A tunnel entrance reinforcement structure

Abstract

This utility model belongs to the field of tunnel engineering technology, specifically relating to a tunnel entrance reinforcement structure, including an arched main support frame. The bottom of the arched main support frame is supported by a bottom platform. A buffer energy-absorbing layer is tightly attached to the outer surface of the arched main support frame. An anchoring system one is locked onto the arched main support frame. A surface protective grid is tightly attached to the outer surface of the buffer energy-absorbing layer. The surface protective grid is fastened to the surface of the rock mass at the tunnel entrance by an anchoring system two. A drainage and water collection trough is provided on the bottom platform located vertically below the arched main support frame. Through the synergistic effect of the prestressed anchoring system, the arched main support frame, and the surface protective grid, combined with the use of the buffer energy-absorbing layer, multi-dimensional stable reinforcement of the tunnel entrance is achieved, including vibration reduction, anti-stripping, and rigid support. The buffer energy-absorbing layer, together with the arched main support frame and the drainage and water collection trough, filters and guides groundwater, effectively relieving groundwater pressure.

Description

Technical Field

[0001] This utility model belongs to the field of tunnel engineering technology, specifically relating to a tunnel entrance reinforcement structure. Background Technology

[0002] With the rapid development of transportation infrastructure construction in my country, tunnel engineering has been widely used in the construction of mountainous highways and railways. As the connection point between the tunnel and the ground, the stability of the tunnel entrance is crucial to the safe operation of the entire tunnel project. However, tunnel entrances are often located in complex geological environments, facing numerous challenges.

[0003] On the one hand, tunnel entrances are susceptible to geological disasters. Strong earthquakes can damage the integrity of the rock mass at the tunnel entrance, causing cracks, loosening, and even large-scale collapses, severely impacting the tunnel's normal operation. On the other hand, groundwater significantly affects the stability of tunnel entrances. The seepage of groundwater creates dynamic water pressure on the rock mass at the tunnel entrance, weakening its stability. Long-term groundwater erosion can also damage the tunnel entrance support structure, such as corrosion of concrete and rusting of steel, reducing its load-bearing capacity. Furthermore, the accumulation of groundwater near the tunnel entrance increases the pressure on the surrounding rock, leading to deformation and cracking. In some tunnels, improper groundwater management has resulted in water leakage at the tunnel entrance, affecting not only the driving environment inside the tunnel but also accelerating structural damage.

[0004] Currently, commonly used tunnel entrance reinforcement technologies have certain limitations. While traditional anchor bolt support can improve rock mass stability to some extent, its ability to protect against complex conditions such as earthquakes and heavy rainfall is limited, and it is difficult to effectively resist large external impacts. Simple concrete lining structures have poor vibration damping performance and are prone to cracking under vibration loads, thus affecting the overall structural stability. Furthermore, existing reinforcement structures often use simple drainage pipes for groundwater treatment, resulting in poor drainage and an inability to effectively manage groundwater pressure, failing to meet the needs of practical engineering projects. Utility Model Content

[0005] To address the above problems, the purpose of this utility model is to provide a tunnel entrance reinforcement structure that solves the problems of limited protection capacity, poor shock absorption, poor drainage, and insufficient coordination among various parts in commonly used reinforcement technologies such as traditional anchor bolt support and concrete lining.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a tunnel entrance reinforcement structure, comprising an arched main support frame, wherein the two sides of the arched main support frame are supported by a bottom bearing platform and fixedly connected to the bottom bearing platform, the bottom bearing platform is fixed to the tunnel entrance rock mass by cast-in-place concrete, a buffer energy-absorbing layer is tightly attached to the outer surface of the arched main support frame, an anchoring system one locking the arched main support frame extends through the arched main support frame and the buffer energy-absorbing layer to the interior of the tunnel entrance rock mass, a surface protective grid is tightly attached to the outer surface of the buffer energy-absorbing layer, the surface protective grid is fastened to the surface of the tunnel entrance rock mass by an anchoring system two, and a drainage collection trough is provided on the bottom bearing platform located vertically below the arched main support frame.

[0007] The beneficial effects of this utility model are as follows: through the synergistic effect of the prestressed anchoring system, the arched main support frame, and the surface protective grid, combined with the use of the buffer energy absorption layer, multi-dimensional stable reinforcement of the tunnel entrance is achieved, including shock absorption, anti-peeling, and rigid support; the buffer energy absorption layer, together with the arched main support frame and the drainage collection trough, filters and guides groundwater, effectively relieving groundwater pressure.

