The invention relates to a sealing arrangement for shaft and tunnel constructions.
Each body that is assembled from single monolithic components has contact joints. This applies, for example, for shaft end tunnel constructions, which consist of precast elements (lining segments). For example, in case that a tunnel construction shall be constructed and used under groundwater level, there is a need for water tightness of the whole construction. For a construction consisting of a plurality of prefabricated individual parts not only the requirement for water tightness of the monolithic components arises but also that of the sealing of the contact joints between the components against the hydrostatic pressure.
High demands are made on corresponding sealing systems. A closer inspection reveals that these demands change with the advancing construction phase of e.g. a tunnel construction. Therefore, the sealing systems must be able to fulfill their sealing function in different sealing situations and sealing phases. In terms of time there are, for example, different demands (1) during the assembly of the components, (2) during the fluidic bedding of the components and (3) during the solid bedding of the components.
Sealing arrangements for sealing constructive joints in tunnel constructions made of prefabricated components (lining segments) are generally known, see e.g. DE 102005039253, DE 102005039056, U.S. Pat. No. 4,946,309, EP 0222968, EP 0441250 and EP 0995013. A sealing element is glued into a groove circumferential around the abutting sides in a constant distance from the outside surface of the lining segments. The sealing effect of the sealing system is achieved after the assembly of the lining segments in that the sealing elements within the joints are contacting each other mirror-symmetrically. The contact has to be effected at least with a surface pressing power, which is greater than the pressure in the adjacent pressure medium. The desired surface pressing power is adjusted by choosing the elastic compression behavior of the two sealing elements depending on the displacement of the compression.
Known sealing arrangements have several disadvantages. When, for example, a non-compressible elastomer is chosen as material for the sealing elements the pressing force may increase enormously. In extreme cases damages to the sealing arrangement and also the environment cannot be excluded when the associated reaction forces in the component are conferred. Especially when several components contact each other with the corner bodies of their sealing systems this results in leakages or damages.
Under consideration of positioning errors between two components of the tunnel the mirror-symmetric arrangement of the sealing elements is practically accidental. The contact of the two sealing elements then only takes place on a reduced bearing portion. Since the surface pressing power is not independent of this bearing portion the danger of a leakage is increased with the reduced pressing power.
In addition, the intended surface pressing power is reduced in case of a subsequent increase of the joint width, so that the danger of a leakage is hereby also increased.
The sealing elements in the contact joints of the tunnel shall preferably have an unlimited lifetime. The technical requirement is defined as a 100 years lifetime. In order to ensure the minimum required surface pressing power for this long period the characteristic of relaxation of the materials has to be taken into account. The decline of the elastic tension forces (up to 40%) over time has to be accounted for by an increased starting tension when assembling the sealing arrangement. All of the already unwanted force reactions of the elastic tension forces are increased accordingly.
The sealing arrangements according to the prior art only act singularly. A leakage inevitably leads to a leakage stream of surrounding medium, e.g. water, into the tunnel. The targeted localization of the leakage is problematic in view of the wall thickness and the spreading possibilities in the contact joints of the components. A sanitization of the leakage can therefore not be performed locally on the inner side of the sealing system and always requires great efforts. With the means known in the prior art, however, redundant sealing systems can only be realized with great effort and in big tunnels.
It is therefore an object of the present invention to improve the sealing of joints between components of shaft and tunnel constructions, such that the disadvantages of the prior art are avoided, and in particular a reliable sealing of shaft and tunnel constructions in different sealing situations and sealing phases and at a long lifetime is achieved.
The problem is solved with the subject-matter according to claims 1 and 10. Advantageous embodiments are given in the subclaims.
In a first aspect the invention provides a sealing arrangement for shaft and tunnel constructions comprising
a) at least two components lying against each other with abutting sides so that between the components a joint is formed that connects a first area with a second area, the first area having a first medium with a first medium pressure and the second area having a second medium with a second medium pressure, wherein a pressure difference is present between the first and second medium pressure, and
b) at least one elastic sealing system at each of the abutting sides of the components for sealing the joint,
characterized in that each of the sealing systems has at least one sealing element projecting to the joint, with which the sealing systems lie against each other on a contact plane, and wherein each of the sealing elements has at least one pressure area exposed to the medium with the higher medium pressure, so that a sealing force is applied between the sealing elements at the contact plane, which is greater than the force applied without the pressure difference, and which generates a contact pressing, which is greater than the pressure difference.
