Large-bias-pressure multi-arch tunnel pilot tunnel supporting and reinforcing device

Abstract

The utility model relates to the technical field of tunnel engineering, and provides a large-bias-pressure multi-arch tunnel pilot tunnel supporting and reinforcing device. The hollow grouting anchor rods are arranged at surrounding rocks of the middle pilot tunnel and the side pilot tunnels in a plum blossom shape, I-shaped steel is erected at the tail ends of the hollow grouting anchor rods, and the I-shaped steel forms a steel arch frame in the transverse direction of the inner walls of the middle pilot tunnel and the side pilot tunnels; the advanced small guide pipes are arranged on surrounding rocks of the middle pilot tunnel and the side pilot tunnels, and are longitudinally and obliquely arranged along the horizontal direction of the surrounding rocks; the reinforcing anchor rods are arranged on the bases of the middle pilot tunnel and the side pilot tunnels. A composite lining is adopted, a hollow grouting anchor rod and a steel arch are used as a primary support, advanced small guide pipes are used for assisting construction and two-layer support, the self-bearing capacity of surrounding rock is fully developed, the device is simple in structure, convenient to construct and high in construction efficiency, loads borne by the deeply-buried side of a tunnel can be effectively reduced, and the construction efficiency is improved. Supporting is carried out from the shallow-buried side and the deep-buried side of the bias tunnel, the supporting is coordinated with stress of the tunnel, it is guaranteed that the tunnel is not subjected to bias deformation, and stability of the bias tunnel is facilitated.

Description

Technical Field

[0001] This utility model relates to the field of tunnel engineering technology, and in particular to a support and reinforcement device for the pilot tunnel of a large-eccentric-pressure continuous arch tunnel. Background Technology

[0002] High-eccentricity arch tunnels are a type of tunnel structure with unique geological and construction challenges. They typically occur in areas with complex geological conditions and significant topographic relief, characterized by uneven pressure on both sides of the tunnel, leading to complex stress distribution within the tunnel structure. This tunnel structure is widely used in highway tunnels, but numerous difficulties need to be overcome during its design and construction.

[0003] Large eccentric arch tunnels are generally shallowly buried, with strongly weathered and fractured surrounding rock and overlapping forces. For the construction of large eccentric arch tunnels, detailed geological surveys and finite element analysis are usually required to determine a reasonable excavation sequence and support measures.

[0004] Therefore, in order to address the above problems, a support and reinforcement device for the pilot tunnel of a large-eccentric-pressure continuous arch tunnel is proposed to solve these problems. Utility Model Content

[0005] This invention addresses the shortcomings of existing technologies by developing a support and reinforcement device for the pilot tunnel of a large-scale eccentrically compressed arch tunnel. This invention is easy to construct and has high construction efficiency. It can effectively reduce the load on the deep-buried side of the tunnel, and provides support from both the shallow and deep-buried sides of the eccentrically compressed tunnel. It is coordinated with the tunnel's stress, ensuring that the tunnel is not deformed by eccentricity, which is beneficial to the stability of the eccentrically compressed tunnel.

[0006] The technical solution to the technical problem solved by this utility model is as follows: This utility model provides a support and reinforcement device for the pilot tunnel of a large-biased continuous arch tunnel, including a pre-drilled small guide pipe, a hollow grouting anchor, a reinforcement anchor, and a steel arch frame; the hollow grouting anchors are arranged in a quincunx pattern in the surrounding rock of the central pilot tunnel and the side pilot tunnel, and I-beams are erected at the tail ends of the hollow grouting anchors, forming a steel arch frame along the transverse direction of the inner wall of the central pilot tunnel and the side pilot tunnel; the pre-drilled small guide pipe is set on the surrounding rock of the central pilot tunnel and the side pilot tunnel, and is set at an inclination to the longitudinal direction along the horizontal direction of the surrounding rock; the reinforcement anchor is set at the base of the central pilot tunnel and the side pilot tunnel.

[0007] As an optimization, the length of the pre-guided tube is 4.5m, the diameter is 50mm, the circumferential spacing is 40cm, and the inclination angle with the horizontal longitudinal direction of the central or side guide pit is 10°~20°.

[0008] As an optimization, the hollow grouting anchor bolt has a diameter of 22mm, a length of 2.5m, a circumferential spacing of 120cm, and a longitudinal spacing of 60cm.

[0009] As an optimization, the I-beams are of type I16 with a longitudinal spacing of 60cm, and are installed on the central or side guide pits by bolting or welding.