[0008] To ensure the stability of anchoring system one and anchoring system two;

[0009] As a further improvement to the above technical solution: both the first anchoring system and the second anchoring system include hollow grouting anchor rods, anchor rod pads and anchor rod nuts, and the first anchoring system and the second anchoring system are interleaved and evenly distributed on the arched main support frame and the surface protective grid.

[0010] The beneficial effects of this improvement are: the evenly distributed, radially arranged anchor array can enhance the connection strength between the reinforced structure and the rock mass as a whole.

[0011] In order to effectively ensure the rigid support strength of the arched main support frame;

[0012] As a further improvement to the above technical solution: the arched main support frame includes an outer steel plate, an H-beam, and an inner steel plate connected from the outside to the inside. There are two H-beams, which are equidistantly spaced along the extension direction of the outer and inner steel plates. Concrete is also poured into the cavity between the outer and inner steel plates.

[0013] The beneficial effects of this improvement are: the arched main support frame is made of steel structure and precast concrete, which can provide stable rigid support for the tunnel entrance.

[0014] To facilitate the installation of anchoring system one;

[0015] As a further improvement to the above technical solution: both the outer steel plate and the inner steel plate are provided with through holes for inserting anchor rods of the anchoring system.

[0016] The beneficial effects of this improvement are: the pre-reserved anchor bolt installation holes on the arched main support frame can avoid the need to drill holes on the steel plate on site during construction, thus reducing the difficulty of construction.

[0017] In order to effectively guide the water flow into the drainage collection tank;

[0018] As a further improvement to the above technical solution: multiple arc-shaped steels are formed at intervals along the extension direction of the outer steel plate, and the drainage collection trough includes multiple collection troughs formed at intervals on the bottom support platform, with the bottom end of the arc-shaped steels connected to the collection troughs.

[0019] The beneficial effect of this improvement is that water can enter the arc-shaped steel and then flow into the water collection tank under the action of gravity.

[0020] In order to effectively guide and drain the water from the collection tank;

[0021] As a further improvement to the above technical solution: the multiple water collection tanks are connected by water guide pipes embedded in the bottom support, and one end of the water guide pipe passes through the end face of the bottom support.

[0022] The beneficial effects of this improvement are: the water pipe can guide the water flow to the outside of the bottom foundation, avoiding the decrease in support strength caused by groundwater seepage.

[0023] In order to enable the buffer energy-absorbing layer to play a buffering and shock-absorbing role while also effectively filtering;

[0024] As a further improvement to the above technical solution: the buffer energy-absorbing layer is formed by the composite curing of rubber particles and epoxy resin, and the interior of the buffer energy-absorbing layer forms a three-dimensional interconnected honeycomb pore.

[0025] The beneficial effects of this improvement are: the elastic deformation of the rubber particles maintains the stability of the pore flux, and the low-viscosity epoxy resin forms a compressive skeleton after curing, realizing the synergistic effect of filtration and energy absorption under vibration conditions.

[0026] The parts of the device not covered herein are the same as or can be implemented using existing technologies. Attached Figure Description

[0027] Figure 1 This is a cross-sectional view of the present invention;

[0028] Figure 2 This is a schematic diagram of the arched main support frame in this utility model;

[0029] Figure 3 This is a schematic diagram of the bottom support structure in this utility model;

[0030] In the diagram: 1. Arched main support frame; 11. Outer steel plate; 12. Inner steel plate; 13. H-beam; 14. Arc-shaped steel; 2. Bottom pier; 3. Tunnel entrance rock mass; 4. Buffer energy-absorbing layer; 5. Anchoring system one; 6. Drainage and water collection trough; 61. Water collection trough; 62. Water guide pipe; 7. Surface protective grid; 8. Anchoring system two. Detailed Implementation

[0031] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings. The description in this part is only exemplary and explanatory, and should not be used to limit the scope of protection of the present invention in any way.