In the sealing arrangement according to the invention the elastic tension forces, which are generated when the sealing systems, after the systems have been brought into contact with each other, are pressed against each other by reducing the joint width are reduced or avoided completely compared to sealing arrangements of the prior art, and the necessary surface pressing pressure is achieved by a self-sealing force effect of the medium pressure. In order to achieve this force effect the sealing elements of the sealing system are designed geometrically in such a manner that they exhibit pressure areas against a low pressure or the atmosphere after mutual contact. On these pressure areas a differential pressures acts because of the pressure difference between the media, resulting in the force securing the necessary surface pressing pressure at the area, with which the sealing elements lie at each other at the contact plane. In this manner, the pressing pressure is inevitably always adapted to the respective medium pressure and essentially independent from the joint width achieved after contact. In order to achieve the necessary contact pressing considerably smaller reaction forces are necessary. By adjusting the contact area, achievable for example by the design of the sealing elements, also the contact pressing can be adjusted. Further, also a misalignment of the components does not change the quality of the sealing, because the contact does not depend on the symmetry of the sealing elements.
In a preferred embodiment of the invention the sealing element is pivotable or tiltable about a hinge. The term “hinge” as used herein refers to a region of the sealing system featuring or forming a static center, around which the pivoting motion takes place and which itself does, at least essentially, not participate in the pivoting motion. In the hinge region the deformation motions generated by the pivoting or tilting of the sealing element are comparatively small (near “zero”). The hinge region may have a reduced cross-section compared to the adjacent base body and/or sealing element and/or a softer material. In preferred embodiments the hinge connects the base body of the sealing system with the sealing element. The pivoting or tilting motion can be in the direction of the joint or in the opposite direction.
In the arrangement according to the invention the force component of the contact pressing generated by a possible pretension of the sealing element is as small as possible compared to the force component of the contact pressing generated by the media differential pressure, i.e. the pressure difference between the media. Preferably the force component of the contact pressing generated by the media differential pressure is >50%, further preferred >60%, >70%, >80%, >85% or >90, especially preferred >95%, >96%, >97%, >98% or >99%.
The term “contact pressing” or “surface pressing power” as used herein is to be understood as being the pressure at the contact area, i.e. the area at which the sealing elements are contacting each other at the contact plane. The term “pressure area” as used herein means any surface of the sealing system, in particular of the sealing elements, exposed to the medium pressure.
In an especially preferred embodiment each of the sealing systems has a base body, with which the sealing system is attached to the component. The attachment can be achieved in many ways, for example by way of adhesion, concrete encasement, force fitting, or by means of anchoring feet.
In an especially preferred embodiment the elastic sealing system consists of elastomeric material.
The term “elastic” as used herein designates the characteristic of a body or a material to change its shape under the application of a force and to revert to the original shape after removal of the acting force. As used herein, an elastic body is in particular to be understood as being a body having an elasticity modulus of 0.1 or lower, preferably 0.01 to 0.1. An example of an elastic material is silicone rubber. The term “elastomeric material” as used herein refers to a rigid but elastic natural or synthetic polymer, the glass transition point of which is preferably below room temperature (25° C.). Examples for elastomeric materials are ethylene propylene rubber (EPM), ethylene propylene diene rubber (EPDM), styrene butadiene rubber (SBR), and nitrile butadiene rubber (NBR).
Preferably each of the sealing systems has at least two sealing elements projecting to the joint with which the sealing systems lie against each other at contact planes. The provision of two, three or more, and thus redundant, sealing elements provides enhanced sealing safety.
The sealing systems can be arranged in a groove circumferential around the abutting sides of the components and/or at a bevel of the components circumferential around the abutting sides of the components.
The groove or bevel will not have to be disposed at a distance from the edge of the abutting sides of the components, but can also be arranged at the edge of the abutting sides, in which case the sealing systems are arranged flush with the side surfaces of the components. Thus, leakage channels are avoided, which otherwise would form and, in embodiments according to the prior art, would additionally have to be sealed with a filler strip.
In an especially preferred embodiment of the sealing arrangement according to the invention a crack is present between the component and the sealing element, which crack is open to the medium with the higher medium pressure. In another preferred embodiment a crack between the base body and the sealing element is present, which crack is open to the medium with the higher medium pressure. The at least one sealing element may, for example, be arranged in a recess of the base body, or the base body may be provided with a lip contacting the component. The medium with the higher medium pressure can enter the crack and thus exert a respective force effect on the sealing element leading to the pressing operation of the sealing elements. In these embodiments the sealing element may be designed in the form of a lip connected to the base body via a hinge, the lip being pivotable around the hinge. In these embodiments, the base body and the sealing element pivotable around the hinge form an essentially angulate form, the sealing element or the sealing lip being preferably angled in the direction of the area with the higher medium pressure.
