A comprehensive support structure for a tunnel in a highly weathered mudstone stratum

Abstract

The application relates to the field of tunnel support, and particularly discloses a comprehensive support structure for a tunnel in a strongly weathered mudstone stratum, which is supported on the inner wall of the tunnel body and comprises a transport vehicle, a plurality of arch frame strips arranged on the transport vehicle and capable of being folded with each other, an extension mechanism for driving the arch frame strips to quickly expand, and a driving mechanism for driving the extension mechanism to work. When the arch frame strips are needed to support the inner wall of the tunnel, the driving mechanism can drive the arch frame strips to be lifted to the inner top wall of the tunnel, then the driving mechanism drives the extension mechanism to work, the extension mechanism drives the arch frame strips to quickly expand, and therefore, the inner top wall of the tunnel is quickly supported, and the construction efficiency during tunnel support is improved.

Description

Technical Field

[0001] This application relates to the field of tunnel support, and in particular to a comprehensive support structure for tunnels in strongly weathered mudstone strata. Background Technology

[0002] With the large-scale construction of tunnel projects, the problems and challenges we encounter during tunnel construction have increased dramatically, and the construction risks have also grown significantly. During tunnel construction, it is inevitable to traverse many complex geological strata. Among them, weak surrounding rock strata are a common geological condition, characterized by low rock strength, significant deformation under disturbance, and poor bearing capacity, posing extremely severe challenges to tunnel construction. Strongly weathered mudstone, as a typical example of weak surrounding rock, is prone to disintegration and collapse upon contact with water, and also exhibits unfavorable characteristics such as creep and long-term strength reduction. Therefore, timely drainage is necessary during construction.

[0003] When constructing in highly weathered mudstone strata, the tunnel body is excavated first, then the tunnel entrance is supported, and the tunnel is excavated inward along the entrance, with the excavated sand and gravel being discharged. Next, the inner wall of the tunnel is initially supported, which requires initial shotcreting of the inner wall, erection of steel frames, installation of anchor bolts and steel mesh, and shotcreting of the mesh. After the initial support is completed, the invert is excavated, and initial support, formwork, and concrete pouring are carried out on the invert. Finally, the inner wall of the tunnel is lined again, so that the inner wall of the tunnel is closed into a ring.

[0004] The steel arch frame used in the initial support process needs to be cut into pieces according to the total length of the tunnel steel arch frame in one go, and then cold-bent into shape as a whole. Then, it is cut into sections according to the cross-sectional size set in the tunnel excavation plan to form arch frame strips. Then, each arch frame strip is transported into the tunnel and welded together to form an arc-shaped steel arch frame, so that the steel arch frame can be installed and erected in the tunnel.

[0005] Regarding the aforementioned technologies, steel arch frames need to be fabricated when supporting tunnels. The fabrication of steel arch frames involves several construction processes, including cold bending, segmentation, transportation to the tunnel, and welding. This makes the operation of supporting tunnels with steel arch frames quite cumbersome, and therefore, improvements are needed. Summary of the Invention

[0006] To improve construction efficiency during tunnel support, this application provides a comprehensive support structure for tunnels in strongly weathered mudstone strata.

[0007] This application provides a comprehensive support structure for tunnels in highly weathered mudstone strata, employing the following technical solution:

[0008] A comprehensive support structure for tunnels in strongly weathered mudstone strata, supporting the inner wall of the tunnel body, includes a transport vehicle, multiple arch beams mounted on the transport vehicle and retracting with each other, an extension mechanism for rapidly extending each of the arch beams, and a drive mechanism for driving the extension mechanism.

[0009] By adopting the above technical solution, when arch support strips are needed to support the inner wall of a tunnel, the transport vehicle is first driven into the tunnel and parked at the location where the tunnel needs support. The drive mechanism drives each arch support strip to rise, so that each arch support strip rises to a position close to the inner top wall of the tunnel. Then, the drive mechanism drives the extension mechanism to work, so that the extension mechanism drives each arch support strip to quickly extend, thereby achieving rapid support for the inner top wall of the tunnel and improving the construction efficiency during tunnel support.

[0010] Optionally, the extension mechanism includes an arc-shaped guide rail, a rotating shaft, a fixed rod, a rotating rod, and a connecting rod. The fixed rod, the rotating rod, and the connecting rod are all arc-shaped, and multiple connecting rods are provided.

