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

Abstract

The invention discloses a high ground stress soft rock tunnel surrounding rock large deformation control system and a construction method thereof. The high ground stress soft rock tunnel surrounding rock large deformation control system 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 comprises a plurality of sections, and the adjacent sections are connected through annular yielding components; the inner ring steel arch frame is connected with the outer ring steel arch frame through a plurality of radial yielding components; the outer ring steel arch and the annular yielding component are both fixedly connected in the first concrete layer; and the inner ring steel arch and the radial yielding component are fixedly connected in the second concrete layer. The invention provides a large deformation control system for surrounding rock of a high-crustal-stress soft rock tunnel and a construction method of the large deformation control system so as to solve the control problem of deformation of the surrounding rock of the high-crustal-stress soft rock tunnel in the prior art and achieve the purposes of fully releasing extrusion deformation of the surrounding rock and providing sufficient supporting resistance in the later period.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of tunnel construction, in particular to a high ground stress soft rock tunnel surrounding rock large deformation control system and a construction method thereof. BACKGROUND

[0002] During the construction of many soft rock tunnels in western China, the problem of large deformation of soft surrounding rock has been encountered. The monitoring data of the surrounding rock of many tunnels shows that the final deformation of soft 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 certain section of the tunnel is excavated, the initial support will be immediately constructed according to the construction process, and then the excavation and support will continue. In this process, the deformation of the surrounding rock of the above section will continue to increase, and the deformation of the initial support structure that has been constructed will also increase. When the deformation of the initial support structure is too large, the bearing capacity of the support structure will decrease, resulting in further increase in the deformation of the soft surrounding rock.

[0004] According to the elastic-plastic theory of tunnel surrounding rock and the New Austrian Tunneling Method (NATM) support theory, after the tunnel is excavated, the ground stress needs to be released to a certain extent, and the deformation process of the surrounding rock after excavation is the result of ground stress release, which includes extrusion deformation and loose deformation. Under high ground stress conditions, a large amount of extrusion deformation of the surrounding rock needs to be released during tunnel excavation and support to reduce the deformation pressure acting on the support structure. During the process of releasing the extrusion deformation of the surrounding rock, the surrounding rock near the excavation contour line will enter a loose state and act on the initial support in the form of loose pressure. Therefore, if the initial support structure provides insufficient support resistance, or the bearing capacity of the initial support structure decreases due to excessive deformation, it cannot provide sufficient support resistance, and the surrounding rock and the support structure will lose stability due to excessive deformation.

[0005] In the prior art, grouting reinforcement measures are generally used to control the loose deformation of soft rock tunnel surrounding rock, but there are disadvantages such as poor control of grouting effect and significant delay of construction progress. Therefore, the surrounding rock deformation control technology for high ground stress soft rock tunnels needs to be optimized. SUMMARY

[0006] The present application provides a high ground stress soft rock tunnel surrounding rock large deformation control system and a construction method thereof to solve the problem of controlling the deformation of high ground stress soft rock tunnel surrounding rock in the prior art, and to achieve the purpose of fully releasing the extrusion deformation of the surrounding rock and providing sufficient support resistance in the later stage.

[0007] The present application is achieved by the following technical solutions:

[0008] A high ground stress soft rock tunnel surrounding rock large deformation control system, comprising an outer ring steel arch support arranged on the inner wall of the tunnel, and an inner ring steel arch support located on the inner side of the outer ring steel arch support.