[0010] As an optimization, the steel arch frame connection point A is bolted together and then welded across the seam, while connection points B and C are fixed to the central guide pit or side guide pit by welding steel plates.

[0011] As an optimization, hollow grouting anchors are grouted with M30 cement mortar, with a single tensile breaking strength of not less than 150kN, and an anchor pull-out resistance of not less than 80kN in Class V surrounding rock and not less than 100kN in Class IV or above surrounding rock.

[0012] As an optimization, cross-connecting bars were added between the two steel arch frames, and the gap between the steel arch frames and the excavation outline was filled with shotcrete.

[0013] The effects provided in the utility model description are merely those of the embodiments, and not all the effects of the utility model. The above technical solution has the following advantages or beneficial effects:

[0014] This device employs a composite lining, using hollow grouting anchors and steel arches as initial support, and advanced small guide pipes to assist construction. The two-layer support fully utilizes the self-supporting capacity of the surrounding rock. This device has a simple structure, is easy to construct, and has high construction efficiency. It can effectively reduce the load on the deep-buried side of the tunnel, providing support from both the shallow and deep-buried sides of the tunnel under eccentric pressure, coordinating with the tunnel's stress, ensuring the tunnel is not deformed by eccentric pressure, and contributing to the stability of the tunnel under eccentric pressure. Attached Figure Description

[0015] The accompanying drawings are provided to further understand the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention and do not constitute a limitation thereof.

[0016] Figure 1 This is a diagram of the guide tunnel lining support structure of this utility model;

[0017] Figure 2 This is a diagram of the support structure of the steel arch frame of this utility model;

[0018] Figure 3 This is a schematic diagram of the longitudinal arrangement of the advanced small conduit of this utility model.

[0019] In the diagram, 1. Pre-drilled small guide pipe; 2. Hollow grouting anchor; 3. Reinforced anchor; 4. Central guide pit; 5. Side guide pit; 6. Steel arch frame. Detailed Implementation

[0020] To clearly illustrate the technical features of this solution, the present invention will be described in detail below through specific embodiments and in conjunction with the accompanying drawings. The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. To simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Furthermore, the present invention may repeat reference numerals and / or letters in different examples. This repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. It should be noted that the components illustrated in the drawings are not necessarily drawn to scale. The present invention omits descriptions of well-known components and processing techniques and processes to avoid unnecessarily limiting the present invention. The terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate orientation or positional relationships based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0021] like Figures 1 to 3 As shown, a support and reinforcement device for the pilot tunnel of a large-eccentric-pressure multi-arch tunnel includes a pre-drilled small guide pipe 1, a hollow grouting anchor 2, a reinforcing anchor 3, and a steel arch frame 6. The hollow grouting anchor 2 is arranged in a quincunx pattern at the surrounding rock of the central pilot tunnel 4 and the side pilot tunnel 5. I-beams are erected at the tail ends of the hollow grouting anchor 2, and the I-beams form the steel arch frame 6 transversely along the inner wall of the central pilot tunnel 4 and the side pilot tunnel 5. The pre-drilled small guide pipe 1 is set on the surrounding rock of the central pilot tunnel 4 and the side pilot tunnel 5, and is set longitudinally inclined along the horizontal direction of the surrounding rock. The reinforcing anchor 3 is set at the base of the central pilot tunnel 4 and the side pilot tunnel 5 to stabilize the central pilot tunnel 4 and the side pilot tunnel 5 and reduce the influence of eccentric force on the central pilot tunnel 4 and the side pilot tunnel 5.

[0022] In this embodiment, the length of the pre-guided small catheter 1 is 4.5m, the diameter is 50mm, the circumferential spacing is 40cm, and the inclination angle with the horizontal longitudinal direction of the central guide pit 4 or the side guide pit 5 is 10°~20°.

[0023] The hollow grouting anchor rod 2 has a diameter of 22mm, a length of 2.5m, a circumferential spacing of 120cm, and a longitudinal spacing of 60cm.

[0024] In this embodiment, the I-beams are of type I16 with a longitudinal spacing of 60cm, and are installed on the central guide pit 4 or the side guide pit 5 by bolt splicing or welding.

[0025] At connection point A of the steel arch frame 6, bolts are used for splicing and then welded across the seam. Connection points B and C are fixed to the central guide pit 4 or the side guide pit 5 by welding with steel plates. The welds should be firm, and all weld seams should be full and free of pinholes.

