necessary, the downstream chamber, and thirdly, the leakage can be repaired because two further chambers are available, the first of which can be used to hold an additional sealant, while the second remains for control purposes.

In order to prevent any leakage from penetrating to the endangered area, the chamber adjacent to the endangered area can also be provided with sealing means.

Sealing means preferably includes a material additionally introduced in the chamber provided for this purpose, for example a casting or a swelling seal understand. However, the connection profiles as such can already be provided with sealing means (for example elastically prestressed sealing lips or a labyrinth). In some cases, even the narrow gap between the chambers, formed by the interlocking C and T profile parts, in conjunction with an externally penetrating sealing compound (for example, a thixotropic screw which fills the trench receiving the septic barrier wall) is sufficient as a sealant.

Advantageously, the interacting connecting profiles on adjacent partial walls are complementarily the same and the T-profile parts are formed by legs of the C-profile parts. This means that the connection profiles become identical by rotating them through 180 °. Accordingly, one and the same profile shape can be used for both connecting elements. It is not important for the invention how the connecting profiles are connected to the surface elements. For example, they can be glued or welded together.

The invention gains a particularly important aspect in connection with the use of such surface elements which enclose a control gap between two foils. Since the control gaps of such surface elements are generally filled with spacers, it can be problematic to gain control access directly to these gaps. The invention enables easy access to the control interspace of a surface element in that the chamber next to this surface element is sealed in the sealing arrangement against fluid passage from outside of the surface elements to be connected and the control interspace is fluidly connected to a chamber located further away so that it communicates with the control interspace and thus allows easy access to control. If this chamber is also connected to the control gap of the other surface element, two surface elements can be checked from here. Finally, this principle can only be used to connect the control spaces between two or more adjacent surface elements. Each of these surface elements is then connected from the outset, for example via a hose connection or via a bore, to, for example, the second or third next chamber of the associated connecting profile, which in turn is unsealed to the corresponding chamber connected to the adjacent surface element of the other connecting profile. In this way, continuous communication between the control spaces in a chain of double surface elements can be created, so that control points only have to be provided at a greater distance.

If, on the other hand, one does not want to connect the control gaps between adjacent surface elements for the purpose of easier localization of any leaks in the surface elements, then such chambers are arranged between the control chambers assigned to them and the connecting profiles that can be provided with sealants.

Standard sealants can be used in the chambers to be sealed. For example, they can be filled with potting compounds based on plastic or hydraulically, or swelling tubes can be inserted or, due to elastic deformation, effective lips can be provided therein.

The lower edges of the surface elements are generally anchored in a concrete grout. The lower, open ends of the chambers of the connecting profiles are expediently closed by such a concrete casting or in some other way.

The connection profile according to the invention can also be used to connect surface elements to other components, for example to concrete, sheet pile walls or the like, with which it is to be connected in a suitable, analogous manner, which does not require any special discussion in the context of the present application.

Fig. 1 und 2

eine einfache Verbindungsvorrichtung in unterschiedlicher Anordnung und

Fig. 3

eine solche mit drei Kammerpaaren

The invention is explained in more detail below with reference to the exemplary embodiments shown in the drawing. Show it:

1 and 2

a simple connection device in a different arrangement and

Fig. 3

one with three pairs of chambers

The surface elements 1, 2, each of which is designed as a double film with a control gap 3, are connected to one another by the connection arrangements generally designated 4 and 5, which consist of two rotationally symmetrical connection profiles 6 with the same cross section, which are tightly welded to the surface elements, in such a way that the control gap 3 communicates with a cavity 7 via the associated connecting profiles and is closed by them. 1 has a cross-sectionally C-shaped profile part at its end, which is formed by the wall sections 8 to 12, the leg 11 being supplemented by the wall part 12 and a further wall part 13 in a T-shaped cross section. The wall parts 12, 13 forming the head of the T-profile part have a substantially larger cross-sectional dimension than the opening of the C-profile part. Between the head 12, 13 of each T-profile part and the surrounding wall parts of the C-profile part, there are spaces which are referred to in the present context as a chamber.

The designation C-profile part or T-profile part is intended to indicate that the shape of the so-called profiles correspond to the Latin capital letters mentioned.

If the arrangement according to FIG. 1 is used under conditions in which the influx of pollutants occurs exclusively from the side in the drawing as a hazardous area, as is conceivable, for example, when including landfills, it may be sufficient to first equip only the chamber 18 with sealants while the chamber 19 is used to control the tightness of the chamber 18. If traces of pollutants become noticeable in the chamber 19, suitable countermeasures can be taken, for example the chamber 19 can additionally be closed or the sealing means of the chamber 18 can be improved. At least chamber 20 is then still available for inspection.

The trenches into which such foils or plates are inserted are generally filled with thixotropic sludge, which - unless suitable precautions are taken - also fills the chambers 18, 19 and 20. If such a chamber is to be emptied for control purposes or to be equipped with sealants or for other reasons, it can be pumped empty. Preferably, a seal is arranged at the foot of the profile to be inserted later, which bears all around on the walls of the chamber, in order to displace the slurry and other foreign bodies previously located there when the profiles are pushed together. The chamber space can also be entirely or partially over its entire or partial length must be filled with sealing material, which is later removed if necessary.