[0009] The outer ring steel arch includes several segments, and adjacent segments are connected through a ring compression member;

[0010] The inner ring steel arch and the outer ring steel arch are connected through a plurality of radial compression members;

[0011] The outer ring steel arch and the ring compression member are both fixed in the first concrete layer;

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

[0013] In view of the control difficulty of high ground stress soft rock tunnel surrounding rock deformation in the prior art, the present application provides a high ground stress soft rock tunnel surrounding rock large deformation control system. The system is composed of an outer ring steel arch and an inner ring steel arch to form a double-layer steel arch structure, which can enhance the supporting capacity compared with the traditional primary support system. The outer ring steel arch in the system is composed of several segments, and adjacent segments are connected through a ring compression member. The outer ring steel arch and the inner ring steel arch are connected through a radial compression member. The ring compression member is mainly used to bear the load along the ring direction of the tunnel, and the radial compression member is mainly used to bear the load along the radial direction of the tunnel. The concrete spraying construction in the application is also divided into two times to form a first concrete layer and a second concrete layer, which are respectively used to fix the outer ring steel arch and the ring compression member, and the inner ring steel arch and the radial compression member.

[0014] In the specific work, the outer ring steel arch and the inner ring steel arch can bear the load of the tunnel surrounding rock. The extrusion deformation load generated by the early ground stress release is mainly borne and absorbed by the radial compression member. In addition, the inventors found in the research process that the load generated by the surrounding rock loosening deformation acts on the steel arch, and the traditional primary support structure is difficult to resist the damage caused by the loosening deformation, and is easy to cause the steel arch to bend, twist or even bend. This is the key reason why the prior art cannot effectively control the high ground stress soft rock tunnel surrounding rock through the primary support structure. In the application, the load generated by the surrounding rock loosening deformation acts on each segment of the outer ring steel arch, and each segment has a mutual extrusion and dislocation movement trend. The load generated by the loosening deformation is consumed by extruding, stretching or twisting the ring compression member, so as to significantly reduce the probability of bending, twisting or even bending of the steel arch, significantly improve the control ability of the loosening deformation, and further improve the supporting resistance of the entire primary support system and the stability of the tunnel. The application also discards the grouting reinforcement technical idea of the prior art, and overcomes the disadvantages of low controllability of grouting effect and forced delay of construction period.

[0015] Further, the ring let - pressure component, radial let - pressure component structure is same, all includes:

[0016] Two mutually parallel connecting plates, first V-shaped plate and 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 the included angle is equal; the line connecting the top end of the first V-shaped plate and the top end of the second V-shaped plate is perpendicular to the connecting plate; the bottom end of the first V-shaped plate and the second V-shaped plate is fixedly connected with the corresponding connecting plate.

[0017] In the present scheme, the structure of the ring let - pressure component and the radial let - pressure component is limited to be the same, but the size, arrangement and the like of the two can be adaptively set as needed.

[0018] In the prior art, some energy dissipation structures for primary support are mostly realized by flexible or elastic systems, which have weak resistance to the surrounding rock loosening deformation in actual application, and are not suitable for high ground stress soft rock working conditions at all. In the present scheme, for the ring let - pressure component or the radial let - pressure component, two mutually parallel connecting plates are included, which are used to be connected with the steel arch. The first V-shaped plate and the second V-shaped plate are arranged between the two connecting plates and intersect each other, and the middle region surrounded by the first V-shaped plate and the second V-shaped plate forms a diamond structure, and four triangular structures are formed around the diamond structure. The top end of the V-shaped plate refers to the sharp end of the "V" shape, and the bottom end of the V-shaped plate refers to the bifurcated end of the "V" shape. The let - pressure component of the present scheme forms a rigid frame structure as a whole, and the top end of the V-shaped plate is perpendicular to the corresponding connecting plate. This arrangement makes the let - pressure component have very high strength and can provide very high support resistance in the direction of the connecting line of the two connecting plates, thereby significantly improving the resistance to surrounding rock loosening deformation and being more suitable for high ground stress soft rock working conditions.

[0019] Further, the included angle of the first V-shaped plate and the second V-shaped plate in the ring let - pressure component is smaller than the included angle of the first V-shaped plate and the second V-shaped plate in the radial let - pressure component.

