EP3580429B1 - Reinforcement system for the concrete lining of the inner shell of a tunnel construction - Google Patents

Description

The invention relates to a reinforcement system for the concrete lining of the inner shell of a tunnel building according to the features of claim 1.

In the case of tunnels driven by miners, the shotcrete construction method (New Austrian Tunnel Construction Method, NED) usually leads to a two-shell construction method with an outer shell made of shotcrete and an inner shell made of in-situ concrete.

In this case, the shotcrete is usually applied immediately after the excavation to temporarily secure the rock. In addition, securing with steel arches, anchors and reinforcement meshes may be necessary.

The subsequently installed inner shell made of in-situ concrete is then used for the permanent expansion of the tunnel and is usually concreted on tunnel formwork wagons. This bowl has a thickness of 30 cm to 60 cm, but can also be made significantly thicker. The section lengths in which the inner shell is concreted are in most cases around 8 m to 12.5 m. The inner shell can be reinforced or unreinforced.

The present invention relates to the construction of tunnels in which the inner shell is reinforced.

A sealing film (KDB) is often installed between the outer and inner shell of a tunnel building, which protects the inner shell from possible aggressive mountain water as well as the interior from the ingress of mountain water. In order not to damage this sealing film between the outer and inner shell, the vault reinforcement of the inner shell must usually not be fixed to the outer shell. This makes self-supporting vault reinforcement necessary, consisting of outer and inner welded wire mesh and steel bars with supporting arches in between.

A reinforcement trolley is used as a scaffolding trolley for the installation of the vault reinforcement of the inner shell. The vault reinforcement stands on the pre-concreted base that was previously created. A vault reinforcement currently in use consists of an outer layer of reinforcement meshes, the supporting arches, an inner layer of reinforcement meshes and spacers. This construction is usually tied up tightly, i.e. tied together with wire in such a way that a firmly connected structure of mats and rods is created.

For this, with the support of the reinforcement wagon, reinforcement mats are first installed to create an outer, mountain-side reinforcement layer, with reinforcement mats first being installed in the direction of the ring with the support of struts arranged on the reinforcement wagon and in the second step reinforcement mats in the longitudinal direction. The supporting arches are then also placed in front of this outer, mountain-side position of the reinforcement with the support of the reinforcement carriages, so that these elements are held on the mountain side by the supporting arches.

Between this outer layer of the reinforcement and the outer shell or a seal arranged on the outer shell, spacers are arranged to provide the necessary minimum concrete cover for the reinforced concrete components e.g. to ensure about 6 cm. Inserted into these spacers are generally approximately U-shaped iron brackets which, for example, have a cross section of 10 mm. These iron stirrups are angled at their free ends in such a way that a desired distance between the outer layer of the reinforcement arranged on the mountain side and the outer shell itself can be set through an interaction of spacer and this U-shaped iron stirrup.

Towards the inside of the inner shell, an inner layer of reinforcement mesh is now placed on the supporting arches. The distance between the outer and inner layers of the reinforcement is thus determined by the supporting arches provided, which are arranged between these layers. Here, too, as with the outer layer, reinforcement meshes are usually first provided in the direction of the ring, in order to then arrange the reinforcement meshes in the longitudinal direction as a final step. Finally attached spacers then point on the outer inner layer towards the formwork of the inner shell, which is brought up to the self-supporting reinforcement with a formwork carriage before concreting. These spacers pointing towards the formwork ensure the necessary minimum concrete cover for the reinforced concrete components, as already described above.

The self-supporting structure, stabilized by supporting arches, is built up in blocks, i.e. the reinforcement is self-supporting and is supported in the elms or the side walls of the tunnel against the rock face. Additional support in the ridge area is therefore not required.

The reinforcement work in the tunnel must run so quickly that there is always sufficient lead time before the concrete work.

However, this assembly sequence has some disadvantages. On the one hand, the supporting arches to be built are prefabricated components that have a self-supporting stability must have. This requires a cross section that enables this stability, in the exemplary illustration of Figure 1 for example an approximately U-shaped cross-section. It is therefore the most complex component in the currently used reinforcement system with a high material weight, which accordingly has a negative impact on the costs of the reinforcement to be created.

A further disadvantage is that the assembly sequence described requires manual training and skill on the part of the workers working on site, which in turn is reflected in higher costs. Conversely, in the most negative case, workers with inadequate manual practice and skill can also lead to poorly executed reinforcement structures. In addition, the time factor for this assembly sequence is high, which has a negative effect on the progress of construction.

In particular, it is disadvantageous that this basic construction can only be installed with dimensional accuracy to a limited extent. After the supporting arches have been placed and the reinforcement mats have been attached on the inside, the reinforcement structure usually sags at least slightly as soon as it is released from the reinforcement carriage. A targeted, defined installation of the reinforcement for the inner shell is only possible to a limited extent.

The AT 362 739 B discloses an arch segment for an extension arch of underground tunnels or routes, which segment has a lattice girder section and a sliding profile section connected at the end to the lattice girder section. These arch segments are to be connected to form self-contained expansion frames.

