EP1362981B1 - Method of connecting concrete elements - Google Patents

Abstract

Recesses (10,11), in the surfaces of the building parts forming the joint-formed cavities, are pressed out after joining the building parts by materials, which are fluid to viscous at the time of their injection, and then change into an elastic or elastoplastic state. The cavities are pressed out after primary deformations of the building parts. For pressing out the cavities, plastics, especially thermoplastic elastomers are used which are liquefied for injection by heat. An Independent claim is also included for a unit used for carrying out the method.

Description

Technical area

The invention relates to a method for producing a non-positive and / or positive and / or sealing connection between colliding in a joint prefabricated structural parts of structures made of steel, steel or prestressed concrete, in particular between tubbing for the production of tunnels, galleries or the like.

State of the art

For lining a tunnel which has been excavated by means of a tunnel boring machine, a multiplicity of segmental rings which abut one another in ring joints and are usually composed of individual segments which adjoin each other in longitudinal joints are used. The segments can be made of steel or reinforced concrete; they can also be prestressed in the sense of prestressed concrete.

The individual segments are based on each other in the ring and longitudinal joints; In both joints usually compressive forces, to a lesser extent, namely depending on the design stiffness, bending moments and shear forces must be transmitted. The compressive forces in the ring joints mainly follow from the propulsion forces generated during propulsion, in the longitudinal joints from the load from the rock pressure or a back pressure and the groundwater. The transmission of shear forces in the joints is only necessary statically in very soft soils, but to increase the rigidity of the tunnel lining and an associated reduction of deformations but constructively desirable.

The transmission of shear forces in the ring joints is usually done by "tongue and groove", "pot-cam" or dowel joints. Hardwood dowels or plastic dowels, possibly with steel core, are used as dowels; they are mounted on one side of the tubbings and threaded into the holes in the opposite tubbings during assembly ( DE 101 19 988 A1 ). Depending on the coupling system, a linear or point-shaped transverse force transmission between adjacent segmental rings is possible.

In the longitudinal joints is usually dispensed with a structural shear force connection; For this purpose, the existing friction component is considered sufficient.

In the case of the usual single-shell segmental linings, the segments also have to ensure the permanent watertightness of the tunnel tube. For this purpose, in the annular joints are usually arranged in circumferential grooves profiles of elastic materials such as rubber, plastic or the like as intermediate elements, for example glued or concreted. Each opposite profiles can be biased when installing the tubbing rings as an additional backup by means of temporary screwing.

An example is also in the document EP 0340659 shown.

The assembly of the tubbing rings is carried out regularly in the protection of the shield tail of the tunnel boring machine. In this case, no external loads act on the tubbing ring, so that in the ideal case it assumes exactly the theoretical circular shape. After the assembly of each tubbing ring this device gets out of the area of the shield tail in the course of further advancing; the resulting annular gap to the mountains is back-pressed with a suitable grout. This annular gap compression represents a primary load of the tubbing ring, which is superimposed in the final state by soil and water pressures.

These external stresses lead to deformations, predominantly an "ovalization" of the closed tubbing ring. These deformations have the consequence that the already loaded penultimate tubbing ring "n", which has just left the shield tail, and the just mounted ring "n + 1", which is still in the protection of the shield tail, not the same axis line, but a mutual Have offset. An additional offset results from unavoidable manufacturing tolerances during assembly of the tubbing rings.

This offset ("offset") is usually taken into account in the usual structural coupling of tubbing rings that the construction must have a sufficient "game"(slip); otherwise there will be impermissible constraints between the rings and the resulting damage, such as flaking.

If one directs oneself, as usual, during the assembly of the ring "n + 1" on the preceding ring "n", which can happen "forcibly" by a tongue and groove connection or the like, then this ring "n + 1 "imposed in the unloaded state a certain ovalization. If this error can also be partially compensated for the keystone installation, further deviations from the desired position result from unavoidable assembly tolerances. In any case, this deviates from the ideal line in indefinite form ring "n + 1" when leaving the shield tail and applying the external loads undergoes additional deformations, which lead to a total undefined deformation and forced voltage state; In particular, the coupling forces acting in the annular joint are undefined.

