Steel arch splicing device for tunneling equipment

Abstract

The invention provides a steel arch splicing device for tunnel boring equipment, which is mounted on a connecting frame between a front shield and a rear shield of a tunnel boring machine, and comprises a support ring, a rotary ring and a splicing structure, the supporting ring is installed on a sliding rail arranged on the connecting frame in a sliding mode through a supporting frame arranged on the inner wall. The rotary ring is rotationally arranged in an annular groove formed in the outer wall of the supporting ring in a sleeved mode through an annular protrusion arranged on the inner wall. A driving mechanism in transmission connection with the rotary ring is mounted on the side wall of the supporting ring, and the driving mechanism drives the rotary ring to rotate on the supporting ring; the assembling structure is mounted on the rotary ring, and after the assembling structure grabs the steel arch, the steel arch is rotated, moved and assembled under the rotation of the rotary ring; a hydraulic cylinder I for pressing the steel arch is arranged on the edge of the rear end of the front shield; the labor cost is reduced, the steel arch is automatically assembled through machinery, the assembling efficiency is improved, the safety risk of workers is reduced, and the safety coefficient is high.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel steel arch frame assembly, and specifically belongs to a steel arch frame assembly device for tunnel excavation equipment. Background Art

[0002] TBM tunnel boring machines are mainly used for tunnel excavation, mine brick shafts and other purposes. After the tunnel boring machine digs the tunnel, it is necessary to assemble a steel arch frame 8 on the wall of the tunnel to support the tunnel, prevent debris from falling, and protect the safety of the workers. At present, when assembling the steel arch frame 8, the workers usually assemble the steel arch frame 8 and fix it with bolts. This method has high labor costs, low construction efficiency, and high risk factors for the workers. Summary of the invention

[0003] In order to overcome the problems existing in the background technology, the present invention provides a steel arch frame 8 assembly device for tunnel excavation equipment to solve the technical problems raised in the background technology that the existing steel arch frame 8 assembly is usually performed by workers assembling the steel arch frame 8 and fixing it with bolts. This method has high labor costs, low construction efficiency, and a high risk factor for the workers.

[0004] To achieve the above purpose, the invention is implemented through the following technical solutions: A steel arch frame assembly device for tunnel boring equipment, the steel arch frame 8 assembly device is installed on the connecting frame 3 between the front shield 1 and the rear shield 2 of the tunnel boring machine, including a support ring 4, a slewing ring 5, and an assembly structure 6; the support ring 4 is slidably installed on the slide rail 31 arranged on the connecting frame 3 through a support frame 41 arranged on the inner wall; the slewing ring 5 is rotatably sleeved in the annular groove 42 arranged on the outer wall of the support ring 4 through an annular protrusion 51 arranged on the inner wall; the side wall of the support ring 4 is equipped with a support ring 5 arranged on the side wall of the support ring 4. A driving mechanism 7 is connected by transmission, and the driving mechanism 7 drives the slewing ring 5 to rotate on the supporting ring 4; the assembling structure 6 is installed on the slewing ring 5, and after the assembling structure 6 grabs the steel arch frame 8, the steel arch frame 8 is rotated and moved and assembled under the rotation of the slewing ring 5; the edge of the rear end of the front shield 1 is provided with a hydraulic cylinder Ⅰ11 for pressing the steel arch frame 8; the front end of the rear shield 2 is provided with a hydraulic cylinder Ⅱ21 for pushing the supporting ring 4 to slide on the connecting frame 3, and the telescopic end of the hydraulic cylinder Ⅱ21 is connected to the supporting frame 41.

[0005] Preferably, the assembly structure 6 includes two clamping devices 61 and a hydraulic cylinder III 62. The two clamping devices 61 are respectively slidably mounted on two support columns 63 arranged parallel to each other at the ends of the slewing ring 5; the hydraulic cylinder III 62 is installed on the side wall of the slewing ring 5, and its telescopic end is connected to a connecting plate 64 connected between the two clamping devices 61. The hydraulic cylinder III 62 pushes the two clamping devices 61 to telescopically move through the connecting plate 64 to grab the steel arch frame 8.

