Method for constructing a traffic tunnel, a pipeline tunnel, or a pressurized water tunnel by segmental construction

Abstract

The invention relates to a method for constructing a traffic tunnel, a pipeline tunnel or a pressurized water tunnel by the segmental method, in which segment parts (10) are assembled in a drilled hole mechanically made in the rock to form a closed lining in the form of a segment pipe, and the ring gap between the drilled hole and the outer wall of the segment pipe is filled with a composition comprising a reactive resin that hardens by polymerization and a filler material, the reactive resin that hardens by polymerization being fed to the filler material before or during its feeding into the ring gap, mixed with the filler material and dispersed in the filler material, characterized in that the composition is cement-free and the filler material comprises a water-non-reactive inorganic material with an average particle size of less than or equal to 500 μm.

Description

[Technical field]

[0001] The present invention relates to a method for constructing traffic tunnels, pipeline tunnels (pipelines for electricity, water or gas) or pressurized water tunnels (headrace tunnels for hydroelectric power plants) by segmental tubbing construction, in which segment parts are assembled in mechanically made boreholes in the rock or soil to form closed linings in the form of segment pipes, and the ring gap between the borehole and the outer wall of the segment pipe is filled with a reactive resin that hardens by polymerization and a filler material. [Background technology]

[0002] Such a segmental tunnel construction method is known from EP 3913186 A1. In the known method, the ring gap between the outer wall of the segment tube and the surrounding rock mass is filled with a mixture of cement as filler and a reactive resin which hardens by polymerization.

[0003] Also, most construction guidelines for tunnels are based on the use of one-component cement suspensions / mortars or two-component cement-water glass composites as filler materials, so that the filler materials have sufficient load-bearing properties.

[0004] However, during cement production, large amounts of carbon dioxide (CO 2 ) are released. When cement reacts with water, hydroxide ions are also released, which can accumulate in the surrounding soil and groundwater. This can increase the pH of the groundwater in these locations and mobilize heavy metals such as cadmium and arsenic that it contains. Summary of the Invention [Problem to be solved by the invention]

[0005] The object of the present invention is to provide an improved method for constructing a traffic tunnel, a pipeline tunnel or a pressurized water tunnel with the segmental method. [Means for solving the problem]

[0006] To solve this problem, a method is used with the features of claim 1. Advantageous embodiments of the invention are presented in the dependent claims.

[0007] According to the invention, it is contemplated that an inorganic material that does not react with water is used as the filler, and that the filler is provided with a reactive resin that is hardened by polymerization before or during delivery to the ring gap, the reactive resin being mixed with and dispersed in the filler before or during injection into the ring gap.

[0008] It has now been surprisingly found that inorganic water-insensitive materials having an average particle size of 500 μm or less can be used as fillers in the method described in EP 3913186 A1, and still achieve sufficient load-bearing capacity for ring gap filling.By using water-insensitive materials having small particle sizes as fillers, good flowability of the composition can still be achieved, so that the material can be pumped over long distances from the tunnel entrance to the place of use, where it can be used for ring gap filling.

[0009] It has further surprisingly been found that the use of inorganic materials that do not react with water achieves improved processability while at the same time providing sufficient strength and load bearing properties to the composition.

[0010] By using materials that do not react with water, a neutral pH of the filler can still be achieved, thereby avoiding soil contamination due to a drop in pH value.

[0011] Furthermore, the method according to the invention has the advantage that it does not require the use of further chemical additives such as flow improvers or conditioners which may be stressful on the soil.

[0012] This composition has the advantage that it still has high ductility with sufficient strength so that stresses in the soil can be compensated for by the ring gap filler and the ring gap filler will not fracture.

[0013] The composition used to fill the ring gap in the method according to the invention is cement-free, i.e. does not contain cement. Instead, the composition comprises a reactive resin that is hardened by polymerization, and a filler, the filler comprising a water-insensitive inorganic material having an average particle size of 500 μm or less.

[0014] In the context of the present invention, a water-insensitive inorganic material is an inorganic material that does not react or reacts only slightly with water at room temperature, and is therefore inert to water. Preferably, the material is practically insoluble or poorly soluble in water and forms a suspension with water.

