EP1538302B1 - Method of filling void spaces outside a machine produced tunnel wall - Google Patents

Abstract

Process for filling or pressing hollow chambers outside light tunnel tubes or a tunnel comprises using dissolved ground material or a ground mixture produced during degradation. Preferred Features: The ground material or a ground mixture is prepared within the tunnel tubes for the purpose of filling or pressing.

Description

The invention relates to a method for filling or pressing cavities outside the clear tunnel tube of a tunnel driven in tunneling tunnel or tunnel, in particular the annular gap between the tunnel lining and the upcoming soil.

• Bettung der Tübbingringe;
• weitgehende Erhaltung des Spannungszustands des Bodens und Minimierung von Setzungen der Geländeoberfläche und damit von Bauwerken;
• gelegentlich zusätzliche Wirkung als Dicht- oder Isoliermittel zur Reduzierung des Wasserandrangs zur Tunnelauskleidung hin oder Abschirmung der Tunnelauskleidung gegenüber aggressiven Stoffen.

In mechanical tunneling with shield tunneling machines (tunnel boring machines) and removal from Tübbingen arises due to the system behind the shield tail seal when ancestor of the shield on the circumference of the shield shell an annular gap between the mountains and outer surface of the tunnel lining, which is usually a thickness of 10 to 15 cm, in exceptional cases up to approx 30 cm. This annular gap is usually filled by a grouting mortar, usually pressurized. The main objectives and tasks are as follows:

• Bedding of the tubbing rings;
• extensive preservation of the state of tension of the soil and minimization of subsidence of the terrain surface and thus of buildings;
• occasionally additional effect as a sealant or insulating agent to reduce the water flow to the tunnel lining or shielding the tunnel lining against aggressive substances.

For procedural reasons, it is necessary that the grout is pumpable and can be introduced with targeted pressurization and volume control. Sufficient distribution of the grout within the cavity must be ensured by sufficient fluidity. If the grout is provided with binders, their hardening time must be adjusted so that it does not prematurely hardened during short interruptions of Verpressvorgangs within the delivery lines, but on the other hand ensures the static required bedding the tubbing rings when leaving the shield tail as quickly as possible.

All such mixtures, both mortar mixtures and binder-free mixtures have in common that they consist in the main components of sand or gravel sand to ensure the required grain structure, water and lower admixtures of bentonite or fly ash as a filler to improve the processability. The compression takes place at Propagation in loose soil usually through the shield tail, usually about four to eight distributed over the circumference injection nozzles are arranged, which are fed via piston pumps.

Grouting mortar is either delivered as ready-mixed mortar or mixed on-site from the supplied components. The conveyance of processed grouting mortar from the tunnel mouth to the injection site in the tunnel is usually carried out via lore operation, then via pumping lines.

Such solutions are for example from the EP-A-0 897 050 and EP-A-0 931 909 known. There, the injection material is stored in a near the Einpressortes and optionally fed in Lorenbetrieb container cached and injected via pipes in the shelter of the shield tail in the annular gap. A similar solution reveals the DE 29 32 430 A , in which the filling mass is introduced and injected via a concrete delivery line from the rear region of the tunnel tube to the annular gap. Here is left open whether the concrete delivery line comes from a buffer in the tunnel tube or whether the concrete delivery line extends over the entire length of the already ascended tunnel tube. One way of distributing the injection material evenly over the circumference of the annular gap is in the US-A-3 561 223 shown. There you can see a central large-volume conveyor line, in which the injection material is pumped into the tunneling area. At its end, the delivery line passes into a distribution system of several hose lines of smaller diameter, which lead to about the circumference of the annular gap evenly distributed opening into the annular gap injection nozzles. Similar solutions are also off US-A-6,082,930 and EP-A-0 348118 known.

As the closest prior art is JP57187499 considered. This document corresponds to the preamble of claim 1.

The material transports for the annular gap compression are often burdened with logistical and environmental protection problems. Thus, the transport of the quantities of grouting mortar, which can be twice as much in a tunnel tube 75 m ³ / day, with two parallel aufzufahrenden tubes, so much, prepares problems in the vicinity of the construction site. This is especially true in densely populated inner city areas, as they repeatedly occur at subway construction sites and inner-city road tunnels. So are material transports during the day because of the associated unwanted increase in traffic by truck transports problematic, during the night for reasons of noise protection for the protection of local residents often inadmissible. The construction site logistics in the tunnel tube must be designed for the injection volumes; Difficulties with the mortar supply inevitably lead to a costly shutdown of the tunneling machine.

Against this background, the object of the invention is to provide a possibility by means of which these problems can be minimized or largely avoided.