[0020] The radial let - pressure component in the present application is mainly used to bear the extrusion deformation load generated by the ground stress release, and a larger included angle can make the internal structure of the radial let - pressure component more "flat", thereby being beneficial to improve the extrusion resistance of the radial let - pressure component and consume more ground stress energy. For the ring let - pressure component, it is mainly used to bear the ring load caused by loosening deformation, so a smaller included angle can make the internal structure of the ring let - pressure component more "slim", thereby providing a larger extrusion, stretching or torsion space and being beneficial to consume more loosening deformation energy.

[0021] Further, the included angle of the first V-shaped plate and the second V-shaped plate in the ring pressure relief component is 30°-40°; the included angle of the first V-shaped plate and the second V-shaped plate in the radial pressure relief component is 40°-60°.

[0022] The included angle refers to the inner angle of the sharp end of the "V" shape.

[0023] Further, in the ring pressure relief component, the line connecting the top end of the first V-shaped plate and the top end of the second V-shaped plate extends along the ring direction of the tunnel; in the radial pressure relief component, the line connecting the top end of the first V-shaped plate and the top end of the second V-shaped plate extends along the radial direction of the tunnel.

[0024] The present scheme sets different arrangement forms for the two pressure relief components, thereby facilitating the respective functions of the two components and fully exerting the respective support resistances to effectively control the extrusion deformation and loose deformation of the tunnel surrounding rock from two directions.

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

[0026] The width referred to in the present scheme refers to the direction of passing through the V-shaped plate along the hollow region in the middle of the V-shaped plate. The present scheme enables the second V-shaped plate to be inserted and installed into the first V-shaped plate on both sides, and the two are buckled to form a relatively stable structure, while avoiding the problem of significantly increasing the on-site operation intensity caused by a large amount of welding.

[0027] Further, the second V-shaped plate comprises a flat plate part and a bent part which are spliced with each other; a positioning protrusion is arranged at one end of the flat plate part facing the bent part, and a positioning groove matched with the positioning protrusion is arranged at one end of the bent part facing the flat plate part; the positioning protrusion is inserted into the positioning groove.

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

[0029] Further, the outer wall of the bending region of the bent part is arranged as a plane, a plurality of grooves are formed on the plane, and a plurality of balls are movably placed in the grooves; the groove bottom of each groove is communicated with the positioning groove through a channel; a jacking piece passing through the channel is further included, one end of the jacking piece is located in the positioning groove, and the other end of the jacking piece is located in the groove.

[0030] In the scheme, after the positioning protrusion enters the positioning groove, the pushing piece is pushed to push the ball, so that the ball locally extends out of the groove and tightly abuts against the external connecting plate. When subjected to a vertical load perpendicular to the connecting plate, the balls are synchronously extruded, the external load needs to crush the balls first to damage the internal frame structure of the yielding member, which can improve the support resistance; when subjected to a horizontal load parallel to the connecting plate, the existence of the balls can be beneficial to the relative displacement between the connecting plate and the first V-shaped plate and the second V-shaped plate, and then the load is transmitted to both ends of the first V-shaped plate and the second V-shaped plate, and then the torsional deformation of the first V-shaped plate and the second V-shaped plate is more beneficial, which is more beneficial to the consumption of the load and improves the support resistance.

[0031] Further, the slot width of the groove is smaller than the outer diameter of the ball, so as to avoid the ball from falling out of the groove automatically before the installation of the application is completed; the pushing piece is provided with an anti-falling protrusion at one end in the groove, so as to avoid the pushing piece from being separated from the range of the groove before the installation of the application is completed.

[0032] The construction method of the high-stress soft rock tunnel surrounding rock large deformation control system in the application comprises the following steps:

[0033] S1, excavate the tunnel and set the anchor rod;

[0034] S2, erect the outer ring steel arch, and connect the ring yielding member between adjacent segments of the outer ring steel arch;

[0035] S3, weld a plurality of radial yielding members on the inner wall of the outer ring steel arch;

[0036] S4, spray the first concrete layer to cover the outer ring steel arch;

[0037] S5, erect the inner ring steel arch and weld the inner ring steel arch with each radial yielding member;

[0038] S6, spray the second concrete layer to cover the inner ring steel arch;

[0039] S7, after the surrounding rock deformation is stable, the secondary lining construction is carried out.