These coupling forces are transmitted in the annular joints usually via friction, often in conjunction with tongue and groove or pot-cam connections. In this case, until the concerns of opposing coupling surfaces still no power transmission, at best by friction; By concern, however, an almost discontinuous jump to a largely rigid connection, at least for a sign direction of the coupling forces.

Even with a theoretically possible alignment of the tubbing ring "n + 1" on the ideal line, d. H. regardless of the previous tubbing ring "n", the planned offset in the ring assembly in combination with unavoidable mounting tolerances and especially the occurring deformations under load leads to an undefined state with respect to the coupling forces in the annular joint. In any case, it is not possible to interpret the geometry of the coupling elements ("tongue-and-groove" or "cup-cam" connection) to all possible deformation and mutual torsional states and thus to generate exactly defined coupling forces in the annular joint.

In the case of dowel connections, the slippage between adjacent segments, which is required as a result of the offset, can indeed be generated by dowel elongated holes ( DE 101 19 988 A1 ). Nevertheless, this slippage required by the system has a very disadvantageous design, since there is a force transmission only after the application of the respective opposing force entry surfaces, that is to say only after the occurrence of slippage, but in principle undesirable deformations of the tubbing ring. Moreover, because these deformations are unevenly distributed around the circumference of the ring, the resulting static system is high indeterminate, not mathematically detectable and equipped with inadequate rigidity.

• Undichtigkeiten durch unzulässigen Versatz der elastischen Profile,
• unzulässige Beanspruchungen der Nutflanken, die zu Abplatzungen und damit Undichtigkeiten und reduzierten Steifigkeiten führen,
• ungenügende Ringsteifigkeit durch mangelnde Kopplung der Tübbinge in der Ringfuge, die zu Ringverformungen und Setzungen führen kann.

As a result of this problem, various damage patterns can occur, in particular:

• Leaks due to impermissible misalignment of the elastic profiles,
• impermissible stresses on the groove flanks, which lead to flaking and thus leaks and reduced rigidity,
• Insufficient ring stiffness due to insufficient coupling of the segments in the ring joint, which can lead to ring deformation and subsidence.

Object of the invention

Against this background, the invention has the object to provide a way to control the above-described, occurring in the production of tubbing linings problems.

Presentation of the invention

According to the invention, this object is achieved by the method specified in claim 1.

Advantageous developments emerge from the subclaims.

The basic idea of the invention is to produce the coupling between structural parts which collide in a joint, in particular between the segments of a tunnel or tunnel lining only after assembly of the structural parts, ie the segmental rings, expediently after approximately primary deformations due to load application after leaving the shield tail namely by the fact that cavities formed in the coupling surfaces are filled with materials that are liquid to the introduction of liquid to viscous and assume an elastic or elastoplastic behavior after filling.

As a result of its flow properties, such a material adapts to any shapes of the cavities and fills them completely. After hardening or cooling in the Operating state, this material forms a power transmission and / or sealing element in the building joint.

In the manufacture of a tubbing joint, the method according to the invention has the advantage that the assembly of the tubbing ring "n + 1" can take place without consideration of any deformations on the tubbing ring "n", ie. H. that an alignment of the segments in "absolutely correct" position is possible. A determination of the deformations of the tubbing ring "n" for positioning is not required. After solidification of the material pressed into the cavities, precisely defined and calculable coupling forces can be transmitted via its properties.

The method according to the invention thus has the advantage that a slip-free, low-deformation, exactly defined and computationally detectable ring coupling of tubbing rings can be achieved.

It is a particularly low-deformation tunnel construction, which meets the highest requirements for rigidity and low permissible subsidence in demanding conditions, for example in heavily populated areas and soft ground.

Through a simple joint training and the construction of the formwork for the production of the segments is simplified; There are only small demands on the tolerances in the manufacture and assembly of the segments.