Through the DE 1 237 160 A counts a butt joint between lattice girders to the state of the art, which serve as reinforcement of a tunnel lining made of concrete. The trusses are lattice girder sections and made from round iron. At the ends of the trusses are between the Upper chord and the lower chord profile sections fastened by welding and connected to one another by a pair of straps and screws and / or wedges in a tensile manner.

A flexible composite structure is possible through the DE 39 27 446 C1 known. The composite construction includes a shotcrete layer on the wall of the mountains surrounding the tunnel or the route as well as a plurality of extension frames arranged in the longitudinal direction of the underground space made of extension segments connected in a flexible manner according to the convergence of the mountains and a concrete backfill between the shotcrete layer and the extension frame. The extension segments are connected by clamps or similar connecting means. The concrete backfill extends along the underground space, if necessary with warping mats. Between adjacent expansion frames are bolting elements that are designed as squeezing elements that can be squeezed together at least in their transverse direction under the influence of the rock pressure.

From the publication DE 20 2006 003 288 U1 a supporting arch for stabilizing the shotcrete lining of a tunnel is known, which consists of several steel belts which are connected to one another by struts, the struts being formed from bent steel parts of one or more different shapes, which are connected to the belts by welded connections, the form is open, i.e. not a closed curve, and has at least three straight partial areas which merge into one another at their connection point in a bending radius with an angle between approximately 45 ° to 135 °. As a result, the support arch should be cheaper to manufacture and at the same time can be better adapted to the tunnel wall.

From the publication AT 258 837 B An expansion system made of iron-reinforced concrete for route expansion, tunnels and other underground structures is known, in which belt and connecting elements that are also welded to one another are used as reinforcement, with individual, Similar, curved to polygons, provided with a parting bracket bracket can be used.

Finally it is from the pamphlet U.S. 3,858,400 A a method for reinforcing tunnels is known that when driving the tunnel behind the milling head of the tunnel milling machine according to the tunnel radius bent and circumferentially reinforced rock protection mats are arranged side by side and connected to each other, which then take over the reinforcement for the shotcrete of the tunnel wall.

Against this background, the object of the present invention is to create a reinforcement system for the concrete lining of the inner shell of a tunnel building, which is a cheaper and structurally simplified alternative to known support arch systems. The overall installation of the reinforcement system should be dimensionally accurate and documentable, while at the same time making work on site easier and reducing installation errors.

This is achieved according to the invention by the reinforcement system for the concrete lining of the inner shell of a tunnel building according to claim 1.

The further subclaims 2 to 13 have advantageous developments and designs of the invention as their subject matter.

The subclaims 14 to 20 relate to a method for installing the reinforcement system of claims 1 to 13.

The inventive basic idea lies in the connection of a structurally simplified tensioning arch or tensioning ring with a tensioning support body and spacer elements which support and align this tensioning arch or tensioning ring through the tensioning support body with spacer on the outer shell of the tunnel wall. The inventive reinforcement system differs fundamentally from the previous approach due to the construction-related changed assembly sequence, which has effects also brings on the work process and the cost of materials.

In contrast to the arrangement of the self-supporting arches between the outer and inner reinforcement layers in the currently predominant system described, the inventive reinforcement system provides for the first assembly step to provide the clamping arch or ring, for which it is guided on the reinforcement carriage by placing the spacers with clamping support bodies on the self-supporting Outer shell is braced. The tension arches or rings arranged parallel to one another thus form the substructure for the first outer layer of the reinforcement mats, which, for example, are first fastened in the ring direction then in the longitudinal direction on this sub-structure of the tension arches or rings.

In contrast to the known arrangement, spacers are then arranged on this outer layer, which in turn set the distance to the inner layer of the reinforcement mats. A supporting arch in the sense of the state of the art between the outer and inner layer is thus completely omitted, which leads to a considerable amount of potential for savings. At the same time, however, the assembly of the outer and inner reinforcement layers after the tensioning arches or rings have been placed is greatly simplified compared to the assembly sequence of the known reinforcement system, which leads to the desired simplification of assembly and, as a result, to a reduction in the risk of installation errors, especially by inexperienced workers leads.

These simplified arches or rings can be designed in an advantageous design as round iron in the form of arch segments, which are connected on site to an expansion arch of the required size depending on the tunnel cross-section and are arranged on the outer shell of the tunnel wall by means of the tension support body and spacer elements according to the invention.

In principle, however, the cross-section of the simplified arch elements in different designs is appropriate, since according to the invention it is primarily a question of these arch elements having a simple design and thus being able to be used as an inexpensive component in contrast to the cost-intensive self-supporting supporting arches. Therefore, the focus is on the question of the stable support of the simplified arch elements on the outer shell of the tunnel wall as a substructure for the reinforcement.

Exemplary designs provide two or four arch segments that are welded to one another at one free end, connected in overlapping areas by cable clamps or inserted into a connecting sleeve and secured here, for example, by screws, and are thus connected to form a supporting arch, the length and shape of which corresponds to the to be reinforced cross-section of the tunnel building is designed accordingly. A combination of various of the aforementioned connecting means can also be expedient, depending on the application.

A significant improvement compared to the known reinforcement systems is that the tension arches or rings are not only held and positioned by the tension support body but are also braced by a final expansion, whereby a high level of strength of the installation as well as dimensional accuracy can be achieved despite the advantageously simple Building this basic structure.

