Tunnel supporting arch foot reinforcing structure

Abstract

The utility model belongs to the technical field of tunnel engineering, and particularly relates to a tunnel supporting arch springing reinforcing structure which comprises an arch springing cable-stayed anchor rod and an arch springing foot-locking anchor rod, one end of the arch springing cable-stayed anchor rod penetrates through a first-layer primary support and then is anchored into a tunnel rock wall, and the other end of the arch springing cable-stayed anchor rod is anchored into a large arch springing. One end of the arch foot locking anchor rod is anchored into a tunnel rock wall, and the other end of the arch foot locking anchor rod is anchored into the large arch foot. According to the utility model, the arch springing cable-stayed anchor rod applies cable-stayed force to the large arch springing, and meanwhile, the arch springing foot-lock anchor rod stabilizes the large arch springing on the tunnel rock wall, so that the large arch springing is reinforced, and the stability of the large arch springing is improved. And moreover, the first layer of primary support and the large arch springing are connected through the arch springing cable-stayed anchor rod, a laminated structure for jointly bearing the vertical pressure of the stratum is formed, and the stability of the large arch springing is further improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of tunnel engineering, and in particular relates to a tunnel support arch foot reinforcement structure. Background Art

[0002] The arch-cover method is a dark excavation construction method based on the open-cut method, cover-cut method and pile-hole method. It is generally used in major urban roads with surrounding rock grade IV or above and good geological conditions, and in subway stations where cover-cut and open-cut methods are not allowed. The core of the arch-cover method is to evenly transfer the upper load of the arch cover to the surrounding rock through the arch foot, thereby making full use of the bearing capacity of the rock.

[0003] In recent years, in subway construction projects in Chongqing, Dalian, Xiamen, Qingdao and other cities, in underground stations where open-cut construction is difficult, the surrounding rock of the arch is often thin or soft on the top and hard on the bottom. The traditional secondary lining arch cover method and primary support arch cover method are difficult to fully adapt to the construction safety and progress requirements. With the development of dark excavation technology, a new arch cover method has been born - the superimposed primary support arch cover method. This construction method sets a double-layer superimposed primary support arch cover on the arch. After the first layer of initial support is formed into a ring, the lower section is not excavated immediately, but the second layer of initial support with a large arch foot is applied. In this way, the second layer of initial support and the first layer of initial support are superimposed and loaded, which greatly improves the safety of the arch cover and overcomes many disadvantages of the traditional secondary lining arch cover method and primary support arch cover method. Due to the complexity and variability of the engineering geology of large-span dark excavation tunnels, how to ensure the stability of the large arch foot of the primary support arch cover is the key to the success of this construction method. In order to ensure that the surrounding rock near the arch foot has sufficient bearing capacity, anchor pipes and hollow anchor rods are usually used to grout the surrounding rock under the arch foot, but there is a general lack of reinforcement measures for the arch foot. Utility Model Content

[0004] The utility model aims to provide a tunnel support arch foot reinforcement structure to solve the problem of lack of reinforcement measures for the large arch foot, so as to improve the stability of the large arch foot.

[0005] In order to achieve the above-mentioned purpose, the scheme of the utility model is: a tunnel supporting arch foot reinforcement structure, including an arch foot oblique anchor rod and an arch foot locking anchor rod, one end of the arch foot oblique anchor rod penetrates through the first layer of initial support and is anchored into the tunnel rock wall, and the other end of the arch foot oblique anchor rod is anchored into the large arch foot, one end of the arch foot locking anchor rod is anchored into the tunnel rock wall, and the other end of the arch foot locking anchor rod is anchored into the large arch foot.

[0006] The working principle and beneficial effect of this scheme are as follows: during the construction of the first layer of initial support, when the anchor rod of the first layer of initial support is anchored into the tunnel rock wall, the arch foot inclined anchor rod is also anchored into the tunnel rock wall at the corresponding position. In this way, after the construction of the first layer of initial support is completed, the arch foot inclined anchor rod is in a state of penetrating the first initial support; and, since the large arch foot is a cast reinforced concrete longitudinal beam, the end of the arch foot inclined anchor rod exposed from the first initial support can be anchored into the large arch foot, applying an inclined tension force to the large arch foot, and at the same time, the arch foot locking anchor rod secures the large arch foot on the tunnel rock wall, thereby achieving reinforcement of the large arch foot and improving the stability of the large arch foot. In addition, the arch foot inclined anchor rod connects the first layer of initial support with the large arch foot, forming a superimposed structure that jointly bears the vertical pressure of the stratum, further improving the stability of the large arch foot.

[0007] Optionally, the arch foot inclined anchor rod is fixedly connected to the large arch foot steel frame.

