A combined support system for controlling large deformation of a tunnel with extremely high stress

Abstract

The application provides a combined support system for controlling large deformation of an extremely high stress tunnel, which comprises a primary pressure-releasing mechanism, a secondary pressure-releasing mechanism and a tertiary pressure-releasing mechanism. The primary pressure-releasing mechanism comprises a plurality of main steel frames and a plurality of secondary steel frames, the main steel frames and the secondary steel frames are arranged alternately, the plurality of main steel frames and the plurality of secondary steel frames enclose a ring shape, and a circumferential compression spring is arranged between adjacent main steel frames and secondary steel frames. The secondary pressure-releasing mechanism is located in the primary pressure-releasing mechanism, and comprises a plurality of friction steel frames and a plurality of friction arc plates, the friction steel frames and the friction arc plates are arranged alternately, the plurality of friction steel frames and the plurality of friction arc plates enclose a ring shape, a space for releasing position is arranged in the friction arc plate, the friction steel frame is inserted into the space for releasing position of the friction arc plate, and the friction steel frame and the friction arc plate are in sliding friction contact. A radial compression spring is arranged between the secondary steel frame and the secondary pressure-releasing mechanism. The combined support system is rigid and flexible, and can guarantee the quality of the tunnel engineering and the safety of the construction.

Description

Technical Field

[0001] This invention belongs to the field of tunnel support technology, specifically relating to a combined support system for controlling large deformation in tunnels with extremely high ground stress. Background Technology

[0002] The transportation infrastructure construction in Southwest China has developed like never before, with more and more large-span, deep-buried and extra-long railway or highway tunnels being built, and the terrain and geological conditions encountered are becoming more and more complex.

[0003] In existing technologies, under high ground stress, some soft rock tunnels are prone to large deformation and failure during excavation; conventional tunnel support truss systems, when applied in extremely high ground stress environments, often experience problems such as lining cracking, steel arch twisting, or even breakage, which seriously affect the construction progress and threaten construction safety.

[0004] Therefore, there is a need to provide an improved technical solution that addresses the shortcomings of the existing technology. Summary of the Invention

[0005] The purpose of this invention is to provide a combined support system for controlling large deformation in tunnels with extremely high ground stress, so as to at least solve the above-mentioned problems existing in the prior art.

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

[0007] A combined support system for controlling large deformation in tunnels with extremely high ground stress, the combined support system comprising:

[0008] A primary pressure relief mechanism, comprising multiple main steel frames and multiple secondary steel frames, the main steel frames and secondary steel frames being arranged alternately, the multiple main steel frames and multiple secondary steel frames forming a ring, and a circumferential compression spring being provided between adjacent main steel frames and secondary steel frames;

[0009] A secondary pressure-relief mechanism is located within a primary pressure-relief mechanism. The secondary pressure-relief structure includes multiple friction steel frames and multiple friction arc plates, which are alternately arranged and arranged in a ring. Each friction arc plate has a relief space, and the friction steel frame is inserted into the relief space of the friction arc plate. The friction steel frame and the friction arc plate are in sliding frictional contact.

[0010] A radial compression spring is provided between the secondary steel frame and the secondary pressure relief mechanism.

[0011] In the above-described combined support system for controlling large deformation in tunnels with extremely high ground stress, preferably, guide grooves are provided at both ends of the main steel frame, and one end of the secondary steel frame is guided to move in the guide groove;

[0012] A guide tube is provided in the guide groove, the circumferential compression spring is sleeved around the guide tube, one end of the secondary steel frame is provided with a clearance hole, the guide tube passes through the clearance hole on the secondary steel frame, and the secondary steel frame moves along the guide tube.

[0013] In the above-described high-stress tunnel control large deformation combined support system, preferably, a limiting rod is provided between the main steel frame and two adjacent secondary steel frames. The limiting rod passes through the main steel frame and extends into the secondary steel frame. A limiting block is provided at the end of the limiting rod. The limiting block cooperates with the secondary steel frame to prevent the secondary steel frame from coming out of the limiting groove of the main steel frame.

[0014] In the above-described high-stress tunnel control large deformation combined support system, preferably, a steel pipe extending radially along the primary pressure relief mechanism is provided on the secondary steel frame, and one end of the radial compression spring is located in the steel pipe on the secondary steel frame, while the other end presses against the secondary pressure relief mechanism.

