EP0812978B1 - Shield excavating machine - Google Patents

Description

The invention relates to a shield tunneling machine according to the Preamble of claim 1.

For underground tunneling in non-stable soils tunneling machines are known that the cavity generated until the tunnel is finally expanded and therefore referred to as shield tunneling machines. This temporary support of the cavity takes place on the dismantling front and on the outer surface. Despite all the support Changes in the state of tension in the soil cannot be completely ruled out, which causes floor deformations. Dependent on corresponding to the soil properties result from this Settlement on the undersurface.

• 1. vorlaufende Setzungen
• 2. an der Bohrfront
• 3. durch Imperfektionen am Schild
• 4. bei der Ringraumverfüllung
• 5. nachträgliche Langzeitsetzungen

Settlements develop in five phases:

• 1. preliminary settlements
• 2. on the drilling front
• 3. by imperfections on the shield
• 4. when filling the annulus
• 5. Subsequent long-term settlements

The settlement proportions of the first two phases are due to the today's support systems of the mining front reduced to a minimum. The settlement influence of the last two phases leaves almost avoid each other with pressure-stable filling of the annulus, so that the serious part is caused by the shield body becomes.

The rigid shield body can of course only be a passive one Support the soil. To activate the support reaction certain soil deformations are therefore unavoidable. These are due to a manufacturing-related, slightly conical The shape of the shield is reinforced. By tilting the rigid shield body when cornering is inevitable Soil displaces the ground when the shield moves forward Support loses and additional relaxation through local relaxation Is subject to deformation. The same effect occurs if a scheduled to avoid ground displacement Free cut is generated around the shield body.

But also by exceeding the ground tension in one pure displacement without relaxation will further deform the soil caused. The negative influence of settlement passive support is essentially determined by the length of the Shield body determined in the longitudinal axis of the tunnel. Currently running Shield body with a diameter of approx. 6.5 m for Segment ring widths of 1.5 m have a length of approximately 7.5 m on. Taking advantage of an embodiment of that in DE 196 33 784 A1 described shield boring machine is a first comparable reduction of the passive support length to approx. 5.4 m, so possible to 72%.

Also in particularly deformation-sensitive soil conditions this size is insufficient, especially if not only the surface settlements are decisive, but already soil deformations in lower levels, as in the case of Pile foundations.

A shield tunneling machine is known from DE 31 25 607 A, which have an integral shield coat and shield tail constant outer diameter. On the inside wall of the Shield tail and at a distance from the end of the shield tail a seal is arranged on the outer jacket of Tübbingen is applied. Between a tunneling shield of the known tunneling machine and the grout between the segment rings and the mountain range is the annulus between the outside of the shield mantle and the tail of the shield with a bentonite filled suspension that serves as a sealant. This suspension is intended to prevent a thin support medium that is used on the front of the excavation, reaches the grout and diluted it.

A shield tunneling machine is known from US-A-3 494 136, which constant a shield body and a shield tail Has outer diameter. The shield tail is continuous on the mountains. At the end of the shield tail is an elastic one Seal arranged between the inside of the shield tail and the tubbing rings for lining the Tunnels formed bridged and attached to the tubbing rings creates a penetration of grout into the Prevent machine.

Furthermore, GB-A-2 191 231 is a shield tunneling machine known for stable mountains. For the assembly of segment rings on the final outside diameter is the shield tail segmented, and these segments are individually telescopic displaceable. To prevent seepage from entering Annulus between the shield body of the machine and the mountains To prevent the gap, the shield body points axially Distance between two circumferential cuffs.

The invention has for its object the axial length of the Passive occurring when operating a shield tunneling machine to further reduce rigid support to settle the minimize third phase.

This task is performed on a shield tunneling machine after Preamble of claim 1 by the in the characterizing part specified features solved. Further training and advantageous Refinements result from the subclaims.

By reducing the outer diameter of the shield tail on a limited length or at least too its end pointing in the opposite feed direction arises L an annular space between the outer surface with reduced outer diameter of the shield tail and the wall of the same Diameter as the shield body cavity. If this annulus is filled with support medium, can be in Annulus generate a constant pressure that is sufficient to create the bottom formation support. In this way, ground displacements as well as avoiding subsidence.

