Rock burst impact prevention supporting structure for tunnel

Abstract

The utility model belongs to the technical field of tunnel construction supporting structures, and particularly relates to a tunnel rockburst impact prevention supporting structure which is particularly suitable for rockburst prevention and control of a high-ground-stress deep-buried tunnel. The tunnel supporting structure comprises a plurality of supporting lagging jacks which are arranged at intervals in the length direction of a tunnel, each supporting lagging jack comprises an inner wing plate, an outer wing plate and a negative Poisson's ratio effect honeycomb sandwich layer, the inner wing plates are attached to the inner wall of the tunnel and are fixedly connected with the inner wall of the tunnel through pre-stressed anchor rods, and the outer wing plates are located on the sides, away from the inner wall of the tunnel, of the inner wing plates. The outer wing plate and the inner wing plate are oppositely arranged, one side of the negative Poisson's ratio effect honeycomb sandwich layer is fixedly connected with the inner wing plate, the other side of the negative Poisson's ratio effect honeycomb sandwich layer is fixedly connected with the outer wing plate, and the negative Poisson's ratio effect honeycomb sandwich layer is formed by periodically arranging a plurality of concave hexagonal honeycomb cell elements. And the inner hole axis of the concave hexagonal honeycomb cell element is consistent with the axis direction of the tunnel. According to the utility model, the rockburst disaster in the high-ground-stress deep-buried cavern can be more effectively dealt with.

Description

Technical Field

[0001] The utility model belongs to the technical field of tunnel construction support structures, and specifically relates to a tunnel rock burst prevention support structure, which is especially suitable for rock burst prevention in deep-buried tunnels with high ground stress. Background Art

[0002] When carrying out deep engineering construction, there are often deep high-energy dynamic disasters such as rock bursts, plate cracks, gas explosions, and earthquakes, which seriously threaten the safety and stability of deep engineering construction. Among them, rock burst is the most prominent dynamic disaster in deep rock mass and has become one of the world's difficult problems in the field of underground engineering. The mechanical mechanism of rock burst is very complex. During the occurrence process, a large amount of elastic strain energy accumulated in the rock mass will be released, causing rock blocks to fly out at high speed, and generating shock waves and vibrations, causing structural damage and casualties, seriously threatening the safety and stability of deep engineering construction. Traditional underground engineering support structures have many problems in the prevention and control of rock burst disasters. The current deep-buried tunnel rock burst protection system usually relies on rigid support structures and adopts traditional support such as steel arch frames and reinforced concrete to resist rock burst disasters (see the Chinese patent document with publication number CN205260055U). However, the huge energy generated by strong rock bursts is often difficult for traditional support systems to protect and resist. Furthermore, rigid support structures severely restrict the deformation of deep rock, leading to a sharp increase in elastic strain energy within the rock mass. This effectively fails to reduce the risk of rockbursts, nor effectively control the stability of the surrounding rock mass. In fact, it can even exacerbate rockburst intensity, rendering effective protection impossible. Therefore, innovative support structures are needed to effectively address rockburst hazards in deep caverns with high geostress.

[0003] Chinese patent publication CN118257388A discloses a subway station anti-collision load-bearing column with a negative Poisson's ratio lattice structure and its operation method. The patent's solution primarily uses industrial pure aluminum or aluminum alloy to combine the negative Poisson's ratio lattice structure with a concrete core, creating an anti-collision outer layer that dynamically cushions and gradually offsets impact forces. This solution primarily ensures that the column does not collapse if a subway train crashes. However, its structural form and material strength do not meet the design requirements for deep tunnels with high ground stresses, making it unsuitable for use in support systems within rockburst areas of deep tunnels.

[0004] Chinese patent publication CN114536888A discloses a composite protective structure with penetration resistance and ballistic deflection, and its preparation method. The solution described in this patent document folds thin steel plates into a negative Poisson's ratio cellular structure, which is then filled with a polyurea layer and self-compacting concrete to achieve a composite protective structure with penetration resistance and ballistic deflection. This solution is capable of withstanding high-velocity impacts, but the thin steel plates cannot withstand the high geostress requirements of deep tunnels. The filled polyurea layer and self-compacting concrete lack the ability to deform in harmony with the surrounding rock of deep tunnels, making it impossible to effectively control the stability of the high-stress surrounding rock and effectively reduce the risk of rockbursts.