One possible design provides for an overlap section serving to introduce post-tensioning between at least two of the arch segments in the tensioning arch or ring, which allows for a possible loss of tension after the tensioning arch or ring has been installed and released by the support elements of the reinforcement carriage or to react to a slight lowering in the ridge area. For this purpose, the clamping arch or ring is held together in the overlapping area of two arch segments, for example by angle hooks on the free ends of adjacent arch segments, on which a clamping device engages. These angle hooks can be formed by the free ends themselves and are by the The tensioning device is pulled towards one another, the tensioning arch or ring is thus widened and the tension in the tensioning arch or ring is increased again overall, whereby the desired arch course can be readjusted, for example in the sunken ridge area. Only then is there a final, fixed connection of the tensioning arch or ring in the overlapping area by the means already mentioned, for example rope clamps or welding.

The significantly improved dimensional accuracy of the reinforcement system according to the invention thus arises from the interaction of the preformed tensioning arch or ring with the tensioning support bodies individually adapted to their respective bracing position on the arch or ring by cutting to length or angling. Thus, the arch or ring is braced in the defined position even if the distances to the outer shell, for example, which are often very unevenly deviate, because these deviations are compensated for by the length-adjusted tension support body. Finally, the final bracing through the expansion of the arch or ring causes a secure fixation in this dimensionally accurate installation position.

It is provided according to the invention that when these tensioning arches or rings are introduced in the tunnel lining, their distances from one another can be the same or greater than is the case with the previous supporting arch systems. This can therefore lead to a further advantage, since fewer clamping arcs or rings would be required per section (block). Due to the connection of the tension support body with the spacer bodies resting on the outer shell, these tension arches or rings are also supported in a self-supporting manner on the outer shell, although they do not have a three-dimensional framework-like cross-section. The stabilization takes place via the bracing with the tension support bodies.

When installing this reinforcement system, it is provided that this is installed in a known manner with the support of reinforcement cars as cantilever reinforcement. The spacers with inserted tension supports are then, for example, only inserted slightly angled between the clamping arch or ring and the outer shell and then manually pulled into their installation position, whereby the clamping support bodies run approximately at right angles to the course of the clamping arch or ring in this connection area and are braced between the outer shell and the clamping arch or ring . Since the outer shell is generally unevenly designed, it is necessary for this to shorten the tension support body to a dimension required for bracing.

Alternatively, the insertion of the tension support bodies and spacers can also be supported by the tensioning arch or ring held on the reinforcement carriage being pulled mechanically to a suitable distance from the support surface of the outer shell against the internal tension of the tensioning arch or ring for the respective insertion of the tensioning support bodies. After the instep support body and spacer have been placed, this tension is relieved so that the tension arch or ring is pressed against the instep support body at this point by its own tension, whereby the tension on the outer shell is achieved.

The process of tensioning by means of tension support body and spacer takes place over the entire circumference of the supporting arch at defined intervals, which ensure a secure, self-supporting stand of the tensioning arch or ring. Since, in the case of the tension arch, the base is already pre-concreted as the contact surface of the tension arch, it serves as a support for the free ends of the tension arch, which ensures its position and tension in relation to the outer shell with defined dimensions. In the case of the tension ring, it is braced with tension support bodies over its entire circumference at defined intervals, i.e. also in the base, since here the tension ring is also part of the reinforcement of the base.

Against this background, as I said, it is necessary to cut the tension support body to the required length on site, which is required for bracing and support. As a rule, the present one is used on site The cross-section of the tunnel building is measured and the tension support bodies are then cut to length according to the removed dimensions. In this case, it is nevertheless provided according to the invention to keep tension support bodies available in different dimensions in order to always be able to keep the section to be cut small.

In order to arrange the tension arches or rings on the outer shell of the tunnel wall, for example, the round iron is pressed against the outer shell and the KDB track possibly arranged on it in an advantageous embodiment of the invention by a connection of a spacer that sits directly on the rock face, and an example. M-shaped bracket supported as a tension support body. Between the laterally angled support arms of the M-shaped bracket engaging in the spacer, the clamping arch or ring is inserted into the trough-like recess formed here and clamped or clamped against the outer shell of the wall of the tunnel in the manner described above.

The tension support body in the form of an M-shaped bracket is just one possible design. An alternative design provides a clamping support body which engages with a fastening means, for example a clamping ring, on the round bar, for example, and holds it. The support arms of the clamping support body go from the fastening means to the spacers receiving them or to the spacers receiving them, provided that a separate spacer is assigned to each support arm.

For this it is necessary to construct a spacer on which the tension support body, for example the M-bracket, can engage or in which the M-bracket can engage with its free ends pointing towards the outer shell. Various structural solutions are possible for this.

There are expediently arranged depressions in the spacer. These can be designed in the manner of a borehole, so that the free ends of the clamping support body, for example the M-bracket, can be inserted directly into these holes. However, slots or projections can also be arranged in the spacer so that the M-brackets have an angled portion at the lower end with which they engage in these slots or rest against the projections. This releasable connection between spacer and clamping support body can basically be designed variably.

