High ground stress soft rock tunnel surrounding rock large deformation control system and construction method thereof

Abstract

The application discloses a high ground stress soft rock tunnel surrounding rock large deformation control system and a construction method thereof, which comprises an outer ring steel arch frame arranged on the inner wall of a tunnel and an inner ring steel arch frame located on the inner side of the outer ring steel arch frame; the outer ring steel arch frame comprises a plurality of segments, and adjacent segments are connected through a ring let-in compression component; the inner ring steel arch frame and the outer ring steel arch frame are connected through a plurality of radial let-in compression components; the outer ring steel arch frame and the ring let-in compression component are both concreted in a first concrete layer; and the inner ring steel arch frame and the radial let-in compression component are both concreted in a second concrete layer. The application provides the high ground stress soft rock tunnel surrounding rock large deformation control system and the construction method thereof, so as to solve the control problem of the high ground stress soft rock tunnel surrounding rock deformation in the prior art, and realize the purpose of fully releasing the extrusion deformation of the surrounding rock and providing sufficient supporting resistance in the later period.

Description

Technical Field

[0001] This invention relates to the field of tunnel construction, specifically to a control system for large deformation of surrounding rock in soft rock tunnels under high ground stress and its construction method. Background Technology

[0002] During the construction of many soft rock tunnels in western China, the engineering challenge of large deformation of weak surrounding rock was encountered. Monitoring data of surrounding rock in many tunnels showed that the final deformation of weak surrounding rock under high ground stress conditions can usually reach more than 30 cm, and in some cases even more than 1 meter.

[0003] After a section of the tunnel is excavated, initial support is immediately constructed according to the construction sequence. Excavation and support then continue. During this process, the deformation of the surrounding rock at the aforementioned section will continuously increase, and the deformation of the already constructed initial support structure will also increase accordingly. Excessive deformation of the initial support structure can lead to a decrease in its load-bearing capacity, thereby causing a further increase in the deformation of the weak surrounding rock.

[0004] According to the elastoplastic theory of tunnel surrounding rock and the New Austrian Tunneling Method (NATM) support theory, a certain degree of stress release is required after tunnel excavation. The deformation process of the surrounding rock after excavation is the result of stress release, including compression deformation and loosening deformation. Tunnel excavation and support under high stress conditions require a significant release of the compression deformation of the surrounding rock to reduce the deformation pressure acting on the support structure. During the release of compression deformation, the surrounding rock near the excavation outline will enter a loosened state and act on the initial support in the form of loosening pressure. Therefore, if the initial support structure provides insufficient support resistance, or if the initial support structure's bearing capacity decreases due to excessive deformation and cannot provide sufficient support resistance, the surrounding rock and support structure will become unstable due to excessive deformation.

[0005] In existing technologies, grouting reinforcement is generally used to control the loosening and deformation of surrounding rock in soft rock tunnels. However, this method has drawbacks such as difficulty in controlling the grouting effect and significant delays in construction progress. Therefore, the technology for controlling the deformation of surrounding rock in soft rock tunnels with high ground stress needs further optimization. Summary of the Invention

[0006] This invention provides a control system and construction method for large deformation of surrounding rock in high-stress soft rock tunnels, in order to solve the problem of controlling the deformation of surrounding rock in high-stress soft rock tunnels in the prior art, and to achieve the purpose of fully releasing the compression deformation of the surrounding rock and providing sufficient support resistance in the later stage.

[0007] This invention is achieved through the following technical solution:

[0008] A high-stress soft rock tunnel surrounding rock large deformation control system includes an outer ring steel arch frame installed on the inner wall of the tunnel and an inner ring steel arch frame located inside the outer ring steel arch frame;

[0009] The outer ring steel arch frame includes several segments, and adjacent segments are connected by circumferential pressure relief members;

[0010] The inner ring steel arch frame and the outer ring steel arch frame are connected by several radial pressure relief members;

[0011] The outer ring steel arch and the circumferential pressure relief member are both fixed within the first concrete layer;

[0012] The inner ring steel arch and the radial relief member are both fixed within the second concrete layer.