[0005] A Chinese patent document with publication number CN114320391A discloses an integrated anti-impact energy absorption device and method. The solution in this patent document utilizes the shear thickening fluid hardening effect of the anti-impact component and the elastic-plastic deformation of the negative Poisson's ratio structure to absorb energy, thereby improving the support performance and energy absorption and anti-impact performance of the support device. However, this solution is only used as an anti-impact device in hydraulic supports for mine support. It cannot bear the surrounding rock load as a support structure, nor does it have the ability to coordinate deformation with the surrounding rock of deep-buried tunnels, and cannot meet the requirements of deep-buried tunnels to withstand high ground stress. Utility Model Content

[0006] The technical problem to be solved by the utility model is to provide a tunnel rock burst prevention support structure, which can more effectively deal with rock burst disasters in deep-buried caverns with high ground stress.

[0007] In order to solve the above-mentioned technical problems, the present invention provides the following technical solutions: a tunnel rock burst impact support structure, comprising a plurality of support arches arranged at intervals along the length direction of the tunnel, each support arch comprising an inner wing plate, an outer wing plate and a negative Poisson's ratio effect honeycomb sandwich layer, the inner wing plate is in contact with the inner wall of the tunnel and the two are connected and fixed by prestressed anchor rods, the outer wing plate is located on the side of the inner wing plate away from the inner wall of the tunnel, the outer wing plate and the inner wing plate are arranged relative to each other, one side of the negative Poisson's ratio effect honeycomb sandwich layer is fixedly connected to the inner wing plate, and the other side is fixedly connected to the outer wing plate, the negative Poisson's ratio effect honeycomb sandwich layer is composed of a plurality of periodically arranged concave hexagonal honeycomb cells, and the inner hole axis of the concave hexagonal honeycomb cells is consistent with the axial direction of the tunnel.

[0008] A further preferred solution is that multiple layers of concave hexagonal honeycomb cells are arranged along the radial direction of the tunnel, and two adjacent layers of concave hexagonal honeycomb cells are fixedly connected to form a whole; multiple rows of concave hexagonal honeycomb cells are arranged at intervals along the axial direction of the tunnel.

[0009] A further preferred solution is that the inner wing panels, the outer wing panels and the negative Poisson's ratio effect honeycomb sandwich layer are all made of steel material and fixed into a whole by welding.

[0010] A further preferred solution is that the supporting arch comprises a plurality of arch units distributed at intervals along the circumferential direction of the inner wall of the tunnel, and two adjacent arch units are welded and fixed.

[0011] A further preferred solution is that the tail end of the prestressed anchor rod is connected and fixed to the inner wing plate via a bolt connection structure.

[0012] A further preferred solution is that a sprayed concrete structural layer is provided on the inner wall of the tunnel in the interval area between two adjacent supporting arches.

[0013] The negative Poisson's ratio honeycomb core layer exhibits significant deformation and load-bearing capacity. Its material, geometry, cell wall and faceplate thickness, and the optimal number of layers and columns for a given protection zone thickness and width can be comprehensively optimized based on the actual rockburst situation. Key parameters such as prestressed anchor length, prestress value, and spacing can be determined based on the rockburst severity in the area. In principle, anchor length should be no less than 3 meters, and prestress should be no less than 60 kN. Prestressed anchors driven into the surrounding rock form an active support system with the support arch, sharing the load with the surrounding rock. The integrated support structure, comprised of the negative Poisson's ratio honeycomb core layer, inner and outer wing panels, and prestressed anchors, is capable of deforming in harmony with the surrounding rock of deep tunnels, meeting the high geostress requirements of deep tunnels. When a rock burst occurs, an axial compression-contraction phenomenon occurs. As the concave hexagonal honeycomb cells diffuse inward, the cell walls gradually contact, the compressive stress increases rapidly and enters the densification zone. A multi-layer non-uniform multi-cellular dense structure is re-formed at the impact position of the negative Poisson's ratio effect honeycomb sandwich layer structure, resulting in an increase in the equivalent elastic modulus of the entire structure, and then a macroscopic negative Poisson's ratio effect is produced, which is mainly manifested in the generation of a stress enhancement zone at the impacted structure position. The closer the structure is to the center of the rock burst impact, the greater the stress enhancement, thereby resisting the rock burst impact and ensuring the safety of the structure and personnel.