[0011] The rotating shaft is rotatably mounted in the middle of the arc-shaped guide rail and located on the outside of the arc-shaped guide rail. The center of the fixed rod is fixed to the rotating shaft, and the center of the rotating rod is rotatably mounted to the rotating shaft. Connecting rods are rotatably mounted at both ends of the fixed rod and both ends of the rotating rod. The middle of the connecting rods on the same side of the fixed rod and the rotating rod are hinged to each other.

[0012] Each of the arch frame bars is fixed to the hinge shaft at the hinge joint of the two connecting rods;

[0013] The drive mechanism is used to drive the rotating shaft to rotate.

[0014] By adopting the above technical solution, when it is necessary to unfold each arch frame strip, the control drive mechanism works, the drive mechanism drives the rotating shaft to rotate, the rotating shaft drives the fixed rod to rotate, and through the cooperation of the fixed rod, rotating rod and connecting rod, each arch frame strip expands outward, so that each arch frame strip can support the inner wall of the tunnel and reduce the possibility of deformation of the tunnel top.

[0015] Optionally, a guide groove is provided on the outer side of the arc-shaped guide rail along its length direction, and a snap-fit ​​component is fixed on the hinge shaft at the hinge joint of the two connecting rods, and each snap-fit ​​component is slidably snapped into the guide groove.

[0016] By adopting the above technical solution, when the connecting rod expands outward, the snap-fit ​​can slide along the guide groove. The guide groove can guide and support the connecting rod, so that the connecting rod can expand outward more stably, and each arch frame strip can move more stably to the position in the tunnel that needs to be supported, thereby providing more stable support for the inner wall of the tunnel.

[0017] Optionally, the two ends of the arc-shaped guide rail are provided with outwardly extending auxiliary guide rails. The direction of the auxiliary guide rails is consistent with that of the arc-shaped guide rails, and the auxiliary guide rails are also provided with guide grooves along their length.

[0018] By adopting the above technical solution, when the connecting rod expands outward, the snap-fit ​​component sliding in the guide groove extends to both ends of the arc-shaped guide rail. When it moves to the end of the arc-shaped guide rail, the snap-fit ​​component drives the auxiliary guide rail to extend from both ends of the arc-shaped guide rail. At this time, the auxiliary guide rail lengthens and extends both ends of the arc-shaped guide rail, so that the auxiliary guide rail can also guide and support the connecting rod, thereby supporting the expansion of the arch frame strip and increasing the support range when the arch frame strip expands.

[0019] Optionally, a positioning groove is provided on one side of the arch frame strip, and a positioning strip is provided on the side of the adjacent arch frame strip corresponding to the positioning groove, the positioning strip slidingly passing through the positioning groove.

[0020] By adopting the above technical solution, since the arch frame strip is fixed on the hinge shaft of the two connecting rods, and the hinge shaft can rotate freely, during the expansion of the arch frame strip, the sliding insertion of the positioning strip and the positioning groove can restrict the free rotation of the two adjacent arch frame strips, making it difficult for the arch frame strip to rotate freely during the expansion process, so that each arch frame strip can fit more closely with the inner wall of the tunnel, thereby providing more stable support for the inner wall of the tunnel.

[0021] Optionally, the drive mechanism includes a base mounted on the transport vehicle, a fixed cylinder mounted on the base, a lifting cylinder slidably inserted into the fixed cylinder, a lifting assembly for driving the lifting cylinder to rise and fall, a rotating assembly for driving the rotating shaft to rotate, and a linkage assembly for enabling the lifting assembly and the rotating assembly to move together.

[0022] By adopting the above technical solution, when it is necessary to raise the arch frame strip to the height of the tunnel inner wall, the lifting component can drive the lifting cylinder to rise in the fixed cylinder, so that the arch frame strip can be raised to the required height. During the rising process, the lifting component drives the rotating component through the linkage component, so that the rotating component can drive the rotating shaft to rotate. The rotation of the rotating shaft drives each arch frame strip to unfold with each other, so that each arch frame strip can complete the extension process during the rising process. When the arch frame strip rises to the same height as the tunnel inner wall, each arch frame strip completes the unfolding process, thereby facilitating the rapid support of the tunnel inner wall.