[0040] The application provides an effective construction method for high ground stress soft rock tunnel surrounding rock large deformation control based on a two-way pressure relief + rigid bearing initial support structure, and the construction operation of the whole system is realized through two times of steel arch erection and two times of concrete spraying, grouting reinforcement is not needed, and after step S6 is completed, the working face can continue to excavate forward, and the secondary lining construction of step S7 is not interfered, so that the application can realize cross operation, is favorable for controlling the construction period cost and improving the construction progress. The application can fully release the extrusion deformation of the surrounding rock, and provides sufficient support resistance in the later period to control the loose deformation, and compared with the prior art, the application can more meet the support demand of the high ground stress soft rock surrounding rock large deformation.

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

[0042] 1. The high ground stress soft rock tunnel surrounding rock large deformation control system and the construction method thereof can fully release the extrusion deformation of the surrounding rock, and provide sufficient support resistance in the later period to control the loose deformation, compared with the prior art, the application can more meet the support demand of the high ground stress soft rock surrounding rock large deformation, and improve the tunnel stability.

[0043] 2. The high ground stress soft rock tunnel surrounding rock large deformation control system and the construction method thereof abandon the technical idea of grouting reinforcement in the prior art, and overcome the problems of low controllability of grouting effect and forced delay of construction period.

[0044] 3. The high ground stress soft rock tunnel surrounding rock large deformation control system and the construction method thereof design a rigid pressure relief component, so that the pressure relief component has extremely high strength in the direction along the connecting line of the two connecting plates, can provide extremely high support resistance, and further significantly improve the resistance to loose deformation of the surrounding rock, and is more suitable for high ground stress soft rock working conditions.

[0045] 4. The high ground stress soft rock tunnel surrounding rock large deformation control system and the construction method thereof have a special ball structure inside the pressure relief component, can improve the support resistance, and are favorable for consumption of the load, and are important for the two-way pressure relief component. DETAILED DESCRIPTION

[0046] The accompanying drawings used to provide further understanding of the embodiments of the application, and form a part of the application, and do not constitute limitations to the embodiments of the application. In the drawings:

[0047] Figure 1 is a sectional view of the embodiment of the application;

[0048] Figure 2 is a longitudinal sectional view of the embodiment of the application;

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

[0050] Figure 4 It is a structural schematic diagram of the annular pressure-yielding member in a specific embodiment of the present invention;

[0051] Figure 5 Schematic diagram of the internal structure of the annular pressure-yielding member in a specific embodiment of the present invention;

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

[0053] Figure 7 for Figure 6 A partial enlarged view of point A in the middle.

[0054] Markings and corresponding parts names in the accompanying drawings:

[0055] 1- Circumferential yield member, 101- First V-shaped plate, 102- Second V-shaped plate, 103- Connecting plate, 1021- Flat plate, 1022- Bent portion, 1023- Positioning protrusion, 1024- Positioning groove, 1025- Plane, 1026- Groove, 1027- Ball, 1028- Push piece, 1029- Anti-slip protrusion, 2- Outer ring steel arch, 3- Inner ring steel arch, 4- First concrete layer, 5- Second concrete layer, 6- Radial yield member, 7- Mounting plate, 8- Anchor rod, 9- Secondary lining, 10- Tunnel face. DETAILED DESCRIPTION

[0056] In order to make the objects, technical solutions and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the examples and drawings. The schematic embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention. In the description of this application, it should be understood that the orientations or positional relationships indicated by terms such as "front", "back", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inside", "outside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of this application.