The free cut can reduce the outside diameter End of the shield tail even when the shield tunneling machine is making curves dodge radially within the annulus, without directly contacting the wall of the cavity to get. Since with such curve movements the shape of the Annulus is changed, but not the volume, can by maintaining the pressure of the support medium Curve movements of the uniform support pressure on the ground formation maintained.

If the annulus is delimited on both sides, it is called fluid Support medium uses a product that is introduced after the annulus between the shield tail and the wall of the formed Cavity is permanently low viscosity.

With an annular space open against the direction of feed as fluid Support medium, on the other hand, uses a product that after insertion in the annulus between the shield tail and the Wall of the cavity formed is still low viscosity and therefore can dodge and spread when cornering, and this in the course of the feed movement of the shield tunneling machine becomes increasingly low and highly viscous and as an annular filling between the built-in segment rings and the wall of the cavity hardened and remains permanently. In this version is the filling material required for the ring space between the tubbing rings and the wall of the cavity at the same time to support the ground formation in the free cut Area at the tail end with reduced diameter with used.

In a development of the invention, the shield tail a paragraph on which its outer diameter of the dimension of Outer diameter of the shield body to a reduced dimension returns. This paragraph is followed by a rounded one Transition area that ends in a conical area.

The paragraph ensures that already at the beginning of the annulus there is a sufficient layer thickness for the medium, from which it cannot be displaced when cornering. The conical shape also has a number of advantages. On the one hand, when cornering, the end is prevented the tail of the shield, which is a rigid connection with the Swings out the shield body as far as possible, but not contact to the wall of the cavity. Furthermore, the layer thickness of the support medium, which is also filling material for is the built-in segment rings, gradually to the larger Dimension of the annular space between the outer diameter of the tubbing rings and adapted to the wall of the cavity.

Another advantage is that the reaction force for the support pressure on the face is no longer exclusively from the end faces of the last installed segment rings is, but also by the support medium to which the conical area of the shield tail supports. This reaction force can be sufficient if another segment ring is installed more feed cylinders of the feed device than Previously common, possibly even all feed cylinders at the same time to retract, so that the other composed of segments First pre-assemble the segment ring as completely as possible and then the pre-assembled segment ring with the to be able to connect previously installed. This represents an essential one Productivity increase.

Finally, the conical shape allows for business interruptions and hardening the shield tail filler simply by operating the feed device his position can be freed.

A further training provides that the free end of the Shield tail connects a lip seal that the used Enclosing segment rings.

This prevents any that has not yet hardened and therefore low viscosity proppant between the end the tail of the shield and the tubbing rings.

In a practical embodiment, the outer diameter reduced area of the shield tail inlet channels embedded for support medium.

The support medium can thus be introduced directly into the annular space be distributed evenly around the circumference and also there is also the possibility to control the pressure and regulate and fresh according to the feed Support medium to maintain the pressure.

According to a further development, the annular space is formed by longitudinal partition walls interrupted in such a way that an independent Pressure can be adjusted.

It is also provided that the shield tail relative to Axis of the shield body is pivotable. Through this configuration is achieved that the annular space is made relatively small there may be a swinging out of the end of the shield tail does not occur when cornering. The possible Curve radii driven with this shield tunneling machine are smaller than in known machines. Also the possible small curve radius is not determined by the segment rings, which are attacked by the end of the shield tail, with special needs.

Near or on the facing end faces of the shield body and the shield tail can be arranged pull / push cylinders be and the gap between the end faces of Shield body and tail can be covered by a sealing jacket be covered.

The shield tail can serve as a lateral boundary of the annulus one between a sealing jacket and an area of the Outer jacket of the tail tail independently longitudinally displaceable Wear ring.

This makes it possible to influence by moving the ring to take on the fluid in the annulus and so pressure fluctuations to settle in the annulus.

