Rapid energy dissipation protection system and method for TBM tunnel rockburst under high ground stress

Abstract

The invention discloses a rapid energy dissipation protection system and method for TBM tunnel rockburst under high ground stress. The open type TBM tunnel is located in an incomplete supporting area in the front supporting operation L1 area. A steel arch frame is installed in a surrounding rock exposed area behind a shield, and the steel arch frame is arranged in a ring mode; a high-toughness energy dissipation net is laid on the surface of the steel arch frame, the high-toughness energy dissipation net is arranged between a surrounding rock exposed area and a guniting bridge in the longitudinal direction of the tunnel, and the annular arrangement range of the high-toughness energy dissipation net is an arch protection area; and the high-toughness energy dissipation net is fixed on the steel arch frame through a plurality of door-shaped clamps. The temporary energy dissipation net and the permanent steel frame are connected and formed, the energy dissipation net is circularly and inversely used for construction, and safe construction of the tunnel in an unfavorable geological section is guaranteed.

Description

Technical Field

[0002] This invention belongs to the field of rockburst tunnel construction technology, and specifically relates to a rapid energy dissipation and protection system and method for rockburst in TBM tunnels under high ground stress. Background Technology

[0003] In the L1 area of ​​the open rock tunnel boring machine (TBM) tunnel, which is about 70 meters long and not fully supported, the rock burst problem becomes particularly prominent when encountering areas with high ground stress rock bursts. Rock fragments ejected by high ground stress rock bursts in areas where the initial support has not been formed endanger construction safety, seriously threaten the safety of construction personnel and equipment, affect the tunnel construction progress, and increase the safety risks of tunnel construction.

[0004] Due to the sudden release of elastic strain energy accumulated in high-stress rock masses during tunnel excavation or other external disturbances, dynamic phenomena such as rock bursting, loosening, peeling, ejection, and even throwing of surrounding rock occur. This is particularly prominent in deep-buried areas with high mountains, deep valleys, and strong tectonic activity, making rock bursts in hard rock tunnels a significant problem. Rock bursts release large amounts of elastic energy, have strong destructive power, and are difficult to control, seriously threatening the safety of construction workers inside the tunnel. However, conventional protection methods for open-face TBM tunnels have gaps in the steel frame supports, making complete protection impossible. Furthermore, TBM excavation is a cyclical process, making rapid and effective dynamic protection a key engineering challenge, especially preventing rock burst ejection from endangering the safety of operators. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention provides a rapid energy dissipation and protection system and method for rockburst in TBM tunnels under high ground stress. It utilizes a temporary energy dissipation net connected to a permanent steel frame, and the energy dissipation net is used cyclically during construction, ensuring safe tunnel construction in adverse geological sections.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A rapid energy dissipation and protection system for rockburst in TBM tunnels under high ground stress, specifically: A steel arch frame is installed in the exposed rock area behind the shield, and the steel arch frame is arranged in a ring. The surface of the steel arch frame is covered with a high-toughness energy dissipation net. The high-toughness energy dissipation net is set along the longitudinal direction of the tunnel between the exposed surrounding rock area and the shotcrete bridge. The circumferential setting range of the high-toughness energy dissipation net is the arch protection zone. The high-strength energy dissipation net is fixed to the steel arch frame by multiple portal clamps.

[0007] Furthermore, the arch protection zone is symmetrically arranged at 110° of the tunnel arch.

[0008] Furthermore, the gate-type clamp includes two clamp steel plates and a nut; the clamp steel plate is rectangular, with a T-shaped through hole on one side, the through hole extending through the thickness of the clamp steel plate; the T-shaped through holes on the two clamp steel plates overlap, and the T-shaped through holes are inserted into the flange plate of the steel arch frame; the two clamp steel plates are fixedly connected by the nut.

[0009] Furthermore, the high-toughness energy dissipation net includes warp and weft threads, forming an orthogonally oriented mesh structure, with binding yarns used to reinforce the mesh points.