[0015] In an advantageous embodiment, the water-non-reactive inorganic material has an average particle size of 0.5 to 500 μm, for example 0.5 to 300 μm.

[0016] In an advantageous embodiment, the inorganic material that does not react with water has an average particle size of 20 μm or less, in particular 100 μm or less. The inorganic material that does not react with water can preferably have an average particle size of 5 to 100 μm. The particle size can be measured by particle size distribution.

[0017] In a preferred embodiment, the filler comprises an inorganic material that does not react with water.

[0018] As an inorganic material that does not react with water, a porous filler can be used.

[0019] As inorganic materials that do not react with water, for example, calcite, silt, clay, ground quartz, fly ash, dust, or powder, or mixtures thereof, can be used.

[0020] In a preferred embodiment, the water non-reactive inorganic material comprises or consists of calcium carbonate.

[0021] In a preferred embodiment, the inorganic material that does not react with water is obtained from a recycling process, for example residues from a crushing or processing plant.

[0022] In a preferred embodiment, the filler is used in the form of an aqueous suspension that is mixed with and dispersed in a reactive resin that hardens by polymerization, thus achieving a homogeneous ring gap filling.

[0023] In an advantageous embodiment, the reactive resin cured by polymerization is a reactive resin cured by polyaddition, polycondensation or radical polymerization. Particularly preferably, reactive resins based on acrylate or silicate resins, or based on polyurethane, or based on epoxy or polyester resins are used. By blending the components of the reactive resin, the curing behavior of the reactive resin can be adapted as desired, on the one hand, ensuring rapid curing in the ring gap, and on the other hand, preventing premature curing already during transport to the ring gap.

[0024] The composition may contain from 20 to 90% by volume, preferably from 40 to 70% by volume, in particular from 55 to 65% by volume of filler.

[0025] Furthermore, the composition may contain 5 to 50% by volume of reactive resin, preferably 20 to 40% by volume, in particular 35 to 35% by volume of reactive resin.

[0026] Furthermore, the composition may contain 0.5 to 30% by volume, preferably 1 to 20% by volume, in particular 5 to 15% by volume of water.

[0027] In an advantageous embodiment, the composition comprises a reactive resin, an inorganic material that does not react with water, and water.

[0028] In a preferred embodiment, the reactive resin and the filler are introduced together and then both components are fed through a mixing device, so that the filler mixes with and is dispersed in the reactive resin, which is hardened by polymerization. Preferably, the mixing device is a static mixer or a forced mixer. A static mixer has a line in the form of a pipe through which the components to be mixed are fed. The pipe has flow-directing elements that split and reunite the material flows, thereby achieving mixing. A forced mixer comprises a stationary vessel in which a mixing tool, for example with a propeller, auger or blades, rotates. Widely used forced mixers are colloid mixers and dissolvers.

[0029] The invention will now be described with reference to exemplary embodiments in the drawings. [Brief description of the drawings]

[0030] [Figure 1] FIG. 2 is a schematic cross-sectional detail view in the region of the shield tail of the tunnel boring machine, where, following the rear of the shield tail, segment parts are inserted to form a segment tube. [Diagram 2] FIG. 2 shows a schematic side view of a tunnel boring machine with a front cutting wheel and adjacent shield casing, below which is depicted a detailed cross-sectional view of the tunnel boring machine in the vertical upper end region and of the drilled hole with the segment parts inserted. [Diagram 3] FIG. 13 is a perspective cross-sectional view perpendicular to the longitudinal axis of the tunnel hole with the segment piece installed and the ring gap between the outer wall of the segment piece and the excavation hole in the rock mass filled. [Figure 4] FIG. 1 is a schematic diagram of the production of an injection material for filling the ring gap, where the filler is first mixed with water to form a suspension, and then the suspension is mixed with a reactive resin in a mixer to form an injection material provided for filling the ring gap. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] The field of application of the method according to the invention will now be described with reference to figures 1 to 3. The creation of the excavation hole in the ground is carried out by a tunnel boring machine, in the illustrated exemplary embodiment a shield machine 1, which is shown in simplified side view in the upper part of figure 2. The shield machine 1 is provided with a cutting wheel 2 at the front, which is followed by a shield casing 4, which is formed by a steel cylinder sleeve with a slightly smaller diameter compared to the cutting wheel 2. The equipment and machines required for the work are accommodated in the shield casing 4, in particular the internal space of which accommodates the drive, the excavation mechanism and the equipment for placing the concrete segments 10 for forming the tunnel lining. The placement of the segments 10 takes place a few meters behind the cutting wheel 2, i.e. immediately following the creation of the excavation hole section in question, and the segments 10 are placed at the rear of the shield casing 4, i.e. at the so-called shield tail 6, using a robot-like device, a so-called erector (not shown). The tunnel boring machine excavates by a mechanical advancing means, which abuts against the end face of the tunnel lining, i.e., the frontmost ring from a segment part of the tunnel lining, and is supported thereon to advance the tunnel boring machine.