[0015] In the above-described high-stress tunnel control large deformation combined support system, preferably, multiple radial compression springs are provided, and the ends of the multiple radial compression springs facing the secondary pressure relief mechanism are connected together to a support plate, and the multiple radial compression springs press the support plate tightly onto the secondary pressure relief mechanism.

[0016] In the aforementioned combined support system for controlling large deformation in tunnels with extremely high ground stress, preferably, the friction steel frame comprises two HW steel frames arranged in parallel.

[0017] The friction arc plate includes two pairs of C-shaped arc plates and two pairs of U-shaped arc plates. The two pairs of C-shaped arc plates are arranged opposite each other, the two pairs of U-shaped arc plates are arranged opposite each other, and the two pairs of U-shaped arc plates are arranged between the two pairs of C-shaped arc plates. An HW steel frame is clamped between any adjacent C-shaped arc plates and U-shaped arc plates.

[0018] In the above-described high-stress tunnel control large deformation combined support system, preferably, multiple pairs of bolts and nuts are installed through the middle of the friction arc plate, avoiding the position of the friction steel frame. The bolts simultaneously penetrate the C-shaped arc plate and two pairs of U-shaped arc plates, and the friction force between the friction arc plate and the friction steel frame is adjusted by the bolts and nuts.

[0019] The combined support system for controlling large deformation in tunnels with extremely high ground stress, as described above, preferably further includes an adaptable deformation anchor bolt, which includes a bolt body, an anchor bolt compression spring, a pressure bearing plate, and a locking nut.

[0020] The rod extends into the surrounding rock of the tunnel through the first-stage pressure relief mechanism and the second-stage pressure relief mechanism. The friction arc plate is provided with a relief hole. The rod passes through the relief hole of the friction arc plate. An anchor compression spring, a pressure bearing plate and a locking nut are sequentially provided on the protruding end of the rod. The pressure bearing plate presses the anchor compression spring tightly onto the friction arc plate.

[0021] In the above-described high-stress tunnel control large deformation combined support system, preferably, the inner circumference of the secondary pressure relief mechanism is provided with a compression layer, which is made of concrete, rubber particles, asphalt, steel fiber and water.

[0022] In the above-described high-stress tunnel control large deformation combined support system, preferably, the inner circumference of the compression layer is provided with a primary lining structure, the primary lining structure including at least a primary lining steel frame and a steel mesh, and a steel mesh is provided on both the outer and inner circumference of the primary lining steel frame.

[0023] Beneficial effects:

[0024] This invention allows for appropriate deformation of the surrounding rock through a retractable primary and secondary pressure-relief structure, effectively releasing the pressure on the surrounding rock and achieving flexible support for the tunnel. The compressed primary and secondary pressure-relief structures form an integral whole with the compression layer and the initial lining structure, providing rigid support for the tunnel. By setting the primary and secondary pressure-relief structures, the steel frame can adaptively adjust to the deformation generated by the surrounding rock and release excess energy accumulated in the support body. This consumes the energy of the surrounding rock and releases the pressure, allowing for large deformations of the surrounding rock and the support structure, and providing sufficient support resistance to prevent lining cracking, steel arch frame twisting, or even breakage, thus ensuring the quality of tunnel engineering and construction safety. Attached Figure Description

[0025] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. Wherein:

[0026] Figure 1 This is a front view of a combined support system according to an embodiment of the present invention;

[0027] Figure 2 This is a three-dimensional schematic diagram of a combined support system according to an embodiment of the present invention;

[0028] Figure 3 This is a three-dimensional schematic diagram of a primary pressure relief mechanism according to an embodiment of the present invention;

[0029] Figure 4 This is a three-dimensional schematic diagram of a two-stage pressure relief mechanism according to an embodiment of the present invention;

[0030] Figure 5This is a three-dimensional schematic diagram of an adaptable deformable anchor bolt according to an embodiment of the present invention;

[0031] Figure 6 This is a schematic diagram of the initial lining steel frame and reinforcing mesh according to an embodiment of the present invention;

[0032] Figure 7 This is a schematic diagram of the main steel frame according to an embodiment of the present invention;

[0033] Figure 8 This is a schematic diagram of the secondary steel frame structure according to an embodiment of the present invention;

[0034] Figure 9 This is a schematic diagram of the structure of a friction arc plate according to an embodiment of the present invention.