[0023] Optionally, the lifting assembly includes a drive component mounted on the base and located inside the lifting cylinder, a first lead screw coaxially fixed to the output end of the drive component, an internal thread corresponding to the first lead screw on the inner peripheral wall of the lifting cylinder, and a first limiting component on the outer peripheral wall of the lifting cylinder for limiting the rotation of the lifting cylinder.

[0024] The first lead screw is adapted to the inner cavity of the lifting cylinder, and the external thread on the first lead screw is adapted to the internal thread.

[0025] By adopting the above technical solution, when it is necessary to raise or lower the arch frame bar, the drive component is controlled to rotate, the drive component drives the first lead screw to rotate, and under the limiting action of the first limiting component, the lifting cylinder rises in the fixed cylinder, thereby completing the raising of the position of the arch frame bar.

[0026] Optionally, the rotating shaft passes through the arc-shaped guide rail and extends into the inner side of the arc-shaped guide rail. The rotating assembly includes a driven bevel gear coaxially fixed to the end of the rotating shaft, a driving bevel gear rotatably installed in the lifting cylinder, and a driving gear coaxially rotating with the driving bevel gear. The driven bevel gear and the driving bevel gear mesh, and the first lead screw can drive the driving gear to rotate through the linkage assembly.

[0027] By adopting the above technical solution, when the first lead screw rotates, the linkage component can drive the driving gear to rotate, the driving gear to rotate, the driving bevel gear to rotate, the driving bevel gear to rotate, the driven bevel gear to rotate, the driven bevel gear to rotate the rotating shaft, thereby driving the extension of the fixed rod, connecting rod and rotating rod, so as to realize the extension of each arch frame bar, so that the arch frame bar can be quickly unfolded.

[0028] Optionally, the linkage assembly includes a second lead screw coaxially fixed to the end of the first lead screw away from the driving member, a movable plate threaded onto the second lead screw, a rack fixed to the end of the movable plate, and a second limiting member for limiting the rotation of the movable plate. The pitch of the first lead screw is greater than the pitch of the second lead screw, and the rack can mesh with the driving gear during the lifting process.

[0029] By adopting the above technical solution, when the first lead screw rotates, the second lead screw rotates together with the first lead screw. Under the limiting action of the second limiting member, the movable plate rises inside the lifting cylinder. Since the pitch on the first lead screw is greater than the pitch on the second lead screw, the rising speed of the movable plate is slower than the rising speed of the lifting cylinder. During the rising process of the movable plate, the rack will rise together. The rising rack will mesh with the driving gear, thereby driving the driving gear to rotate. The driving gear drives the rotating shaft to rotate through the driving bevel gear and the driven bevel gear, thereby realizing the extension of the arch frame bar, so that the arch frame bar can quickly support the roof of the tunnel.

[0030] Optionally, the base is provided with lifting mechanisms on both sides for lifting the base upward.

[0031] By adopting the above technical solution, after the arch frame bar abuts against the inner top wall of the tunnel, the lifting mechanism is controlled to lift the base, so that the base rises, thereby making the arch frame bar abut against the inner top wall of the tunnel more stably, and making the support effect of the arch frame bar better.

[0032] In summary, this application includes at least one of the following beneficial technical effects:

[0033] 1. The transport vehicle can easily transport each arch frame strip, the drive mechanism can lift each arch frame strip to the required height, and the extension mechanism can extend each arch frame strip to quickly support the tunnel roof.

[0034] 2. The auxiliary guide rail can be lengthened and extended at both ends of the arc guide rail, so that the auxiliary guide rail can also guide and support the connecting rod, thereby supporting the expansion of the arch frame strip and increasing the support range when the arch frame strip is expanded.

[0035] 3. The lifting assembly can drive the lifting cylinder to rise inside the fixed cylinder, so that the arch frame bars can be raised to the required height. During the rising process, the lifting assembly drives the rotating assembly through the linkage assembly, so that the rotating assembly can drive the rotating shaft to rotate. The rotation of the rotating shaft drives each arch frame bar to unfold with each other, so that each arch frame bar can complete the extension process during the rising process. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the overall structure of this application in use.

[0037] Figure 2 yes Figure 1 A first-person view of the overall structure of the central support structure.

[0038] Figure 3 yes Figure 2 A partial structural diagram of the intermediate support structure.

[0039] Figure 4 yes Figure 2 A cross-sectional view of the drive mechanism.