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

Advantageous developments emerge from the subclaims.

The invention is based on the finding that in the known methods the annular gap filling takes place both in terms of process and materials independently of soil degradation and soil extraction. In contrast, the invention proposes to couple these two processes together. This is done procedurally such that a part of the soil just dismantled or soil-liquid mixture branched off immediately behind the working face of the delivery line, if necessary, processed directly in the tunnel, but in any case immediately used again for Ringpaltverpressung, ie the material does not leave the tunnel tube between degradation and compression. The invention is based on the basic principle that the material to be incorporated into the annular gap need not have better mechanical properties than the pending surrounding soil, since otherwise this would be decisive for bedding and settlement behavior.

The invention has the significant advantage that by using the mined soil or soil mixture as Verpressmaterial under direct removal from the feed line no separately to be transported and einzufahrzufahren in the tunnel grout is more needed. This reduces the traffic volume and the noise pollution of the environment, which has an effect especially on inner-city highly-stressed construction sites. Since no storage space is required for the grouting mortar, the area required for construction site equipment is also reduced. Finally, the construction site logistics are simplified, since mortar transports through the tunnel are eliminated.

The immediate consequence of these advantages is an increase in operational safety, since the propulsion operation can no longer be hindered or interrupted by logistical problems in mortar transport. Since the grouting material is present as a soil or soil mixture and does not need to be procured separately, there are also cost savings. Finally, the volume of material to be removed from the tunnel is reduced by branching off a portion of the dissolved soil that remains underground.

Another advantage that should not be underestimated in terms of operation is that the grouting mortar can be produced in situ precisely when it is actually needed for grouting. A hardening and disposal of too much or because of standstill not needed mortar is eliminated.

Fig. 1

einen Längsschnitt durch einen Schildvortrieb im Slurry-Betrieb,

Fig. 2

einen Längsschnitt durch einen Schildvortrieb im EPB-Betrieb und

Fig. 3

einen Längsschnitt durch einen Schildvortrieb mit offener Ortsbrust.

The invention is explained below with reference to the drawing. It shows

Fig. 1

a longitudinal section through a shield tunneling in slurry mode,

Fig. 2

a longitudinal section through a shield tunneling in EPB operation and

Fig. 3

a longitudinal section through a shield tunneling with open working face.

In the Fig. 1 to 3 schematically shows how in a mountain formation 1 by means of a shield machine 2, a tunnel tube 3 is ascended. The shield machine 2 comprises in a known manner a cylindrical shield shell 4. The degradation of the pending at the working face 5 soil is carried out by a drill head 6; the excavation chamber 7 is usually completed by a bulkhead 8.

In the protection of the shield tail 9, the tunnel lining, consisting here of tubbing rings 10 made of reinforced concrete or steel, installed; the resulting in the ancestor of the shield machine 2 behind the shield tail 9 annular gap 11 is, as described above, pressed by a suitable backfill material 12.

Based Fig. 1 can the invention in a tunnel or tunnel propulsion in the slurry mode, ie a propulsion with liquid-supported face, be explained, especially in cohesive soils such. As toning is applied. In this case, the working face is fed via a feed line 15 to a supporting liquid, usually a bentonite-water suspension. There, the support liquid mixes with the degraded by the drill head 6 ground; This bentonite-soil-water mixture is removed via a bulkhead 8 passing through the outlet opening 16 and pumped through a delivery line 17 through the tunnel tube 3 through to a daytime separation system 18. In the Separieranlage 18, the soil material is separated from the supporting liquid, which can then be pumped back to the working face 5 again.

According to the invention, a portion of the bentonite-soil-water mixture discharged from the working face is branched off from the delivery line 17 via a branching valve 19 and, if appropriate, after passing through a small separation plant 20 and a small processing plant 21 as a grouting material, is forced through a slurry pump 22 into a grouting line 23 from which it exits through arranged on the shield tail 9 Verpressdüsen 24 in the annular gap 11. In the separation unit 20, a coarse separation, for example screening out of undesired grain fractions, in the processing plant 21 a targeted admixing of further components, for example cement, can take place. If necessary, can also be an intermediate container for Volume buffering can be arranged. Such systems are known in the Nachläuferbereich.

The water contained in the bentonite-soil-water mixture is harmless when pressed, as long as the pressure application during the pressing ensures that it can be pressed through the pore spaces of the pending soil material, ie. H. that there is a grain-to-grain contact of the built-in soil material and thus a sufficient compaction according to the density of the surrounding soil. This is usually given in rolling or mixed-grained soils. The addition of a binder for solidification is then not required. For economic reasons, however, efforts will be made to reduce the bentonite contained in the soil mixture to the level necessary for pumpability, in order to be able to feed the separated bentonite back into the working face support. This Bentonitseparierung can be done easily in the described small processing plant 20, 21 in the tunnel.