[0013] To address the challenge of controlling the deformation of surrounding rock in high-stress soft rock tunnels in existing technologies, this invention proposes a large deformation control system for surrounding rock in high-stress soft rock tunnels. This system comprises a double-layer steel arch structure consisting of an outer ring steel arch and an inner ring steel arch, which enhances support capacity compared to traditional initial support systems. The outer ring steel arch in this system is composed of several segments spliced ​​together, with adjacent segments connected by circumferential pressure-relief members, and the outer and inner ring steel arches connected by radial pressure-relief members. The circumferential pressure-relief members primarily bear loads along the circumferential direction of the tunnel, while the radial pressure-relief members primarily bear loads along the radial direction. In this application, the sprayed concrete application is also carried out in two stages, forming a first concrete layer and a second concrete layer, which are used to fix the outer ring steel arch and circumferential pressure-relief members, and the inner ring steel arch and radial pressure-relief members, respectively.

[0014] In practical application, both the outer and inner ring steel arches can bear the load of the tunnel surrounding rock. The compressive deformation load generated by the early release of ground stress is mainly borne and absorbed by the radial pressure relief members. Furthermore, the inventors' team discovered during their research that the load generated by the loosening deformation of the surrounding rock acts on the steel arches. Traditional initial support structures are unable to resist the damage caused by this loosening deformation, easily leading to bending, torsion, or even breakage of the steel arches. This is the key reason why existing technologies struggle to effectively control the surrounding rock of high-stress soft rock tunnels through initial support structures. In this application, however, the load generated by the loosening deformation of the surrounding rock acts on each segment of the outer ring steel arches, creating a tendency for mutual compression and misalignment between the segments. The load generated by the loosening deformation is consumed by the compression, stretching, or torsion of the circumferential pressure relief members. Therefore, the probability of the steel arches bending, torsion, or even breaking can be significantly reduced, significantly improving the control capability against loosening deformation, thereby increasing the support resistance of the entire initial support system and improving tunnel stability. This application also abandons the existing technology of using grouting reinforcement, and overcomes the drawbacks such as low controllability of grouting effect and forced delay of construction period.

[0015] Furthermore, the circumferential pressure-relief member and the radial pressure-relief member have the same structure, both including:

[0016] Two parallel connecting plates, a first V-shaped plate and a second V-shaped plate located between the two connecting plates; the first V-shaped plate and the second V-shaped plate intersect each other and have equal included angles; the line connecting the top of the first V-shaped plate and the top of the second V-shaped plate is perpendicular to the connecting plates; the bottom ends of the first V-shaped plate and the second V-shaped plate are fixedly connected to the corresponding connecting plates.

[0017] In this scheme, the circumferential pressure relief member and the radial pressure relief member are structurally identical, but their dimensions, arrangement, etc., can be adapted as needed.

[0018] In existing technologies, many energy-dissipating structures used for initial support employ flexible or elastic systems, which offer very weak resistance to loosening and deformation of the surrounding rock in practical applications, making them unsuitable for high-stress soft rock conditions. In this solution, the circumferential or radial pressure-relief components consist of two parallel connecting plates that connect to the steel arch frame. A first V-shaped plate and a second V-shaped plate intersect between the two connecting plates, forming a rhombus-like structure in the central area surrounded by the first and second V-shaped plates. Around this rhombus structure, four triangular structures are formed. The top of the V-shaped plate refers to the apex of the "V," and the bottom refers to the two forked ends of the "V." The pressure-relief components of this scheme form a rigid frame structure as a whole, and the top of the V-shaped plates is perpendicular to the corresponding connecting plates. This arrangement makes the pressure-relief components have extremely high strength and can provide extremely high support resistance along the line connecting the two connecting plates, thereby significantly improving the resistance to loosening and deformation of the surrounding rock and making it more suitable for high ground stress soft rock conditions.

[0019] Furthermore, the included angle between the first V-shaped plate and the second V-shaped plate in the circumferential pressure relief member is smaller than the included angle between the first V-shaped plate and the second V-shaped plate in the radial pressure relief member.

[0020] The radial relief members in this application are mainly used to bear the compressive deformation load generated by the release of ground stress. A larger included angle allows the internal structure of the radial relief members to be more "flat", which is beneficial to improving the compressive resistance of the radial relief members and consuming more ground stress energy. As for the circumferential relief members, they are mainly used to bear the circumferential load caused by loosening deformation. Therefore, a smaller included angle allows the internal structure of the circumferential relief members to be more "slender", providing them with a larger range of compression, tension or torsion space, which is beneficial to consuming more loosening deformation energy.

