The shield tunneling machine initiates its operation in water-rich strata, receiving devices to reduce water leakage at the tunnel portal.

Abstract

This invention relates to a device for reducing water leakage at the tunnel portal during shield tunneling in water-rich strata, and pertains to the field of shield tunneling technology. The invention includes a pre-embedded steel ring and an extended steel ring fixed to the pre-embedded steel ring. A fixed ring is arranged circumferentially on the rear side of the extended steel ring, and a set of flaps is arranged circumferentially inside the fixed ring. Each flap is connected to the fixed ring via its own shaft. A rubber ring plate is fixed between the extended steel ring and the fixed ring. A set of tail brushes is fixed circumferentially on the inner circumferential surface of the extended steel ring between the pre-embedded steel ring and the rubber ring plate. One end of the tail brush near the rubber ring plate is fixed to the inner surface of the extended steel ring, and the other end is inclined towards the pre-embedded steel ring. This invention, by placing tail brushes between the pre-embedded steel ring and the rubber ring plate, and filling the tail brushes with tail grease, improves their sealing and water-stopping effect. Combined with the flaps and the rubber ring plate, it achieves two-stage waterproofing, reducing water and sand inflow at the shield tunnel portal.

Description

Technical Field

[0001] This invention relates to a device for reducing water leakage at the tunnel portal when a tunnel boring machine (TBM) starts its operation in a water-rich stratum, and pertains to the field of TBM construction technology. Background Technology

[0002] Shield tunneling is widely used in tunnel engineering due to its advantages such as low disturbance, strong adaptability, and high quality. The basic working principle of a shield tunneling machine is that a cylindrical steel assembly advances along the tunnel axis to excavate the soil. The shell of this cylindrical assembly, the shield, provides temporary support for the excavated, unlined tunnel section, withstands the pressure of the surrounding soil layers, and sometimes also withstands groundwater pressure and blocks groundwater from entering. Currently, during shield tunnel construction, sealing devices need to be pre-embedded at the starting and ending points of the shield tunneling machine to ensure its normal advancement.

[0003] Conventional launching and receiving end sealing devices use an extended steel ring plus a flap and rubber curtain structure. During shield tunneling, the flap may fail to flip into place, especially in water-rich sandy geological conditions, which can lead to water and sand gushing in at the tunnel entrance, making it impossible to guarantee the sealing when the shield machine enters the tunnel in advance, posing a certain risk. Summary of the Invention

[0004] The purpose of this invention is to design a device that can improve the sealing of the shield tunneling initiation and receiving end and reduce water leakage at the tunnel portal.

[0005] This invention includes a pre-embedded steel ring and an extended steel ring fixed on the pre-embedded steel ring. A fixed ring is arranged circumferentially on the rear side of the extended steel ring, and a set of flaps is arranged circumferentially on the inner side of the fixed ring. Each flap is connected to the fixed ring through its own shaft. A rubber ring plate is fixed between the extended steel ring and the fixed ring. A set of shield tail brushes is fixed circumferentially on the inner circumferential surface of the extended steel ring between the pre-embedded steel ring and the rubber ring plate. One end of the shield tail brush near the rubber ring plate is fixed on the inner surface of the extended steel ring, and the other end is inclined towards the pre-embedded steel ring. The shield tail brush includes bristles and front clamping plates and rear clamping plates located on the front and rear sides of the bristles, respectively. The front clamping plates and rear clamping plates are respectively composed of a set of front unit plates and rear unit plates arranged circumferentially. A flexible connecting plate is arranged between adjacent front unit plates or adjacent rear unit plates to connect the two.

[0006] Furthermore, the two adjacent flaps have corresponding bending structures on both sides.

[0007] Furthermore, the flap is T-shaped, with its radial portion connected to the fixing ring via a shaft, and its chordal portion having a toothed structure on both sides.

[0008] Furthermore, each flap is T-shaped, and its radial portion is connected to a fixing ring via a shaft. In the case of adjacent first flaps and second flaps, the length of the first flap is less than the length of the radial portion of the adjacent second flap.

[0009] Furthermore, the inner end face of the first flap and the outer end face of the chordal portion of the second flap are in a corresponding arc shape.