Finally, the tubbing assembly is simplified. Thus, an exact alignment and fitting of the segments to the previous, already deformed tubbing ring is no longer necessary; Rather, the installation of the individual segments can be made into a ring completely independent of the previous tubbing ring. Since no restoring forces occur in the subsequent compression according to the invention, the otherwise common tubbing screw connection can be dispensed with. These advantages are further enhanced when the coupling elements are designed in the form of Verpress dowels to tensile forces.

• unabhängig voneinander und auch einzeln - sowohl für die Ringfugen als auch für die Längsfugen eines Tübbingausbaus anwendbar. Nach der Montage eines - vollständigen Tübbingrings können auch die Längsfugen, diese allerdings zweckmäßig noch vor Verlassen des Schildschwanzes, verfüllt werden. Hierdurch treten insbesondere bei der Montage der Schlusssteine keine Relativverschiebungen der Dichtungen mehr auf. Durch Dichtschotte können die Fugenhohlräume der Längs- und Ringfugen gegeneinander abgetrennt werden, so dass eine unabhängig voneinander erfolgende Verfüllung (zum Beispiel Längsfugen noch im Schildschwanz, Ringfugen bei oder unmittelbar nach Verlassen des Schildschwanzes) möglich ist.

For the production of joint gaskets is the inventive method

• independent of each other and also individually - applicable for the ring joints as well as for the longitudinal joints of a segmental lining. After mounting a - complete tubbing ring can also be the longitudinal joints, this however expedient even before leaving the shield tail, filled. As a result, no relative displacements of the seals occur more particularly during assembly of the capstones. By sealing bulkhead, the joint cavities of the longitudinal and annular joints can be separated against each other, so that an independent backfilling (for example, longitudinal joints still in the tail, ring joints at or immediately after leaving the shield tail) is possible.

By applying a pressure to the liquefied material until hardening / cooling, a bias can also be applied. In this way, if necessary, a slight spreading of a tubbing ring can be generated, for example, to achieve a power transmission in the longitudinal joints on the joint material and not as otherwise via concrete contact.

As materials for this purpose are basically all materials suitable that meet the static requirements; this may be in addition to cement or synthetic resin mortar all other suitable plastics such. As thermoplastics, especially TPV, but also duoplastics, especially PV elastomers. Thermoplastic elastomers (TPEs) which are polyphase polymers (eg polypropylene matrix) with embedding highly crosslinked synthetic elastomers in accordance with DIN 7724 have proved particularly suitable.

Thermoplastic elastomers behave entropy-elastically (rubber-elastic) in the temperature range of use, ie they correspond to the usually factory-installed elastomers, but change with increasing temperature into a liquid (thermoplastic) state. This change of state is reversible. The flow temperature is, for example, in thermoplastic PU elastomers in the order of about 180 ° C.

Description of the drawing

Fig. 1

einen Querschnitt durch eine Ringfuge eines Tübbingausbaus mit Dübelverbindung im Einbauzustand,

Fig. 2

den entsprechenden Querschnitt im Endzustand,

Fig. 3

in entsprechender Weise einen Querschnitt durch eine Ringfuge mit Fugendichtung im Einbauzustand und

Fig. 4

den entsprechenden Querschnitt im Endzustand,

Fig. 5

einen Querschnitt durch eine Längsfuge eines Tübbingausbaus mit Fugendichtung,

Fig. 6

eine teilweise geschnittene Ansicht einer Längsfuge und schließlich

Fig. 7

eine Möglichkeit zur Ausgestaltung einer in einer Fugenfläche vorzusehenden Ausnehmung zur Aufnahme von Zugkräften.

Further features and advantageous features of the invention will become apparent from the following description of the embodiments illustrated in the drawings. It shows

Fig. 1

a cross section through a ring joint of a segmental lining with dowel joint in the installed state,

Fig. 2

the corresponding cross section in the final state,

Fig. 3

in a corresponding manner a cross section through a ring joint with joint seal in the installed state and

Fig. 4

the corresponding cross section in the final state,

Fig. 5

a cross section through a longitudinal joint of a segmental lining with joint seal,

Fig. 6

a partially sectioned view of a longitudinal joint and finally

Fig. 7

a possibility for the design of a recess to be provided in a joint surface for receiving tensile forces.