[0032] Example 1:

[0033] like Figure 1As shown in Figure 3: A tunnel entrance reinforcement structure includes an arched main support frame 1. The two sides of the arched main support frame 1 are supported by a bottom support platform 2 and fixedly connected to the bottom support platform 2. The bottom support platform 2 is fixed to the tunnel entrance rock mass 3 by cast-in-place concrete. A buffer energy-absorbing layer 4 is tightly attached to the outer surface of the arched main support frame 1. An anchoring system 5, which is locked onto the arched main support frame 1, extends through the arched main support frame 1 and the buffer energy-absorbing layer 4 into the interior of the tunnel entrance rock mass 3. A surface protective grid 7 is tightly attached to the outer surface of the buffer energy-absorbing layer 4. The surface protective grid 7 is fastened to the surface of the tunnel entrance rock mass 3 by an anchoring system 8. A drainage collection trough 6 is provided on the bottom support platform 2 located vertically below the arched main support frame 1. Through the synergistic effect of the prestressed anchoring system, the arched main support frame 1, and the surface protective grid 7, combined with the use of the buffer energy-absorbing layer 4, multi-dimensional stable reinforcement of the tunnel entrance is achieved, including vibration reduction, anti-stripping, and rigid support. The buffer energy-absorbing layer 4, together with the arched main support frame 1 and the drainage collection trough 6, filters and diverts groundwater, effectively relieving groundwater pressure. Both the anchoring system one 5 and the anchoring system two 8 include hollow grouting anchor rods, anchor rod pads, and anchor rod nuts. The anchoring system one 5 and the anchoring system two 8 are interleaved and evenly distributed on the arched main support frame 1 and the surface protective grid 7. The evenly distributed radially arranged anchor rod array can enhance the connection strength between the reinforced structure and the overall rock mass. The arched main support frame 1 includes an outer steel plate connected from the outside to the inside. 11. Two H-beams 13 and two inner steel plates 12 are provided, equidistantly spaced along the extension direction of the outer steel plate 11 and the inner steel plate 12. Concrete is poured into the cavity between the outer steel plate 11 and the inner steel plate 12. The arched main support frame 1 is prefabricated from steel and concrete, providing stable rigid support for the tunnel entrance. Through holes for inserting anchor rods of the anchoring system 5 are provided on both the outer steel plate 11 and the inner steel plate 12. The pre-drilled anchor rod installation holes on the arched main support frame 1 avoid the need to drill holes on the steel plate during construction, reducing construction difficulty. Multiple arc-shaped steel sections 14 are spaced along the extension direction of the outer steel plate 11. The drainage collection trough 6 includes multiple sections spaced on the bottom support platform 2. The bottom end of the arc-shaped steel 14 is connected to the water collection tank 61. Water can enter the arc-shaped steel 14 and flow into the water collection tank 61 under the action of gravity. Multiple water collection tanks 61 are connected by water guide pipes 62 embedded in the bottom support 2. One end of the water guide pipe 62 passes through the end face of the bottom support 2. The water guide pipe 62 can guide the water flow to the outside of the bottom support 2 to avoid the decrease in support force caused by groundwater infiltration. The buffer energy absorption layer 4 is formed by the composite curing of rubber particles and epoxy resin. The interior of the buffer energy absorption layer 4 forms a three-dimensional interconnected honeycomb pore. The elastic deformation of the rubber particles maintains the stability of the pore flux. After the low viscosity epoxy resin is cured, it forms a compressive skeleton to realize the synergistic effect of filtration and energy absorption under vibration conditions.

[0034] The working principle of this technical solution is as follows: The rock mass at the tunnel entrance is cleaned and trimmed; the surface protective grid 7 is installed; hollow grouting anchors are inserted into the rock mass through pre-drilled holes; after installing anchor pads and anchor nuts, grouting is performed to ensure a tight bond between the anchors and the rock mass, ensuring the surface protective grid 7 is firmly fixed to the rock surface, providing initial protection and preventing rock fragments from falling during construction; the bottom foundation 2 is constructed by excavating a foundation trench at the bottom of the rock mass 3 at the tunnel entrance and pouring bottom foundation 2 with cast-in-place concrete, ensuring a firm bond between the bottom foundation 2 and the rock mass 3 at the tunnel entrance; a shaped buffer energy-absorbing layer 4 is sprayed onto the surface protective grid 7, which is made of rubber... The energy-absorbing buffer layer 4, formed by the composite curing of particles and epoxy resin, is bonded to the surface protective grid 7, and the arched main support frame 1 is immediately installed. During installation, care is taken to protect the three-dimensional interconnected honeycomb pore structure inside the energy-absorbing buffer layer 4 to prevent it from being squeezed. The pre-processed arched main support frame 1 is placed on the bottom support platform 2, so that the two sides of the arched main support frame 1 are in close contact with the bottom support platform 2. The arched main support frame 1 and the bottom support platform 2 are fixedly connected by welding or high-strength bolts to ensure the strength and stability of the connection. The drainage collection trough 6 is formed when the arched main support frame 1 is poured. The anchoring system 5 is installed and grouting is performed.