An advantage of arranging the instep support body on the spacer with bends on its support arms is that the mentioned required length adjustment of the instep support body to the respective distance between the outer shell and the tension arch or ring cannot be achieved by cutting off the iron but solely by bending it.

Alternatively, the spacer can have connecting means which, for example, have been inserted into a concrete spacer during the manufacturing process, for example, recessed plastic or metal receptacles or plastic or metal receptacles protruding from the upper side of the spacer facing the reinforcement.

In addition, each support arm of the clamping support body can engage in its own spacer or be connected to such a spacer. Care must be taken that the support arms of the clamping support body do not expand unintentionally when it is braced with the clamping arch or ring, which could lead to a loss of tension in the arrangement of the clamping arch or ring.

One design of the spacers can have a protective overlay, for example a type of geotextile, on their underside pointing towards the outer shell and resting on a KDB membrane, so that the KDB membrane is not damaged by the upstand of the spacer. Elongated rod-shaped spacers or individual round spacers can be attached to the M-brackets. In this case, flat contact areas are preferred so that the KDB track is not stressed at certain points.

The method for installing the reinforcement system according to the invention provides that the tension arches or rings are mounted in the form of the tunnel cross-section to be reinforced so that they have a defined installation position in relation to the first outer outer layer of the reinforcement, these tension arches or rings on a reinforcement carriage guided and placed in the tunnel cross-section. One procedural solution now provides that the tensioning arches or rings for inserting the tensioning support bodies between the supporting floors and the outer shell of the reinforcement carriage are pulled into a holding position and, after positioning the tensioning support bodies in their connecting areas, are inserted by returning them from the holding position, whereby the tensioning arcs or rings are inserted into the Engage connecting areas of the tension support body and are braced and supported against the outer shell of the tunnel building via the tension support body. Alternatively, the clamping arches or rings are only held on the reinforcement carriage, with the clamping being carried out by manually inserting the combination of spacer and clamping support body.

In order to determine the desired installation position of the arches and to secure them against displacement when inserting the arch supports, the arches are mounted in a defined arch length and placed on the pre-concreted base of the tunnel building or in holes that are arranged in this base that has already been concreted. The sole serves as a support for the erected tension arches, whereby the arrangement in prefabricated holes prevents the tension arches from deviating in the construction joint between sole and arch.

To further stabilize the built-in reinforcement system, the tension arches or rings can be fastened after the tensioning by the tension support body by fastening means or a welded connection in the connection area of the tension support body.

An alternative arrangement also has a stabilizing effect, which provides that the clamping arches or rings installed in parallel in pairs and firmly connected by means of cross connectors. The clamping arches or rings connected in pairs in this way form a very robust support for the further reinforcement means.

In order to adapt the tension support bodies exactly to the conditions on site, it will generally be expedient that the tension support bodies are cut to length or adjusted on site to the required size. For this purpose, the specific dimensions are taken on site and the length adjustment of the tension support body is used as a basis. There may be special cases in which such adaptation measures are not necessary due to an outer shell that is already uniformly designed, for example when an inner shell is arranged on a segmental lining.

Figur 1

einen Schnitt durch ein Bewehrungssystem nach dem Stand der Technik,

Figur 2

einen Schnitt durch das erfindungsgemäße Bewehrungssystem,

Figur 3

den beispielhaften Aufbau des Bewehrungs-systems umfassend den Abstandhalter 1 mit M-Bügel 2 und Spannbogen 4,

Figur 4

einen erfindungsgemäßen Spannstützkörper 2 in Form eines M-Förmigen Bügels sowie

Figur 5

eine Detailansicht die Kombination aus Abstandhalter 1, Spannstützkörper 2 und Spannbogen 4 in perspektivischer Ansicht,

Figur 6

einen Teilbereich des Spannbogens 4 bestehend aus 2 Teilbereichen,

Figur 7

eine Seitenansicht eines vollständig eingebauten Spannbogens 4 mit Detailansicht sowie

Figuren 8 bis 17

verschiedene gestalterische Bauformen der erfindungsgemäßen Abstandhalter 1.

In the following, the invention will be explained in more detail with reference to drawings. Show it

Figure 1

a section through a reinforcement system according to the state of the art,

Figure 2

a section through the reinforcement system according to the invention,

Figure 3

the exemplary structure of the reinforcement system including the spacer 1 with M-bracket 2 and clamping bow 4,

Figure 4

a tension support body 2 according to the invention in the form of an M-shaped bracket as well

Figure 5

a detailed view of the combination of spacer 1, clamping support body 2 and clamping bow 4 in a perspective view,

Figure 6

a sub-area of the tensioning arch 4 consisting of 2 sub-areas,

Figure 7

a side view of a fully installed clamping bow 4 with a detailed view and

Figures 8 to 17

various design designs of the spacers 1 according to the invention.

Figure 1 illustrates the structure of a reinforcement of the inner shell as already explained in the introduction to the description, comprising a spacer 16 with inserted position securing body 17, on which the outer layer 19 of the reinforcement mats rests, which is fixed in its position relative to the outer shell 15 by the supporting arch 18 provided. The inner layer 20 of the reinforcement is attached to the supporting arch 18, which determines the spacing of the reinforcement layers, and finally carries spacers for the formwork, which are not shown in the drawing here.