The inside diameter of the shield tail preferably corresponds in the area of the segment joints almost the outside diameter the one used for lining and supporting the cavity Segment rings. This measure becomes a template formed, using the incorrectly positioned segments of the to be installed Segment ring can inevitably be recognized and this ensures that the tubbing rings are fitted appropriately and thus the course of the segment rings lined tunnels through the drilling of the Shield tunneling machine corresponds exactly to the given course.

Fig. 1

einen Längsschnitt durch eine Schildvortriebsmaschine üblicher Bauart;

Fig. 2

eine verkürzte Schildvortriebsmaschine nach einer in der DE 196 33 784 A1 beschriebenen Ausführung;

Fig. 3

eine erste einfache Ausgestaltung einer Schildvortriebsmaschine nach der Erfindung;

Fig. 4 bis 7

eine Weiterbildung einer Schildvortriebsmaschine nach der Erfindung mit schwenkbarem Schildschwanz;

The invention is explained below with reference to the drawing. In this show:

Fig. 1

a longitudinal section through a shield tunneling machine of the usual type;

Fig. 2

a shortened shield tunneling machine according to an embodiment described in DE 196 33 784 A1;

Fig. 3

a first simple embodiment of a shield tunneling machine according to the invention;

4 to 7

a further development of a shield tunneling machine according to the invention with a pivotable shield tail;

The shield tunneling machines shown in the drawing comprise a dismantling device 22, a shield body 1, a Shield tail 2 and a feed device 23. By the tunneling is formed, the wall 27 of which is passive is supported by the outer jacket 28 of the shield body 1. The cavity with segment rings is behind the shield tunneling machine 3 lined. Since the segment rings 3 first under the protection of the shield tail supporting the mountain pressure 2 are mounted, their outer diameter is inevitable smaller than the inside diameter of the wall 27 of the cavity. To later settlement phenomena of the soil 11 too avoid the annular space 10 between the tubbing rings 3 and the wall 27 of the cavity is filled with a filling material.

Fig. 1 shows a longitudinal section through a shield tunneling machine usual design. Because of this version desired contact of the shield body 1 and the shield tail 2 to the surrounding floor 11 for the purpose of being more passive Support is the diameter of the shield body 1 and Shield tail 2 almost constant. With the Shield tail 2 will be the transition to the final tunnel expansion produced by segment rings 3. Since the shield body 1 just like the shield tail 2 for passive support of the surrounding Floor 11 is intended and for inclined positions For the purposes of curve movements, it must also displace the ground a space around the tail 2, in which the floor 11 is not supported.

The material for filling the annular space between the tubbing rings 3 and the wall 27 of the cavity is only behind here introduced the free end of the tail 2. An exit the filler material is sealed by a lip seal 4 between the end of the tail 2 and the tubbing rings 3 prevented.

In the sectional drawing shown in Fig. 2 Shield boring machine is a version as described in DE 196 33 784 A1. In contrast to conventional designs in which the site-side attack points the feed cylinder of the feed device 23 are articulated on a pressure wall 25, here are the points of attack hinged to a diving wall or sole wall 26. Thereby this results in a shorter length of the shield body 1 in comparison to Fig. 1. The base 11 is also supported here passively through the shield body 1 and the shield tail 2. When cornering is due to the reduced overall length from shield body 1 and shield tail 2, however, the floor displacement in comparison to the embodiment according to FIG. 1 less.

3 shows a first embodiment of a shield tunneling machine according to the invention. Here is the diameter of the outer jacket 29 of the tail 2 compared to the diameter of the outer shell 28 of the shield body 1 over its entire Reduced length. There is a paragraph 30 on the entire circumference, the one annular space 7 between the surrounding floor 11 and the outer surface of the shield tail 2 generated. In the feed direction is this annulus 7 by the larger one Shield body 1 limited while moving backwards into the annulus 10 opens out to the tubbing rings 3.

With the choice of the position of the diameter jump 6, the passive Support length can be greatly reduced. The filling of the new created annular space 7 with a fluid support medium an active influencing of the support pressure for adaptation or balance of earth and water pressure in the soil 11. The remaining passive support is only provided by the shield body 1 exercised and is therefore minimized. Are with her also minimizes the effects of soil displacement effects.

