An underground tunnel construction support structure

Abstract

This invention discloses a support structure for underground tunnel construction, including an outer lining layer. Grouting anchors are spaced apart on the outer lining layer, and each grouting anchor is fixed with a branch pipe at an incline. The branch pipes are internally connected to the grouting anchors. An inner lining layer is also provided inside the outer lining layer, with a gap between the outer and inner lining layers. This invention, through the arrangement of the branch pipes, allows drainage to be collected within the gaps, and the inlet pipe of the drainage pump can be inserted into the drainage hole at the bottom for centralized discharge, enhancing the convenience of drainage during construction. Furthermore, it reduces water accumulation within the tunnel, improving the construction environment. After drainage of weak surrounding rock, it facilitates subsequent grouting bonding, enhancing the stability of subsequent grouting. The inner lining layer also incorporates the branch pipes within the gaps, creating a triangular support mechanism between the inclined branch pipes and the grouting anchors, strengthening the structural strength between the outer lining layer, the grouting anchors, and the inner lining layer.

Description

Technical Field

[0001] This invention belongs to the field of external lining technology, specifically relating to a support structure for underground tunnel construction. Background Technology

[0002] Underground tunnel construction refers to the process of building underground transportation tunnels, hydraulic tunnels, municipal tunnels, mining tunnels, and military tunnels. Support structures are commonly used during underground tunnel construction to ensure safety. However, accidents such as tunnel collapses and worker injuries / fatalities frequently occur when encountering weak surrounding rock during construction.

[0003] This is because the rock mass of weak surrounding rock is broken and loose with weak cohesion. After the tunnel is excavated, only the friction effect between particles and the weak cementation effect form an arch. This type of rock mass is extremely unstable, especially in shallow buried areas where it is prone to collapse and roof fall. Therefore, weak surrounding rock is characterized by short self-stability and easy collapse.

[0004] However, traditional external lining methods such as anchor bolt support are not suitable for the characteristics of weak surrounding rock, leading to frequent accidents such as tunnel collapses and casualties among workers. Therefore, this problem urgently needs to be solved. Summary of the Invention

[0005] The purpose of this invention is to provide a support structure for underground tunnel construction, which solves the problem that traditional external lining methods such as anchor bolt support are not suitable for weak surrounding rock, leading to frequent accidents such as tunnel collapse and worker injuries and deaths.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An underground tunnel construction support structure includes an outer lining layer, on which grouting anchors are spaced apart, and each grouting anchor is fixed with a forked pipe at an incline. The forked pipe is connected to the interior of the grouting anchor, and an inner lining layer is also provided on the inner side of the outer lining layer.

[0008] A gap is left between the outer liner and the inner liner to allow the inner liner to seal the grouting anchor and the branch pipe;

[0009] The bottom wall of the inner lining layer has multiple drainage holes, which are connected to the spacer.

[0010] Preferably, a rockfall protection component is installed within the interval, which is used to protect the tunnel lining from rockfalls.

[0011] Preferably, the rockfall protection component includes multiple arc-shaped parts, both ends of which are curled and fixed to connecting rods, and the multiple connecting rods are connected and fixed and arranged circumferentially along the outer liner.

[0012] Preferably, the rockfall protection component includes multiple U-shaped frames, the middle of which is hinged to the bracket by a torsion spring;

[0013] The bracket is fixedly connected to the inner lining layer, and the U-shaped frame is set in an inclined shape, with the lower end of the U-shaped frame being covered by the higher end of the adjacent U-shaped frame.

[0014] Preferably, the U-shaped frame is provided with a plurality of spring pieces, one end of which is raised and the other end is fixed to the side wall of the U-shaped frame.

[0015] Preferably, a mesh component is fixed on the inner wall of the lining layer.

[0016] Technical effects and advantages of the present invention: The underground tunnel construction support structure proposed in this invention has the following advantages compared with the prior art:

[0017] 1. The present invention, through the setting of the branch pipe, can, on the one hand, collect drainage into the interval and discharge it centrally after inserting the water inlet pipe of the drainage pump into the drainage hole at the bottom, thereby enhancing the convenience of drainage during construction; on the other hand, it also reduces water accumulation in the tunnel, improves the construction environment, and facilitates the subsequent grouting bonding purpose after drainage of weak surrounding rock, thereby enhancing the stability of subsequent grouting; and the inner lining layer chalks the branch pipe in the interval, so that the inclined branch pipe and the grouting anchor rod form a triangular support mechanism, which enhances the structural strength between the outer lining layer, the grouting anchor rod and the inner lining layer.

[0018] 2. The invention sets a gap between the outer lining and the inner lining, which can reduce the damage of construction vibrations in the tunnel to the surrounding weak rock, and isolate the weak rock from the tunnel space. At the same time, the gap can also provide continuous drainage. Once water seeps into the grouting anchor, it will be collected in the gap and stored at the bottom. At the same time, grouting can be injected from the drainage hole at the bottom at any time through the grouting machine, filling the gap from bottom to top, so that the inner lining and the outer lining form a whole, effectively enhancing the blast resistance and strengthening the support strength of the overall weak rock.