In the embodiment according to FIG. 1, three chambers 18, 19, 20 are formed with only two C or T profile parts, in that the heads 12, 13 of the T profile parts rest on the opposite wall parts 10.

However, intermediate positions of these elements according to FIG. 2 can also be considered, in which the chamber system can be divided into a plurality of chamber parts by a plurality of indicated sealing strips, which can serve different functions if desired. The sealing strips can, for example, be extruded in one piece with the connecting profiles from a suitable, usually softer material and have a cross-sectional shape that is appropriate to their function and is known in the prior art.

In some cases, space 7 is available for checking the space between the surface elements, which, with the corresponding rigidity of the walls forming it, remains open and therefore accessible even without a spreading intermediate layer. If high sealing reliability or a multitude of chamber functions is required, it may be preferable to provide the connecting profiles with several C and T profile parts. For example, Fig. 3 shows three such profile parts on each connecting profile, which together form six chambers. This naturally increases the number of functions available. In addition, the connection strength increases, of course, and there are alternatives if one of the profile parts should be damaged during assembly.

In the diagram it is provided that the chambers 21 and 26 serve as sealing chambers, by using suitable sealing members or one indicated by dots in the drawing Contain potting, while the chambers 23 and 24 communicate via suitable connections 27, 28 with the control spaces 3 of the associated surface elements 1,2. The chambers 22 and 25 serve as a sealing or control reserve in the event of repairs or can also be used for sealing from the outset. For the sake of clarity, the connections 27, 28 are made outside the cross section of the connection profiles. It goes without saying that they can be protected in a suitable manner with regard to the stresses which occur, for example, during assembly.

In this arrangement, the chambers 23, 24 serve to control the associated control spaces. In this case, they should be sealed against each other. If this seal is of great importance, the chamber distribution can also be such that only the chambers 21, 26 serve to seal the outside, while the chambers 23 and 24 or one of these is used for internal sealing, while the chambers 22, 25 as Control chambers are used.

As an alternative, a further connection 29 is shown between the chambers 23, 24 connected to the control interspaces 3 of the surface elements, which ensures communication between the control interspaces 3 of the interconnected surface elements 1, 2 and thus enables a communicating chain of such control interspaces create that allows control to be limited to larger distances.

Because the sequence of the CT profiles lies in the direction of the extension of the surface elements 1, 2, the thickness of the composite connecting profiles transverse to this surface extension is small, especially in the mutual arrangement according to FIG. 1. This has the great advantage that it in connection with laying devices of the type of U.S. Patent 3,968,658 can be used, which consists of a vertical cassette containing a roll of the material to be laid with a sealed outlet slot. As soon as a roll is used up, with its rear edge still in the cassette, a new roll can be inserted into the cassette from above in such a way that the connecting profiles are pushed one inside the other to protect the cassette. The interconnected profiles, as can be seen from the drawing, are also flat in the direction of the extent of the surface elements. Therefore, the seal at the outlet slot of the cassette can easily be designed in such a way that it can pass through the connecting section which is only slightly thickened compared to the surface elements.

Claims (7)

1. Seepage barrier wall, which is composed of a plurality of partial walls let into the ground between a danger region and an endangered region, which consist respectively of hermetic surface elements (1, 2) and connecting sections (6) for connection to adjacent partial walls, cooperating pairs of connecting sections (6) comprising a plurality of C-section parts (8 - 12), in which T-section parts (12, 13) of the respectively opposed connecting section engage, forming chambers (18 - 26) with sealing means, a plurality of chambers (18 - 26) arranged one behind the other in the gap of the connecting sections (6) being provided, whereof at least the outer chamber (20 or 26) facing the danger region is provided with sealing means, characterised in that at least three chambers (18 - 26) arranged one behind the other are provided, whereof the central chamber (19; 22 - 25) is accessible for inspection.
2. Seepage barrier wall according to Claim 1, characterised in that the connecting sections (6) are identical in a complementary manner and the T-section parts (11, 12, 13) are formed by legs of the C-section parts.
3. Seepage barrier wall according to Claim 1 or 2, characterised in that the surface element (1, 2) has a duplex construction and consists of two hermetic surface members enclosing an intermediate inspection chamber (3), which is connected to the central chamber (19; 22 - 25).
4. Seepage barrier wall according to Claim 3, characterised in that the chamber (21 or 26) closest to the associated double surface element (1, 2) can be sealed with respect to a passage of fluid from outside the surface elements (1, 2) to be connected and the intermediate inspection chamber (3) comprising a flow connection (27, 28) to a more remote chamber (23, 24).
5. Seepage barrier wall according to Claim 4, characterised in that the intermediate inspection chambers of the surface elements (1, 2) respectively communicate with each other by way of a more remote chamber (23, 24).
6. Seepage barrier wall according to Claim 4 or 5, characterised in that provided between the chambers connected to the intermediate inspection chambers (3) are further chambers provided with sealing means.
7. Partial wall for a seepage barrier wall, which comprises a double-layered hermetic surface element (1, 2) with an intermediate inspection chamber (3) located between both layers and at least one connecting section (6) connected thereto, which for connection to a complementary connecting section (6) comprises C-shaped and Tshaped sectional parts (8 - 12 or 11 - 13), characterised in that at least two C-shaped and two T-shaped sectional parts are respectively provided and the intermediate inspection chamber (3) of each surface element (1, 2) is connected as regards flow to the next but one adjacent C-section.

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