[0021] Furthermore, the included angle between the first V-shaped plate and the second V-shaped plate in the circumferential pressure relief member is 30°~40°; the included angle between the first V-shaped plate and the second V-shaped plate in the radial pressure relief member is 40°~60°.

[0022] The included angle refers to the interior angle of the tip of the "V" shape.

[0023] Furthermore, in the circumferential pressure relief member, the line connecting the top ends of the first V-shaped plate and the second V-shaped plate extends circumferentially along the tunnel; in the radial pressure relief member, the line connecting the top ends of the first V-shaped plate and the second V-shaped plate extends radially along the tunnel.

[0024] This scheme sets different arrangement forms for the two types of pressure relief components, which is conducive to each of them performing their respective functions and giving full play to their respective support resistance, effectively controlling the compression deformation and loosening deformation of the tunnel surrounding rock from two directions respectively.

[0025] Furthermore, the width of the first V-shaped plate is greater than the width of the second V-shaped plate; and strip-shaped holes are opened on both sides of the first V-shaped plate for the second V-shaped plate to pass through.

[0026] The width referred to in this design refers to the direction through the V-shaped plate along the hollowed-out area in the middle of the V-shaped plate. This design allows the second V-shaped plate to be inserted into the first V-shaped plate from both sides, and the two interlock to form a relatively stable structure, while avoiding the problem of significantly increasing the on-site work intensity due to the need for extensive welding.

[0027] Furthermore, the second V-shaped plate includes a flat plate portion and a bent portion that are spliced ​​together; a positioning protrusion is provided at one end of the flat plate portion facing the bent portion, and a positioning groove matching the positioning protrusion is provided at one end of the bent portion facing the flat plate portion; the positioning protrusion is inserted into the positioning groove.

[0028] During installation, the bent part is first inserted into the strip hole on one side of the first V-shaped plate, and then the flat part is inserted into the strip hole on the other side of the first V-shaped plate, so that the positioning protrusion enters the positioning groove, realizing the positioning connection between the flat part and the bent part, and also realizing the connection between the first V-shaped plate and the second V-shaped plate.

[0029] Furthermore, the outer wall of the bending area of ​​the bending part is set as a plane, and a plurality of grooves are formed on the plane. Ball bearings are movably placed in the grooves, and the bottom of each groove is connected to the positioning groove through a channel; it also includes a pusher that passes through the channel, one end of the pusher being located in the positioning groove and the other end being located in the groove.

[0030] In this design, after the positioning protrusion enters the positioning groove, it pushes the jacking component, which in turn pushes the ball bearings, causing them to partially extend out of the groove and tightly abut against the external connecting plate. When subjected to a vertical load perpendicular to the connecting plate, several balls are simultaneously compressed. The external load must first crush the balls before it can damage the internal frame structure of the pressure-relief component, thus improving the support resistance. When subjected to a lateral load parallel to the connecting plate, the presence of several balls facilitates relative misalignment between the connecting plate and the first and second V-shaped plates, thereby transferring the load to both ends of the first and second V-shaped plates. This further promotes torsional deformation of the first and second V-shaped plates themselves, which is more conducive to load dissipation and improves the support resistance.

[0031] Furthermore, the groove opening width is smaller than the outer diameter of the ball to prevent the ball from automatically falling out of the groove before the installation of this application is completed; the end of the pusher located in the groove is provided with an anti-detachment protrusion to prevent the pusher from leaving the groove range before the installation of this application is completed.

[0032] The construction method for the large deformation control system of surrounding rock in high-stress soft rock tunnels in this application includes the following steps:

[0033] S1. Excavate the tunnel and install anchor bolts;

[0034] S2. Erect an outer ring steel arch frame and connect circumferential pressure relief members between adjacent segments of the outer ring steel arch frame;

[0035] S3. Weld several radial pressure relief components to the inner wall of the outer ring steel arch frame;

[0036] S4. Spray the first layer of concrete to cover the outer ring steel arch frame;

[0037] S5. Erect the inner ring steel arch frame and weld the inner ring steel arch frame to each radial pressure relief component;

[0038] S6. Spray the second layer of concrete to cover the inner ring steel arch frame;

[0039] S7. After the surrounding rock deformation stabilizes, the secondary lining construction will begin.