[0035] During tunnel operation, when the tunnel entrance is impacted by external forces such as earthquakes or falling rocks, the rubber particles in the buffer energy-absorbing layer 4 undergo elastic deformation to absorb energy and reduce the impact of the impact force on the arched main support frame 1 and the tunnel entrance rock mass 3. At the same time, the anchoring system 1 5 and the anchoring system 2 8 work together with the arched main support frame 1 and the surface protective grid 7 to enhance the overall stability of the structure and prevent the structure from peeling off and collapsing. When groundwater seeps into the buffer energy-absorbing layer 4, it can be filtered to prevent impurities such as mud and sand from entering the arched main support frame 1. The filtered groundwater enters the arc-shaped steel 14 and flows into the water collection tank 61 under the action of gravity, and then is discharged through the water pipe 62, effectively relieving the groundwater pressure and ensuring the stability of the tunnel entrance.

[0036] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0037] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only for the purpose of helping to understand the method and core ideas of the present invention. The above descriptions are only preferred embodiments of the present invention. It should be noted that due to the limitations of textual expression, there are objectively infinite specific structures. For those skilled in the art, several improvements, modifications, or changes can be made without departing from the principles of the present invention, and the above technical features can also be combined in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of the present invention.

Claims

1. A tunnel entrance reinforcement structure, characterized in that: The system includes an arched main support frame (1), the two sides of which are supported by a bottom platform (2) and fixedly connected to the bottom platform (2). The bottom platform (2) is fixed to the tunnel entrance rock mass (3) by cast-in-place concrete. A buffer energy-absorbing layer (4) is tightly attached to the outer surface of the arched main support frame (1). An anchoring system one (5) on the arched main support frame (1) extends through the arched main support frame (1) and the buffer energy-absorbing layer (4) to the interior of the tunnel entrance rock mass (3). A surface protective grid (7) is tightly attached to the outer surface of the buffer energy-absorbing layer (4). The surface protective grid (7) is fastened to the surface of the tunnel entrance rock mass (3) by an anchoring system two (8). A drainage collection trough (6) is provided on the bottom platform (2) located vertically below the arched main support frame (1).

2. The tunnel entrance reinforcement structure according to claim 1, characterized in that: Both the first anchoring system (5) and the second anchoring system (8) include hollow grouting anchors, anchor pads and anchor nuts. The first anchoring system (5) and the second anchoring system (8) are interleaved and evenly distributed on the arched main support frame (1) and the surface protective grid (7).

3. The tunnel entrance reinforcement structure according to claim 1, characterized in that: The arched main support frame (1) includes an outer steel plate (11), an H-beam (13), and an inner steel plate (12) connected from the outside to the inside. There are two H-beams (13) and they are equidistantly spaced along the extension direction of the outer steel plate (11) and the inner steel plate (12). Concrete is also poured into the cavity between the outer steel plate (11) and the inner steel plate (12).

4. The tunnel entrance reinforcement structure according to claim 3, characterized in that: Both the outer steel plate (11) and the inner steel plate (12) are provided with through holes for inserting anchor rods of the anchoring system (5).

5. The tunnel entrance reinforcement structure according to claim 3, characterized in that: The outer steel plate (11) has multiple arc-shaped steels (14) spaced apart along the extension direction of the outer steel plate (11), and the drainage collection trough (6) includes multiple collection troughs (61) spaced apart on the bottom support (2), and the bottom end of the arc-shaped steels (14) is connected to the collection troughs (61).

6. The tunnel entrance reinforcement structure according to claim 1, characterized in that: The multiple water collection tanks (61) are connected by water guide pipes (62) embedded in the bottom support (2), and one end of the water guide pipe (62) passes through the end face of the bottom support (2).

7. The tunnel entrance reinforcement structure according to claim 1, characterized in that: The buffer energy-absorbing layer (4) is formed by the composite curing of rubber particles and epoxy resin, and the interior of the buffer energy-absorbing layer (4) forms a three-dimensional interconnected honeycomb pore.

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