[0010] Furthermore, the extended steel ring is formed by connecting a set of arc-shaped segments arranged circumferentially. Adjacent left and right arc-shaped segments have opposing grooves at their connection points. The mating surfaces of the two grooves are respectively provided with a left inner water-stop groove and a left outer water-stop groove, a right inner water-stop groove and a right outer water-stop groove, and they are paired to form an inner water-stop groove and an outer water-stop groove, each containing a water-stop tape. A stop strip close to the inner and outer water-stop grooves is provided between the inner and outer water-stop grooves and the bottom of the groove of the left arc-shaped segment. The support plate is connected to the bottom of the groove of the left arc-shaped segment by bolts. The inner and outer sides of the support plate are connected to an inner elastic plate and an outer elastic plate by studs, respectively. The size of the assembly connecting the inner and outer elastic plates and the support plate is larger than the radial size of the groove, and the radial size of the support plate is smaller than the radial size of the groove. The inner elastic plate can cooperate with the inner water-stop tape, and the outer elastic plate can cooperate with the outer water-stop tape. The support plate and inner and outer elastic plates designed above can compress the water-stop tape through the anti-bending elastic force generated by the elastic plates, thereby improving the sealing effect of the water-stop tape at the arc-shaped joint.

[0011] Furthermore, the cross-section of the left inner waterstop groove is larger than that of the right inner waterstop groove, and the cross-section of the left outer waterstop groove is larger than that of the right outer waterstop groove. Using the above-designed waterstop grooves prevents the waterstop tape from falling off during installation.

[0012] Furthermore, an injection hole is provided on the right arc-shaped segment to connect its groove to the outside. This injection hole, designed as described above, allows for the injection of water-stopping gel into the groove. The gel solidifies upon contact with water, aiding in the fixation of the elastic plate and further improving the sealing effect at the joint of the extended steel ring.

[0013] This invention incorporates a tail brush between a pre-embedded steel ring and a rubber ring plate. Filling the tail brush with tail grease enhances its sealing and water-stopping effect. Combined with the flap and rubber ring plate, this achieves two levels of waterproofing, reducing water and sand inflow at the tunnel entrance. A flexible connecting plate is installed on the tail brush. When the tail brush is compressed and unfolded, the flexible connecting plate seals the gaps between the unit plates on the tail brush, further improving its sealing performance.

[0014] In this invention, grooves are provided at the joints of each arc segment, and a water-stopping tape supported by inner and outer elastic plates is placed in the grooves. The water-stopping tape is fixed by the recurving elastic force of the elastic plates, reducing the water flow into the opening through the joint of the extended steel ring. An injection hole is provided in the groove on one side of the joint of the extended steel ring, allowing water-stopping gel to be injected into the groove. The water-stopping gel solidifies upon contact with water, which helps to fix the elastic plates and further improves the sealing effect of the joint of the extended steel ring. Attached Figure Description

[0015] Figure 1 This is a front cross-sectional view of Embodiment 1 of the present invention;

[0016] Figure 2 for Figure 1 A directional view of the shield tail brush in direction A;

[0017] Figure 3 for Figure 2 A schematic diagram of the structure of the central shield tail brush after deployment;

[0018] Figure 4 for Figure 1 A view of the shield tail brush in the B direction;

[0019] Figure 5 for Figure 1 Right view of the middle flap section;

[0020] Figure 6 for Figure 5 A magnified view of a section at point C;

[0021] Figure 7 for Figure 6 A structural diagram of the middle support plate before it is installed;

[0022] Figure 8 for Figure 7 View from the D direction;

[0023] Figure 9 This is a schematic diagram of the flap section in Embodiment 2 of the present invention;

[0024] Among them, 1. Embedded steel ring, 2. Extended steel ring, 3. Fixed ring, 4. Flip plate, 5. Rubber ring plate, 6. Shield tail brush, 7. Front unit plate, 8. Brush bristles, 9. Rear unit plate, 10. Flexible connecting plate, 11. Left arc segment, 12. Right arc segment, 13. Groove, 14. Inner waterstop groove, 15. Outer waterstop groove, 16. Waterstop tape, 17. Stop bar, 18. Support plate, 19. Bolt, 20. Inner elastic plate, 21. Outer elastic plate, 22. Glue injection hole, 23. First flip plate, 24. Second flip plate. Detailed Implementation Example 1

[0025] by Figure 1 In this embodiment, the directions of up, down, left, and right are defined. The direction of the tunnel boring machine's movement is defined as the front of this embodiment, and the opposite direction is defined as the rear. One side of the outer surface of the tunnel body is defined as the outer side of this embodiment, and one side of the inner wall of the tunnel entrance is defined as the inner side of this embodiment.