[0019] 3. By using arc-shaped components, the vibration of the outer lining layer is blocked by the outer arc of the components when the flying rock impacts it, thereby weakening the impact force of the flying rock. Furthermore, when the flying rock impacts the arc-shaped components, due to the structural characteristics of the arc structure, a relatively stable impact-resistant state is formed. Multiple arc-shaped components arranged to form a barrier zone can also better play the role of weakening the impact of flying rock. If, after a rock burst, grout is injected into the interval through the bottom drainage holes for reinforcement, the arc-shaped components and connecting rods form a skeleton, which can strengthen the connection strength between the inner and outer lining layers and improve the impact resistance. Attached Figure Description

[0020] Figure 1This is a schematic diagram of the structure of the present invention.

[0021] Figure 2 for Figure 1 A magnified schematic diagram of the structure at point A in the middle.

[0022] Figure 3 This is a partial structural diagram of another embodiment of the present invention.

[0023] Figure 4 This is a schematic diagram showing the positions of the loop-shaped frame and the spring in this invention. Detailed Implementation

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] This invention provides, for example Figure 1-4 The image shows a support structure for underground tunnel construction.

[0026] The system includes an outer liner 1, on which grouting anchors 2 are distributed at intervals of 5. Each grouting anchor 2 is fixed with a forked pipe 3 at an incline. The forked pipe 3 communicates with the interior of the grouting anchor 2. An inner liner 4 is also provided on the inner side of the outer liner 1. A gap 5 is left between the outer liner 1 and the inner liner 4 so that the inner liner 4 can seal the grouting anchors 2 and the forked pipe 3. Multiple drainage holes 6 are provided on the bottom wall of the inner liner 4, and the drainage holes 6 communicate with the gap 5.

[0027] To address the problem that weak surrounding rock has a short self-stabilizing time and is prone to collapse, making traditional external lining methods such as anchor bolt support unsuitable and frequently leading to tunnel collapses and worker injuries,

[0028] When using this invention, holes are first drilled in the tunnel sidewall. After drilling, the grouting anchor rod 2 is installed in the anchor hole. Then, the inner lining layer 4 is fixedly installed in the already formed outer lining layer 1. The connection position of the grouting anchor rod 2 is reserved on the sidewall of the inner lining layer 4. After the inner lining layer 4 is fixed, the workers inject grout from the joint through pressure, and then inject it into the surrounding weak rock layer, thereby increasing the adhesion between the weak rock layers and achieving the purpose of enhancing the structural stability of the weak rock layer. At the same time, the grouting anchor rod 2 is a hollow structure with one end sealed. Therefore, before grouting, it can drain the water in the weak surrounding rock from the connected branch pipe 3 into the interval 5, and under its own weight, it all collects at the bottom of the interval 5. If the water volume is large, it will be discharged from the drainage hole 6.

[0029] By setting up the branch pipe 3, on the one hand, the drainage can be collected in the interval 5, and the water inlet pipe of the drainage pump can be inserted into the bottom drainage hole 6 for centralized discharge, which enhances the convenience of drainage during construction; on the other hand, it also reduces water accumulation in the tunnel, improves the construction environment, and after the weak surrounding rock is drained, it is easier to achieve the purpose of subsequent grouting and bonding, and enhances the stability of subsequent grouting; and the inner lining layer 4 encloses the branch pipe 3 in the interval 5, so that the inclined branch pipe 3 and the grouting anchor 2 form a triangular support mechanism, which enhances the structural strength between the outer lining layer 1, the grouting anchor 2 and the inner lining layer 4.

[0030] Furthermore, when delayed rock bursts occur in the tunnel, the inner lining layer 4 can block the flying rocks that are ejected from the burst, reducing their damage to the already formed tunnel.

[0031] The gap 5 between the outer lining layer 1 and the inner lining layer 4 can reduce the damage of construction vibration in the tunnel to the surrounding weak rock, and play the role of isolating the weak rock and the space inside the tunnel. At the same time, the gap 5 can also play a continuous drainage function. Once water seeps in at the grouting anchor 2, it will be collected by the gap 5 and stored at the bottom.

[0032] At the same time, grouting can be injected from the bottom drainage hole 6 at any time through the grouting machine, filling the gap 5 from bottom to top, so that the inner lining layer 4 and the outer lining layer 1 form a whole, effectively enhancing the blast-resistant rock capability and also enhancing the support strength for the overall weak surrounding rock.

[0033] Furthermore, a flyrock protection component 7 is installed within the interval 5. The flyrock protection component 7 is used to protect the inner lining layer 4 from flyrock impacts generated by tunnel rockbursts. Flyrock ejected from delayed rockbursts breaks through the outer lining layer 1 and directly impacts the inner lining layer 4, easily causing damage to the inner lining layer 4 and consequently damaging the already constructed tunnel support. This invention, by installing the flyrock protection component 7, releases and buffers the flyrock, reducing the impact force of the flyrock on the outer lining layer 1 and the inner lining layer 4, and maintaining the supporting effect of the entire support structure on the surrounding rock.