[0008] In this scheme, when the arch foot inclined anchor rod is fixedly connected to the large arch foot steel frame, the arch foot inclined anchor rod and the large arch foot steel frame are connected as one, and the inclined pulling effect of the arch foot inclined anchor rod on the large arch foot is more stable, thereby enhancing the reinforcement effect on the large arch foot.

[0009] Optionally, the arch foot locking anchor rod is fixedly connected to the large arch foot steel frame.

[0010] In this solution, when the arch foot locking anchor rod is fixedly connected to the large arch foot steel frame, the arch foot locking anchor rod and the large arch foot steel frame are connected as one, and the arch foot locking anchor rod has a more stable reinforcement effect on the large arch foot.

[0011] Optionally, the arch foot locking anchor rod is a hollow grouting anchor rod.

[0012] In this scheme, when the arch foot locking anchor rod is a hollow grouting anchor rod, the surrounding rock under the large arch foot can be reinforced by grouting, thereby improving the stability of the large arch foot.

[0013] Optionally, the arch foot oblique anchor rod is a hollow grouting anchor rod.

[0014] In this scheme, when the arch foot inclined anchor rod is a hollow grouting anchor rod, the tunnel surrounding rock can be reinforced by grouting, thereby improving the stability of the arch foot inclined anchor rod applying inclined tension to the large arch foot.

[0015] Optionally, the arch foot inclined anchor rod is welded to the large arch foot steel frame through a U-shaped steel bar.

[0016] Optionally, the arch foot locking anchor rod is welded to the large arch foot steel frame through a U-shaped steel bar.

[0017] Optionally, the arch foot inclined anchor rod is fixedly connected to the first layer of initial support steel frame.

[0018] In this solution, when the arch foot inclined anchor rod is fixedly connected to the first layer of initial support steel frame, the arch foot inclined anchor rod and the first layer of initial support steel frame are connected as one, thereby improving the connectivity between the large arch foot and the first initial support.

[0019] Optionally, the arch foot inclined anchor rod is welded to the first layer of initial support steel frame through U-shaped steel bars. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the structure of the tunnel support arch foot reinforcement structure in the first embodiment of the utility model;

[0021] Figure 2 The tunnel cross-section diagram of the cross-section where the arch foot inclined anchor rod is located in the first embodiment of the utility model;

[0022] Figure 3 A tunnel cross-sectional view of the section where the first anchor rod is located in the first embodiment of the utility model;

[0023] Figure 4 This is a schematic diagram of the connection between the first layer of initial support and the large arch foot in the second embodiment of the utility model (along the axial direction of the inclined anchor rod of the arch foot);

[0024] Figure 5 It is a schematic diagram of the connection method between the arch foot locking foot anchor rod and the large arch foot in the third embodiment of the utility model (along the axial direction of the arch foot locking foot anchor rod). DETAILED DESCRIPTION

[0025] The following is further described in detail through specific implementation methods:

[0026] The marks in the drawings of the specification include: arch foot inclined anchor rod 1, arch foot locking anchor rod 2, first layer of initial support 3, first shotcrete layer 31, first layer of initial support steel frame 32, first anchor rod 33, second layer of initial support 4, large arch foot 41, large arch foot cast concrete layer 411, large arch foot steel frame 412, tunnel rock wall 5, U-shaped steel bar 6.

[0027] Embodiment 1

[0028] This embodiment is basically Figure 1 , Figure 2 and Figure 3 As shown: Tunnel support arch foot reinforcement structure Tunnel support arch foot reinforcement structure, including arch foot inclined anchor rod 1 and arch foot locking anchor rod 2, one end of the arch foot inclined anchor rod 1 passes through the first layer of initial support 3 and is anchored in the tunnel rock wall 5, the other end of the arch foot inclined anchor rod 1 is anchored in the large arch foot 41, one end of the arch foot locking anchor rod 2 is anchored in the tunnel rock wall 5, and the other end of the arch foot locking anchor rod 2 is anchored in the large arch foot 41.

[0029] The arch foot 41 is a cast reinforced concrete longitudinal beam. Therefore, the arch foot 41 includes a cast concrete layer 411 and a steel frame 412 (such as a steel frame 413) embedded therein. Figure 4 The first layer of initial support 3 includes a first sprayed concrete layer 31 and a first layer of initial support steel frame 32 buried therein (as shown); Figure 4 The arch portion of the second initial support 4 includes a second shotcrete layer and a second initial support steel frame buried therein. The arch foot inclined anchor rod 1 and the first anchor rod 33 are staggered in the longitudinal direction of the tunnel, that is, the arch foot inclined anchor rod 1 is not on the same tunnel section as the first anchor rod 33.

