TBM tunnel embedded steel arch support structure

Abstract

The utility model discloses a TBM tunnel embedded type steel arch support structure which comprises a support tunnel wall, and the support tunnel wall is formed in the mode that an initial tunnel wall of a TBM construction tunnel continues to be excavated towards the outer side. A plurality of grooves are formed in the supporting tunnel wall at intervals in the axial direction of the TBM construction tunnel, each groove is formed by digging in the circumferential direction of the TBM construction tunnel, and an annular steel arch is arranged in each groove; gaps between the annular steel arches and the walls of the corresponding grooves are filled with grouting materials. A reinforcing mesh and a connecting reinforcing steel bar are arranged on the supporting tunnel wall between every two adjacent annular steel arches; the annular steel arch, the reinforcing mesh and the connecting steel bars are all arranged on the outer side of the initial tunnel wall. It can be guaranteed that a soft rock area is in a supporting state for a long time, and the stability and safety of tunnel wall surrounding rock are guaranteed when the TBM overall unit retreats; and when the whole TBM retreats, repeated disassembly and assembly of a conventional steel arch support structure are avoided, the construction process is simplified, and the construction period is shortened.

Description

Technical Field

[0001] The utility model relates to the technical field of steel arch frames, in particular to a TBM tunnel embedded steel arch frame supporting structure. Background Art

[0002] During the TBM tunneling process, when the surrounding rock grade is IV to VI, in order to ensure the stability of the tunnel surrounding rock, a steel arch structure needs to be used for timely support to resist surrounding rock deformation and ensure surrounding rock stability. Steel arches are often made of steel sections, and the steel arches fit tightly with the tunnel wall formed by excavation. After the tunnel excavation is completed, if the TBM machine is withdrawn, the constructed steel arches must be removed. After the TBM withdraws, the steel arch support must be repeated. The construction method of repeatedly disassembling and assembling the steel arch increases the construction process, and the surrounding rock of the steel arch support section is generally relatively poor. Removing the steel arch will undoubtedly increase the risk of surrounding rock collapse, which is not conducive to tunnel safety. Utility Model Content

[0003] The problem to be solved by the utility model is to overcome the defects of the existing technology and provide a TBM tunnel embedded steel arch support structure. When the TBM retreats, there is no need to construct and dismantle the steel arch support, which reduces the construction process, saves construction time, and ensures the safety of the tunnel surrounding rock.

[0004] In order to solve the above technical problems, the utility model provides a TBM tunnel embedded steel arch support structure, including a supporting cavern wall, which is formed by continuing to excavate outward from the initial cavern wall of the TBM construction tunnel; a plurality of grooves are arranged on the supporting cavern wall at intervals along the axial direction of the TBM construction tunnel, and each of the grooves is excavated along the circumference of the TBM construction tunnel, and an annular steel arch is arranged inside; the gap between the annular steel arch and the corresponding groove wall is filled with grouting material; a steel mesh and connecting steel bars are provided on the supporting cavern wall between two adjacent annular steel arches; the annular steel arch, the steel mesh and the connecting steel bars are all arranged on the outside of the initial cavern wall.

[0005] In the above-mentioned TBM tunnel embedded steel arch support structure, during the TBM tunnel excavation process, when the surrounding rock grade is IV to VI, the TBM tunnel embedded steel arch support structure is constructed in a certain section and embedded in the initial wall of the TBM construction tunnel. When the TBM retreats, there is no need to construct and dismantle the steel arch support, which reduces construction procedures, saves construction time, and ensures the safety of the tunnel surrounding rock.

[0006] Preferably, the supporting cave wall and the initial cave wall both have circular cross-sections, and the inner diameter of the supporting cave wall is larger than that of the initial cave wall.

[0007] Furthermore, the depth of the groove is greater than the radial thickness of a single side of the annular steel arch, and the width of the groove is greater than the axial thickness of the annular steel arch.

[0008] Furthermore, the depth of the groove is greater than the radial thickness of the annular steel arch by 4-6 cm, and the width of the groove is greater than the axial thickness of the annular steel arch by 1-3 cm.

[0009] Furthermore, the annular steel arch frame is formed by splicing together multiple sections, and each section is made of I-beams.

[0010] Furthermore, the material of the I-beam is Q345 steel, and the model is I16~I22.

[0011] Furthermore, the arc length of each section of the annular steel arch is 3 to 4 meters, and each section is connected by high-strength bolts.

[0012] Furthermore, the steel mesh is fixedly connected to the annular steel arch frames on both sides, and the mesh surface is attached to the wall surface of the supporting tunnel.

[0013] Furthermore, the steel mesh is welded from a plurality of meshes, and each mesh is made of HPB300 steel bars with a diameter of 6 mm and a specification of 150 mm×150 mm.