[0032] In Fig. 1 a schematic cross-section of the upper region of the just-prepared borehole is shown, showing only the upper end region of the shield tail 6 of the tunnel boring machine and the upper end region of the last installed rings of the tunnel lining from the segment part 10. As shown in Fig. 1, successive rings from the segment part 10 are sealed by seals 12.

[0033] From the detail at the bottom of FIG. 2 it can be seen that the outer diameter of the cutting wheel 2 is slightly larger than the outer diameter of the shield casing 4 which follows it. Therefore, the excavation hole in the surrounding rock has a somewhat larger diameter than the shield casing 4. Moreover, as can be seen from the detail at the bottom of FIG. 2, the segment parts 10 are assembled as rings respectively at the rear inside the shield tail, which rings emerge rearward from the shield tail 4 as the tunnel boring machine advances, so that the outer diameter of the ring segments assembled from the segment parts is even smaller than the diameter of the excavation hole in the rock made by the cutting wheel 2. Thus, between the outer shell of the tunnel lining formed by the segment parts 10 and the inner wall of the excavation hole in the rock made by the cutting wheel 2, a gap remains. This gap is called the ring gap. As explained in the introduction, the ring gap must be filled with grout in order to embed and support the tunnel lining in the excavation hole.

[0034] To produce the grout for filling the ring gap, the reactive resin and the filler are introduced together into a vessel 20 of a forced mixer inside the shield tail and mixed by a forced mixer rotating in the vessel 20. The mixed grout is then pumped from the forced mixer 20 through a line driven by a pump 22. The grout is fed into a line 24 which first extends radially outwards into the outer wall of the shield tail 6, where it has a 90° bend in the cavity of the shield tail 6 and in a further section extends parallel to the longitudinal axis of the cylindrical shield tail 6 to the end of the shield tail 6, where it opens into the ring gap. There can be several of these lines 24, which are also present in conventional tunnel boring machines and are called grout pipes (Lisene).

[0035] At the rear end of the shield tail 6 there are brush seals 8 on both the inner and outer walls, which on the one hand seal the end region of the shield tail 6 against the outer wall of the last formed ring from the segment parts 10, and on the other hand seal the outer wall of the shield tail 6 against the surrounding rock mass. These brush seals 8 ensure that the injection material forced into the ring gap from the end of the injection tube 24 never escapes beyond the filling of the ring gap and is also forced forward beyond the end region of the shield tail 6.

[0036] In this way, the grout is pumped by the pump 22 from the forced mixer container 20 through the line extending from the container 20 and further through the grouting pipe 24 into the ring gap, so that as the tunnel boring machine proceeds with the excavation, the ring gap filling 100 is continuously formed in the ring gap occurring between the tunnel lining and the surrounding rock mass 102. Here, there are basically a number of grouting pipes 24, for example six grouting pipes distributed around the circumference of the shield tail 6, which are distributed in the circumferential direction to deliver the grouting material to the ring gap to fill it, and after the ring gap filling 100 has hardened, it forms a stable filling layer for the tunnel lining composed of the segment parts 10.