Figure 2 makes the difference to the previous solution clear. The most striking difference is the absence of the supporting arch 18 between the inner and outer reinforcement layers 19 and 20, since these are only separated from one another by spacers 21. This construction is possible because the self-supporting component in the system is the combination of spacer 1 with clamping support body 2 and clamping arch 4 or ring, which is first arranged and clamped on the outer shell 15.

Due to the arrangement of the outer layer 19 of the reinforcement mats, this arrangement already achieves a high degree of stability, so that it can support the further arrangement of the spacers 21 and the inner layer 20 of the reinforcement mats. The spacers 22 facing the formwork on the inner layer 20 serve to ensure the minimum concrete cover of the reinforced concrete components used to form the formwork.

In Figure 3 an exemplary arrangement of the reinforcement system according to the invention in a tunnel building is shown schematically. It is here on the right half of the picture the reinforcement with reinforcement meshes arranged on the arches 4 shown, which are attached to the reinforcement substructure according to the invention.

On the left half of the picture, the reinforcement system according to the invention is shown in front of the cladding with reinforcement mats. On this page it can be seen that three basic components are crucial for this reinforcement substructure, as shown in Figure 5 are shown in more detail. On the one hand, there is a spacer 1, which sits directly on the tunnel wall to be reinforced or the outer shell of the tunnel building and the KDB 15, which may be arranged here. This is, for example, a cast concrete body which has special receptacles 8 as connection areas for the arrangement of the tension support body 2. This clamping support body 2 is connected to the spacer 1, for example inserted or clamped into corresponding receptacles 8 of the spacer 1.

The instep support body 2 has at least two support arms 3 ( Figure 4 ), which engage in the spacer 1 and extend to the clamping arch 4 or ring to be supported. The clamping arch 4 or ring thus engages in this exemplary design in a connection area 5 formed between the support arms 3 and thus fixes the connection of the clamping support body and spacer in its actual position. It is essential here that the tension arch or ring is braced in the tunnel cross-section via the tension support body 2 on the tunnel wall or the outer shell of the tunnel building and is thus designed to be self-supporting.

In the design shown, the clamping arch 4 or ring is formed from individual round bars, which is even clearer in FIGS. 5 and 6. Alternatively, on the one hand, other cross-sections of the tensioning arch 4 or ring and, on the other hand, also for example two juxtaposed tensioning arches 4 or rings can be used, which are connected to one another via spacers as connecting bodies, e.g. inserted round iron sections. In this way it can also be achieved that this consists of two parallel Round iron formed clamping arch 4 or ring already has its own status, which can then be braced against the tunnel wall by inserting the clamping support body 2 and spacer 1. The tension support body 2 then has a correspondingly shaped connection area 5 to the parallel tension arches or rings.

On the right-hand side of the picture it is then shown, as already stated, that the reinforcement system according to the invention is connected to reinforcement mats 6. These reinforcement mats 6 are attached to the previously provided tension arches 4 or rings with appropriate fastening means, for example wires. In this way, the overall reinforcement structure is created consisting of the inventive reinforcement system, which on the one hand forms the basis for the reinforcement mats, but on the other hand also defines their distance to the outer shell or the KDB sheet 15 arranged on the outer shell.

Figure 4 now shows a possible instep support body 2 in a design as M-shaped instep support body 2. This has the advantage that the M-shaped instep support body 2 has a centrally arranged connection area 5, which is designed as a recess between the two laterally branching support arms 3. The support arms 3 extend in this case from the clamping arch 4 or ring obliquely outwards, whereby the supporting function is guaranteed. This is essential because the central task of this tension support body 2 is not only the bracing but also the support on the outer shell. When bracing, the tensioning arch 4 or ring seeks a possible tension relief by evading in the longitudinal direction of the tunnel building to be reinforced. This tilting away must therefore be avoided in order to achieve the desired bracing and the resulting self-supporting structure. The lateral deployment of the support arms 3 on the clamping support body 2 causes precisely this lateral support against the lateral breaking out of the clamping arch 4 or ring in an inventive manner.

At its free lower ends 9 pointing towards the spacer 1, this exemplary clamping support body 2 is angled in the present design, so that it can be inserted into corresponding, for example, slot-like receptacles 8 in the spacer 1, as shown in FIG Figure 5 shown. It is also provided that the intrinsic tension of the clamping support body 2 can be inserted into the slot-like receptacles 8 in the spacer 1, also under a certain intrinsic tension, whereby a secure arrangement of the clamping support body 2 in the receptacles 8 in the spacer 1 is ensured.

In addition, by creating these bends 14 only on site, the possibility is created to produce the usually required length adjustment of the support arms 3 to the given installation position to achieve the required tension for the clamping arch 4 or ring. This represents an alternative to adapting the support arms 3 by shortening these support arms 3.

Figure 5 shows the arrangement according to the invention of these structural components of the reinforcement system in an exemplary detailed perspective view.