[0035] In the picture:

[0036] 1-Surrounding rock; 2-Primary pressure relief mechanism; 3-Secondary pressure relief mechanism; 4-Adaptable deformable anchor bolt; 5-Compression layer; 6-Primary lining structure; 7-Main steel frame; 8-Secondary steel frame; 9-Shotcrete layer; 10-Circumferential compression spring; 11-Radial compression spring; 12-Limiting rod; 13-Steel pipe; 14-Support plate; 15-Friction steel frame; 16-Friction arc plate; 17-Rod body; 18-Anchor bolt compression spring; 19-Bearing pad plate; 20-Nut; 21-Primary lining steel frame; 22-Reinforcing mesh; 23-Transverse support plate; 24-Circumferential support plate; 25-C-shaped arc plate; 26-U-shaped arc plate; 27-Bolt. Detailed Implementation

[0037] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0038] In the description of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and do not require the invention to be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. The terms "connected" and "linked" used in this invention should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; they can refer to a direct connection or an indirect connection through intermediate components. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0039] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0040] According to specific embodiments of the present invention, such as Figure 1-9 As shown, the present invention provides a combined support system for controlling large deformation in tunnels with extremely high ground stress. The combined support system includes:

[0041] The first-stage pressure relief mechanism 2 includes multiple main steel frames 7 and multiple secondary steel frames 8, which are arranged alternately. The multiple main steel frames 7 and multiple secondary steel frames 8 form a ring, and a circumferential compression spring 10 is provided between adjacent main steel frames 7 and secondary steel frames 8.

[0042] The secondary pressure relief mechanism 3 is located inside the primary pressure relief mechanism 2, or in other words, the primary pressure relief mechanism 2 is located outside the secondary pressure relief mechanism 3. The secondary pressure relief structure includes multiple friction steel frames 15 and multiple friction arc plates 16. The friction steel frames 15 and friction arc plates 16 are arranged alternately, and the multiple friction steel frames 15 and multiple friction arc plates 16 are arranged in a ring. The friction arc plates 16 are provided with relief space. The friction steel frames 15 are inserted into the relief space of the friction arc plates 16, and the friction steel frames 15 and friction arc plates 16 are in sliding frictional contact.

[0043] A radial compression spring 11 is provided between the secondary steel frame 8 and the secondary pressure relief mechanism 3.

[0044] In this combined support system, when the surrounding rock 1 inside the tunnel deforms, the main steel frame 7 and the secondary steel frame 8 can shift. During this process, the circumferential compression spring 10 is compressed or extended. Simultaneously, the radial compression spring 11, which is installed between the primary pressure-relief mechanism 2 and the secondary pressure-relief mechanism 3, is also compressed or extended, allowing the circumferential compression spring 10 and the radial compression spring 11 to also play a certain role in pressure relief and energy dissipation. Both the primary pressure-relief mechanism 2 and the secondary pressure-relief mechanism 3 undergo circumferential contraction or expansion. Due to the frictional contact between the friction steel frame 15 and the friction arc plate 16, during the circumferential expansion or contraction of the secondary pressure-relief mechanism 3... The friction steel frame 15 and the friction arc plate 16 undergo relative sliding friction, which further dissipates energy, thereby consuming the energy of the surrounding rock 1 and releasing the pressure on the surrounding rock 1. Moreover, it allows the support system to deform accordingly with the deformation of the surrounding rock 1, avoiding the situation of initial mortar cracking and damage to the support system. In addition, the secondary pressure relief mechanism 3 does not have an elastic structure. Instead, it uses the sliding friction contact between the friction steel frame 15 and the friction arc plate 16 to maintain the rigidity of the secondary pressure relief mechanism 3 as much as possible after deformation, so as to better exert the support capacity of the support system and ensure the quality of tunnel engineering and construction safety.

[0045] The main steel frame 7 has guide grooves at both ends, and one end of the secondary steel frame 8 is guided to move in the guide groove.

[0046] A guide tube is provided in the guide groove, and a circumferential compression spring 10 is sleeved on the periphery of the guide tube. A clearance hole is provided at one end of the secondary steel frame 8. The guide tube passes through the clearance hole on the secondary steel frame 8, and the secondary steel frame 8 moves along the guide tube.