[0057] Example 1:

[0058] like Figures 1 to 4 The large deformation control system of surrounding rock of a high ground stress soft rock tunnel shown in the figure comprises an outer ring steel arch frame 2 arranged on the inner wall of the tunnel and an inner ring steel arch frame 3 located inside the outer ring steel arch frame 2;

[0059] The outer ring steel arch 2 includes several segments, and adjacent segments are connected by an annular pressure-yielding member 1;

[0060] The inner ring steel arch frame 3 is connected to the outer ring steel arch frame 2 via a plurality of radial pressure-relieving members 6;

[0061] The outer ring steel arch 2 and the annular pressure-yielding member 1 are both solidified in the first concrete layer 4;

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

[0063] In this embodiment, the annular pressure-releasing member 1 and the radial pressure-releasing member 6 have the same structure. Figure 3 and Figure 4 Shown, including:

[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 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 plates 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 plates 103.

[0065] The included angle between the first V-shaped plate 101 and the second V-shaped plate 102 in the annular pressure-releasing 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-releasing 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 annular pressure-relieving member 1 is 30° to 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° to 60°, preferably 45°.

[0068] In addition, if Figure 1 As shown, in this embodiment, in the annular pressure-releasing member 1, the line connecting the top of the first V-shaped plate 101 and the top of the second V-shaped plate 102 extends along the annular direction of the tunnel; in the radial pressure-releasing member 6, the line connecting the top of the first V-shaped plate 101 and the top of the second V-shaped plate 102 extends along the radial direction of the tunnel.

[0069] The annular pressure-yielding member 1 and the radial pressure-yielding member 6 in this embodiment are both metal members, preferably made of steel, and can be formed into an integral structure by welding several steel plates.

[0070] In a more preferred embodiment:

[0071] For the circumferential yielding member 1, as shown in Figure 3 As shown in Figure 4 : the size of the connecting plate 103 at both ends is larger than the size of the corresponding first V-shaped plate 101 or second V-shaped plate 102, and a plurality of threaded holes are formed on the connecting plate 103; the two ends of any segment of the outer ring steel arch 2 are provided with mounting plates 7, and the mounting plates 7 are connected with the connecting plates 103 through bolts.

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

[0073] In a more preferred embodiment, the circumferential yielding member 1 and the radial yielding member 6 are annularly and uniformly distributed, and the number is preferably between 4 and 20.

[0074] This embodiment can not only fully release the extrusion deformation of surrounding rock, but also control the loose deformation of surrounding rock.

[0075] Example 2:

[0076] A high ground stress soft rock tunnel surrounding rock large deformation control system, 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; strip-shaped holes for the second V-shaped plate 102 to pass through are formed on both sides of the first V-shaped plate 101.

[0078] The second V-shaped plate 102 comprises a flat plate part 1021 and a bending part 1022 which are spliced with each other; a positioning protrusion 1023 is arranged at one end of the flat plate part 1021 facing the bending part 1022, and a positioning groove 1024 matched with the positioning protrusion 1023 is arranged at one end of the bending part 1022 facing the flat plate part 1021; the positioning protrusion 1023 is inserted into the positioning groove 1024.

[0079] The outer wall of the bending area of the bending part 1022 is arranged as a plane 1025, a plurality of grooves 1026 are formed on the plane 1025, and a plurality of rolling balls 1027 are movably placed in the grooves 1026; the groove bottom of each groove 1026 is communicated with the positioning groove 1024 through a channel; a pushing piece 1028 passing through the channel is further arranged, one end of the pushing piece 1028 is located in the positioning groove 1024, and the other end is located in the groove 1026. The slot width of the groove 1026 is smaller than the outer diameter of the rolling ball 1027; the one end of the pushing piece 1028 located in the groove 1026 is provided with an anti-disengagement protrusion 1029.

[0080] The bending part 1022 comprises a long side and a short side, and the included angle of the two sides is the V-shaped included angle of the second V-shaped plate 102. The positioning groove, the pushing piece 1028, and the like are located in the short side region.