[0037] In Fig. 3 it can be seen that each of the segment parts 10 is provided with injection openings 11 passing through the segment parts. These injection openings 11 are normally closed by seals. The injection openings 11 are used to fill any remaining or newly created cavities in the ring gap after the ring gap filling 100 has hardened by reinjecting the mixed reactive resin and filler material.

[0038] In Fig. 4 an embodiment of the method according to the invention is shown very diagrammatically. In this case the filler is formed by a mixture of water and inorganic material that does not react with water. Here, inorganic material 50 that does not react with water (schematically shown as a bag) is filled into a container 22 and mixed there with water supplied from a water container 24, after which the mixture is pumped through a line to an aeration tank 80. In the aeration tank 80 the mixture is kneaded by a rotating propeller. In parallel thereto, two pumps 60 deliver two monomer components A, B, which join behind the outlets of the pumps 60 and are extruded through a static mixer 62. From the outlet of the static mixer 62 the reacted resin is delivered to the inlet of a static mixer 64. The static mixer 64 also has a second inlet for a line from the aeration tank 80 to which the filler suspension is supplied. In the mixer 64, the reactive resin and the filler suspension are mixed with one another, in this respect the mixer 64 can also be configured as a static mixer. After mixing of the filler suspension and the reactive resin, the mixture obtained is fed for further injection into the ring gap, i.e. in particular into the injection tube 24, the outlet opening of which opens into the ring gap at the end of the shield tail 6.

Claims

1. A method for constructing traffic tunnels, pipeline tunnels, or pressurized water tunnels using the segment construction method, The segment components (10) are assembled in a mechanically constructed borehole in rock or soil to form a closed lining in the form of a segment tube. The annular gap between the excavated hole and the outer wall of the segment pipe is filled with a composition comprising a polymerizable reactive resin and a filler, wherein the filler receives the polymerizable reactive resin before or during its supply to the annular gap, and the polymerizable reactive resin is mixed with and dispersed therein. The composition does not contain cement, and the filler contains an inorganic material that does not react with water and has an average particle size of 500 μm or less. A method characterized by the following:

2. The method according to claim 1, characterized in that the inorganic material that does not react with water has an average particle size of 0.5 to 300 μm, preferably 5 to 100 μm.

3. The method according to 1 or 2, characterized in that the filler is made of an inorganic material that does not react with water.

4. The method according to 1 or 2, characterized in that the inorganic material that does not react with water contains or consists of calcium carbonate.

5. The method according to 1 or 2, characterized in that the inorganic material that does not react with water is selected from calcite, silt, clay, quartz powder, fly ash, dust, or powder, or a mixture thereof.

6. The method according to 1 or 2, characterized in that the inorganic material that does not react with water is obtained from a recycling process.

7. The method according to 1 or 2, characterized in that the filler is used as an aqueous suspension.

8. The method according to 1 or 2, characterized in that the reaction resin cured by polymerization is a reaction resin cured by polyaddition, polycondensation, or radical polymerization.

9. The method according to 1 or 2, characterized in that a reactive resin based on acrylate or silicate resin, or based on polyurethane, or based on epoxy resin or polyester resin is used.

10. The method according to 1 or 2, characterized in that the composition contains 5 to 50 volume percent of a reactive resin, preferably 20 to 40 volume percent of a reactive resin.

11. The method according to 1 or 2, characterized in that the composition contains 20 to 90% by volume of a filler, preferably 40 to 70% by volume of a filler.

12. The method according to 1 or 2, characterized in that the composition comprises a reactive resin, an inorganic material that does not react with water, and water.

13. The method according to 1 or 2, characterized in that the filler is mixed with the reaction resin to be cured by polymerization before polymerization.

14. The method according to 1 or 2, characterized in that after combining the reaction resin and the filler, the two components are mixed by a mixing device, preferably a static mixer (64) or a forced mixer (20), so that the filler is mixed with the reaction resin that is cured by polymerization and dispersed in the reaction resin.

15. Use of a composition comprising a polymer-curing reactive resin and a filler for filling an annular gap between a drilled hole and the outer wall of a segment pipe, wherein the filler does not contain cement and contains an inorganic material that does not react with water, and the inorganic material that does not react with water has a particle size of 500 μm or less.

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