[0040] Reference numerals: 1. Tunnel body; 2. Transport vehicle; 3. Arch frame bar; 31. Positioning groove; 32. Positioning strip; 4. Extension mechanism; 41. Arc-shaped guide rail; 411. Mounting frame; 412. Guide groove; 413. Auxiliary guide rail; 42. Rotating shaft; 43. Fixed rod; 44. Rotating rod; 45. Connecting rod; 5. Drive mechanism; 51. Base; 52. Fixed cylinder; 521. Limiting groove; 53. Lifting cylinder; 54. Lifting assembly; 541. Drive component; 542. First lead screw; 55. Rotating assembly; 551. Driven bevel gear; 552. Driving bevel gear; 553. Driving gear; 56. Linkage assembly; 561. Second lead screw; 562. Movable plate; 563. Rack; 6. Snap-fit ​​component; 7. Lifting mechanism; 71. Lifting cylinder; 72. Abutment plate. Detailed Implementation

[0041] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail below.

[0042] This application discloses a comprehensive support structure for tunnels in strongly weathered mudstone strata.

[0043] Reference Figure 1 A comprehensive support structure for a tunnel in a strongly weathered mudstone stratum supports the inner top wall of the tunnel body 1. It includes a transport vehicle 2, multiple arch frame bars 3 mounted on the transport vehicle 2 and stacked on each other, an extension mechanism 4 for rapidly extending each arch frame bar 3, and a drive mechanism 5 for driving the extension mechanism 4.

[0044] Because the structure of strongly weathered mudstone strata is relatively soft and the structural strength is not high, in the actual construction process, the inner wall of the excavated tunnel will first be initially supported and then lined. After the reinforcement of the inner wall of the tunnel is completed, the support structure in this application will then provide a second support for the inner wall of the tunnel after construction, so that the tunnel will not easily deform after construction.

[0045] The arch frame strip 3 is prefabricated from steel. There are multiple arch frame strips 3. The cross-section of the arch frame strip 3 is arc-shaped, and its length extends in a straight line. The arc-shaped plate surface of each arch frame strip 3 is adapted to the inner top wall of the tunnel, so that the arch frame strip 3 can perfectly fit the inner wall of the tunnel, thereby achieving the support of the inner top wall of the tunnel.

[0046] Specifically, refer to Figure 2 and Figure 3The extension mechanism 4 includes an arc-shaped guide rail 41, a rotating shaft 42, a fixed rod 43, a rotating rod 44, and a connecting rod 45. The fixed rod 43, the rotating rod 44, and the connecting rod 45 are all arc-shaped. The rotating shaft 42 passes through the middle of the arc-shaped guide rail 41 and is rotatably mounted on the arc-shaped guide rail 41. The center of the fixed rod 43 is fixed on the rotating shaft 42 and is located on the outside of the arc-shaped guide rail 41. The center of the rotating rod 44 is rotatably mounted on the rotating shaft 42. There are multiple connecting rods 45. Both ends of the fixed rod 43 and both ends of the rotating rod 44 are rotatably mounted with connecting rods 45, and the middle of the connecting rods 45 on the same side of the fixed rod 43 and the rotating rod 44 is hinged to each other.

[0047] When the rotating shaft 42 rotates, it drives the fixed rod 43 to rotate. The rotation of the fixed rod 43 drives the connecting rod 45 to rotate. The mutual rotation between the connecting rods 45 drives the rotating rod 44 to rotate, thereby opening the fixed rod 43, the rotating rod 44, and the connecting rod 45. Each arch frame strip 3 is welded and fixed to the hinge shaft at the hinge point of the two connecting rods 45. When the driving mechanism 5 drives the rotating shaft 42 to rotate, it drives each arch frame strip 3 to unfold through the connecting rod 45, so that the arch frame strips 3, which are folded and closed, can be unfolded to the position that needs support, thereby achieving support for the roof wall inside the tunnel.

[0048] Since the hinge shaft at the joint of the two connecting rods 45 is in a state of free rotation, in order to limit the rotation of each arch frame bar 3 and ensure that each arch frame bar 3 remains parallel to each other during the extension process, refer to Figure 1 and Figure 2 A positioning groove 31 is provided on one side of the arch frame strip 3. A positioning strip 32 is fixed on the side of the adjacent arch frame strip 3 corresponding to the positioning groove 31. The positioning strip 32 is fixed to the side of the arch frame strip 3 in an integral connection manner, and the positioning strip 32 slides through the positioning groove 31. When the adjacent arch frame strips 3 are folded together, the positioning strip 32 slides into the positioning groove 31, realizing the folding of the positioning strip 32.