[0047] The guide groove partially encloses the outer perimeter of the secondary steel frame 8 to guide it, while the guide tube is located inside the secondary steel frame 8 to guide it, thereby ensuring that the secondary steel frame 8 and the main steel frame 7 can undergo more stable circumferential deformation.

[0048] In one embodiment of this application, the main steel frame 7 includes at least two HW steel frames with an arc-shaped structure. The two HW steel frames are arranged side by side through transverse support plates 23 provided at both ends. A guide tube is provided at one end of the transverse support plate 23 facing the secondary steel frame 8. In this embodiment, the guide tube is made of steel pipe 13.

[0049] Along the axial direction of the first-stage pressure relief mechanism 2, arc-shaped plates are provided on both sides of the transverse support plate 23. The guide groove is formed by at least two arc-shaped plates and the transverse support plate 23. The axial sides of the secondary steel frame 8 are in contact with the arc-shaped plates, thereby playing the role of guiding movement in the guide groove.

[0050] In this embodiment, based on the length of the transverse support plate 23, at least two guide tubes can be evenly distributed, and a circumferential compression spring 10 is fitted on each guide tube accordingly.

[0051] A concrete spray layer 9 is provided between the surrounding rock 1 and the first-level pressure relief mechanism 2. The concrete spray layer 9 helps the first-level pressure relief mechanism 2 to fit more tightly onto the surrounding rock 1.

[0052] A limiting rod 12 is provided between the main steel frame 7 and the two adjacent secondary steel frames 8. The limiting rod 12 passes through the main steel frame 7 and extends into the secondary steel frame 8. A limiting block is provided at the end of the limiting rod 12. The limiting block is in stop cooperation with the secondary steel frame 8 to prevent the secondary steel frame 8 from coming out of the limiting groove of the main steel frame 7.

[0053] In one embodiment of this application, the limiting rod 12 is an arc-shaped rod with an external thread at the end of the arc-shaped rod, and the limiting block is a nut 20 screwed onto the limiting rod 12. After the limiting rod 12 extends into the secondary steel frame 8, the nut 20 is screwed onto the end of the limiting rod 12, so that the main steel frame 7 and the secondary steel frames 8 at both ends are connected in series on a limiting rod 12, which can prevent the secondary steel frame 8 from separating from the main steel frame 7, and ensure that the first-stage pressure relief mechanism 2 always remains a complete annular structure.

[0054] A steel pipe 13 extending radially along the primary pressure relief mechanism 2 is provided on the secondary steel frame 8. One end of the radial compression spring 11 is located in the steel pipe 13 on the secondary steel frame 8, and the other end presses against the secondary pressure relief mechanism 3.

[0055] Multiple radial compression springs 11 are provided, and the ends of the multiple radial compression springs 11 facing the secondary pressure relief mechanism 3 are connected together to a support plate 14. The multiple radial compression springs 11 press the support plate 14 tightly onto the secondary pressure relief mechanism 3.

[0056] In one embodiment of this application, the ends of multiple radial compression springs 11 are connected to a support plate 14, which can ensure the uniformity of the pressure applied by the multiple radial compression springs 11 and is beneficial to the uniform deformation of the entire support system.

[0057] In one embodiment of this application, the main body of the secondary steel frame 8 is a square frame structure. In the middle of the square frame structure, a pair of transverse support plates 23 form an installation space for the radial compression spring 11. The square frame structure is also provided with a circumferential support plate 24 perpendicular to the transverse support plates 23. The circumferential support plate 24 acts as a reinforcing rib, which strengthens the overall structural strength of the secondary steel frame 8.

[0058] The friction steel frame 15 includes two HW steel frames arranged side by side; the friction arc plate 16 includes two pairs of C-shaped arc plates 25 and two pairs of U-shaped arc plates 26, the two pairs of C-shaped arc plates 25 are arranged opposite each other, the two pairs of U-shaped arc plates 26 are arranged opposite each other, the two pairs of U-shaped arc plates 26 are arranged between the two pairs of C-shaped arc plates 25, and the HW steel frame is clamped between any adjacent C-shaped arc plates 25 and U-shaped arc plates 26.

[0059] In one embodiment of this application, the HW steel frame is an I-shaped steel frame with two I-shaped holes formed between two pairs of oppositely arranged C-shaped arc plates and two pairs of U-shaped arc plates, so that one end of the HW steel frame can be inserted into the friction arc plate 16, facilitating the connection between the friction arc plate 16 and the friction steel frame 15.