[0026] As shown in the figure, this embodiment includes a pre-embedded steel ring 1, which is a ring-shaped steel structure and is pre-embedded in the inner lining wall at the portal. An extension steel ring 2 is provided on the rear side of the pre-embedded steel ring 1. The extension steel ring 2 is also a ring-shaped steel structure, connected and positioned to the pre-embedded steel ring 1 by double-ended studs and then welded in place. A fixing ring 3 is bolted to the rear side of the extension steel ring 2 along its circumference. A set of flaps 4 is provided on the inner side of the fixing ring 3 along its circumference. The radial portion of each flap 4 is rotatably connected to the fixing ring 3 via its respective shaft and a connector welded to the fixing ring 3. A rubber ring plate 5 is clamped and fixed between the extension steel ring 2 and the fixing ring 3. In this embodiment, the rubber ring plate 5 uses an existing product, and its specific structure will not be described in detail here.

[0027] A set of tail brushes 6 are arranged circumferentially on the inner circumferential surface of the extended steel ring 2 between the pre-embedded steel ring 1 and the rubber ring plate 5. One end of each tail brush 6 is welded and fixed to the inner surface of the extended steel ring 2 near the rubber ring plate 5, and the other end is inclined towards one side of the pre-embedded steel ring 1. In use, tail grease needs to be filled into the tail brushes 6. When the tunnel boring machine passes through the tail brushes 6, the inclined end of the tail brush 6 is squeezed and expands forward. The part filled with tail grease comes into contact with the surface of the tunnel boring machine, forming a two-stage waterproofing with the rubber ring plate 5, reducing the inflow of water and sand into the tunnel portal. In this embodiment, the tail shield brush 6 includes a front clamping plate and a rear clamping plate, with bristles 8 clamped and fixed between the front and rear clamping plates by bolts. The front and rear clamping plates are each composed of a set of front unit plates 7 and a rear unit plate 9 arranged circumferentially along the extending steel ring 2. A flexible connecting plate 10 is provided between adjacent front unit plates 7, connecting them. The flexible connecting plate 10 is fixed to the front surface of the front unit plate 7 by bolts. When the tail shield brush 6 is pressed forward and expands outward, the flexible connecting plate 10 can contact the tunnel boring machine in the gaps between the front unit plates 7, filling the gaps and further improving the sealing effect of the tail shield brush 6. In practical applications, the flexible connecting plate 10 can improve the sealing effect of the tail shield brush 6 by being installed on both the front unit plate 7 and the rear unit plate 9. Alternatively, the flexible connecting plate 10 can be installed on both unit plates simultaneously to double-seal the gaps between the unit plates. The specific installation method can be selected according to the site conditions.

[0028] In this embodiment, each flap 4 is T-shaped, and the two sides of two adjacent flaps 4 have corresponding bending structures; the left and right sides of the chordal portion of each flap 4 have toothed structures. In actual application, the bending portions on both sides of each flap 4 can also adopt arc bending structures, or a combination of arc bending structures and toothed bending structures. Among them, when the toothed bending structure is adopted, when the flap 4 is tilted forward, the toothed structures between adjacent flaps 4 are interlocked with each other. Compared with other bending structures, the support strength of the rubber ring plate 5 is higher, which improves the water-blocking effect of the rubber ring plate 5.

[0029] In this embodiment, the extended steel ring 2 is composed of a set of circumferentially arranged arc-shaped segments spliced ​​together, which can be four, six, or eight segments. The arc-shaped segments can be connected by bolts to facilitate the transport of the extended steel ring 2. Two adjacent arc-shaped segments can be divided into a left arc-shaped segment 11 and a right arc-shaped segment 12. The connection between the left arc-shaped segment 11 and the right arc-shaped segment 12 is provided with opposing grooves 13. The mating surfaces of the two grooves 13 are respectively provided with an inner water-stop groove 14 and an outer water-stop groove 15. The inner water-stop groove 14 includes two opposing left inner water-stop grooves and a right inner water-stop groove. The outer water-stop groove 15 includes two opposing left outer water-stop grooves and a right outer water-stop groove. Water-stop tape 16 is placed in the inner and outer water-stop grooves respectively. In this embodiment, the water-stop tape 16 is an existing product that expands after contact with water and can seal the connection of the arc-shaped segments. A baffle 17 is provided between the inner and outer waterstop grooves and the bottom of the groove of the left arc-shaped section 11. The position of each baffle 17 in the groove 13 is close to the inner and outer waterstop grooves and matches the size of the waterstop tape 16.