Figures 4 to 7 show further developments of a shield tunneling machine according to the invention with a pivotable Shield tail 2. The diameter jumps at a step 30 of the outer casing 29 from the dimension of the outer casing 28 of the shield body 1 to a reduced level. Behind the paragraph 30 the tail 2 runs conically to its free end from, d. H. it decreases in the opposite direction of advance Diameter steady.

In the outer jacket 29 of reduced outer diameter Shield tail 2 or in paragraph 30 are circumferential inlet channels 31 embedded for support medium. So the introduction of the support medium take place radially, which causes the flow conditions for the tangential spreading of the support medium in the Ring plane in front of the formwork can be improved and the so-called Clod formation through zone-hardened support medium is counteracted. The inlet channels 31 are accessible at all times, so that disruptions in the supply up to the point of introduction 15 can be eliminated.

The shield tail 2 can by pull / push cylinder 24, the near or on the mutually facing end faces of the shield body 1 and the tail 2 are arranged, targeted be pivoted. With the articulated coupling 12 of the Shield tail 2 on the shield body 1 fits the shield tail 2 so that the inner surface of the tunnel can be used as an installation template 14 for the segments 3 can. Incorrectly inserted segments 3 are due to the narrow Leadership recognized directly without it being driven later lead to dangerous constraints. The tunnel expansion always optimally follows the sign.

The shield tail 2 also provides temporary interior formwork and is made possible by the local separation of the Introduction of the support medium from the place of support of the Tunnel expansion a good use of the time-changing Consistency for different requirements on the Supporting medium. During the introduction and filling of the annulus 7 is a very high fluidity in the front, i.e. H. area of the annulus pointing in the feed direction is desired, to ensure both a void-free filling, as well as largely lossless pressure transmission to get in the support medium. Such a thin filling material but is for the bedding and stabilization of tunnel expansion unsuitable with tubbings. With increasing distance of the Location 15 for tunnel expansion and by the speed of advance there is a period of time with which the adjustment of the consistency to the subsequent function the stable permanent support of the segments 3 enclosing Wall 27 is made possible.

The seal 20 at the end of the tail 2 is subject to significant lower requirements than conventional ones Conditions, since the medium to be sealed here is a more rigid one Has a consistency and thus seals itself e.g. against the more fluid area of the support medium and against groundwater takes over. Local pressure peaks at the point of introduction 15 no longer occur here.

4 and 5 has the shield tail after coupling 12 to shield body 1 a short section 13 that has the same outside diameter as the shield body 1 has. Between paragraph 30 and the conical area there is a rounded Transition area. Compared to the representation according to FIG. 4, at the one articulation point 8 of the train / pressure cylinder 24 on the Pressure wall 25 of the shield body 1 and the other articulation point 9 on projections 5 projecting inwards over the inner jacket 17 of the tail 2 attack, is the articulation point in Fig. 5 9 on the shield tail 2 relative to the inner jacket 17 shifted outside. This is achieved in that on paragraph 30 the jump in diameter 6 is enlarged, so that a inside Annulus 18 arises, which is around the ring width of the end face 19 is larger than the diameter of the inner jacket 17.

In this version, one can completely from its segments composite tubbing ring 3 in the template 14 forming inner jacket 17 of the tail 2 used be without the train / pressure cylinder 24 are in the way. Indeed the larger diameter jump 6 leads to a larger one Annulus 7, whereby the need for support medium increases sharply.

In the embodiment in Fig. 6, the approach with the pivot point is omitted for the pull / push cylinder 24 on the shield body 1. The train / pressure cylinder 24 is rigid there on the pressure wall 25 directly attached to the inner jacket 16 of the shield body 1 and only articulated on the end face 18 of the shield tail 2. By eliminating approach 5 above the radial installation depth is less. This in turn enables to reduce the jump in diameter 6 and thus the annular space 7. A sealing jacket 32 that the transition area between bridging the shield body 1 and the shield tail 2, is an integral part of the outer shell 28 of the Shield body 1 executed. A narrow ring 21 bridges the distance between the outer shell 28 of the shield body and the outer jacket 29 of the shield tail. The combination of these Characteristics means that despite the overall reduction Annular gap thickness 6 compared to FIG. 5 the length of the passive Support of the shield body 1 is not significantly increased. Rather, the surface of the shield body 1 and Schildschwanzes 2 undisturbed, what ground deformations by the Friction influence reduced.