[0040] This application, based on an initial support structure of "bidirectional pressure relief + rigid bearing," provides an effective construction method for controlling large deformations in the surrounding rock of high-stress soft rock tunnels. Through two erections of steel arches and two applications of sprayed concrete, the entire system can be constructed without grouting reinforcement. Furthermore, after completing step S6, the tunnel face can continue excavation without interference from the secondary lining construction in step S7. Therefore, this scheme allows for cross-operation, which is beneficial for controlling construction time and costs and improving construction progress. This application can fully release the compression deformation of the surrounding rock and provide sufficient support resistance in the later stages to control loosening deformation. Compared with existing technologies, it can better meet the support requirements for large deformations in high-stress soft rock.

[0041] Compared with the prior art, the present invention has at least the following advantages and beneficial effects:

[0042] 1. The present invention provides a control system and construction method for large deformation of surrounding rock in soft rock tunnels under high ground stress. It can fully release the squeezing deformation of the surrounding rock and provide sufficient support resistance in the later stage to control loosening deformation. Compared with the prior art, it can better meet the support requirements for large deformation of surrounding rock under high ground stress and improve the stability of the tunnel.

[0043] 2. The present invention provides a control system and construction method for large deformation of surrounding rock in soft rock tunnels under high ground stress. It abandons the existing technical approach of grouting reinforcement and overcomes the drawbacks of low controllability of grouting effect and forced delay of construction period.

[0044] 3. The present invention provides a control system and construction method for large deformation of surrounding rock in soft rock tunnels under high ground stress. A rigid pressure-relief component is designed so that the pressure-relief component has extremely high strength and can provide extremely high support resistance along the line connecting the two connecting plates, thereby significantly improving the resistance to loosening and deformation of the surrounding rock and making it more suitable for high ground stress soft rock conditions.

[0045] 4. The present invention provides a control system and construction method for large deformation of surrounding rock in soft rock tunnels under high ground stress. The pressure-bearing component has a special ball bearing structure inside, which can improve the support resistance and facilitate the consumption of load. It is of great significance for bidirectional pressure-bearing components. Attached Figure Description

[0046] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0047] Figure 1 This is a cross-sectional schematic diagram of a specific embodiment of the present invention;

[0048] Figure 2 This is a longitudinal cross-sectional view of a specific embodiment of the present invention;

[0049] Figure 3 This is a schematic diagram of the connection of the circumferential pressure relief member in a specific embodiment of the present invention;

[0050] Figure 4 This is a schematic diagram of the circumferential pressure relief member in a specific embodiment of the present invention;

[0051] Figure 5 This is a schematic diagram of the internal structure of the circumferential pressure relief member in a specific embodiment of the present invention;

[0052] Figure 6 This is a cross-sectional view of the radial relief member in a specific embodiment of the present invention;

[0053] Figure 7 for Figure 6 A magnified view of a portion of point A in the middle.

[0054] The attached diagram shows the markings and corresponding component names:

[0055] 1-Circumferential pressure relief component, 101-First V-shaped plate, 102-Second V-shaped plate, 103-Connecting plate, 1021-Flat plate, 1022-Bending part, 1023-Positioning protrusion, 1024-Positioning groove, 1025-Flat surface, 1026-Groove, 1027-Ball bearing, 1028-Pushing component, 1029-Anti-detachment protrusion, 2-Outer ring steel arch frame, 3-Inner ring steel arch frame, 4-First concrete layer, 5-Second concrete layer, 6-Radial pressure relief component, 7-Mounting plate, 8-Anchor bolt, 9-Secondary lining, 10-Working face. Detailed Implementation

[0056] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments and accompanying drawings. The illustrative embodiments and descriptions of this invention are for explaining the invention only and are not intended to limit the invention. In the description of this application, it should be understood that terms such as "front," "rear," "left," "right," "upper," "lower," "vertical," "horizontal," "high," "low," "inner," and "outer," indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the scope of protection of this application.

[0057] Example 1:

[0058] like Figures 1 to 4 The control system for large deformation of surrounding rock in a high-stress soft rock tunnel shown includes an outer ring steel arch 2 installed on the inner wall of the tunnel and an inner ring steel arch 3 located inside the outer ring steel arch 2.