Reference to the drawings, the invention will be explained in application to a tunnel lining Stahlbetontübbingen. Although this is also the main field of application of the invention, an extension of the application to other materials, such. As steel and other joint structures in construction with power transmission and leakage requirements z. B. in container construction, silo construction or the like, of course, possible.

In the Fig. 1 and 2 are each sections of longitudinal sections through a tubing lining of a tunnel with a cross section through a ring joint and possibility for power transmission in this shown in different stages of construction, namely in Fig. 1 in the installed state and in Fig. 2 in the final state.

The tubing lining, which is generally designated 1, consists of individual segments 2 and 3, which are each assembled into a ring. The tubbing rings, which are each designated according to their installation state as ring "n" and "n + 1", collide in a ring joint 4 in which the power transmission between the adjacent tubbing rings is to be ensured.

The installation of the segments 2 and 3 and their assembly to tubbing rings in a conventional manner in the shelter of the shield tail 5 a - not shown - tunnel boring machine, which continues in a shield tail seal 6. The annular gap 7 between the shield tail 5 and the lining 1 and the mountains 8 is pressed with a grout 9.

In the in Fig. 1 shown installation state of the tubbing ring n has just left the shield tail 5; The external loads, under the effect of which he has deformed ("ovalized"), already have an effect on him. The tubbing ring n + 1 was just mounted; he still has the "absolutely correct" position with the longitudinal axis S _{n + 1} . An offset V between the axis S _{n of} the tubbing ring n and the axis S _{n + 1 of} the tubbing ring n + 1 can clearly be seen here.

The annular surfaces 4 forming end surfaces of the segments 2 and 3 have recesses 10 and 11 which lie respectively in the axis S _n and S _{n + 1} . The recesses 10 and 11 are so with respect to the annular joint 4 opposite each other and form a cavity. In the recess 10 opens a press-in channel 12 and into the recess 11 a vent channel 13 or vice versa. The end faces of the tubbing rings n or n + 1 touch each other directly in the annular joint 4; the ring joint 4 is closed to the ground side by a joint seal 14; a corresponding joint seal can be attached to the air side.

While Fig. 1 the installation state of the two annular ring 4 forming tubbing rings n or n + 1 shows, in which the joint offset V of the ring axes S _n and S _{n + 1} occurs shows Fig. 2 the final state in which also the tubbing ring n + 1 has been adapted by the now acting on him external load on the ovalized shape of the tubbing ring n. In this state, the cavity formed from the recesses 10 and 11 is pressed by the press-in channel 12 in accordance with the invention; the grouting material is indicated at 15. If a residual offset "V" still remained in this phase, this is harmless in the context of the invention.

As a pressing material 15 is preferably a thermoplastic elastomer (TPE), the plasticized in a - not shown - heating tool and by means of a corresponding press-pumping tool, which is also not the subject of the invention, through the press-fit 12 in the from the recesses 10 and 11 formed Cavities of the ring joints 4 is injected. Depending on the composition of the material temperatures up to about 200 ° C are required for the plasticization, which are harmless for trained as ready-mixed concrete segments. After cooling of the material, an elastic or elastoplastic state sets in, which ensures the transmission of forces in the annular joint 4.

The compression of the cavities for the production of dowels can be done before, during or after the further tunneling of the tunnel boring machine and the associated advance of the shield tail; In any case, it should take place when the deformations of the segmental rings caused by the condition of construction have occurred.

The passage of normal forces through the annular joint 4 can be done in a conventional manner by concrete-concrete contact or by inserting joint plates. If these joint plates are provided with a central opening whose diameter corresponds to that of the recesses 10, 12 and if they are fastened at the location of the recesses, then at the same time a seal against the penetration of the grouting material into the joint gap succeeds.

In a similar way, dowel joints can be made on the longitudinal joints of the tubbing rings. The normal forces acting in the ring direction are usually transmitted by concrete contact of the end faces.