[0081] In the embodiment, the first V-shaped plate 101 and the second V-shaped plate 102 are arranged in a V-shaped manner.

[0082] For the radial yielding member 6, the ball 1027 is directed to the connecting plate 103 on the radially outward side.

[0083] For the radial yielding member 6, the ball 1027 is directed to the connecting plate 103 on the radially outward side.

[0084] In use, the two ends of the first V-shaped plate 101 are respectively welded on the surface of a connecting plate 103, and at this time, the plane 1025 has a gap with the same side surface of the connecting plate 103, and the ball 1027 is abutted on the surface. Preferably, the width of the gap is 1-5 mm.

[0085] Embodiment 3

[0086] A construction method of a high ground stress soft rock tunnel surrounding rock large deformation control system comprises the following steps:

[0087] Step S1, tunnel face construction, complete excavation, deslagging, ventilation, and conventional construction steps such as setting system anchor rods;

[0088] Step S2, transporting the required components of the outer ring steel arch 2 and the inner ring steel arch 3 to the supporting position of the working face, erecting the outer ring steel arch 2, and connecting the radial yielding member 1 between adjacent segments of the outer ring steel arch 2;

[0089] Step S3, welding a plurality of radial yielding members 6 on the inner wall of the outer ring steel arch 2;

[0090] Step S4, spraying the first concrete layer 4, so that the first concrete layer 4 covers the outer ring steel arch 2;

[0091] Step S5, erecting the inner ring steel arch 3, and welding the inner ring steel arch 3 and the radially inward end of each radial yielding member 6;

[0092] Step S6, spraying the second concrete layer 5, so that the second concrete layer 5 covers the inner ring steel arch 3;

[0093] Step S7, after the surrounding rock deformation is stable, the secondary lining construction is carried out. The surrounding rock deformation is stable, which means that the surrounding rock deformation no longer has a significant growth rate.

[0094] Preferably, after the completion of step S6, the working face can continue to excavate forward, which does not interfere with the normal construction process, and is conducive to maintaining the stability of the construction period.

[0095] In a more preferable embodiment, the assembling of the ring yielding member 1 and the radial yielding member 6 is completed in advance to avoid delaying the construction period. The assembling method of the ring yielding member 1 and the radial yielding member 6 comprises:

[0096] Insert the long side of the bent part 1022 into the strip-shaped hole on one side of the first V-shaped plate 101, and make the short side of the bent part 1022 face the strip-shaped hole on the other side of the first V-shaped plate 101;

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

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

[0099] Install the first connecting plate 103: weld the two ends of the second V-shaped plate 102 on the first connecting plate; and simultaneously weld the top end of the first V-shaped plate 101 and the first connecting plate;

[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, so that the second connecting plate is aligned 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 1027 are in contact with the same side surface of the second connecting plate; and weld the two bottom ends of the first V-shaped plate 101 and the second connecting plate.

[0101] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application, and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application should be included in the protection scope of the present application.

[0102] It is to be noted that, as used in this text, the terms "comprises", "comprising", or other variations such as "comprises", "comprising", or "including" merely specify the presence of stated features, integers, steps, or components, but do not preclude the presence or addition of one or more other features, integers, steps, components, or groups thereof. Furthermore, as used in this text, the term "coupled" means either a direct connection between components that are directly in contact with each other, or an indirect connection through other components where the coupling of intervention of other components is not explicitly shown.

Claims

1. A large deformation control system for surrounding rock of a high ground stress soft rock tunnel, characterized by: It comprises an outer ring steel arch frame (2) arranged 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) comprises a plurality of segments, and adjacent segments are connected via an annular pressure-releasing member (1); The inner ring steel arch frame (3) and the outer ring steel arch frame (2) are connected via a plurality of radial pressure-releasing members (6); The outer ring steel arch frame (2) and the annular pressure-yielding member (1) are both fixed in the first concrete layer (4); The inner ring steel arch frame (3) and the radial pressure-yielding member (6) are both fixed in the second concrete layer (5).