[0049] During the process of extending the arch frame 3 outward, we found that only the mounting bracket 411 is fixed below the middle part of the arc guide rail 41, and the extension mechanism 4 of other parts is in a suspended state. The suspended extension mechanism 4 is not particularly stable when extending the arch frame 3. Therefore, a guide groove 412 is provided on the outer side of the arc guide rail 41 along its length direction, penetrating the arc guide rail 41. A snap-fit ​​piece 6 is fixed on the hinge shaft at the hinge of the two connecting rods 45. The snap-fit ​​piece 6 is a snap-fit ​​block, and each snap-fit ​​block is slidably snapped into the guide groove 412.

[0050] When the connecting rod 45 drives each arch frame bar 3 to extend outward, due to the length limitation of the arc guide rail 41, the arc guide rail 41 provides limited support for the snap-fit ​​part 6. Therefore, auxiliary guide rails 413 that can extend outward are provided at both ends of the arc guide rail 41. The direction of the auxiliary guide rail 413 is consistent with the direction of the arc guide rail 41, and the auxiliary guide rail 413 also has a guide groove 412 along its length. When each arch frame bar 3 is in the retracted state, the auxiliary guide rail 413 is retracted inside both ends of the arc guide rail 41.

[0051] Reference Figure 1 , Figure 2 and Figure 4 The drive mechanism 5 includes a base 51 placed on the transport vehicle 2, a fixed cylinder 52 welded and fixed to the base 51, a lifting cylinder 53 slidably inserted into the fixed cylinder 52, a lifting assembly 54 for driving the lifting cylinder 53 to rise and fall, a rotating assembly 55 for driving the rotating shaft 42 to rotate, and a linkage assembly 56 for linking the lifting assembly 54 and the rotating assembly 55 together.

[0052] Reference Figure 2 and Figure 4 The lifting assembly 54 includes a drive component 541 mounted on the base 51 and located inside the lifting cylinder 53. In this embodiment, the drive component 541 is preferably a geared motor, but in other embodiments, a servo motor, stepper motor, etc., may also be used. The lifting assembly 54 also includes a first lead screw 542 coaxially welded and fixed to the output end of the geared motor, an internal thread corresponding to the first lead screw 542 on the inner peripheral wall of the lifting cylinder 53, and a first limiting member on the outer peripheral wall of the lifting cylinder 53 for limiting the rotation of the lifting cylinder 53. The first lead screw 542 is slidably adapted to the inner cavity of the lifting cylinder 53, and the external thread on the first lead screw 542 is adapted to the internal thread. The first limiting member is a limiting rod, which is welded and fixed to the outer peripheral wall of the lifting cylinder 53. A limiting groove 521 is opened on the inner peripheral wall of the fixed cylinder 52 corresponding to the limiting rod, and the limiting rod slides in the limiting groove 521.

[0053] To facilitate the placement of the base 51 on the bottom plate of the transport vehicle 2, a receiving groove for placing the geared motor is provided on the bottom plate of the transport vehicle 2. When the base 51 is placed on the bottom plate of the transport vehicle 2, the geared motor is located in the receiving groove.

[0054] The geared motor is controlled to work, and the geared motor can drive the first lead screw 542 to rotate. Under the limiting action of the limit rod and the limit groove 521, the lifting cylinder 53 rises in the direction perpendicular to the base 51, thereby driving the entire extension mechanism 4 to rise, so as to realize the raising of the arch frame bar 3.

[0055] Reference Figure 3 and Figure 4The rotating assembly 55 includes a driven bevel gear 551, a driving bevel gear 552, and a driving gear 553. The rotating shaft 42 passes through the arc-shaped guide rail 41 and extends into the inner side of the arc-shaped guide rail 41. The driven bevel gear 551 is coaxially welded and fixed to the end of the rotating shaft 42 and is located inside the arc-shaped guide rail 41. The driving bevel gear 552 and the driving bevel gear are coaxially welded and fixed, and are rotatably mounted on the inner wall of the lifting cylinder 53. The driving bevel gear 552 and the driven bevel gear 551 mesh.