[0014] Furthermore, the connecting steel bars are arranged on the steel mesh along the axial direction of the TBM construction tunnel, and a plurality of the connecting steel bars are arranged at intervals along the circumferential direction of the TBM construction tunnel between two adjacent annular steel arches.

[0015] Furthermore, the connecting steel bars are all HRB400 threaded steel bars with a diameter of 20 mm.

[0016] In summary, the use of the above-mentioned embedded steel arch support structure in the TBM tunnel can ensure that the soft rock area is in a supported state for a long time, ensuring the stability and safety of the surrounding rock of the tunnel wall when the TBM is withdrawn. In addition, when the TBM is withdrawn, the repeated disassembly and assembly of the conventional steel arch support structure is avoided, which simplifies the construction process and shortens the construction period. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In the attached figure:

[0018] Figure 1 This is a schematic diagram of the TBM tunnel embedded steel arch support structure of the utility model.

[0019] Figure 2 for Figure 1 AA cross-sectional diagram of .

[0020] Figure 3 A partial schematic diagram of the TBM tunnel embedded steel arch support structure of the utility model.

[0021] In the figure, 1. Supporting cave wall; 2. Initial cave wall; 3. Groove; 4. Annular steel arch; 5. Steel mesh; 6. Connecting steel bars. DETAILED DESCRIPTION

[0022] The following is a further description of the specific embodiments of the present invention in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention.

[0023] Example 1

[0024] Figure 1-3 The utility model shows a TBM tunnel embedded steel arch support structure. Figure 1-3 As shown, the TBM tunnel embedded steel arch support structure includes a supporting cavern wall 1, which is formed by continuing to excavate outward from the initial cavern wall 2 of the TBM construction tunnel; a plurality of grooves 3 are arranged at intervals along the axial direction of the TBM construction tunnel on the supporting cavern wall 1, and each groove 3 is excavated along the circumference of the TBM construction tunnel, and an annular steel arch 4 is arranged inside; the gap between the annular steel arch 4 and the corresponding groove 3 is filled with grouting material; a steel mesh 5 and connecting steel bars 6 are provided on the supporting cavern wall 1 between two adjacent annular steel arches 4; the annular steel arch 4, the steel mesh 5 and the connecting steel bars 6 are all arranged on the outside of the initial cavern wall 2.

[0025] The supporting wall 1 and the initial wall 2 are both circular in cross-section, and the inner diameter of the supporting wall 1 is larger than that of the initial wall 2. The outer side of the initial wall 2 refers to the side away from the center of the tunnel, and the inner side and outer side in this context both refer to the side close to or away from the center of the tunnel. The groove wall of the groove 3 includes a side wall and a bottom wall; the gap between the annular steel arch 4 and the corresponding groove 3 wall refers to the gap between the inner side of the annular steel arch and the side wall and bottom wall of the groove 3. The length of the supporting wall 1 and the spacing between the grooves 3 need to be designed according to the actual construction geological conditions and will not be described in detail.

[0026] To facilitate installation, the depth of the groove 3 is greater than the radial thickness of the annular steel arch 4, and the width of the groove 3 is greater than the axial thickness of the annular steel arch 4. Specifically, the depth of the groove 3 is 4-6 cm greater than the radial thickness of the annular steel arch 4, and the width of the groove 3 is 1-3 cm greater than the axial thickness of the annular steel arch 4. The axial thickness refers to the thickness of the annular steel arch 4, not the thickness of the connecting sections.

[0027] Optionally, the annular steel arch 4 is formed by splicing multiple sections, each section being made of I-beams. Specifically, the I-beams are made of Q345 steel, with models ranging from I16 to I22. Each section of the annular steel arch 4 has an arc length of 3 to 4 meters, and is connected by high-strength bolts.

[0028] like Figure 3 As shown, the steel mesh 5 is fixedly connected to the annular steel arches 4 on both sides, and the mesh surface is attached to the surface of the supporting cave wall 1, that is, attached to the surface of the supporting cave wall 1 between the corresponding two annular steel arches 4.

[0029] Optionally, the steel mesh 5 is welded from multiple meshes, each made of 6mm diameter HPB300 steel bars with a size of 150mm x 150mm. The mesh is tied with 6mm diameter HPB300 round steel bars, with a distance of 150mm between two steel bars, intersecting vertically and horizontally, and the meshes are connected by welding.

[0030] like Figure 3 As shown, the connecting steel bars 6 are arranged on the steel mesh 5 along the axial direction of the TBM construction tunnel, and multiple connecting steel bars 6 are arranged at intervals along the circumference of the TBM construction tunnel between two adjacent annular steel arches 4. The interval distance is designed according to actual conditions, and it is best to arrange them evenly.

[0031] Optionally, the connecting steel bars 6 are all made of HRB400 threaded steel bars with a diameter of 20 mm. The two ends of the connecting steel bars 6 are welded to the annular steel arch 4, using double-sided welding with a welding length of 100 mm. The ends of the connecting steel bars 6 can be bent first and then welded.