2. A large deformation control system for surrounding rock of a high ground stress soft rock tunnel according to claim 1, characterized in that: The annular pressure-releasing member (1) and the radial pressure-releasing member (6) have the same structure and both include: Two mutually 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; a line connecting the top end of the first V-shaped plate (101) and the top end of the second V-shaped plate (102) is perpendicular to the connecting plates (103); and the bottom ends of the first V-shaped plate (101) and the second V-shaped plate (102) are fixedly connected to the corresponding connecting plates (103).

3. A large deformation control system for surrounding rock of a high ground stress soft rock tunnel 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 annular pressure-releasing 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-releasing member (6).

4. A large deformation control system for surrounding rock of a high ground stress soft rock tunnel according to claim 3, characterized in that: The included angle between the first V-shaped plate (101) and the second V-shaped plate (102) in the annular pressure-releasing member (1) is 30° to 40°; The included angle between the first V-shaped plate (101) and the second V-shaped plate (102) in the radial pressure-relieving member (6) is 40° to 60°.

5. The large deformation control system for surrounding rock of a high ground stress soft rock tunnel according to claim 2, characterized in that: In the annular pressure-releasing member (1), a line connecting the top end of the first V-shaped plate (101) and the top end of the second V-shaped plate (102) extends along the annular direction of the tunnel; In the radial pressure-relieving member (6), a 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.

6. A large deformation control system for surrounding rock of a high ground stress soft rock tunnel according to claim 2, characterized in that: The width of the first V-shaped plate (101) is greater than the width of the second V-shaped plate (102); and strip holes for the second V-shaped plate (102) to pass through are provided on both side wings of the first V-shaped plate (101).

7. A large deformation control system for surrounding rock of a high ground stress soft rock tunnel according to claim 6, characterized in that: The second V-shaped plate (102) comprises a flat plate portion (1021) and a bent portion (1022) that are spliced ​​together; a positioning protrusion (1023) is provided on 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 on one end of the bent portion (1022) facing the flat plate portion (1021); and the positioning protrusion (1023) is inserted into the positioning groove (1024).

8. A large deformation control system for surrounding rock of a high ground stress soft rock tunnel according to claim 7, characterized in that: The outer wall of the bending area of ​​the bending portion (1022) is set as a plane (1025), and a plurality of grooves (1026) are provided on the plane (1025). Balls (1027) are movably placed in the grooves (1026), and the bottom of each groove (1026) is connected to the positioning groove (1024) through a channel; and a pushing member (1028) passing through the channel is also included, and one end of the pushing member (1028) is located in the positioning groove (1024) and the other end is located in the groove (1026).

9. A large deformation control system for surrounding rock of a high ground stress soft rock tunnel according to claim 8, characterized in that: The slot width of the groove (1026) is smaller than the outer diameter of the ball (1027); and an anti-slip protrusion (1029) is provided at one end of the pushing member (1028) located in the groove (1026).

10. A construction method for a large deformation control system for surrounding rock of a high ground stress soft rock tunnel according to any one of claims 1 to 9, characterized in that: include: S1. Excavate the tunnel and install anchor bolts; S2, erecting an outer ring steel arch frame (2), and connecting annular pressure-yielding members (1) between adjacent segments of the outer ring steel arch frame (2); S3, welding a plurality of radial pressure-yielding members (6) on the inner wall of the outer ring steel arch (2); S4, spraying a first concrete layer (4) so ​​that the first concrete layer (4) covers the outer ring steel arch frame (2); S5, erecting the inner ring steel arch frame (3), and welding the inner ring steel arch frame (3) to each radial pressure-yielding member (6); S6, spraying a second concrete layer (5) so that the second concrete layer (5) covers the inner ring steel arch frame (3); S7. After the deformation of the surrounding rock is stable, start the secondary lining construction.

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