[0010] Furthermore, each gate-shaped clamp has two warp lines that secure the gap between the gate-shaped clamp and the steel arch frame.

[0011] Furthermore, the gate-shaped clamps are arranged in a quincunx pattern.

[0012] A rapid energy dissipation and protection method for rockburst in TBM tunnels under high ground stress includes the following steps: Step 1: The TBM tunneling exposes the surrounding rock. A steel arch frame is installed in the exposed rock area behind the shield of the TBM rockburst tunnel. The steel arch frame is arranged in a ring. Step 2: Lay high-toughness energy dissipation nets longitudinally on the steel arch frame ring; the high-toughness energy dissipation nets are set longitudinally along the tunnel between the exposed surrounding rock area and the shotcrete bridge, and the circumferential setting range of the high-toughness energy dissipation nets is 110° of the tunnel arch; Step 3: Use portal clamps to secure the high-strength energy dissipation net and the steel arch frame; Step 4: As the TBM equipment advances, remove a certain distance of the high-strength energy dissipation net at the shotcrete bridge to achieve recycling.

[0013] The beneficial effects of this invention are: 1) This invention can quickly realize rockburst prevention and control in the risk section of the front L1 support operation area of ​​open rock tunnel boring machine (TBM) tunnel. It utilizes temporary energy dissipation nets connected to permanent steel frames, and the energy dissipation nets are used in a cyclical manner during construction, which ensures safe construction of the tunnel in adverse geological sections and speeds up the efficiency of protective construction. 2) This invention uses two steel plates and two sets of bolts to create a portal-shaped clamp, which effectively ensures the connection safety between the energy dissipation net and the steel frame; by embedding the steel plates into the flange plates of the steel frame, the operation is simple and quick, accelerating the construction progress; by reducing the time personnel spend operating, the contact time of personnel in the rockburst area is minimized, ensuring complete construction. 3) This invention, through a tough energy dissipation net, increases the operability for construction personnel while meeting the protection energy level requirements, and reduces the risks to construction personnel in the event of rockburst. 4) This invention has high construction efficiency and high safety. According to the TBM protection range, combined with the construction progress, steel frame spacing and other requirements, the range of the protective net can be dynamically adjusted. It is flexible in operation and combines permanent and temporary measures, making it easier to control the impact of rockburst on personnel and equipment in TBM tunnels. Attached Figure Description

[0014] Figure 1 This is a longitudinal section view of the TBM tunnel rapid energy dissipation protection system of the present invention; Figure 2 This is a cross-sectional view of the TBM tunnel rapid energy dissipation protection system of the present invention; Figure 3 A schematic diagram of the energy dissipation network installation; Figure 4 This is a schematic diagram of the gate-type clamp structure of the present invention; Figure 5 This is a schematic diagram of the high-toughness energy dissipation net structure of the present invention; In the diagram, 1-steel arch frame, 2-high-toughness energy dissipation net, 3-gantry clamp, 4-arch protection zone, 5-shield, 6-shotcrete bridge, 7-anchor bolt, 9-surrounding rock, 11-TBM L1 zone equipment, 12-invert arch precast block, 13-support shoe, 14-energy dissipation net roll, 201-warp, 202-weft, 203-binding yarn, 301-clamp steel plate, 302-nut. Detailed Implementation

[0015] The present invention will now be described in detail with reference to specific embodiments.

[0016] This invention enables rapid rockburst prevention in the high-risk section of the L1 support operation area of ​​an open-face rock tunnel boring machine (TBM). It utilizes a temporary energy dissipation net connected to a permanent steel frame, and the energy dissipation net is used cyclically during construction, ensuring safe tunnel construction in adverse geological sections and accelerating the efficiency of protective construction.

[0017] like Figure 1 , 2 As shown, the rapid energy dissipation and protection system for rockburst in TBM tunnels under high ground stress according to the present invention is specifically as follows: A steel arch frame 1 is installed in the exposed area of ​​the surrounding rock 9 behind the shield 5, and the steel arch frame 1 is set in a ring; anchor bolts 7 are installed on the surrounding rock 9. Support boots 13 are installed below the shield 5.