[0006] Preferably, the clamping device 61 includes a sliding sleeve 611, a fixed clamping plate 612, a movable clamping plate 613, a mounting plate 614, and a hydraulic cylinder IV 615; the sliding sleeve 611 is sleeved on the support column 63, the fixed clamping plate 612 is installed on the end of the sliding sleeve 611, the mounting plate 614 is fixedly connected to the upper end of the side wall of the sliding sleeve 611, the hydraulic cylinder IV 615 is installed on the mounting plate 614, and the movable clamping plate 613 is connected to the telescopic end of the hydraulic cylinder IV 615. The hydraulic cylinder IV 615 is used to move the movable clamping plate 613 and the fixed clamping plate 612 to clamp and grab the steel arch frame 8.

[0007] Preferably, the driving mechanism 7 includes a driving gear 71, a U-shaped mounting frame 72, and a driving motor 73, and the mounting frame 72 is installed on the side wall of the support ring 4; the driving gear 71 is rotatably installed between the side wall of the support ring 4 and the mounting frame 72, and is transmission-connected to the driving motor 73 installed on the mounting frame 72, and the driving gear 71 is meshed with the transmission tooth 74 arranged on the side wall of the slewing ring 5.

[0008] Preferably, a conveyor belt is installed at the lower part of the backing 2 to transport the steel arch frame 8 from outside the tunnel to the bottom of the assembled structure 6.

[0009] A steel arch frame 8 for the above-mentioned assembling device, wherein both ends of the steel arch frame 8 are provided with snap-in sockets 81 for mutually clamping the two ends of the steel arch frame 8, and the front side of the steel arch frame 8 is provided with a slot 82 for clamping and fixing by a clamping device 61; and the back side of the steel arch frame 8 is provided with a positioning pin 84 matching the positioning hole 83 provided on the front side of the steel arch frame 8.

[0010] Preferably, the end of the positioning pin 84 is configured as a round head for easy insertion into the positioning hole 83 .

[0011] An assembling method based on the above-mentioned steel arch frame 8 and the steel arch frame 8 assembling device comprises the following steps; S1, the steel arch frame 8 is transported to the bottom of the assembly device by a conveyor belt; S2, the driving mechanism 7 drives the slewing ring 5 to rotate and drives the assembling device to rotate and be located above the steel arch frame 8, and the hydraulic cylinder III 62 pushes the two clamping devices 61 to move downward, so that the clamping devices 61 are clamped in the clamping groove 82 of the steel arch frame 8; S3, hydraulic cylinder III 62 lifts the steel arch frame 8, and pushes the support ring 4 through hydraulic cylinder II 21 to drive the steel arch frame 8 to move horizontally. Hydraulic cylinder III 62 pushes the steel arch frame 8 to fit with the tunnel wall, and pushes the steel arch frame 8 through hydraulic cylinder I 11 so that the positioning pin 84 on the back of the steel arch frame 8 is inserted into the positioning hole 83 on the side wall of the assembled steel arch frame 8, thereby fixing the steel arch frame 8; S4, then the next steel arch frame 8 is clamped by the clamping device 61, and the rotating end of the steel arch frame 8 is docked in the clamping groove 82 at the end of the installed steel arch frame 8 through the slewing ring 5, and then the steel arch frame 8 is pushed by the hydraulic cylinder I11 so that the positioning pin 84 on the back of the steel arch frame 8 is inserted into the positioning hole 83 on the side wall of the assembled steel arch frame 8, and the steel arch frame 8 is fixed; S5, assembling the plurality of steel arch frames 8 in sequence by docking, so as to assemble into a ring-shaped steel arch frame 8 assembly.

[0012] Preferably, when the steel arch frame 8 is assembled, two positioning pins 84 are provided on the back of the steel arch frame 8 and are respectively inserted into two steel arch frames 8 of the upper layer of steel arch frame 8 assembly, so that the steel arch frame 8 is staggered with the upper layer of steel arch frame 8 during installation.

[0013] The beneficial effects of the present invention are as follows: when the present invention assembles the steel arch frame 8, the steel arch frame 8 can be easily grasped and moved to the corresponding position through the slewing ring 5 and the clamping device 61, and the steel arch frame 8 is pushed by the hydraulic cylinder Ⅰ11 arranged on the front shield 1 to be pressed and docked with the assembled steel arch frame 8 of the upper layer, so that the steel arch frame 8 can be assembled more tightly and stably. The invention reduces the labor cost, assembles the steel arch frame 8 automatically by machinery, improves the assembly efficiency, reduces the safety risks of workers, and has a high safety factor. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the assembly device of the present invention installed on a tunnel boring machine.