If cohesive soils are driven up in slurry mode, insufficient separation can lead to the result that optimum compaction of the material filled into the annular gap is not achieved since the water-bentonite mixture can not be displaced sufficiently quickly from the grain structure of the soil. This can be countered by appropriate treatment of the soil or by additional coarse-grained admixtures.

The procedure for traversing cohesive or fine-grained soils in EPB (earthpressure-balance) mode can be explained with reference to Fig. 2 be explained. Here is the mined at the working face 5 and mixed with the groundwater "soil slurry" as a support medium for the working face; Often foams made of plastics are also added for conditioning. Here, the soil dissolved at the working face 5 is conveyed out of the excavation chamber 7 by means of a suitable conveying device 25, for example a screw conveyor, into the interior of the tunnel in order to be transferred to a further conveying device 26, for example a conveyor belt. Before the soil material at the end of the conveyor 26 is transferred out of the tunnel to a further conveyor belt 27, a branching device 28, for example a flap, is arranged in order to feed a portion of the soil material to a small processing plant 29 again. From there, the optionally treated material by means of a slurry pump 30 in a Pressed pressing line 31, from which it again passes directly to the injection nozzles 24 on the shield tail 9 and exits into the annular gap 11.

Binding soils are often raised in the EPB mode, in which the mined soil is already treated at the working face with a conditioning agent, for example a foam, and therefore has no additional bentonite components. Also, this soil is basically suitable for direct recompression, provided that it is brought by means of flow agents in a pumpable and compressible state.

The inventive method is basically suitable for drives with open working face; how this can be done, can be based on Fig. 3 be explained.

Here, too, the material excavated at the working face 5 is conveyed out of the excavating chamber 7 by means of a conveying device 35, for example a conveyor belt, a branching device 37, for example a flap, again being provided in the region of a transition station to a further conveyor belt 36, by means of which a part of the conveyed soil material is branched off and a screening plant 38, optionally also a treatment plant 39 can be supplied. In order to make the mined soil pumpable, it may be necessary to screen out coarse-grained fractions and / or to add fluxing agents.

The processed material is pressed again via a slurry pump 40 in a Verpressleitung 41, through which it passes to the Verpressdüsen 24 at the end of the shield tail 9. If necessary, 42 water can be supplied via a line.

In summary, it can be stated that the method according to the invention can advantageously be used for rolling or mixed-grained soils (gravels, sands, optionally with cohesive admixtures). The conveyed soil mixture can be used in virtually unchanged form for compression; reprocessing will not make sense for technical reasons, but at most for economic reasons. With cohesive soils, on the other hand, as a rule, a preparation to be adapted to the requirements of the annular gap compression must be carried out.

By targeted admixture of cement or other binders to the branched, just degraded soil mixture, a "concrete floor" can be generated, which can be assigned a sealing or insulating, depending even a static-bearing function. It is thus possible according to the invention to produce a kind of "extruded concrete" as a tunnel safety in the tunnel. The pending soil is the supplement and the existing groundwater is the mixing water.

Claims (4)

1. A method of filling or pressure-grouting the annular gap (11) between a tunnel lining (10) and the surrounding ground (1) of an underground cavity driven in a shield-tunnelling operation, in particular of a tunnel or gallery, wherein for filling or pressure-grouting the annular gap (11) a portion of the ground material loosened at the working face (5) or of the ground mixture produced during excavation is deviated inside the tunnel duct (3) and, without leaving the tunnel duct (3), is used for filling or pressure-grouting the annular gap (11) and is fed directly to the annular gap (11) between the tunnel lining (10) and the surrounding ground (1), characterised in that, before the filling or pressure-grouting of the annular gap (11), undesirable particle fractions and/or bentonite components are separated out from the deviated portion of the ground material or ground mixture inside a separating unit.
2. A method according to Claim 1, characterised in that the ground material loosened at the working face (5) or the ground mixture produced during excavation is processed inside the tunnel duct (3) for the purpose of filling or pressure-grouting.
3. A method according to Claim 1 or 2, characterised in that the securing element, especially the support of the driven tunnel duct (3), is produced from the ground material loosened at the working face (5) or from the ground mixture produced during excavation.
4. A method according to any one of Claims 1 to 3, characterised in that the ground material loosened at the working face (5) or the ground mixture produced during excavation is used as a sealing or insulating element for the internal tunnel duct (3).

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