[0026] In this embodiment, the hollow grouting anchor rod 2 is grouted with M30 cement mortar, and the tensile breaking strength of a single rod is not less than 150kN. The anchor pull-out resistance is not less than 80kN in Class V surrounding rock and not less than 100kN in Class IV or above surrounding rock.

[0027] Cross-connecting bars are added between the two steel arch frames 6, and the gap between the steel arch frames 6 and the excavation outline is filled and compacted with shotcrete. First, the gap between the steel arch frames 6 and the outline is shotcreted, then the area around the steel arch frames 6 is shotcreted, and then the area between the steel arch frames 6 is shotcreted to form a concrete layer on the inner wall of the tunnel.

[0028] Double-layer steel mesh, 20x20cm, is also installed at the tunnel arch and sidewalls, with wet sprayed concrete (steel mesh).

[0029] The pilot tunnel 5 on the side with poorer rock mass is constructed first, followed by the other pilot tunnel 5. Composite lining is adopted, with hollow grouting anchor rods 2 and steel arch frames 6 as initial support, and advanced small guide pipes 1 as auxiliary construction. The two-layer support fully mobilizes and utilizes the self-supporting capacity of the surrounding rock. This device has a simple structure, is easy to construct, and has high construction efficiency. It can effectively reduce the load on the deep buried side of the tunnel. Support is provided from the shallow and deep buried sides of the biased tunnel, which is coordinated with the tunnel stress and ensures that the tunnel is not deformed by bias, which is conducive to the stability of the biased tunnel.

[0030] Although the specific embodiments of the utility model have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the utility model. Based on the technical solution of the utility model, various modifications or variations that can be made by those skilled in the art without creative effort are still within the scope of protection of the utility model.

Claims

1. A support and reinforcement device for the pilot tunnel of a large-eccentric-pressure multi-arch tunnel, characterized in that: It includes advanced small guide pipe (1), hollow grouting anchor (2), reinforced anchor (3) and steel arch frame (6); Hollow grouting anchors (2) are arranged in a plum blossom pattern in the surrounding rock of the central guide pit (4) and the side guide pit (5). I-beams are erected at the tail end of the hollow grouting anchors (2), and the I-beams form steel arch frames (6) along the transverse side of the inner wall of the central guide pit (4) and the side guide pit (5). The advanced small guide pipe (1) is set on the surrounding rock of the central guide pit (4) and the side guide pit (5), and is set longitudinally inclined along the horizontal direction of the surrounding rock; Reinforcing anchors (3) are installed on the base of the central guide pit (4) and the side guide pit (5).

2. The large-biased arch tunnel pilot tunnel support and reinforcement device according to claim 1, characterized in that: it is advanced. The length of the small guide tube (1) is 4.5m, the diameter is 50mm, the circumferential spacing is 40cm, and the inclination angle with the horizontal longitudinal direction of the central guide pit (4) or the side guide pit (5) is 10°~20°.

3. The support and reinforcement device for the pilot tunnel of a large-eccentric-pressure multi-arch tunnel according to claim 1, characterized in that: The hollow grouting anchor (2) has a diameter of 22mm, a length of 2.5m, a circumferential spacing of 120cm, and a longitudinal spacing of 60cm.

4. The support and reinforcement device for the pilot tunnel of a large-eccentric-pressure multi-arch tunnel according to claim 1, characterized in that: The I-beams are of type I16 with a longitudinal spacing of 60cm. They are installed on the central guide pit (4) or the side guide pit (5) by bolt splicing or welding.

5. The support and reinforcement device for the pilot tunnel of a large-eccentric-pressure multi-arch tunnel according to claim 4, characterized in that: The steel arch frame (6) is bolted together at connection point A and then welded across the seam. Connection points B and C are fixed to the central guide pit (4) or the side guide pit (5) by welding steel plates.

6. The support and reinforcement device for the pilot tunnel of a large-eccentric-pressure multi-arch tunnel according to claim 1, characterized in that: Hollow grouting anchor (2) is grouted with M30 cement mortar. The tensile breaking strength of a single anchor is not less than 150kN, and the anchor pull-out strength is not less than 80kN in Class V surrounding rock and not less than 100kN in Class IV or above surrounding rock.

7. The support and reinforcement device for the pilot tunnel of a large-eccentric-pressure multi-arch tunnel according to claim 1, characterized in that: Cross-connecting bars are added between the two steel arch frames (6), and the gap between the steel arch frame (6) and the excavation outline is filled with sprayed concrete.

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