[0015] Figure 2 It is a structural schematic diagram of the assembling device.

[0016] Figure 3 It is a structural schematic diagram of the support ring and the slewing ring.

[0017] Figure 4 It is a structural schematic diagram of the driving mechanism.

[0018] Figure 5 It is a structural schematic diagram of the assembled structure.

[0019] Figure 6 It is a schematic structural diagram of the clamping device.

[0020] Figure 7 Schematic diagram of the structure of the steel arch. DETAILED DESCRIPTION

[0021] In order to make the objectives, technical solutions and beneficial effects of the present invention more clear, preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings to facilitate understanding by technicians.

[0022] like Figure 1-7As shown, the present invention provides a steel arch frame assembly device for tunnel boring equipment, the steel arch frame 8 assembly device is installed on the connecting frame 3 between the front shield 1 and the rear shield 2 of the tunnel boring machine, and includes a support ring 4, a slewing ring 5, and an assembly structure 6; the support ring 4 is slidably installed on the slide rail 31 arranged on the connecting frame 3 through a support frame 41 arranged on the inner wall; the slewing ring 5 is rotatably sleeved in the annular groove 42 arranged on the outer wall of the support ring 4 through an annular protrusion 51 arranged on the inner wall; the side wall of the support ring 4 is provided with The driving mechanism 7 is connected to the slewing ring 5, and the driving mechanism 7 drives the slewing ring 5 to rotate on the supporting ring 4; the assembling structure 6 is installed on the slewing ring 5, and after the assembling structure 6 grabs the steel arch frame 8, the steel arch frame 8 is rotated and moved and assembled under the rotation of the slewing ring 5; the edge of the rear end of the front shield 1 is provided with a hydraulic cylinder I11 for pressing the steel arch frame 8; the front end of the rear shield 2 is provided with a hydraulic cylinder II21 for pushing the supporting ring 4 to slide on the connecting frame 3, and the telescopic end of the hydraulic cylinder II21 is connected to the supporting frame 41. When assembling the steel arch frame 8, the support ring 4 is pushed by the hydraulic cylinder II 21 to slide along the slide rail 31 on the connecting frame 3, so as to facilitate the clamping of the steel arch frame 8 and move the position laterally. Then, the slewing ring 5 is driven by the driving mechanism 7 to rotate along the annular groove 42 arranged on the outer wall of the support ring 4. The assembling device grabs the steel arch frame 8 and rotates it to splice it on the tunnel wall. The hydraulic cylinder I 11 presses the side wall of the steel arch frame 8 to press the steel arch frame 8 tightly against the side wall of the assembled steel arch frame 8, so that the assembly of the steel arch frame 8 is more stable and tight. The invention reduces the labor cost, assembles the steel arch frame 8 automatically by machinery, improves the assembly efficiency, reduces the safety risks of workers, and has a high safety factor.

[0023] like Figure 2-3 As shown, the assembly structure 6 includes two clamping devices 61 and a hydraulic cylinder III 62. The two clamping devices 61 are respectively slidably sleeved on two supporting columns 63 arranged parallel to each other at the ends of the slewing ring 5; the hydraulic cylinder III 62 is installed on the side wall of the slewing ring 5, and its telescopic end is connected to the connecting plate 64 connected between the two clamping devices 61. The hydraulic cylinder III 62 pushes the two clamping devices 61 to move telescopically through the connecting plate 64 to grab the steel arch frame 8. The two clamping devices 61 are pushed to slide on the supporting column 63 by the hydraulic cylinder III 62, so that the clamping devices 61 can clamp the steel arch frame 8, and rotate the steel arch frame 8 through the slewing ring 5, and the steel arch frame 8 is pushed to be spliced ​​on the tunnel wall by the hydraulic cylinder III 62, and the steel arch frame 8 is pushed to be close to the side wall of the assembled steel arch frame 8 on the upper layer by the hydraulic cylinder I 11; the assembly device can conveniently and quickly clamp the steel arch frame 8 and push the steel arch frame 8 to be assembled on the tunnel wall, thereby improving the efficiency of assembling the steel arch frame 8.