After cooling in the cavity formed by the recesses 10, 11, the specified plastics behave in accordance with their material law, usually "steel-elastic" according to DIN 7724 in a well-defined form and are thus able to their assigned transverse forces as a function of the determined To transmit deformations. In plastics technology, sufficient thermoplastic materials are available to select the optimum material for each individual case. The material must have a sufficient shear strength with simultaneous elasticity against shear deformation.

It is also possible to insert into the recesses 10 and 11 before or during assembly steel rods or similar smaller diameter, which form a "reinforcement" and reinforcement of the dowel connection after pressing. The finished dowel joint then has a similar mode of action as conventional plastic anchors with steel core without the disadvantage of the described slip and the compliance.

In a corresponding manner, it is also possible to give the recesses a special shape in order, if appropriate, to be able to absorb tensile forces in the annular joint 4. A section through such a recess 10a is in Fig. 7 shown. The recess 10a, into which again a press-in channel 12a opens, has here, for example, at the end an expansion 16 in the form of an anchor head; Furthermore, an expansion 17 is indicated, which may for example also represent a thread-like profiling. In this case, a plug connection according to the invention by eccentric arrangement and bending moments can be assigned or it can be omitted by such a dowel connection the usual fittings to ensure the biasing forces for sealing profiles.

While the invention is based on the Fig. 1 and 2 on the example of a dowel connection between adjacent, in a ring joint colliding tubbing rings has been explained, show the Fig. 3 and 4 the application of the invention to the production of a ring joint seal. Again, the show Fig. 3 and 4 each sections of longitudinal sections through a tubing lining with a cross section through a ring joint in different stages of construction, namely in Fig. 3 in the installed state and in Fig. 4 in the final state.

In the in Fig. 3 shown installation state of the tubbing ring n has just left the shield tail 5; The external loads, under whose effect he has ovalized, already affect him. The tubbing ring n + 1 was just mounted; he still has the "absolutely correct" position with the longitudinal axis S _{n + 1} . The offset between the axis S _{n of} the tubbing ring n and the axis S _{n + 1 of} the tubbing ring n + 1 is again denoted by V.

The annular surfaces 4 forming end surfaces of the segments 2a and 3a here comprise a kind of tongue and groove connection. In the end face of the - left - tubbings 3a is a recess 20 in the form of an annular groove, while the opposite end face of the - right - tubule 2a has an annular strip 21 as a spring ( Fig. 4 ). The annular groove 20 has a greater width than the annular strip 21, so that remains in the assembled state, a two-chambered cavity into which an accessible from the inside of the lining 1a ago injection channel 22 opens. The End faces of the tubbing rings n or n + 1 can touch each other directly in the ring joint 4 or be sealed off by seals 23 towards the air side or earth side. Likewise, a sliding possibility 24 may optionally be provided on the end face of the annular strip 21.

While Fig. 3 shows the installation state in which between the tubbing rings n or n + 1 nor the joint offset V of the ring axes S _n and S _{n + 1} occurs shows Fig. 4 the final state in which also the tubbing ring n + 1 has been adapted by the now acting on him external load on the ovalized shape of the tubbing ring n. In this state, the annular joint 4 including the cavities between the annular groove 20 and the annular strip 21 is pressed in accordance with the invention; the grouting material is indicated at 25.

While the Fig. 3 and 4 refer to the seal of the ring joints between tubbing rings a tubing lining of a tunnel, show the Fig. 5 and 6 a possibility for sealing the longitudinal joints. So shows Fig. 5 a section of a cross section through a tunnel lining 1 b, in which the tubbing segments 2 b, 2 b combined to form a tubbing ring form a longitudinal joint 30. This longitudinal joint 30 may in principle be formed in the same way as the ring joints, ie corresponding depressions may be arranged in the end surfaces of the individual segments which form a single or multi-chamber cavity after joining two adjacent segments. In Fig. 6 , in the left half a section through the longitudinal joint along the line VI-VI in Fig. 5 with view of the joint surface of a tubbings and in the right half shows a section through the tubbing, recesses 31 are indicated in the joint surface of the tubb 2bb, which are separated by a longitudinal rib 32 from each other. Here too, a press-in channel 33 leads from the air side of the tunnel lining 1 into the cavities for pressing in the material according to the invention.