[0059] The outer ring steel arch 2 includes several segments, and adjacent segments are connected by circumferential pressure relief members 1;

[0060] The inner ring steel arch frame 3 and the outer ring steel arch frame 2 are connected by several radial pressure relief members 6;

[0061] The outer ring steel arch 2 and the circumferential pressure relief member 1 are both fixed within the first concrete layer 4;

[0062] The inner ring steel arch 3 and the radial pressure relief member 6 are both fixed within the second concrete layer 5.

[0063] In this embodiment, the circumferential pressure-relief member 1 and the radial pressure-relief member 6 have the same structure, as shown in the figure. Figure 3 and Figure 4 As shown, it includes:

[0064] Two parallel connecting plates 103, a first V-shaped plate 101 and a second V-shaped plate 102 located between the two connecting plates 103; the first V-shaped plate 101 and the second V-shaped plate 102 intersect each other and have equal included angles; the line connecting the top of the first V-shaped plate 101 and the top of the second V-shaped plate 102 is perpendicular to the connecting plate 103; the bottom ends of the first V-shaped plate 101 and the second V-shaped plate 102 are fixedly connected to the corresponding connecting plate 103.

[0065] The included angle between the first V-shaped plate 101 and the second V-shaped plate 102 in the circumferential pressure-relief member 1 is smaller than the included angle between the first V-shaped plate 101 and the second V-shaped plate 102 in the radial pressure-relief member 6. Specifically, in this embodiment:

[0066] The included angle between the first V-shaped plate 101 and the second V-shaped plate 102 in the circumferential pressure relief member 1 is 30°~40°, preferably 35°;

[0067] The included angle between the first V-shaped plate 101 and the second V-shaped plate 102 in the radial pressure relief member 6 is 40°~60°, preferably 45°.

[0068] In addition, such as Figure 1 As shown, in this embodiment, in the circumferential pressure relief member 1, the line connecting the top end of the first V-shaped plate 101 and the top end of the second V-shaped plate 102 extends circumferentially along the tunnel; in the radial pressure relief member 6, the line connecting the top end of the first V-shaped plate 101 and the top end of the second V-shaped plate 102 extends radially along the tunnel.

[0069] In this embodiment, both the circumferential pressure relief member 1 and the radial pressure relief member 6 are metal components, preferably made of steel, and can be made by welding several steel plates into an integral structure.

[0070] In a more preferred embodiment:

[0071] For the circumferential pressure relief member 1, such as Figure 3 and Figure 4 As shown: the dimensions of the connecting plates 103 at both ends are larger than the dimensions of the corresponding first V-shaped plate 101 or second V-shaped plate 102, and several threaded holes are opened on the connecting plates 103; mounting plates 7 are provided at both ends of any segment of the outer ring steel arch frame 2, and the mounting plates 7 are connected to the connecting plates 103 by bolts.

[0072] For radial relief member 6, such as Figure 6 As shown: the dimensions of the connecting plates 103 at both ends are equal to the dimensions of the corresponding first V-shaped plate 101 or second V-shaped plate 102, and the connecting plates 103 at both ends are welded to the outer ring steel arch frame 2 and the inner ring steel arch frame 3 respectively.

[0073] In a more preferred embodiment, the circumferential pressure relief member 1 and the radial pressure relief member 6 are both evenly distributed in a ring, and the number is preferably between 4 and 20.

[0074] This embodiment can both fully release the compression deformation of the surrounding rock and control the loosening deformation of the surrounding rock.

[0075] Example 2:

[0076] A control system for large deformation of surrounding rock in soft rock tunnels under high ground stress, based on Example 1,

[0077] The width of the first V-shaped plate 101 is greater than the width of the second V-shaped plate 102; both sides of the first V-shaped plate 101 have strip-shaped holes for the second V-shaped plate 102 to pass through.

[0078] The second V-shaped plate 102 includes a flat plate portion 1021 and a bent portion 1022 that are spliced ​​together; a positioning protrusion 1023 is provided at one end of the flat plate portion 1021 facing the bent portion 1022, and a positioning groove 1024 that matches the positioning protrusion 1023 is provided at one end of the bent portion 1022 facing the flat plate portion 1021; the positioning protrusion 1023 is inserted into the positioning groove 1024.

[0079] The outer wall of the bending area of ​​the bending portion 1022 is set as a plane 1025. Several grooves 1026 are formed on the plane 1025. A ball bearing 1027 is movably placed within each groove 1026. The bottom of each groove 1026 is connected to the positioning groove 1024 via a channel. The device also includes a pusher 1028 passing through the channel. One end of the pusher 1028 is located within the positioning groove 1024, and the other end is located within the groove 1026. The width of the groove 1026 is smaller than the outer diameter of the ball bearing 1027. An anti-detachment protrusion 1029 is provided at the end of the pusher 1028 located within the groove 1026.