[0018] The surface of the steel arch frame 1 is covered with a high-toughness energy dissipation net 2. The high-toughness energy dissipation net 2 is set along the longitudinal direction of the tunnel between the exposed area of ​​the surrounding rock 9 and the shotcrete bridge 6. The circumferential setting range of the high-toughness energy dissipation net 2 is the arch protection zone 4. The arch protection zone 4 is the tunnel arch 110°, symmetrically set.

[0019] The high-strength energy dissipation net 2 is fixed to the steel arch frame 1 by multiple portal clamps 3. To ensure the impact resistance, the portal clamps 3 are arranged in a staggered pattern with a circumferential spacing of 1.8m and a longitudinal spacing of 0.9m. The spacing can be adjusted according to the position of the steel arch frame 1.

[0020] like Figure 4As shown, the gate-type clamp 3 includes two clamp steel plates 301 and a nut 302. The clamp steel plate 301 is rectangular, and its size is adjusted according to the size of the steel arch frame. A T-shaped through hole is provided on one side, which extends through the thickness of the clamp steel plate 301. The T-shaped through holes on the two clamp steel plates 301 overlap and are inserted into the flange plate of the steel arch frame 1. The two clamp steel plates 301 are fixedly connected by the nut 302. In this embodiment, the clamp steel plate 301 is made of two 20mm steel plates with a size of 295mm × 165mm; it is fixed by the M24 nut 302.

[0021] like Figure 5 As shown, the high-toughness energy dissipation net 2 is made of polyester fiber material, fully utilizing the lightweight and high-strength characteristics of the polymer. It includes warp threads 201 and weft threads 202, forming an orthogonal oriented mesh structure, reinforced at mesh points with binding yarns 203. The mesh spacing of the high-toughness energy dissipation net 2 is 14cm × 14cm, and the width of the warp and weft threads is 20cm. Different protection level specifications are achieved by selecting different warp and weft yarn linear densities, quantities, and strip spacing according to the protection level, enabling lightweight installation, disassembly, and reuse, quickly serving as protection against tunnel rockburst hazards. Metal mesh rockburst protection can also be used; users can choose according to their conditions. Each portal clamp 3 has two warp threads 201 that clamp into the gap between the portal clamp 3 and the steel arch frame 1.

[0022] In this embodiment, the high-strength energy dissipation net 2 has a width of 4.9 meters × 5.4 meters (circumferential × longitudinal). Two strips are generally installed circumferentially in the tunnel (the width can be adjusted according to the laying range), and the longitudinal strips are installed according to the spacing of the steel frame. The overlap length between two strips of energy dissipation net 2 is not less than 16 cm, and the overlap position must be secured with a portal clamp 3 at the steel frame location.

[0023] This invention also provides a method for rapid energy dissipation and protection against rockburst in TBM tunnels under high ground stress, comprising the following steps: Step 1: The TBM tunneling exposes the surrounding rock. A steel arch frame 1 is installed in the exposed area of ​​the surrounding rock 9 behind the shield 5 of the TBM rockburst tunnel. The steel arch frame 1 is set in a ring. The steel arch frame is installed using an arch frame installer to erect the main support frame for the initial support. Step Two: High-strength energy dissipation netting 2 is laid longitudinally along the steel arch frame 1. The specifications of high-strength energy dissipation netting 2 vary depending on the rockburst energy level and protection requirements of different rockburst sections. High-strength energy dissipation netting 2 is installed longitudinally along the tunnel from the exposed surrounding rock 9 to the shotcrete bridge 6. The circumferential installation range of high-strength energy dissipation netting 2 is 110° around the tunnel arch. The area from the tunnel exiting the shield 5 to the shotcrete bridge 6 is the area where shotcrete 10 has not been applied, representing the weakest point in TBM rockburst prevention. Installing high-strength energy dissipation netting 2 in this area ensures the safety of TBM construction personnel and equipment. In this embodiment, the energy dissipation netting roll is energy dissipation netting material 14, which is brought in for installation. Figure 3 As shown.