[0060] The secondary pressure relief structure uses combined HW-shaped steel as the main load-bearing component. Friction arc plates 16 are set at the joints. The pressure relief function is achieved by sliding between the HW-shaped steel and the friction arc plates 16, which prevents the support steel frame from being deformed by the extrusion pressure. The combined HW-shaped steel after shrinkage can provide rigid support.

[0061] Multiple pairs of bolts 27 and nuts 20 are installed in the middle of the friction arc plate 16, avoiding the position of the friction steel frame 15. The bolts 27 pass through both the C-shaped arc plate and two pairs of U-shaped arc plates. The friction between the friction arc plate 16 and the friction steel frame 15 is adjusted by the bolts 27 and nuts 20.

[0062] In one embodiment of this application, multiple pairs of bolts 27 and nuts 20 are disposed between two adjacent HW steel frames in the friction steel frame 15. By tightening the bolts 27 and nuts 20, the pressure between the friction steel frame 15 and the friction arc plate 16 is increased, resulting in greater friction between the friction steel frame 15 and the friction arc plate 16. Conversely, by loosening the bolts 27 and nuts 20, the friction between the friction steel frame 15 and the friction arc plate 16 decreases.

[0063] The support system also includes an adaptable deformable anchor bolt 4, which includes a bolt body 17, an anchor bolt compression spring 18, a pressure bearing plate 19, and a locking nut 20.

[0064] The rod 17 extends into the surrounding rock 1 of the tunnel through the first-stage pressure relief mechanism 2 and the second-stage pressure relief mechanism 3. The friction arc plate 16 is provided with a relief hole. The rod 17 passes through the relief hole of the friction arc plate 16. An anchor compression spring 18, a pressure bearing plate 19 and a locking nut 20 are sequentially provided on the protruding end of the rod 17. The pressure bearing plate 19 presses the anchor compression spring 18 onto the friction arc plate 16.

[0065] In one embodiment of this application, the anchor compression spring 18 not only adjusts the support capacity of the deformable anchor 4, but also adjusts the prestress according to the compression amount of the anchor compression spring 18, thereby improving the adaptability to the deformation of the surrounding rock 1. Furthermore, the anchor compression spring 18 at the end of the rod 17 passes through the secondary pressure relief mechanism 3, allowing it to be compressed from inside the secondary pressure relief mechanism 3. Meanwhile, the radial compression spring 11 compresses it from the outside of the secondary pressure relief mechanism 3, ensuring good compression both inside and outside the secondary pressure relief mechanism 3. This guarantees the stability of the secondary pressure relief mechanism 3, enabling it to exert its own good rigid structural strength and achieve better rigid support for the tunnel surrounding rock after the flexible deformation of the support system.

[0066] The secondary pressure-relief mechanism 3 has a compression layer 5 inside, which is made of concrete, rubber particles, asphalt, steel fibers and water. The compression layer 5 separates the secondary pressure-relief mechanism from the primary lining structure 6. The compression layer 5 can absorb a certain amount of deformation energy, thereby helping to ensure that the primary lining structure 6 is not affected by external deformation as much as possible, and thus has better structural strength.

[0067] The compression layer 5 is provided with a primary lining structure 6. The primary lining structure 6 includes at least a primary lining steel frame 21 and a steel mesh 22. The steel mesh 22 is provided on both the outer and inner sides of the primary lining steel frame 21.

[0068] In one embodiment of this application, the initial lining steel frame 21 is made of HW steel frame into a ring structure, and steel mesh 22 is provided inside and outside the ring HW steel frame to form the skeleton of the initial lining structure 6. Then, concrete is used to wrap the ring HW steel frame, so that the initial lining structure 6 has strong structural strength.

[0069] This combined support system, when the surrounding rock deforms, releases energy from the surrounding rock by adapting to the deformation through the primary and secondary pressure-relief mechanisms on the periphery, ensuring that the combined support system itself is not damaged and achieving flexible support for the tunnel. After the deformation of the surrounding rock and the combined support system is completed, the primary pressure-relief mechanism, the secondary pressure-relief mechanism, the compression layer and the initial lining structure form an integral structure, achieving rigid support for the tunnel, thus providing better support for the tunnel under large deformation of the surrounding rock.