In this case, a spacer 1 is placed on a KDB 15, which in the illustration is designed as a rod-like spacer 1 with receptacles 8, 13 arranged in the manner of a slot on its upper side. In the middle area of its top side, the spacer also has a continuous depression 11. Both this design of the receptacles 8 and the recess 11 are only to be understood as exemplary designs, which is also made clear by the other designs in the following figures.

Engaging in the receptacles 8, a clamping support body 2 is connected to the spacer 1. For this purpose, the clamping support body 2 has angled portions 14 at its free ends 9 of the support arms 3, which are inserted into the slot-like receptacles 8, 13 engage the spacer 1 and are connected to this and supported on it.

Between the support arms 3 of the clamping support body 2, the connection area 5, in which the clamping arch 4 or ring is inserted, is arranged as a recess. In the design shown, there is no special connection between the clamping arch 4 or ring and the connection area 5. There is no connecting means arranged in this connecting area 5, but this can be quite useful in the case of other designs of this tension support body 2. The tensioning arch 4 or ring has an arched basic shape in order to simulate the arching of the tunnel cross-section accordingly.

Figure 6 shows a detail of two arch segments 23, 24 in a tension arch 4 composed of 4 segments, that is, half the tension arch 4. The connection area 26, which can be produced, for example, by welding, is indicated schematically. Arch segment 24 has at its free end ending approximately below the ridge an angled hook 27 which meets with a second angled hook at the end of the arch segments 24 connected here in an overlap 25 and a further third arch segment indicated only in dashed lines. The overlap 25 causes these angle hooks 27 to be spaced apart, as a result of which the bracing according to the invention is possible here, for example by means of a lashing strap engaging on both angle hooks 27.

Furthermore, for example, cable clamps can connect the two arch segments in the overlap area 25 such that they can be moved relative to one another. If the internal tension of the tensioned tensioning bow 4 or ring should therefore give way when the holding devices of the reinforcement trolley move back, the tensioning bow 4 or ring can be brought back into the correct position by increasing the inherent tension by bringing the angle hooks 27 together. Then, for example, the cable clamps can be tightened or welding can be carried out.

Figure 7 shows an entire assembled tensioning arch 4 with outer and inner reinforcement layers 19 and 20, the tension support bodies 2 and spacers 1 and 22, which are not shown in detail in the dimension. It becomes clear with what minimal structural effort a self-supporting reinforcement of the inner shell has been built.

The Figures 8 to 17 now show the most varied designs of the spacer bodies 1, essentially rod-shaped spacer bodies 1 being shown. As a rule, these have a continuous support surface 10 or two independent support surfaces 10, which are connected by an arcuate or recessed central region 11. In the latter design, the contact area 10 is reduced to the two permanent contact areas 10, which ensures a secure stand on the subsurface of the tunnel wall of the outer formwork and contributes to material savings in the spacers 1.

In the surface 12 of the spacer 1 facing the clamping arch 4 or ring, fastening means or receptacles 8 are now arranged, which are connected to the clamping support body 2. These receptacles 8 are either in the form of bores 7 or, as already explained in connection with the clamping support bodies 2, as slot-like receptacles 13 or projections into which corresponding angled portions 14 of the clamping support body 2 can then be inserted and clamped. Plastic or metal bodies can also be used as fastening means in the spacer.

It should be noted here in principle that the design of the spacers 1 can vary greatly, since they function in their functionality in different designs and must always be designed in their functional connection with the clamping support body 2. The rod-shaped design has the advantage here of simultaneously supporting and defining the tension of the clamping support body 2 in that it defines the distance between the laterally exposed Define support arms 3 effectively. The tension of the tensioning support body 2 in the gap between the tensioning arch 4 or ring and the outer shell 15 can also be set differently by several receptacles 8 at different distances from one another, depending on whether the support arms 3 engage closer to one another or further apart in the spacer 1. As a result, the tension support body 2 is shortened or lengthened.

In addition to the rod-shaped or rod-shaped training is also a one-piece training in the sense of Figure 16 possible, which is then only in connection with a free end 9 of the clamping support body 2. That is, here the spacer body 1 is plugged directly onto the free end 9 of the clamping support body 2, whereby two of these spacers are to be connected to the support arms 3 of a clamping support body 2 here as a rule.

Structural forms of the reinforcement system according to the invention are to be described in more detail below. Basically, an advantage of the reinforcement system according to the invention is that the tensioning arches or rings, which are used as supports for the reinforcement mats to be installed later, are kept clearly simple in construction than the supporting arches installed as standard in the prior art. The tension arches or rings consist of reinforcing iron, which are installed as round bars, for example. Alternatively, cross-sections other than the round bar are also possible, as it is primarily important that a structurally complex solution such as the supporting arch is not used here, but a simple reinforcing iron.

The question of the construction of the tension support body allows various structural solutions, which will now be discussed in more detail. In each case, the structural solution described below is to be disclosed in combination with the previously described designs of the clamping arches or rings as a combination, which relates, for example, to the various alternative cross-sections of the clamping arches or rings or their connection from segments.

A basic design of the reinforcement according to the invention provides, for example, a clamping arch or ring in the form described above, which can engage in an approximately M-shaped clamping support body. It engages in the recess approximately in the middle of the M-shaped clamping support body. The result is that this tension support body provides the distance and the bracing as well as the support on the outer shell of the tunnel building via two extended lateral support arms.