Preferably the sealing systems are each monolithically designed, thus each forming a physical unit. Base body and sealing element preferably form such a physical unit, and may consist e.g. of a single piece of elastomeric material. Also in case of two or more sealing elements the sealing system is preferably designed monolithically. The redundancy already mentioned may, for example, also be achieved by arranging two or more sealing systems, which, for example, each possess a sealing element, twice or multiple times in parallel, e.g. together in a groove or at a bevel.
In a preferred embodiment the sealing systems are arranged generally mirror-symmetric to each other, i.e. mirror-symmetric in relation to the contact plane.
In a further embodiment the sealing systems are designed generally wedge-shaped and are arranged at a bevel of the components circumferential around the abutting sides of the components. In this embodiment the forces acting on the pressure area(s) of the sealing element due to the medium pressure are redirected from the bevel in direction of the contact plane, such that a respective sealing force is generated.
In a second aspect the invention provides a method for sealing a joint between components of shaft and tunnel constructions, the joint connecting a first area with a first medium and a second area with a second medium, wherein
a) the components are each, at their abutting sides, equipped with an elastic sealing system, which has a sealing element projecting to the joint,
b) the sealing systems are, with their sealing elements, brought into contact at a contact plane, and
c) by means of a pressure difference, which is present or generated between the first medium and the second medium, a force is exerted to pressure areas of the sealing elements directed to one of the areas in such a manner, that a sealing force is generated between the sealing elements at the contact plane, which is greater than the force generated without the pressure difference, and which generates a contact pressing greater than the pressure difference.
In a preferred embodiment of the method a sealing element is used that is pivotable or tiltable about a hinge. The hinge may, for example, be a region of the sealing system having a reduced cross-section or is made of a softer material.
In the method of the invention it is preferred that the force component of the contact pressing generated by the pressure difference is >50%, preferably >60%, >70%, >80%, >85% or >90, especially preferred >95%, >96%, >97%, >98% or >99%.
In the method of the invention it is preferred that the contact area, with which the sealing elements are brought in contact at the contact plane is smaller than the pressure area(s) exposed to the higher medium pressure, wherein the ratio of the pressure area(s) to the contact area is preferably at least 2:1, further preferred at least 5:1, at least 10:1, at least 20:1 or at least 30:1, and especially preferred at least 50:1.
The sealing systems used in the method preferably have a base body and are attached to the component with this base body, for example by adhesion, concrete encasement, force fitting, or by means of anchoring feet.
In the method of the invention sealing systems of elastomeric material are preferably used.
Further, it is preferred to use sealing systems that have at least two sealing elements projecting to the joint with which the sealing systems are brought into contact at contact planes.
In a preferred embodiment the sealing systems are arranged in a groove circumferential around the abutting sides of the components and/or at a bevel of the components circumferential around the abutting sides of the components.
Further preferred, the sealing systems are arranged flush with the side surfaces of the components in a groove or bevel at the edge of the abutting sides of the components.
In the method of the invention a crack may be provided between the component and the sealing element and/or between the base body and the sealing element, the crack being open to the medium with the higher medium pressure. The at least one sealing element may, for example, be arranged in a recess of the base body, or the lip of the base body can be arranged between the sealing element and the component in such a manner, that a crack remains between the base body and the sealing element, in which crack medium can enter.
It is preferred to use monolithically designed sealing systems.
It is especially preferred to arrange the sealing systems generally mirror-symmetric to each other.
In a further embodiment of the method of the invention sealing systems are used that are designed generally wedge-shaped, and the sealing systems are arranged at a bevel of the components circumferential around the abutting sides of the components.
In a third aspect the invention also relates to a tunnel or shaft construction with a sealing arrangement according to the invention.
In the following, the invention is further exemplified by means of figures showing preferred embodiments of the invention.
The sealing system 7 serves the sealing of the joint 4, whereby the sealing of two areas 5, 6 on opposite sides of the sealing systems 7 against each other is achieved.
The first area 5 may, for example, be the exterior and the second area 6 the interior of a tunnel, both during the fluidic as well as the solid bedding of the tunnel. In both areas 5, 6 are different or, as the case may be, also identical media 17, 18, which, however, exhibit different pressures, such that a pressure difference is present between the first medium 17 in the first area 5 and the second medium 18 in the second area 6. In the embodiment shown in
In
In
Number | Date | Country | Kind |
---|---|---|---|
10 2009 015 232.6 | Apr 2009 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/DE2010/000377 | 3/31/2010 | WO | 00 | 12/23/2011 |