[0056] When the first lead screw 542 rotates, it can drive the rotation of the drive gear 553 through the linkage of the linkage component 56. Through the meshing of the drive bevel gear 552 and the driven bevel gear 551, it can drive the rotating shaft 42 to rotate, thereby realizing the unfolding of the extension mechanism 4 and thus realizing the unfolding of each arch frame bar 3.

[0057] Specifically, refer to Figure 4 The linkage component 56 includes a second lead screw 561, a movable plate 562, a rack 563, and a second limiting member. The second lead screw 561 is coaxially welded and fixed to the end of the first lead screw 542 away from the reduction motor. The movable plate 562 is sleeved on the rod body of the second lead screw 561 and threadedly connected to the second lead screw 561. The rack 563 is welded and fixed to the side away from the first lead screw 542. The length direction of the rack 563 is consistent with the length direction of the lifting cylinder 53. The second limiting member is also a limiting rod. A limiting groove 521 is also opened on the inner peripheral wall of the lifting cylinder 53 corresponding to the limiting rod. The cooperation between the limiting rod and the limiting rod can realize the lifting and lowering of the movable plate 562. The pitch of the thread on the outer peripheral wall of the first lead screw 542 is greater than the pitch of the thread on the outer peripheral wall of the second lead screw 561. The rack 563 can mesh with the drive gear 553 during the rising process.

[0058] Therefore, the speed at which the geared motor drives the lifting cylinder 53 to rise is faster than the speed at which the movable plate 562 rises. In other words, the geared motor first drives multiple arch frame bars 3 to rise. When they rise to a certain height, the multiple arch frame bars 3 begin to unfold outward. When the arch frame bars 3 are fully unfolded, they rise to the position where they contact the top wall of the tunnel.

[0059] To further ensure good contact between the arch frame strip 3 and the tunnel ceiling, refer to Figure 2 Lifting mechanisms 7 for lifting the base 51 are fixedly installed on both sides of the base 51. The lifting mechanism 7 includes a lifting cylinder 71 fixedly installed on the side of the base 51 near the ground and an abutment plate 72 fixedly installed at the bottom of the lifting cylinder 71.

[0060] The implementation principle of the integrated support structure for a tunnel in a strongly weathered mudstone stratum according to the embodiments of this application is as follows: When it is necessary to use the arch frame strip 3 to support the inner wall of the tunnel, the transport vehicle 2 is first driven into the tunnel and stopped at the position where the tunnel needs to be supported. The speed reduction motor is controlled to rotate, the speed reduction motor drives the first lead screw 542 to rotate, the first lead screw 542 drives the second lead screw 561 to rotate, thereby causing the lifting cylinder 53 to rise to the top of the tunnel.

[0061] At the same time, the movable plate 562 drives the rack 563 to rise. At this time, the arch frame 3 rises under the drive of the lifting cylinder 53. When the rack 563 moves to mesh with the driving gear 553, the driving gear 553 drives the driven bevel gear 551 to rotate. The driven bevel gear 551 drives the driving bevel gear 552 to rotate. The driving bevel gear 552 drives the rotating shaft 42 to rotate. When the rotating shaft 42 rotates, the extension mechanism 4 unfolds, thereby unfolding each arch frame 3.

[0062] When the arch frame 3 is fully extended, the arch frame 3 rises to the position where it contacts the inner top wall of the tunnel. The lifting cylinder 71 is controlled to extend, so that the base 51 drives all the arch frames to more firmly abut against the inner top wall of the tunnel, thereby achieving support for the inner top wall of the tunnel.

[0063] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A comprehensive support structure for a tunnel in strongly weathered mudstone strata, supporting the inner wall of the tunnel body (1), characterized in that: The system includes a transport vehicle (2), multiple arched frame bars (3) mounted on the transport vehicle (2) and retracting from each other, an extension mechanism (4) for rapidly extending each of the arched frame bars (3), and a drive mechanism (5) for driving the extension mechanism (4); the extension mechanism (4) includes an arc-shaped guide rail (41), a rotating shaft (42), a fixed rod (43), a rotating rod (44), and a connecting rod (45), wherein the fixed rod (43), the rotating rod (44), and the connecting rod (45) are all arc-shaped, and multiple connecting rods (45) are provided; The rotating shaft (42) is rotatably mounted on the middle part of the arc-shaped guide rail (41) and located on the outside of the arc-shaped guide rail (41). The center of the fixed rod (43) is fixed on the rotating shaft (42), and the center of the rotating rod (44) is rotatably mounted on the rotating shaft (42). Both ends of the fixed rod (43) and both ends of the rotating rod (44) are rotatably mounted with connecting rods (45). The middle parts of the connecting rods (45) on the same side of the fixed rod (43) and the rotating rod (44) are hinged to each other. Each of the arch frame bars (3) is fixed to the hinge shaft at the hinge joint of the two connecting rods (45); The drive mechanism (5) is used to drive the rotating shaft (42) to rotate.