[0030] An elastic sealing mechanism is provided between the inner and outer waterstop grooves. The elastic sealing mechanism includes a support plate 18, with a set of countersunk holes in the middle of the support plate 18. A set of threaded holes corresponding to each countersunk hole are provided in the groove 13 of the left arc-shaped section 11. The support plate 18 is fixedly connected to the bottom of the groove of the left arc-shaped section 11 by bolts 19. An inner elastic plate 20 and an outer elastic plate 21 are respectively provided on the inner and outer sides of the support plate 18. The ends of the inner and outer elastic plates near the support plate 18 are fixedly connected to the support plate 18 by studs. The radial dimension of the support plate 18 is smaller than the radial dimension of the groove 13. The overall dimension of the inner elastic plate 20, the outer elastic plate 21 and the support plate 18 after connection is larger than the radial dimension of the groove 13. When the inner and outer elastic plates are not installed, both elastic plates are bent toward the left arc segment 11. When the support plate 18 is installed into the groove 13 of the left arc segment 11 by the bolt 19, the inner and outer elastic plates are deformed by pressure and bend toward the right arc segment 12. At this time, the inner elastic plate 20 squeezes the inner water-stop tape 16 by its own anti-bending elasticity, and the outer elastic plate 21 squeezes the outer water-stop tape 16 by its own anti-bending elasticity. The anti-bending elasticity of the inner and outer elastic plates fixes the water-stop tape 16 and seals the gap between the left and right arc segments.

[0031] In this embodiment, the cross-section of the left inner waterstop groove is larger than that of the right inner waterstop groove, and the cross-section of the left outer waterstop groove is larger than that of the right outer waterstop groove. When installing the waterstop tape 16, the support plate 18 needs to be installed first, and then the waterstop tape 16 is inserted between the left inner waterstop groove and the inner elastic plate 20, and between the left outer waterstop groove and the outer elastic plate 21, respectively. The larger left waterstop groove can prevent the waterstop tape 16 from falling off. Then the right arc segment 12 is installed. During installation, the parts of the inner and outer elastic plates that extend beyond the groove 13 need to be inserted into the groove 13 of the right arc segment 12 first, and then the left and right arc segments are fixedly connected by bolts. During use, the waterstop tape 16 will expand when exposed to water. The baffle 17 set in the left arc segment 11 can prevent the expanded waterstop tape 16 from falling out of the inner and outer waterstop grooves. The right arc segment 12 is provided with an injection hole 22 that connects its groove 13 to the outside. After the left arc segment 11 and the right arc segment 12 are connected, water-stopping gel is injected into the groove 13 through the injection hole 22. When there is too much water at the outer elastic plate 21 or the elasticity of the outer elastic plate 21 is weakened due to elastic fatigue, the water will leak to the right arc segment 12. The water-stopping gel solidifies after contacting the water, supports the elastic plate and seals the leakage point, thus improving the sealing effect at the arc segment connection.

[0032] In this embodiment, after each arc segment is processed, it is transported to the site. The arc segments are then spliced ​​together on site. During the splicing process, an elastic sealing mechanism and a water-stop tape 16 need to be installed in the groove 13 at the connection of each arc segment. After the splicing is completed, water-stop gel is injected into the groove 13 through each injection hole 22. After completion, each injection hole 22 is sealed by welding to complete the assembly of the extension steel ring 2.

[0033] At the rear end of the extension steel ring 2, the fixing ring 3 of the flap 4 and the rubber ring plate 5 are installed and connected by bolts. Then, the shield tail brush 6 is welded and fixed to the inner surface of the extension steel ring 2. After completion, the extension steel ring 2 is lifted by a truck crane to the pre-embedded steel ring 1, and then connected and positioned to the pre-embedded steel ring 1 by double-ended studs before welding and fixing. After fixing, the workers fill the shield tail brush 6 with shield tail grease, completing the installation of the extension steel ring 2.

