Rock burst tunnel supporting structure suitable for TBM construction method

Abstract

A rockburst tunnel supporting structure suitable for a TBM construction method belongs to the technical field of tunnel boring machine construction, and comprises a pre-stressed anchor rod embedded in tunnel surrounding rock, and a primary spraying fiber concrete layer, a reinforcing mesh, a steel frame and a re-spraying fiber concrete layer which are sequentially arranged on the wall surface of a tunnel, a first arch buffer layer is arranged between the primary spraying concrete layer and the reinforcing mesh, and a second arch buffer layer, reinforcing steel bars and a molded concrete layer are sequentially arranged on the upper surface of the re-spraying fiber concrete layer. The first arch portion buffer layer and the second arch portion buffer layer can absorb rockburst impact energy respectively, the buffer energy consumption threshold value coping with strong rockburst impact is increased, and therefore the safety of the tunnel supporting structure is improved.

Description

Technical Field

[0001] This utility model belongs to the field of tunnel boring machine (TBM) construction technology, and relates to a rockburst tunnel support structure, particularly a rockburst tunnel support structure suitable for TBM construction method. Background Technology

[0002] TBM (Tunnel Boring Machine) is a factory-produced, assembly-line tunnel construction equipment that integrates tunneling, support, and muck removal into one construction process. It is particularly suitable for the construction of deep-buried long tunnels in complex geographical terrain. It has the advantages of fast tunneling speed, environmental friendliness, high efficiency, and high safety performance. It is widely used in tunnel projects such as railways, hydropower, transportation, mining, and municipal engineering, and is one of the key technologies in the field of tunnel construction.

[0003] In formations with strong to extremely strong rockbursts, TBM construction faces challenges such as surrounding rock instability and damage to support structures, severely impacting construction progress and safety. Existing support structures suffer from insufficient support strength and poor adaptability when dealing with rockbursts, necessitating a novel approach to address these issues.

[0004] Therefore, in order to solve this problem, this utility model proposes a rockburst tunnel support structure suitable for TBM construction method. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide a rockburst tunnel support structure suitable for TBM construction, which solves the technical problem that the existing rockburst tunnel support structure has insufficient support strength and poor adaptability when dealing with rockbursts, thus affecting the safety of rockburst tunnel construction.

[0006] To achieve the above and other related objectives, this utility model provides a rockburst tunnel support structure suitable for TBM construction, including prestressed anchor bolts embedded in the surrounding rock of the tunnel, and a primary sprayed fiber concrete layer, a steel mesh and a steel frame and a secondary sprayed fiber concrete layer sequentially arranged on the tunnel wall. A first arch buffer layer is provided between the primary sprayed fiber concrete layer and the steel mesh and the steel frame. A second arch buffer layer, steel bars and a cast-in-place concrete layer are sequentially provided on the upper surface of the secondary sprayed fiber concrete layer.

[0007] In any of the above embodiments, it is preferred that the length of the prestressed anchor rod is 480–520 cm.

[0008] Preferably, in any of the above embodiments, the thickness of both the first arch buffer layer and the second arch buffer layer is 6 to 10 mm.

[0009] Preferably, in any of the above embodiments, the thickness of both the first arch buffer layer and the second arch buffer layer is 8 mm.

[0010] Preferably, in any of the above embodiments, both the first arch buffer layer and the second arch buffer layer are filled with polyethylene foam.

[0011] Preferably, in any of the above embodiments, the thickness of the initial sprayed fiber concrete layer is 40–80 mm.

[0012] Preferably, in any of the above embodiments, the thickness of the sprayed fiber concrete layer is 120–150 mm.

[0013] Preferably, in any of the above embodiments, the thickness of the cast-in-place concrete layer is greater than 200 mm.

[0014] As described above, the rockburst tunnel support structure of this utility model, which is applicable to the TBM method, has the following beneficial effects: In this utility model, the first arch buffer layer and the second arch buffer layer can absorb the rockburst impact energy respectively, increase the buffer energy consumption threshold when dealing with strong rockburst impact, and thus increase the safety of the tunnel support structure. Attached Figure Description

[0015] Figure 1 The diagram shown is a structural schematic of this utility model.

[0016] Component designation explanation

[0017] 1-Prestressed anchor; 2-Initial sprayed fiber concrete layer; 3-First arch buffer layer; 4-Reinforcing mesh and steel frame; 5-Re-sprayed fiber concrete layer; 6-Second arch buffer layer; 7-Reinforcing steel; 8-Cast concrete layer. Detailed Implementation

[0018] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification.

[0019] Please see Figure 1It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the scope of this invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of this invention, should still fall within the scope of the disclosed technical content. Furthermore, the terms "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of this invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of this invention.

[0020] Please see Figure 1 This utility model provides a rockburst tunnel support structure suitable for TBM construction method, including prestressed anchor rods 1 embedded in the surrounding rock of the tunnel, and a primary sprayed fiber concrete layer 2, a steel mesh and a steel frame 4 and a secondary sprayed fiber concrete layer 5 sequentially arranged on the tunnel wall. A first arch buffer layer 3 is provided between the primary sprayed fiber concrete layer 2 and the steel mesh and steel frame 4. A second arch buffer layer 6, a steel bar 7 and a cast-in-place concrete layer 8 are sequentially arranged on the upper surface of the secondary sprayed fiber concrete layer 5.