[0014] The beneficial effects of the utility model are as follows:

[0015] 1. A support arch with a macroscopic negative Poisson's ratio effect and prestressed anchor rods are used as the active support system. Its structural form and material strength can fully meet the design requirements of deep-buried tunnels with high ground stress and can be directly applied to the support system of rock burst sections of deep-buried tunnels.

[0016] 2. Compared with the current rigid support structure of deep-buried tunnels, it has the ability to coordinate deformation with the surrounding rock of deep-buried tunnels. While meeting the requirements of deep-buried tunnels to withstand high ground stress, it effectively reduces the risk of rock bursts.

[0017] 3. When a rock burst occurs, a stress enhancement zone is generated at the impacted structure, and the closer the structure is to the center of the rock burst, the greater the stress enhancement, thereby resisting the rock burst and ensuring the safety of the structure and personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall facade layout structure of the utility model.

[0019] Figure 2 for Figure 1 A partial enlarged view of point A.

[0020] Figure 3 Schematic diagram of the facade layout structure of a single arch unit.

[0021] Figure 4 Schematic diagram of the planar layout structure of a single arch unit.

[0022] Figure 5 Schematic diagram of the structure of a single concave hexagonal honeycomb cell.

[0023] Parts markings in the figure: concave hexagonal honeycomb cell 1, inner wing plate 2, outer wing plate 3, prestressed anchor rod 4, support arch 5, bolt connection hole 6. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0025] See also Figures 1 to 5 The utility model includes a plurality of support arches 5 arranged at intervals along the length direction of the tunnel, each support arch 5 includes an inner wing panel 2, an outer wing panel 3 and a negative Poisson's ratio effect honeycomb sandwich layer, the inner wing panel 2 is in contact with the inner wall of the tunnel and the two are connected and fixed by a prestressed anchor rod 4, the outer wing panel 3 is located on the side of the inner wing panel 2 away from the inner wall of the tunnel, the outer wing panel 3 and the inner wing panel 2 are arranged relative to each other, one side of the negative Poisson's ratio effect honeycomb sandwich layer is fixedly connected to the inner wing panel 2, and the other side is fixedly connected to the outer wing panel 3, the negative Poisson's ratio effect honeycomb sandwich layer is composed of a plurality of periodically arranged concave hexagonal honeycomb cells 1, and the inner hole axis of the concave hexagonal honeycomb cell 1 is consistent with the axial direction of the tunnel.

[0026] In order to make the negative Poisson's ratio effect honeycomb sandwich layer have better coordinated deformation ability and be easy to process and manufacture, the negative Poisson's ratio effect honeycomb sandwich layer preferably adopts a multi-layer and multi-column structure, and the concave hexagonal honeycomb cells 1 are arranged in multiple layers along the radial direction of the tunnel, and the two adjacent layers of concave hexagonal honeycomb cells 1 are fixedly connected into a whole; the concave hexagonal honeycomb cells 1 are arranged in multiple rows at intervals along the axial direction of the tunnel.

[0027] The support arch can be made of various metal materials or alloy materials with strong deformation ability and good toughness in the existing technology. The processing method and processing quality of the honeycomb cells have a significant impact on the explosion-proof results, and additive manufacturing can be considered as needed. In order to make the structure economical and applicable, and easy to process and manufacture, the inner wing panel 2, the outer wing panel 3 and the negative Poisson's ratio effect honeycomb sandwich layer are all made of steel materials and fixed into a whole by welding. To further facilitate processing and manufacturing, the support arch 5 includes a plurality of arch units distributed at circumferential intervals along the inner wall of the tunnel, and the adjacent two arch units are welded and fixed. Each column of concave hexagonal honeycomb cells 1 corresponding to a single arch unit can generally be designed as an integral structure, manufactured by casting or integral cutting.

[0028] To further facilitate assembly, the tail end of the prestressed anchor rod 4 is connected and fixed to the inner wing plate 2 through a bolt connection structure, that is, the tail end of the prestressed anchor rod 4 is provided with an external thread structure, and the inner wing plate 2 is provided with a bolt connection hole 6. The tail end of the prestressed anchor rod 4 passes through the bolt connection hole 6, and the inner wing plate 2 is pressed and fixed by a locking nut that matches the external thread structure of the tail end of the prestressed anchor rod 4.

[0029] Various conventional support methods can be used to implement the interval area between two adjacent support arches 5 on the inner wall of the tunnel. In order to make the structure economical and applicable, the preferred solution is to provide a sprayed concrete structural layer in the interval area between two adjacent support arches 5 on the inner wall of the tunnel.