[0024] like Figure 5-6As shown, the clamping device 61 includes a sliding sleeve 611, a fixed clamping plate 612, a movable clamping plate 613, a mounting plate 614, and a hydraulic cylinder IV 615; the sliding sleeve 611 is sleeved on the support column 63, the fixed clamping plate 612 is installed on the end of the sliding sleeve 611, the mounting plate 614 is fixedly connected to the upper end of the side wall of the sliding sleeve 611, the hydraulic cylinder IV 615 is installed on the mounting plate 614, and the movable clamping plate 613 is connected to the telescopic end of the hydraulic cylinder IV 615. The hydraulic cylinder IV 615 is used to move the movable clamping plate 613 and the fixed clamping plate 612 to clamp and grab the steel arch frame 8. The clamping device 61 is pushed by the hydraulic cylinder III 62 to move the fixed clamping plate 612 to the side of the steel arch frame 8, and then the fixed clamping plate 612 is moved laterally and inserted under the steel arch frame 8 by the hydraulic cylinder II 21, and then the movable clamping plate 613 is pushed by the hydraulic cylinder IV 615 to move the fixed clamping plate 612 and the movable clamping plate 613 to clamp and grab the steel arch frame 8, and then the steel arch frame 8 is moved for assembly. The clamping device 61 can conveniently and quickly clamp the steel arch frame 8 and move it to the tunnel wall for assembly, thereby improving the assembly efficiency of the steel arch frame 8.

[0025] like Figure 4 As shown, the driving mechanism 7 includes a driving gear 71, a U-shaped mounting frame 72, and a driving motor 73. The mounting frame 72 is mounted on the side wall of the support ring 4; the driving gear 71 is rotatably mounted between the side wall of the support ring 4 and the mounting frame 72, and is in transmission connection with the driving motor 73 mounted on the mounting frame 72, and the driving gear 71 is meshed with a transmission tooth 74 provided on the side wall of the slewing ring 5. The driving motor 73 drives the driving gear 71 to rotate, and the driving gear 71 drives the slewing ring 5 to rotate through the transmission tooth 74 meshed therewith, thereby driving the steel arch frame 8 clamped on the clamping device 61 to rotate and assemble it to the tunnel wall. The driving mechanism 7 conveniently drives the steel arch frame 8 to rotate, and facilitates the adjustment of the assembled position of the steel arch frame 8.

[0026] The lower part of the backing 2 is provided with a conveyor belt for conveying the steel arch frame 8 from outside the tunnel to the bottom of the assembly structure 6. The conveyor belt facilitates the conveyance of the steel arch frame 8 to the assembly device for assembly, thereby improving the assembly efficiency of the steel arch frame 8.

[0027] like Figure 7As shown, a steel arch frame 8 used for the above-mentioned assembling device, the two ends of the steel arch frame 8 are provided with snap-in sockets 81 for enabling the two ends of the steel arch frame 8 to be clamped together, the front side of the steel arch frame 8 is provided with a clamping groove 82 for facilitating clamping and fixing by the clamping device 61; the back side of the steel arch frame 8 is provided with a positioning pin 84 matching the positioning hole 83 provided on the front side of the steel arch frame 8. When the steel arch frame 8 is assembled by the above-mentioned assembling device, the clamping device 61 is moved to insert the fixed clamping plate 612 into the slot 82, and then the movable clamping plate 613 and the fixed clamping plate 612 are moved by the hydraulic cylinder III 62 and the hydraulic cylinder IV 615 to clamp the steel arch frame 8, and then the steel arch frame 8 is driven by the hydraulic cylinder II 21, the hydraulic cylinder III 62 and the driving mechanism 7 to rotate in a circular manner and move horizontally and longitudinally, and the steel arch frame 8 is moved to the tunnel wall for assembly and docked to the end bayonet 81 of the steel arch frame 8 that has been assembled on the tunnel wall, and then the steel arch frame 8 is pushed by the hydraulic cylinder I 11 to insert the locating pin 84 on the back of the steel arch frame 8 into the locating hole 83 set on the steel arch frame 8 assembled on the upper layer. Since the locating pin 84 and the locating hole 83 are tightly matched, the steel arch frames 8 are stably connected to each other, thereby improving the stability and safety of the assembly of the steel arch frames 8.