[0024] Step 3: Use the portal clamp 3 to clamp the high-toughness energy dissipation net 2 and the steel arch frame 1, insert the steel plate 301 into the flange plate of the steel frame, and fit the warp thread 201, and quickly fix it with bolts 302; Step 4: As the TBM equipment advances, before spraying concrete, remove a certain distance of the high-toughness energy dissipation net 2 at the shotcrete bridge to achieve recycling. The dismantling length is determined according to the width of the energy dissipation net, and dismantling is achieved by removing the bolts and steel plates of the gate-type clamps.

[0025] In the description of this invention, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," "link," and "fix" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] The content of this invention is not limited to the embodiments listed. Any equivalent modifications made by those skilled in the art to the technical solutions of this invention by reading this specification are covered by the claims of this invention.

Claims

1. A TBM tunnel rock burst rapid energy dissipation protection system under high ground stress, characterized in that: a steel arch (1) is installed in the exposed area of the surrounding rock (9) behind the shield (5), and the steel arch (1) is arranged in a ring; a high-toughness energy dissipation net (2) is laid on the surface of the steel arch (1), the high-toughness energy dissipation net (2) is arranged between the exposed area of the surrounding rock (9) and the guniting bridge (6) along the longitudinal direction of the tunnel, and the high-toughness energy dissipation net (2) is arranged in a ring and covers the arch protection area (4); the high-toughness energy dissipation net (2) is fixed on the steel arch (1) by a plurality of door-shaped clamps (3). The arch protection area (4) is 110° of the tunnel arch, and is symmetrically arranged.

2. The TBM tunnel rock burst rapid energy dissipation protection system under high ground stress according to claim 1, characterized in that: The door-shaped clamp (3) comprises two clamp steel plates (301) and a nut (302); the clamp steel plate (301) is rectangular, one side of which is provided with a T-shaped through hole, and the through hole penetrates the thickness of the clamp steel plate (301); the T-shaped through holes of the two clamp steel plates (301) are coincided, and the T-shaped through holes are inserted into the flange plate of the steel arch (1); and the two clamp steel plates (301) are fixedly connected by the nut (302).

3. The TBM tunnel rock burst rapid energy dissipation protection system under high ground stress according to claim 2, characterized in that: The high-toughness energy dissipation net (2) comprises warp threads (201) and weft threads (202), and is a quadrature oriented net structure, and a binding yarn (203) is used for strengthening at the net point.

4. The TBM tunnel rock burst rapid energy dissipation protection system under high ground stress according to claim 3, characterized in that: Each door-shaped clamp (3) has two warp threads (201) clamped into the gap between the door-shaped clamp (3) and the steel arch (1).

5. The TBM tunnel rock burst rapid energy dissipation protection system under high ground stress according to claim 4, characterized in that: The position of the door-shaped clamp (3) is arranged in a quincunx shape.

6. The TBM tunnel rock burst rapid energy dissipation protection system under high ground stress according to claim 5, characterized in that: The method comprises the following steps:

7. A method for rapid energy dissipation and protection against rock burst in TBM tunneling under high ground stress, characterized in that: Step one: installing a steel arch (1) in the exposed area of the surrounding rock (9) behind the shield (5) of the TBM rock burst tunnel, and arranging the steel arch (1) in a ring; Step two: laying a high-toughness energy dissipation net (2) in a ring and longitudinally on the steel arch (1); the high-toughness energy dissipation net (2) is arranged between the exposed area of the surrounding rock (9) and the guniting bridge (6) along the longitudinal direction of the tunnel, and the high-toughness energy dissipation net (2) is arranged in a ring and covers 110° of the tunnel arch; Step three: clamping the high-toughness energy dissipation net (2) and the steel arch (1) by using a door-shaped clamp (3); Step four: as the TBM equipment advances, the high-toughness energy dissipation net (2) at a certain distance from the guniting bridge is removed, and the high-toughness energy dissipation net (2) is recycled. ​

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