As shown in Fig. 7, the shield boring machine according to the invention in addition to the tunnel expansion with prefabricated Tubbingen 3 and external annular gap filling also for the process of so-called extruded in-situ concrete can be used. A specific advantage for this is achieved that the front formwork 34 of the extrusion in-situ concrete method of the Shield tail seal 20 freed against the inner tunnel formwork becomes. It is so independent of the pull / push cylinder 35 movable back and forth.

LIST OF REFERENCE NUMBERS

Shield body 1

Shield tail 2

Segment rings 3

Lip seal 4

Approach 5

Diameter jump 6

Annulus 7

Articulation point 8

Articulation point 9

Annulus 10

Floor 11

Coupling 12

Area 13

Installation template 14

Location 15

Inner jacket 16

Inner jacket 17

Annulus 18

End face 19

Seal 20

Ring 21

Mining device 22

Feed device 23

Train / push cylinder 24

Print wall 25

Immersion or sole wall 26

Wall 27

Outer jacket 28

Outer jacket 29

Paragraph 30

Inlet channels 31

Sealing jacket 32

Longitudinal walls 33

Face formwork / ring 34

Train / push cylinder 35

Claims (9)

1. Shield tunnelling machine comprising a working device (22), a shield body (1), a shield tail (2) connected to the shield body (1) and a feed mechanism (23), the annular space (7) formed between the smaller diameter outer jacket (29) of the shield tail (2) and the wall of the cavity being fillable with a fluid support medium, which actively supports the cavity wall (27), said fluid support medium being constituted by a product which, after introduction into the annular space (7) between the shield tail (2) and the wall (27) of the cavity formed still has a low viscosity and during the advance movement of the shield tunnelling machine increasingly hardens in order to remain as an annular space filling (10) between the installed segment rings (3) and the cavity wall (27), characterized in that the shield body (1) and shield tail (2) are used for radially supporting the walls (27) of the cavity created in unstable soils and the diameter of the outer jacket (29) of the shield tail (2) at least in its end directed counter to the advance direction is reduced compared with the diameter of the outer jacket (28) of the shield body (1).
2. Shield tunnelling machine according to claim 1, characterized in that the shield tail (2) has a step (30), where its external diameter jumps back to a reduced amount from that of the external diameter of the shield body (1) and to said step (30) is connected a round transition area, which tapers into a conical area.
3. Shield tunnelling machine according to claims 1 or 2, characterized in that to the free end of the shield tail (2) is connected a lip-type seal (20), which surrounds the inserted segment rings (3).
4. Shield tunnelling machine according to one of the claims 1 to 3, characterized in that intake channels (31) for the support medium are formed in the reduced external diameter area of the shield tail (2).
5. Shield tunnelling machine according to claim 4, characterized in that with the intake channels (31) are associated spaces subdivided by longitudinal walls (33) and in which can be produced independent pressures.
6. Shield tunnelling machine according to one of the claims 1 to 5, characterized in that the shield tail (2) can be pivoted relative to the axis of the shield body (1).
7. Shield tunnelling machine according to claim 6, characterized in that close to or at the facing front faces of the shield body (1) and shield tail (2) are provided tension-compression cylinders (24) and the gap between the front faces of the shield body (1) and shield tail (2) is covered by a sealing jacket (32).
8. Shield tunnelling machine according to one of the claims 1 to 7, characterized in that, as the lateral boundary of the annular space (7), the shield tail (2) carries a ring (34) independently longitudinally displaceable between a sealing jacket (32) and an area of the outer jacket (29) of the shield tail (2).
9. Shield tunnelling machine according to claims 6 to 8, characterized in that the internal diameter (14) of the shield tail (2) virtually corresponds to the external diameter of the segment rings (3) used for lining and supporting the cavity.

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