[0028] like Figure 7 As shown, the end of the positioning pin 84 is configured as a round head for easy insertion into the positioning hole 83. The end of the positioning pin 84 is configured as a round head for easy insertion of the positioning pin 84 into the positioning hole 83, thereby improving the assembly efficiency of the steel arch frame 8.

[0029] Working process: S1, the steel arch frame 8 is transported to the bottom of the assembly device by a conveyor belt; S2, the driving mechanism 7 drives the slewing ring 5 to rotate and drives the assembling device to rotate and be located above the steel arch frame 8, and the hydraulic cylinder III 62 pushes the two clamping devices 61 to move downward, so that the clamping devices 61 are clamped in the clamping groove 82 of the steel arch frame 8; S3, hydraulic cylinder III 62 lifts the steel arch frame 8, and pushes the support ring 4 through hydraulic cylinder II 21 to drive the steel arch frame 8 to move horizontally. Hydraulic cylinder III 62 pushes the steel arch frame 8 to fit with the tunnel wall, and pushes the steel arch frame 8 through hydraulic cylinder I 11 so that the positioning pin 84 on the back of the steel arch frame 8 is inserted into the positioning hole 83 on the side wall of the assembled steel arch frame 8, thereby fixing the steel arch frame 8; S4, then the next steel arch frame 8 is clamped by the clamping device 61, and the rotating end of the steel arch frame 8 is docked in the clamping groove 82 at the end of the installed steel arch frame 8 through the slewing ring 5, and then the steel arch frame 8 is pushed by the hydraulic cylinder I11 so that the positioning pin 84 on the back of the steel arch frame 8 is inserted into the positioning hole 83 on the side wall of the assembled steel arch frame 8, and the steel arch frame 8 is fixed; S5, assemble multiple steel arch frames 8 in sequence by docking, so as to assemble into a ring-shaped steel arch frame 8 assembly; when the steel arch frames 8 are assembled, two positioning pins 84 are provided on the back of the steel arch frames 8, which are respectively inserted into two steel arch frames 8 of the upper layer of steel arch frame 8 assembly, so that the steel arch frames 8 are staggered with the upper layer of steel arch frames 8 during installation, thereby increasing the stability of the assembly of the steel arch frames 8.

[0030] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A steel arch assembly device for tunnel boring equipment, characterized in that: The steel arch frame assembly device is installed on a connecting frame (3) between a front shield (1) and a rear shield (2) of a tunnel boring machine, and comprises a support ring (4), a slewing ring (5), and an assembly structure (6); the support ring (4) is slidably mounted on a slide rail (31) provided on the connecting frame (3) via a support frame (41) provided on the inner wall; the slewing ring (5) is rotatably sleeved in an annular groove (42) provided on the outer wall of the support ring (4) via an annular protrusion (51) provided on the inner wall; a driving mechanism (7) drivingly connected to the slewing ring (5) is installed on the side wall of the support ring (4). The driving mechanism (7) drives the slewing ring (5) to rotate on the supporting ring (4); the assembling structure (6) is installed on the slewing ring (5); after the assembling structure (6) grabs the steel arch frame (8), the steel arch frame (8) is rotated and moved and assembled under the rotation of the slewing ring (5); the edge of the rear end of the front shield (1) is provided with a hydraulic cylinder I (11) for pressing the steel arch frame (8); the front end of the rear shield (2) is provided with a hydraulic cylinder II (21) for pushing the supporting ring (4) to slide on the connecting frame (3), and the telescopic end of the hydraulic cylinder II (21) is connected to the supporting frame (41).

2. The steel arch assembly device for tunnel boring equipment according to claim 1, characterized in that: The assembly structure (6) comprises two clamping devices (61) and a hydraulic cylinder III (62). The two clamping devices (61) are respectively slidably mounted on two support columns (63) arranged parallel to each other at the ends of the slewing ring (5). The hydraulic cylinder III (62) is mounted on the side wall of the slewing ring (5), and its telescopic end is connected to a connecting plate (64) connecting the two clamping devices (61). The hydraulic cylinder III (62) pushes the two clamping devices (61) to telescopically move through the connecting plate (64) to grab the steel arch frame (8).