[0030] The arch foot locking anchor rod 2 can be adjusted to a hollow grouting anchor rod, which can reinforce the surrounding rock under the large arch foot 41 through grouting, thereby improving the stability of the large arch foot 41.

[0031] In this embodiment, the arch foot inclined anchor rod 1 applies an oblique upward pulling force to the large arch foot 41, and at the same time, the arch foot locking anchor rod 2 stabilizes the large arch on the surrounding rock below the large arch foot 41, thereby reinforcing the large arch foot 41. In addition, the arch foot inclined anchor rod 1 connects the first layer of initial support 3 with the large arch foot 41, forming a superimposed structure that jointly bears the bottom layer vertical pressure, further improving the stability of the large arch foot 41.

[0032] Embodiment 2

[0033] The difference between this embodiment and the first embodiment is that: Figure 4 As shown, in this embodiment, the arch foot oblique anchor rod 1 is fixedly connected to the large arch foot steel frame 412, and the arch foot oblique anchor rod 1 is fixedly connected to the first layer of initial support steel frame 32. Specifically, the arch foot oblique anchor rod 1 is welded to the large arch foot steel frame 412 through the U-shaped steel bar 6, and the arch foot oblique anchor rod 1 is welded to the first layer of initial support steel frame 32 through the U-shaped steel bar 6.

[0034] In this embodiment, the arch foot inclined anchor rod 1 is connected to the first layer initial support steel frame 32 and the large arch foot steel frame 412 as a whole, thereby improving the connectivity between the large arch foot 41 and the first layer initial support 3, thereby further improving the stability of the large arch foot 41.

[0035] Embodiment 3

[0036] The difference between this embodiment and the second embodiment is that the arch foot inclined anchor rod 1 is a hollow grouting anchor rod, so that the surrounding rock near the arch foot inclined anchor rod 1 is reinforced by grouting, thereby improving the stability of the arch foot inclined anchor rod 1 in applying the inclined tension to the large arch foot 41.

[0037] Embodiment 4

[0038] The difference between this embodiment and the second embodiment is that: Figure 5As shown, the arch foot locking foot anchor rod 2 is fixedly connected to the large arch foot steel frame 412. Specifically, the arch foot locking foot anchor rod 2 is welded to the large arch foot steel frame 412 through the U-shaped steel bar 6. In this way, in this embodiment, the arch foot locking foot anchor rod 2 is connected to the large arch foot steel frame 412 as a whole, and the arch foot locking foot anchor rod 2 has a more stable reinforcement effect on the large arch foot 41.

[0039] The above is only an embodiment of the utility model, and the common knowledge such as the known specific structure and characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the utility model, which should also be regarded as the protection scope of the utility model, and these will not affect the effect of the implementation of the utility model and the practicality of the utility model. The specific implementation methods and other records in the specification can be used to explain the content of the claims.

Claims

1. The tunnel support arch foot reinforcement structure is characterized by: It includes an arch foot inclined anchor rod and an arch foot locking anchor rod. One end of the arch foot inclined anchor rod penetrates through the first layer of initial support and is anchored in the tunnel rock wall, and the other end of the arch foot inclined anchor rod is anchored in the large arch foot. One end of the arch foot locking anchor rod is anchored in the tunnel rock wall, and the other end of the arch foot locking anchor rod is anchored in the large arch foot.

2. The tunnel support arch foot reinforcement structure according to claim 1, characterized in that: The arch foot inclined anchor rod is fixedly connected to the large arch foot steel frame.

3. The tunnel support arch foot reinforcement structure according to claim 1 or 2, characterized in that: The arch foot locking anchor rod is fixedly connected to the large arch foot steel frame.

4. The tunnel support arch foot reinforcement structure according to claim 1, characterized in that: The arch foot locking anchor rod is a hollow grouting anchor rod.

5. The tunnel support arch foot reinforcement structure according to claim 2, characterized in that: The arch foot inclined anchor rod is a hollow grouting anchor rod.

6. The tunnel support arch foot reinforcement structure according to claim 3, characterized in that: The arch foot inclined anchor rod is welded to the large arch foot steel frame through U-shaped steel bars.

7. The tunnel support arch foot reinforcement structure according to claim 1, characterized in that: The arch foot locking anchor rod is welded to the large arch foot steel frame through U-shaped steel bars.

8. The tunnel support arch foot reinforcement structure according to claim 1, characterized in that: The arch foot inclined anchor rod is fixedly connected to the first layer of initial support steel frame.

9. The tunnel support arch foot reinforcement structure according to claim 8, characterized in that: The arch foot inclined anchor rod is welded to the first layer of initial support steel frame through U-shaped steel bars.

Images