[0032] During construction, the TBM equipment is first used to excavate to form the initial cave wall 2, which is an unlined cave wall; then the first groove is cut on the initial cave wall 2 of the tunnel that needs to be supported to form the supporting cave wall 1. The groove is shallow and only needs to be able to embed the steel mesh 5 and the connecting steel bars 6. Of course, for a TBM with a variable diameter, the diameter of the TBM cutter head can be directly expanded to advance and form the supporting cave wall 1; then the second groove is cut at the set position to form a groove 3, which can be cut with a handheld jackhammer; then the groove is cut in the groove. An annular steel arch frame 4 is assembled and placed in the groove 3; then a caulking agent is used to seal the gap between the arch frame and the groove, and the pores between the annular steel arch frame 4 and the groove wall of the groove 3 are grouting-compacted through a grouting pipe. The grouting material uses cement slurry with a water-cement ratio of 0.5:1 and a strength grade of not less than M20. The grouting is ensured to be full to ensure that the surrounding rock pressure is effectively transmitted to the annular steel arch frame 4; finally, a steel mesh 5 is set between two adjacent annular steel arch frames 4, and steel bars 6 are welded to the outside of the steel mesh 5.

[0033] In addition, during construction, it is generally necessary to support the tunnel while digging. Therefore, it is planned in advance which section of the tunnel needs to be supported and where the annular steel arch 4 is to be set. Before the initial tunnel wall 2 is fully formed, the groove 3 can be constructed and the annular steel arch 4 can be set on the already formed initial tunnel wall 2. When constructing the groove 3, temporary support can be provided on both sides.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit its scope of protection. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that after reading the present invention, those skilled in the art can still make various changes, modifications or equivalent substitutions to the specific implementation methods of the utility model, but these changes, modifications or equivalent substitutions are all within the scope of protection of the pending claims of the utility model.

Claims

1. A TBM tunnel embedded steel arch support structure, characterized in that: The invention comprises a supporting cave wall (1), wherein the supporting cave wall (1) is formed by continuously excavating outward from the initial cave wall (2) of the TBM construction tunnel; a plurality of grooves (3) are arranged at intervals along the axial direction of the TBM construction tunnel on the supporting cave wall (1); each groove (3) is excavated along the circumference of the TBM construction tunnel, and an annular steel arch (4) is arranged inside each groove; the gap between the annular steel arch (4) and the corresponding groove wall of the groove (3) is filled with grouting material; a steel mesh (5) and connecting steel bars (6) are arranged on the supporting cave wall (1) between two adjacent annular steel arches (4); the annular steel arch (4), the steel mesh (5) and the connecting steel bars (6) are all arranged outside the initial cave wall (2).

2. A TBM tunnel embedded steel arch support structure according to claim 1, characterized in that: The depth of the groove (3) is greater than the radial thickness of a single side of the annular steel arch (4), and the width of the groove (3) is greater than the axial thickness of the annular steel arch (4).

3. A TBM tunnel embedded steel arch support structure according to claim 2, characterized in that: The depth of the groove (3) is greater than the radial thickness of the annular steel arch (4) by 4-6 cm, and the width of the groove (3) is greater than the axial thickness of the annular steel arch (4) by 1-3 cm.

4. A TBM tunnel embedded steel arch support structure according to claim 1, characterized in that: The annular steel arch frame (4) is formed by splicing together multiple sections, and each section is made of I-beams.

5. A TBM tunnel embedded steel arch support structure according to claim 4, characterized in that: The material of the I-beam is Q345 steel, and the model is I16-I22.

6. A TBM tunnel embedded steel arch support structure according to claim 4, characterized in that: The arc length of each section of the annular steel arch (4) is 3 to 4 meters, and each section is connected by high-strength bolts.

7. The TBM tunnel embedded steel arch support structure according to claim 1, characterized in that: The steel mesh (5) is fixedly connected to the annular steel arches (4) on both sides, and the mesh surface is attached to the surface of the supporting cave wall (1).

8. The TBM tunnel embedded steel arch support structure according to claim 7, characterized in that: The steel mesh (5) is welded from a plurality of meshes, each mesh being made of HPB300 steel bars with a diameter of 6 mm and a specification of 150 mm×150 mm.

9. The TBM tunnel embedded steel arch support structure according to claim 1, characterized in that: The connecting steel bars (6) are arranged on the steel mesh (5) along the axial direction of the TBM construction tunnel, and a plurality of the connecting steel bars (6) are arranged at intervals along the circumferential direction of the TBM construction tunnel between two adjacent annular steel arches (4).

10. A TBM tunnel embedded steel arch support structure according to claim 9, characterized in that: The connecting steel bars (6) are all made of HRB400 threaded steel bars with a diameter of 20 mm.

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