3. The steel arch assembly device for tunnel boring equipment according to claim 2, characterized in that: The clamping device (61) comprises a sliding sleeve (611), a fixed clamping plate (612), a movable clamping plate (613), a mounting plate (614), and a hydraulic cylinder IV (615); the sliding sleeve (611) is sleeved on the support column (63), the fixed clamping plate (612) is mounted on the end of the sliding sleeve (611), the mounting plate (614) is fixedly connected to the upper end of the side wall of the sliding sleeve (611), the hydraulic cylinder IV (615) is mounted on the mounting plate (614), and the movable clamping plate (613) is connected to the telescopic end of the hydraulic cylinder IV (615), and the movable clamping plate (613) is moved by the hydraulic cylinder IV (615) to clamp and grab the steel arch frame (8) with the fixed clamping plate (612).

4. A steel arch assembly device for tunnel boring equipment according to any one of claims 1 to 3, characterized in that: The driving mechanism (7) comprises a driving gear (71), a U-shaped mounting frame (72), and a driving motor (73); the mounting frame (72) is mounted on the side wall of the support ring (4); the driving gear (71) is rotatably mounted between the side wall of the support ring (4) and the mounting frame (72), and is drivingly connected to the driving motor (73) mounted on the mounting frame (72); the driving gear (71) is meshed with a driving tooth (74) provided on the side wall of the slewing ring (5).

5. The steel arch assembly device for tunnel boring equipment according to claim 4, characterized in that: A conveyor belt is installed at the bottom of the backing (2) to transport the steel arch frame (8) from outside the tunnel to the bottom of the assembled structure (6).

6. A steel arch frame for the assembly device according to claim 5, characterized in that: Both ends of the steel arch frame (8) are provided with snap-fitting holes (81) for mutually snapping the ends of the two steel arch frames (8); the front side of the steel arch frame (8) is provided with a snap-fitting groove (82) for facilitating the clamping and fixing by the clamping device (61); and the back side of the steel arch frame (8) is provided with a positioning pin (84) matching with a positioning hole (83) provided on the front side of the steel arch frame (8).

7. The steel arch according to claim 6, characterized in that: The end of the positioning pin (84) is configured as a round head for easy insertion into the positioning hole (83).

8. An assembling method based on the assembling device according to claim 5 and the steel arch frame according to claim 6, characterized in that: The steps include: S1, the steel arch frame (8) is transported to the bottom of the assembly device via a conveyor belt; S2, the driving mechanism (7) drives the slewing ring (5) to rotate, driving the assembly device to rotate above the steel arch frame (8), and the hydraulic cylinder III (62) pushes the two clamping devices (61) to move downward, so that the clamping devices (61) are clamped in the clamping grooves (82) of the steel arch frame (8); S3, the hydraulic cylinder III (62) lifts the steel arch frame (8), and the hydraulic cylinder II (21) pushes the support ring (4) to drive the steel arch frame (8) to move laterally, the hydraulic cylinder III (62) pushes the steel arch frame (8) to fit with the tunnel wall, and the hydraulic cylinder I (11) pushes the steel arch frame (8) so that the positioning pin (84) on the back of the steel arch frame (8) is inserted into the positioning hole (83) on the side wall of the assembled steel arch frame (8), thereby fixing the steel arch frame (8); S4, then the next steel arch frame (8) is clamped by the clamping device (61), and the rotating end of the steel arch frame (8) is docked in the clamping groove (82) at the end of the already installed steel arch frame (8) by the slewing ring (5), and then the steel arch frame (8) is pushed by the hydraulic cylinder I (11) so that the positioning pin (84) on the back of the steel arch frame (8) is inserted into the positioning hole (83) on the side wall of the assembled steel arch frame (8), thereby fixing the steel arch frame (8); S5, a plurality of steel arch frames (8) are sequentially butt-jointed and assembled to form a ring-shaped steel arch frame (8) assembly.

9. The assembling method according to claim 8, characterized in that: When the steel arch frame (8) is assembled, two positioning pins (84) are provided on the back of the steel arch frame (8) and are respectively inserted into two steel arch frames (8) of the upper layer of steel arch frame (8) assembly, so that the steel arch frame (8) is staggered with the upper layer of steel arch frame (8) when installed.

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