[0034] Example 1: The rockfall protection component 7 includes multiple arc-shaped parts 71, both ends of which are curled and fixed on connecting rods 72. The multiple connecting rods 72 are connected and fixed and arranged circumferentially along the outer liner 1.

[0035] By setting the arc-shaped component 71, when the flying rock impacts the outer lining layer 1, the vibration of the outer lining layer 1 is blocked by the outer arc of the arc-shaped component 71, thereby weakening the impact force of the flying rock. When the flying rock impacts the arc-shaped component 71, due to the structural characteristics of the arc structure, a relatively stable impact resistance state is formed. The arrangement of multiple arc-shaped components 71 forms a barrier zone, which can also better play the role of weakening the impact of flying rock. If, after a rock burst, grout is injected into the interval 5 through the bottom drainage hole 6 for reinforcement, the arc-shaped component 71 and the connecting rod 72 form a skeleton, which can strengthen the connection strength between the inner lining layer 4 and the outer lining layer 1 and improve the impact resistance performance.

[0036] Example 2: The rockfall protection component 7 includes multiple loop frames 73. The middle part of the loop frame 73 is hinged to the bracket 75 by a torsion spring 74. The bracket 75 is fixedly connected to the inner lining layer 4. The loop frame 73 is set in an inclined shape. The lower end of the loop frame 73 is covered by the higher end of the adjacent loop frame 73.

[0037] This invention uses multiple hinged ring frames 73 with torsion springs 74 as an isolation zone to reduce impact. When a flying rock impacts the outer lining layer 1, its impact force will act on the side in contact with the ring frame 73, causing the ring frame 73 to swing slightly along the hinge, thereby releasing the impact energy and protecting the outer lining layer 1. If the flying rock breaks through the outer lining layer 1, it will further impact the ring frame 73, causing the ring frame 73 to forcefully compress the torsion spring 74 seat to rotate further, achieving the purpose of fully releasing the impact energy. Since the ring frames 73 in the initial state cover each other in sequence, the barrier zone formed after the ring plates are combined is similar to a scale structure, which has a better impact resistance and further protects the support effect of the weak surrounding rock.

[0038] Furthermore, the U-shaped frame 73 is provided with a plurality of spring tabs 76, one end of each spring tab 76 being raised and the other end being fixed to the side wall of the U-shaped frame 73. The arrangement of the spring tabs 76 can densely fill the empty parts of the U-shaped frame 73, enabling it to perform more comprehensive cushioning operations and improving the overall impact resistance.

[0039] Furthermore, a mesh component 8 is fixed to the inner wall of the inner lining layer 4. The mesh component 8 is a mesh skeleton made of welded steel bars. The mesh component 8 can form a certain tension and adhere to the surface of the inner lining layer 4, forming a protective net-like effect to protect the inner wall of the inner lining layer 4 and improve the overall tunnel support effect.

[0040] In the description of this invention, it should be noted that the terms "upper," "lower," "left," "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the invention.

[0041] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A support structure for underground tunnel construction, comprising an outer lining (1), characterized in that: Grouting anchors (2) are distributed at intervals (5) on the outer lining layer (1). Each grouting anchor (2) is fixed with a fork pipe (3) at an incline. The fork pipe (3) is connected to the inside of the grouting anchor (2). The outer lining layer (1) is further provided with an inner lining layer (4), and there is a gap (5) between the outer lining layer (1) and the inner lining layer (4) so ​​that the inner lining layer (4) can seal the grouting anchor (2) and the branch pipe (3). The inner lining layer (4) has multiple drainage holes (6) on its bottom wall, and the drainage holes (6) are connected to the interval (5); A rockfall protection component (7) is installed in the interval (5), and the rockfall protection component (7) is used to protect the inner lining (4) from rockfall caused by tunnel rock bursts; The rockfall protection component (7) includes multiple arc-shaped parts (71), both ends of which are curled and fixed on connecting rods (72). The multiple connecting rods (72) are connected and fixed and arranged circumferentially along the outer liner (1). The rockfall protection component (7) includes multiple loop frames (73), which are arranged circumferentially along the outer liner (1). The middle part of each loop frame (73) is hinged to the bracket (75) by a torsion spring (74). The bracket (75) is fixedly connected to the inner lining layer (4), the loop frame (73) is set in an inclined shape, and the lower end of the loop frame (73) is covered by the higher end of the adjacent loop frame (73); The loop frame (73) is provided with a plurality of spring pieces (76), one end of the spring piece (76) is raised, and the other end is fixed to the side wall of the loop frame (73); A mesh component (8) is fixed on the inner wall of the lining layer (4).

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