[0070] It is understood that the above description is merely exemplary and the embodiments of this application do not limit the scope of the application.

[0071] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention shall be within the scope of protection of the pending claims of the present invention.

Claims

1. A combined support system for controlling large deformation in tunnels with extremely high ground stress, characterized in that, The combined support system includes: A primary pressure relief mechanism, comprising multiple main steel frames and multiple secondary steel frames, the main steel frames and secondary steel frames being arranged alternately, the multiple main steel frames and multiple secondary steel frames forming a ring, and a circumferential compression spring being provided between adjacent main steel frames and secondary steel frames; A secondary pressure-relief mechanism is located within a primary pressure-relief mechanism. The secondary pressure-relief structure includes multiple friction steel frames and multiple friction arc plates, which are alternately arranged and arranged in a ring. Each friction arc plate has a relief space, and the friction steel frame is inserted into the relief space of the friction arc plate. The friction steel frame and the friction arc plate are in sliding frictional contact. A radial compression spring is provided between the secondary steel frame and the secondary pressure relief mechanism; A limiting rod is provided between the main steel frame and two adjacent secondary steel frames. The limiting rod passes through the main steel frame and extends into the secondary steel frame. A limiting block is provided at the end of the limiting rod. The limiting block is engaged with the secondary steel frame to prevent the secondary steel frame from coming out of the limiting groove of the main steel frame. The secondary steel frame is provided with a steel pipe extending radially along the primary pressure relief mechanism. One end of the radial compression spring is located in the steel pipe on the secondary steel frame, and the other end presses against the secondary pressure relief mechanism. Multiple radial compression springs are provided, and the ends of the multiple radial compression springs facing the secondary pressure relief mechanism are connected to a support plate. The multiple radial compression springs press the support plate tightly onto the secondary pressure relief mechanism. The friction steel frame includes two HW steel frames arranged side by side; The friction arc plate includes two pairs of C-shaped arc plates and two pairs of U-shaped arc plates. The two pairs of C-shaped arc plates are arranged opposite each other, the two pairs of U-shaped arc plates are arranged opposite each other, and the two pairs of U-shaped arc plates are arranged between the two pairs of C-shaped arc plates. An HW steel frame is clamped between any adjacent C-shaped arc plates and U-shaped arc plates.

2. The combined support system for controlling large deformation in tunnels with extremely high ground stress according to claim 1, characterized in that, The main steel frame is provided with guide grooves at both ends, and one end of the secondary steel frame is guided to move in the guide grooves; A guide tube is provided in the guide groove, the circumferential compression spring is sleeved around the guide tube, one end of the secondary steel frame is provided with a clearance hole, the guide tube passes through the clearance hole on the secondary steel frame, and the secondary steel frame moves along the guide tube.

3. The combined support system for controlling large deformation in tunnels with extremely high ground stress according to claim 2, characterized in that, Multiple pairs of bolts and nuts are installed through the middle of the friction arc plate, avoiding the position of the friction steel frame. The bolts pass through both the C-shaped arc plate and two pairs of U-shaped arc plates. The friction between the friction arc plate and the friction steel frame is adjusted by the bolts and nuts.

4. The combined support system for controlling large deformation in tunnels with extremely high ground stress according to claim 2, characterized in that, The support system also includes an adaptable deformable anchor bolt, which includes a bolt body, an anchor bolt compression spring, a pressure-bearing pad, and a locking nut. The rod extends into the surrounding rock of the tunnel through the first-stage pressure relief mechanism and the second-stage pressure relief mechanism. The friction arc plate is provided with a relief hole. The rod passes through the relief hole of the friction arc plate. An anchor compression spring, a pressure bearing plate and a locking nut are sequentially provided on the protruding end of the rod. The pressure bearing plate presses the anchor compression spring tightly onto the friction arc plate.

5. The combined support system for controlling large deformation in tunnels with extremely high ground stress according to claim 4, characterized in that, The inner circumference of the secondary pressure relief mechanism is provided with a compression layer, which is made of concrete, rubber particles, asphalt, steel fibers and water.

6. The combined support system for controlling large deformation in tunnels with extremely high ground stress according to claim 5, characterized in that, The compression layer is provided with a primary lining structure, which includes at least a primary lining steel frame and a steel mesh, with steel mesh provided on both the outer and inner sides of the primary lining steel frame.

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