[0030] The honeycomb sandwich layer with negative Poisson's ratio effect has large deformation and bearing capacity. Its material, geometric dimensions, cell wall and panel thickness, and the optimal distribution layers and columns of cells under a given protection domain thickness and width can be comprehensively optimized according to the actual rock burst situation. Key parameters such as prestressed anchor length, prestress value and layout spacing can be determined according to the grade of rock burst in the rock burst area.

[0031] The specific scheme and parameters used in a certain engineering embodiment are as follows: the overall structure is as shown in 1 and Figure 2 As shown, multiple arch frame units are welded in sections along the circumference of the inner wall of the tunnel to form a support arch frame 5 in the rock burst section. The inner wing plate 2 of the support arch frame 5 and the tail end of the prestressed anchor rod 4 are fixed with a bolt connection structure to form an anti-rock burst impact support structure. The radius of the support arch frame 5 is 9m, the length of the prestressed anchor rod 4 is 3m, and the prestress is 60kN. The prestressed anchor rod 4 driven into the surrounding rock and the support arch frame 5 form an active support system and share the load with the surrounding rock.

[0032] The protection zone length H1 = 100cm and the protection zone width H2 = 36cm for a single arch unit. For the specific size markings of H1 and H2, please refer to Figure 4The thickness of the inner wing panel 2 and the outer wing panel 3 are both 12.5 mm. The inward-concave hexagonal honeycomb cells 1 are arranged in 6 layers within a given protection field thickness. The inner wing panel 2 and the outer wing panel 3 are welded and fixed to the inward-concave hexagonal honeycomb cells 1.

[0033] The concave hexagonal honeycomb cell 1 is made of Q235 steel and cut as a whole. Studies have shown that the processing method and processing quality of the honeycomb cell have a significant impact on the explosion-proof result. The specific size parameters of the concave hexagonal honeycomb cell 1 in this embodiment can be found in Figure 5 , where L1=44.3mm, L2=45.3mm, L3=18.75mm, and the cell wall thickness is 1.0mm.

Claims

1. A tunnel rock burst support structure, comprising a plurality of support arches (5) arranged at intervals along the length of the tunnel, characterized in that: Each supporting arch frame (5) comprises an inner wing plate (2), an outer wing plate (3) and a honeycomb sandwich layer with a negative Poisson's ratio effect. The inner wing plate (2) is in contact with the inner wall of the tunnel and the two are connected and fixed by a prestressed anchor rod (4). The outer wing plate (3) is located on the side of the inner wing plate (2) away from the inner wall of the tunnel. The outer wing plate (3) and the inner wing plate (2) are arranged relative to each other. One side of the honeycomb sandwich layer with a negative Poisson's ratio effect is fixedly connected to the inner wing plate (2), and the other side is fixedly connected to the outer wing plate (3). The honeycomb sandwich layer with a negative Poisson's ratio effect is composed of a plurality of periodically arranged concave hexagonal honeycomb cells (1). The inner hole axis of the concave hexagonal honeycomb cells (1) is consistent with the axial direction of the tunnel.

2. The tunnel rockburst protection support structure according to claim 1, characterized in that: The concave hexagonal honeycomb cells (1) are arranged in multiple layers along the radial direction of the tunnel, and two adjacent layers of the concave hexagonal honeycomb cells (1) are fixedly connected to form a whole; the concave hexagonal honeycomb cells (1) are arranged in multiple rows at intervals along the axial direction of the tunnel.

3. The tunnel rockburst protection support structure according to claim 1, characterized in that: The inner wing plate (2), the outer wing plate (3) and the negative Poisson's ratio effect honeycomb sandwich layer are all made of steel material and are fixed into a whole by welding.

4. The tunnel rockburst protection support structure according to claim 1, characterized in that: The supporting arch frame (5) comprises a plurality of arch frame units distributed at intervals along the circumferential direction of the inner wall of the tunnel, and two adjacent arch frame units are welded and fixed.

5. The tunnel rockburst protection support structure according to claim 1, characterized in that: The tail end of the prestressed anchor rod (4) is connected and fixed to the inner wing plate (2) via a bolt connection structure.

6. The tunnel rockburst protection support structure according to any one of claims 1 to 5, characterized in that: A sprayed concrete structural layer is provided on the inner wall of the tunnel in the interval area between two adjacent supporting arch frames (5).

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