[0080] The bent portion 1022 includes a long side and a short side, and the angle between them is the V-shaped angle of the second V-shaped plate 102. The positioning groove, the pushing member 1028, etc. are all located in the short side area.

[0081] In this embodiment:

[0082] For the circumferential pressure relief member 1, the ball 1027 can be oriented toward either side of the connecting plate 103;

[0083] For the radial relief member 6, the ball 1027 is oriented toward the connecting plate 103 on the radially outward side.

[0084] In this embodiment, both ends of the first V-shaped plate 101 are welded to the surface of a connecting plate 103. At this time, there is a gap between the plane 1025 and the same-side surface of the connecting plate 103, and the ball bearing 1027 abuts against this surface. Preferably, the width of the gap is 1~5mm.

[0085] Example 3:

[0086] A construction method for a large deformation control system for surrounding rock in a high-stress soft rock tunnel includes the following steps:

[0087] Step S1: Construction on a section of the tunnel, including routine construction steps such as excavation, slag removal, ventilation, and installation of system anchor bolts;

[0088] Step S2: Transport the required components of the outer ring steel arch frame 2 and the inner ring steel arch frame 3 to the working face to be supported, erect the outer ring steel arch frame 2, and connect the circumferential pressure relief component 1 between adjacent segments of the outer ring steel arch frame 2;

[0089] Step S3: Weld several radial pressure relief members 6 onto the inner wall of the outer ring steel arch frame 2;

[0090] Step S4: Spray the first concrete layer 4 to cover the outer ring steel arch frame 2.

[0091] Step S5: Erect the inner ring steel arch frame 3 and weld the inner ring steel arch frame 3 to the radially inward end of each radial pressure relief member 6;

[0092] Step S6: Spray the second concrete layer 5 to cover the inner ring steel arch frame 3.

[0093] Step S7: After the surrounding rock deformation stabilizes, proceed with the secondary lining construction. Stable surrounding rock deformation means that the deformation of the surrounding rock no longer shows a significant rate of increase.

[0094] Preferably, once step S6 is completed, the excavation face can continue to move forward without interfering with normal construction procedures, which is conducive to maintaining a stable construction period.

[0095] In a more preferred embodiment, the assembly of the circumferential pressure-relief member 1 and the radial pressure-relief member 6 is completed in advance to avoid delays in the construction period. The assembly method of the circumferential pressure-relief member 1 and the radial pressure-relief member 6 includes:

[0096] Insert the long side of the bent part 1022 into the strip hole on one side of the first V-shaped plate 101, so that the short side of the bent part 1022 is facing the strip hole on the other side of the first V-shaped plate 101.

[0097] Insert the flat plate 1021 into the strip hole on the other side of the first V-shaped plate 101 from the outside in;

[0098] Adjust the positions of the bent part 1022 and the flat part 1021 so that the positioning protrusion 1023 enters the positioning groove 1024 and pushes the flat part 1021 inward until the two bottom ends of the second V-shaped plate 102 are flush. During this process, the positioning protrusion 1023 pushes the pusher 1028 and the pusher 1028 pushes the ball 1027 partially out of the groove 1026.

[0099] Install the first connecting plate 103: weld both ends of the second V-shaped plate 102 to the first connecting plate; the top of the first V-shaped plate 101 can also be welded to the first connecting plate at the same time;

[0100] Install the second connecting plate 103: Place the second connecting plate 103 at the two bottom ends of the first V-shaped plate 101, align the second connecting plate with the first connecting plate, press the second connecting plate inward, so that the two bottom ends of the first V-shaped plate 101 and each ball bearing 1027 are in contact with the same side surface of the second connecting plate; weld the two bottom ends of the first V-shaped plate 101 to the second connecting plate.

[0101] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0102] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, 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. Additionally, the term "connection" as used herein, unless otherwise specified, can refer to a direct connection or an indirect connection via other components.