The M-shaped arrangement ensures that the laterally branching support arms ensure that, due to their course, which is arranged obliquely to the outer shell, a lateral tilting of the tensioned clamping arch or ring is not possible. There are now various options for the design of the approximately M-shaped tension support body, such as the connection to the outer shell of the tunnel building.

An advantageous design provides that the tension support body engages in standing areas in the form of spacers, which can consist, for example, of poured or extruded concrete, but in principle can also be, for example, plastic bodies. These spacers can either be assigned individually to the ends of the support arms or in the form of an approximately rod-shaped spacer in which both free ends engage, with holes or slot-shaped receptacles in the spacers being possible here.

Alternatively, it is also possible to arrange simplified standing areas at the free ends of the clamping support body, for example standing feet, which can be made of plastic, for example. In addition, there is the option of already integrally arranging the standing area on the tension support bodies, so that it does not have to be attached as a separate body but is already arranged on the tension support bodies when they are braced.

In addition to the design of the approximately M-shaped clamping support body described above, it is also alternatively in a Design provided to design a clamping support body from only one support arm, which engages the clamping arch or ring via a corresponding terminal receiving element. The inventive solution here is to secure this tension support body against tilting of the supporting arch when it is braced, which is why the standing area on the outer shell of the tunnel building is to be designed accordingly in a tilt-proof manner.

For example, a structural solution is provided in which an approximately trapezoidal spacer or standing area is provided for receiving the free end of the instep support body, the instep support body being inserted into a bore in this spacer. A wide contact area on the outer shell of the tunnel building ensures that this tension support body cannot tip over.

Fundamentally, in this context, further structural constructions for securing the tensioning support body consisting of a support arm are envisaged, which for example consist of a branching stand area consisting of several cantilever arms, which can be supported on the outer shell of the tunnel or a type of flat plate on which the Attacks the support arm of the instep support body.

It is thus clear that the clamping support body can basically be designed in different ways, provided that reliable protection against tilting of the clamping support body is achieved when the clamping arch or ring is braced. The tension support body must ensure the task of both bracing and secure support of the supporting arch.

Claims (20)

1. Self-supporting reinforcement system for the concrete lining of the inner shell of a tunnel construction having at least an outer layer (19) and an inner layer (20) of a reinforcement and spacers (1, 21),
   characterized by

   - tensioning arches (4) or tensioning rings with an adaptable arch length or an adaptable ring circumference, formed from at least two arch segments (23, 24) to form a tunnel reinforcement arch or tunnel reinforcement ring for the reinforcement of the inner shell of the tunnel construction, as support for at least an outer layer (19) made at least of welded wire meshes,

   - wherein the arch segments (23, 24) are each formed from an individual reinforcement steel rod,

   - tensioning support bodies (2) with a connecting region (5) to the tensioning arches (4) and with at least one support arm (3) for tensioning the tensioning arches (4) or tensioning rings on the outer shell or rock face wall of the tunnel construction in a supporting manner and so as to produce the spacing with respect to an outer shell (15) or the rock face wall,

   - first spacers (1) on the tensioning support bodies (2) for supporting on the outer shell or rock face wall of the tunnel construction and for generating the minimum concrete coverage of the installed reinforced concrete parts, and