[0021] In this embodiment, an initial support layer and a secondary lining layer are set in the surrounding rock of the tunnel to improve the stability of the tunnel support structure and the safety of the TBM method construction process.

[0022] Among them, the prestressed anchor rod 1, the initial sprayed fiber concrete layer 2, the first arch buffer layer 3, the steel mesh and steel frame 4, and the re-sprayed fiber concrete layer 5 form the initial support layer, achieving the effect of first being flexible and then being steel.

[0023] The second arch buffer layer 6, the reinforcing steel 7, and the cast-in-place concrete layer 8 form a secondary lining layer.

[0024] The two sprayed fiber concrete layers can quickly seal the surrounding rock and effectively control its deformation, and work synergistically with the first arch buffer layer 3 and the second arch buffer layer 6, respectively.

[0025] The thickness of the first sprayed nanofiber concrete is 50mm, and the thickness of the second sprayed nanofiber concrete is 130mm. Of course, the thickness of the two sprayed nanofiber concrete is not limited to these and can be adjusted according to the actual construction situation. For example, the thickness of the first sprayed nanofiber concrete is 40-80mm, and the thickness of the second sprayed nanofiber concrete is 120-150mm.

[0026] After the tunnel boring machine begins excavation, a 3cm over-excavation is performed using a bolt drilling rig to prepare for the application of a buffer layer. The over-excavation area is the tunnel arch. The buffer layer consists of a first arch buffer layer 3 and a second arch buffer layer 6. Both the first arch buffer layer 3 and the second arch buffer layer 6 are filled with polyethylene foam, providing waterproofing and shock absorption. The installation of the first arch buffer layer 3 and the second arch buffer layer 6 allows for the graded absorption of rockburst impact energy, increasing the buffer energy dissipation threshold for strong rockburst impacts and enhancing the safety of the rockburst tunnel support structure.

[0027] In this embodiment, the prestressed anchor rod 1 is 500cm long and is evenly distributed along the circumference of the tunnel surrounding rock. Of course, the length of the prestressed anchor rod 1 is not limited to 500cm; it can be in the range of 480-520cm, and the workers can make the appropriate selection according to the actual construction conditions.

[0028] In this embodiment, the thickness of both the first arch buffer layer 3 and the second arch buffer layer 6 is 8mm. Of course, the thickness of the first arch buffer layer 3 and the second arch buffer layer 6 is not limited to 8mm, and can be in the range of 6 to 10mm. The workers can make the appropriate selection according to the actual construction situation.

[0029] In this embodiment, the thickness of the initial sprayed fiber concrete layer 2 is 60mm, but it is not limited to 60mm and can be in the range of 40 to 80mm.

[0030] In this embodiment, the thickness of the sprayed fiber concrete layer 5 is 130mm, but it is not limited to 130mm and can be in the range of 120 to 150mm.

[0031] In this embodiment, the thickness of the cast-in-place concrete layer 8 is greater than 200 mm.

[0032] In summary, the first and second arch buffer layers in this invention can absorb rockburst impact energy respectively, increasing the buffer energy consumption threshold when dealing with strong rockburst impacts, thereby increasing the safety of the tunnel support structure. Therefore, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0033] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A rockburst tunnel support structure suitable for TBM construction, comprising prestressed anchor bolts (1) embedded in the surrounding rock of the tunnel, and a primary shotcrete fiber concrete layer (2), a steel mesh and steel frame (4), and a secondary shotcrete fiber concrete layer (5) sequentially arranged on the tunnel wall, characterized in that: A first arched buffer layer (3) is provided between the initial sprayed fiber concrete layer (2) and the steel mesh and steel frame (4). A second arched buffer layer (6), steel bars (7) and cast-in-place concrete layer (8) are sequentially provided on the upper surface of the re-sprayed fiber concrete layer (5).

2. The rockburst tunnel support structure applicable to TBM construction method according to claim 1, characterized in that: The length of the prestressed anchor rod (1) is 480-520cm.

3. The rockburst tunnel support structure applicable to TBM construction method according to claim 1, characterized in that: The thickness of the first arch buffer layer (3) and the second arch buffer layer (6) is 6-10 mm.

4. The rockburst tunnel support structure applicable to TBM construction method according to claim 3, characterized in that: The thickness of the first arch buffer layer (3) and the second arch buffer layer (6) is 8 mm.

5. The rockburst tunnel support structure applicable to TBM construction method according to claim 1, characterized in that: Both the first arch buffer layer (3) and the second arch buffer layer (6) are filled with polyethylene foam.

6. The rockburst tunnel support structure applicable to TBM construction method according to claim 1, characterized in that: The thickness of the initial sprayed fiber concrete layer (2) is 40-80 mm.

7. The rockburst tunnel support structure applicable to TBM construction method according to claim 1, characterized in that: The thickness of the sprayed fiber concrete layer (5) is 120-150 mm.

8. The rockburst tunnel support structure applicable to TBM construction method according to claim 1, characterized in that: The thickness of the cast-in-place concrete layer (8) is greater than 200 mm.

Images