The longitudinal joints are filled according to the invention after assembly of a complete tubbing ring, expediently before leaving the shield tail. As a result, no relative displacements of the seals occur, in particular during the assembly of the cap. By a partition 34 in conjunction with provisional seals 35, the joint cavities of the longitudinal and annular joints 30 and 4 can be delimited from each other, so that the cavities can be pressed independently of each other. By forming individual chambers, a multiple seal can be created.

The inventive design and introduction of the seal of annular and longitudinal joints all major problems of conventional segmental lining can be solved. Consequently, a significantly improved quality of the segmental lining is achieved and the repair effort is significantly reduced. The simplified installation of the tubbing rings also results in cost and time advantages in segmental lining.

By largely central arrangement of the intermediate element, which can serve both the seal and the power transmission, a more favorable introduction of force is given in the tubbing concrete, so that in principle a reduction of the segment thickness over conventional joint structures can be realized.

When using thermoplastic elastomers as joint grout material, a leaking joint may be renewed due to the reversible behavior of such materials by heating, flowing out of the material, and re-injection molding, if necessary even multiple times. Even after emergency situations, such as fire, a renewal of the joint material is readily possible.

Claims (12)

1. A method of producing a force-locking and/or form-locking and/or sealing connection between butt-jointed prefabricated structural elements of structures made of steel, reinforced concrete or prestressed concrete, in particular between tubbing rings for the production of tunnels, galleries or the like,
   characterised in
   that cavities formed by recesses (10,11,31) in the surfaces of the structural elements (2,3) forming the joint (4,30) are pressure-grouted with materials which at the time of their application are fluid to viscous and subsequently pass into an elastic or elasto-plastic state.
2. A method according to Claim 1, characterised in that the cavities are formed by mutually opposed recesses in the faces of the structural elements forming the joint.
3. A method according to Claim 1 or 2, characterised in that the cavities are pressured-grouted only after any primary deformation of the structural elements has taken place.
4. A method according to any one of Claims 1 to 3, characterised in that the recesses forming the cavities are so configured and/or the pressure-grouting material is so chosen that, in addition to coupling forces acting parallel to the joint, also tensile forces at right angles to the joint and/or bending moments acting can be transmitted.
5. A method according to any one of Claims 1 to 3, characterised in that the recesses forming the cavities are so configured and/or the pressure-grouting material is so chosen that sealing of the joint interstice is effected between the structural elements forming the joint.
6. A method according to Claim 4, characterised in that reinforcing elements are inserted into the recesses before the joining-together of the structural elements.
7. A method according to any one of Claims 1 to 6, characterised in that, before the application of the pressure-grouting material, the cavities are at least provisionally sealed towards the outer surfaces of the structural elements.
8. A method according to any one of Claims 1 to 7, characterised in that preloading is exerted on the structural elements by the application of pressure from the pressure-grouting material as it is introduced into the cavities.
9. A method according to any one of Claims 1 to 8, characterised in that synthetic materials are used for the pressure-grouting of the cavities, in particular thermoplastic elastomers (TPE) which, for application, are liquefied by heat input.
10. A unit comprising at least two butt-jointed prefabricated structural elements made of steel, reinforced concrete or prestressed concrete, in particular tubbing rings for the production of tunnels, galleries or the like, characterised in that in at least one of the faces of the structural elements (2,3) forming the joint (4,30) there are provided recesses (10,11,31) which after the joining-together each form a cavity which can be pressure-grouted with materials which at the time of their application are fluid to viscous and which subsequently pass into an elastic or elasto-plastic state.
11. A unit according to Claim 10, characterised in that corresponding recesses (10,11) are provided in the faces of the structural elements (2,3) forming the joint.
12. A unit according to Claim 10 or 11, characterised in that reinforcing elements are disposed in one of the structural elements, which protrude over the respective outer surface and project into the corresponding recess of the opposing structural element.

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