   - second spacers (21) between an outer layer (19) and an inner layer (20) of the reinforcement.
2. Self-supporting reinforcement system for the concrete lining of the inner shell of a tunnel construction according to Claim 1,
   characterized in that
   at least two arch segments (23, 24) of the tensioning arches (4) or tensioning rings for adapting the arch length or the ring circumference are connected to each other by means of a releasable connecting element.
3. Self-supporting reinforcement system for the concrete lining of the inner shell of a tunnel construction according to Claim 2,
   characterized in that,
   in order to adapt the arch length or the ring circumference, at least two arch segments (23, 24) of the tensioning arches (4) or tensioning rings have overlapping regions, which are releasably connected to each other by means of a cable clamp.
4. Self-supporting reinforcement system for the concrete lining of the inner shell of a tunnel construction according to either of Claims 2 and 3,
   characterized in that,
   in order to adapt the arch length or the ring circumference, at least two arch segments (23, 24) of the tensioning arches (4) or tensioning rings have angled free ends as angled hooks or engagement points at which a tensioning device can be placed.
5. Self-supporting reinforcement system for the concrete lining of the inner shell of a tunnel construction according to Claim 1,
   characterized in that,
   in order to adapt the arch length or the ring circumference, at least two arch segments (23, 24) of the tensioning arches (4) or tensioning rings are connected to each other by means of a length-adjustable intermediate piece or connecting element.
6. Self-supporting reinforcement system for the concrete lining of the inner shell of a tunnel construction according to one of the preceding claims,
   characterized in that
   the arch segments (23, 24) of the tensioning arches (4) or tensioning rings are configured as reinforcement steel rods of round, oval or rectangular cross section, which have a diameter or a diagonal of approximately 15 mm to 50 mm.
7. Self-supporting reinforcement system for the concrete lining of the inner shell of a tunnel construction according to one of the preceding claims,
   characterized in that
   the tensioning support bodies (2) are arranged on and distributed approximately uniformly over the tensioning arches (4) or tensioning rings, which are composed of the arch segments (23, 24).
8. Self-supporting reinforcement system for the concrete lining of the inner shell of a tunnel construction according to one of the preceding claims,
   characterized in that
   the tensioning support bodies (2) are approximately M-shaped, wherein the connecting region (5) for receiving the tensioning arch (4) or tensioning ring is arranged in the centrally disposed, approximately V-shaped recess between the support arms (3) of the tensioning support body (2).
9. Self-supporting reinforcement system for the concrete lining of the inner shell of a tunnel construction according to one of Claims 1 to 7,
   characterized in that
   the tensioning support bodies (2) have a connecting region (5) for receiving the tensioning arch (4) or tensioning ring in the form of a fastening means to the tensioning arch (4), from which the at least one support arm (3) of the tensioning support body (2) branches off.
10. Self-supporting reinforcement system for the concrete lining of the inner shell of a tunnel construction according to one of the preceding claims,
    characterized in that
    an individual elongate spacer (1) is provided for receiving free ends (9) of the support arms (3) of the tensioning support body (2) and for supporting on the outer shell of the tunnel construction or the rock face wall, which spacer (1) has, on its top directed towards the tensioning arch (4) and the tensioning support body (2), receptacles (8) for the free ends (9) of the support arms (3), which receptacles (8) are configured as slit-like depressions (13), bores (7), projections or inserted connecting means.
11. Self-supporting reinforcement system for the concrete lining of the inner shell of a tunnel construction according to Claim 10,
    characterized in that
    the elongate, bar-like spacer (1) has, on its bottom-side contact face, a central region (11) which is configured in a recessed manner in relation to the contact faces arranged at the periphery.
12. Self-supporting reinforcement system for the concrete lining of the inner shell of a tunnel construction according to one of Claims 1 to 9,
    characterized in that
    an individual spacer (1) or foot is arranged at each of the free ends (9) of the support arms (3) of the tensioning support body (2).
13. Self-supporting reinforcement system for the concrete lining of the inner shell of a tunnel construction according to one of the preceding claims,
    characterized in that
    the spacers (1) are coated, on their rear contact face, with a protective support that counteracts damage.
14. Method for installing a reinforcement system according to one of the preceding claims,
    characterized in that

    - tensioning arches (4) or tensioning rings produced from the arch segments (23, 24) are preformed and assembled such that, in their position and basic form in the tunnel cross section, they form a support for the defined installation position of the outer layer (19) of the reinforcement,

    - these tensioning arches (4) or tensioning rings, guided on a reinforcement carriage, are placed or held and aligned in the tunnel cross section,

    - the distance from the tensioning arch (4) or tensioning ring to the outer shell or rock face wall is measured in a punctiform manner at the circumferentially defined engagement points of the tensioning support bodies, and each tensioning support body to be inserted is shortened in situ, by trimming or angling, to the necessary measurement that is determined in such a manner,

    - spacers (1), and tensioning support bodies (2) adapted in length, are arranged in a clamped manner between the outer shell of the tunnel construction or the rock face wall and the tensioning arches (4) and are distributed over the entire circumference thereof,

    - as a result of which the tensioning arches (4) or tensioning rings are tensioned and supported against the outer shell of the tunnel construction or the rock face wall via the tensioning support bodies (2) and spacers (1), and

    - a final defined tensioning of the tensioning arches (4) or tensioning rings is effected by expanding and subsequently fixing the tensioning arches (4) or tensioning rings themselves.
15. Method for installing a reinforcement system according to Claim 14,
    characterized in that
    the arch segments (23, 24) are mounted at least in part by releasable connecting means to form tensioning arches (4) or tensioning rings, wherein this connection between at least two of the arch segments (23, 24) is released before the final expansion of the tensioning arches (4) or tensioning rings and is fixed again after the expansion.
16. Method for installing a reinforcement system according to Claim 14,
    characterized in that
    length-adjustable intermediate pieces are inserted between at least two of the arch segments (23, 24), wherein these intermediate pieces are lengthened for the subsequent expansion of the tensioning arches (4) or tensioning rings and are fixed again after the expansion.
17. Method for installing a reinforcement system according to Claim 14, 15 or 16,
    characterized in that
    the tensioning arches (4) are set up as supports on the precast concrete floor of the tunnel construction or in holes which are arranged in this already concreted floor.
18. Method for installing a reinforcement system according to one of Claims 14 to 17,
    characterized in that,
    after the tensioning by the tensioning support bodies (2), the tensioning arches (4) or tensioning rings are fastened by fastening means or a welded connection in the connecting region (5) of the tensioning support bodies (2).
19. Method for installing a reinforcement system according to one of Claims 14 to 18,
    characterized in that
    the tensioning arches (4) or tensioning rings are installed in parallel in pairs and are connected fixedly by means of transverse connectors.
20. Method for installing a reinforcement system according to Claim 14 or 15,
    characterized in that
    a tensioning device is positioned on two adjacent arch segments (23, 24) for the final expansion of the tensioning arches (4) or tensioning rings, the connection between these arch segments (23, 24) is then released and is fixed again by the tensioning device after the expansion.

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