Claims

1. A control system for large deformation of surrounding rock in high-stress soft rock tunnels, characterized in that, It includes an outer ring steel arch frame (2) installed on the inner wall of the tunnel and an inner ring steel arch frame (3) located inside the outer ring steel arch frame (2). The outer ring steel arch frame (2) includes several segments, and adjacent segments are connected by circumferential pressure relief members (1); The inner ring steel arch frame (3) and the outer ring steel arch frame (2) are connected by several radial pressure relief members (6); The outer ring steel arch frame (2) and the circumferential pressure relief member (1) are both fixed within the first concrete layer (4); The inner ring steel arch frame (3) and the radial pressure relief member (6) are both fixed within the second concrete layer (5); The circumferential pressure relief member (1) and the radial pressure relief member (6) have the same structure, both including: Two parallel connecting plates (103), a first V-shaped plate (101) and a second V-shaped plate (102) located between the two connecting plates (103); the first V-shaped plate (101) and the second V-shaped plate (102) intersect each other and have equal included angles; the line connecting the top of the first V-shaped plate (101) and the top of the second V-shaped plate (102) is perpendicular to the connecting plate (103); the bottom ends of the first V-shaped plate (101) and the second V-shaped plate (102) are fixedly connected to the corresponding connecting plate (103); The width of the first V-shaped plate (101) is greater than the width of the second V-shaped plate (102); the first V-shaped plate (101) has strip-shaped holes on both sides for the second V-shaped plate (102) to pass through; The second V-shaped plate (102) includes a flat plate portion (1021) and a bent portion (1022) that are spliced ​​together; a positioning protrusion (1023) is provided at one end of the flat plate portion (1021) facing the bent portion (1022), and a positioning groove (1024) matching the positioning protrusion (1023) is provided at one end of the bent portion (1022) facing the flat plate portion (1021); the positioning protrusion (1023) is inserted into the positioning groove (1024); The outer wall of the bending area of ​​the bending part (1022) is set as a plane (1025), and a plurality of grooves (1026) are opened on the plane (1025). A ball bearing (1027) is movably placed in the groove (1026). The bottom of each groove (1026) is connected to the positioning groove (1024) through a channel. It also includes a pusher (1028) passing through the channel. One end of the pusher (1028) is located in the positioning groove (1024) and the other end is located in the groove (1026).

2. The high-stress soft rock tunnel surrounding rock large deformation control system according to claim 1, characterized in that, The included angle between the first V-shaped plate (101) and the second V-shaped plate (102) in the circumferential pressure relief member (1) is smaller than the included angle between the first V-shaped plate (101) and the second V-shaped plate (102) in the radial pressure relief member (6).

3. The high-stress soft rock tunnel surrounding rock large deformation control system according to claim 2, characterized in that, The included angle between the first V-shaped plate (101) and the second V-shaped plate (102) in the circumferential pressure relief member (1) is 30°~40°; The included angle between the first V-shaped plate (101) and the second V-shaped plate (102) in the radial pressure relief member (6) is 40°~60°.

4. A high-stress soft rock tunnel surrounding rock large deformation control system according to claim 1, characterized in that, In the circumferential pressure relief member (1), the line connecting the top end of the first V-shaped plate (101) and the top end of the second V-shaped plate (102) extends circumferentially along the tunnel. In the radial pressure relief member (6), the line connecting the top end of the first V-shaped plate (101) and the top end of the second V-shaped plate (102) extends radially along the tunnel.

5. A high-stress soft rock tunnel surrounding rock large deformation control system according to claim 4, characterized in that, The groove (1026) has a groove width smaller than the outer diameter of the ball (1027); the pusher (1028) is provided with an anti-detachment protrusion (1029) at one end located in the groove (1026).

6. A construction method for a high-stress soft rock tunnel surrounding rock large deformation control system according to any one of claims 1 to 5, characterized in that, include: S1. Excavate the tunnel and install anchor bolts; S2. Erect an outer ring steel arch frame (2) and connect circumferential pressure relief members (1) between adjacent segments of the outer ring steel arch frame (2). S3. Weld several radial pressure relief components (6) on the inner wall of the outer ring steel arch frame (2). S4. Spray the first concrete layer (4) to cover the outer ring steel arch frame (2). S5. Erect the inner ring steel arch frame (3) and weld the inner ring steel arch frame (3) to each radial pressure relief component (6); S6. Spray the second concrete layer (5) to cover the inner ring steel arch frame (3). S7. After the surrounding rock deformation stabilizes, the secondary lining construction will begin.

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