2. The comprehensive support structure for a tunnel in strongly weathered mudstone strata according to claim 1, characterized in that: The outer side of the arc-shaped guide rail (41) is provided with a guide groove (412) along its length direction. A snap-fit ​​component (6) is fixed on the hinge shaft at the hinge joint of the two connecting rods (45). Each snap-fit ​​component (6) is slidably snapped into the guide groove (412).

3. The comprehensive support structure for a tunnel in strongly weathered mudstone strata according to claim 1, characterized in that: The two ends of the arc-shaped guide rail (41) are provided with outwardly extending auxiliary guide rails (413). The direction of the auxiliary guide rail (413) is consistent with that of the arc-shaped guide rail (41), and the auxiliary guide rail (413) is also provided with guide grooves (412) along its length.

4. The comprehensive support structure for a tunnel in strongly weathered mudstone strata according to claim 3, characterized in that: A positioning groove (31) is provided on one side of the arch frame strip (3), and a positioning strip (32) is provided on the side of the adjacent arch frame strip (3) corresponding to the positioning groove (31). The positioning strip (32) slides through the positioning groove (31).

5. The comprehensive support structure for a tunnel in strongly weathered mudstone strata according to claim 4, characterized in that: The drive mechanism (5) includes a base (51) disposed on the transport vehicle (2), a fixed cylinder (52) disposed on the base (51), a lifting cylinder (53) slidably inserted into the fixed cylinder (52), a lifting assembly (54) for driving the lifting cylinder (53) to lift, a rotating assembly (55) for driving the rotating shaft (42) to rotate, and a linkage assembly (56) for linking the lifting assembly (54) and the rotating assembly (55) together.

6. The comprehensive support structure for a tunnel in strongly weathered mudstone strata according to claim 5, characterized in that: The lifting assembly (54) includes a drive member (541) mounted on the base (51) and located inside the lifting cylinder (53), a first lead screw (542) coaxially fixed to the output end of the drive member (541), an internal thread corresponding to the first lead screw (542) on the inner peripheral wall of the lifting cylinder (53), and a first limiting member on the outer peripheral wall of the lifting cylinder (53) for limiting the rotation of the lifting cylinder (53); The first lead screw (542) is adapted to the inner cavity of the lifting cylinder (53), and the external thread on the first lead screw (542) is adapted to the internal thread.

7. The comprehensive support structure for a tunnel in strongly weathered mudstone strata according to claim 6, characterized in that: The rotating shaft (42) passes through the arc-shaped guide rail (41) and extends into the inner side of the arc-shaped guide rail (41). The rotating assembly (55) includes a driven bevel gear (551) coaxially fixed to the end of the rotating shaft (42), an active bevel gear (552) rotatably installed in the lifting cylinder (53), and an active gear (553) coaxially rotating with the active bevel gear (552). The driven bevel gear (551) and the active bevel gear (552) mesh. The first lead screw (542) can drive the active gear (553) to rotate through the linkage assembly (56).

8. The comprehensive support structure for a tunnel in strongly weathered mudstone strata according to claim 7, characterized in that: The linkage assembly (56) includes a second lead screw (561) coaxially fixed to the end of the first lead screw (542) away from the driving member (541), a movable plate (562) threaded onto the second lead screw (561), a rack (563) fixed to the end of the movable plate (562), and a second limiting member for limiting the rotation of the movable plate (562). The pitch of the first lead screw (542) is greater than the pitch of the second lead screw (561), and the rack (563) can mesh with the driving gear (553) during the lifting and lowering process.

9. The comprehensive support structure for a tunnel in strongly weathered mudstone strata according to claim 5, characterized in that: The base (51) is provided with lifting mechanisms (7) on both sides for lifting the base (51) upward.

Images