[0034] In this embodiment, all technical features not described in detail are existing technologies or conventional technical means, and will not be elaborated here. Example 2

[0035] This embodiment is basically the same in structure as Embodiment 1, except that the flap 4 in this embodiment includes adjacent first flaps 23 and second flaps 24, each flap being T-shaped, wherein the length of the first flap 23 is less than the length of the radial portion of the adjacent second flap 24. In this embodiment, the first flap 23 and the second flap 24 are two adjacent flaps arbitrarily selected from each flap. The inner end face of each first flap 23 and the outer end face of each second flap 24 form a corresponding arc shape. When each flap is pressed and tilted, the arc-shaped contact surfaces of the adjacent flaps are pressed tightly against each other, avoiding the phenomenon of mutual jamming and damage to the contact surfaces.

Claims

1. A device for reducing water leakage at the tunnel portal during shield tunneling in water-rich strata, comprising a pre-embedded steel ring and an extended steel ring fixed to the pre-embedded steel ring, wherein a fixed ring is provided along the circumference of the rear side of the extended steel ring and a set of flaps is provided along the circumference of the inner side of the fixed ring, each flap being connected to the fixed ring via its own shaft; a rubber ring plate is fixed between the extended steel ring and the fixed ring, characterized in that: A set of shield tail brushes is fixed along the circumferential direction on the inner circumferential surface of the extended steel ring between the pre-embedded steel ring and the rubber ring plate. One end of the shield tail brush near the rubber ring plate is fixed on the inner surface of the extended steel ring, and the other end is inclined towards the pre-embedded steel ring. The shield tail brush includes bristles and front clamping plates and rear clamping plates located on the front and rear sides of the bristles, respectively. The front clamping plates and rear clamping plates are each composed of a set of front unit plates and rear unit plates arranged along the circumferential direction. A flexible connecting plate is provided between adjacent front unit plates or between adjacent rear unit plates to connect the two. The extended steel ring is formed by connecting a set of arc-shaped segments arranged circumferentially. Adjacent left and right arc-shaped segments have opposing grooves at their connection points. The mating surfaces of the two grooves are respectively provided with left inner and left outer water-stop grooves, right inner and right outer water-stop grooves, and opposite each other to form inner and outer water-stop grooves, each containing water-stop tape. A retaining strip is provided between the inner and outer water-stop grooves and the bottom of the groove in the left arc-shaped segment, respectively, close to the inner and outer water-stop grooves. The support plate is connected to the bottom of the groove in the left arc-shaped segment by bolts. The inner and outer sides of the support plate are connected to an inner elastic plate and an outer elastic plate by studs, respectively. The assembly size of the inner and outer elastic plates connected to the support plate is larger than the radial dimension of the groove, and the radial dimension of the support plate is smaller than the radial dimension of the groove. The inner elastic plate can cooperate with the inner water-stop tape, and the outer elastic plate can cooperate with the outer water-stop tape. An injection hole is provided on the right arc segment to connect its groove with the outside.

2. The device for reducing water leakage at the tunnel portal during shield tunneling in water-rich strata as described in claim 1, characterized in that: The two adjacent flaps have corresponding curved structures on both sides.

3. The device for reducing water leakage at the tunnel portal during shield tunneling in water-rich strata as described in claim 2, characterized in that: The flap is T-shaped, with its radial portion connected to the fixing ring via a shaft, and its chordal portion having a toothed structure on both sides.

4. The device for reducing water leakage at the tunnel portal during shield tunneling in water-rich strata as described in claim 1, characterized in that: Each flap is T-shaped, and its radial portion is connected to a fixed ring via a shaft. In the case of adjacent first flaps and second flaps, the length of the first flap is less than the length of the radial portion of the adjacent second flap.

5. The device for reducing water leakage at the tunnel portal during shield tunneling in water-rich strata as described in claim 4, characterized in that: The inner end face of the first flap and the outer end face of the chordal portion of the second flap are in a corresponding arc shape.

6. The device for reducing water leakage at the tunnel portal during shield tunneling in water-rich strata as described in claim 1, characterized in that: The cross-section of the left inner waterstop groove is larger than that of the right inner waterstop groove, and the cross-section of the left outer waterstop groove is larger than that of the right outer waterstop groove.

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