Mold spraying test device for tunnel wall support and method thereof

Abstract

The invention relates to the technical field of tunnel supporting, and discloses a mold spraying test device for tunnel wall supporting and a method thereof. The technical problems that in the prior art, a traditional research method cannot repeatedly simulate various complex working conditions of tunnel inner wall concrete spraying in a controlled environment, and adjustment is difficult are solved. The device comprises a poured concrete foundation, a tunnel type steel arch, a rubber plate, a mold spraying mechanism, power supply equipment, a sliding rail, a rotary telescopic mechanism, a belt type template, a rotary structure, a telescopic structure and a front support. The belt type formwork is used for slowly rolling over the concrete surface, the concrete rebound rate is finally reduced, the flatness error of the concrete surface is reduced, and meanwhile the concrete guniting efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of tunnel support technology, and in particular to a test device and method for spraying tunnel walls. Background Technology

[0002] Tunnel boring machines (TBMs), as efficient and continuous tunnel construction equipment, have been widely used in underground engineering fields such as transportation, water conservancy, and municipal engineering. However, in TBM construction, the efficiency of the tunnel support process has always been a key bottleneck restricting the overall construction progress and project economy. Especially under complex geological conditions (such as fractured zones, weak surrounding rock, and high ground stress areas), the shortcomings of traditional support technologies are further highlighted, leading to excessively long support operations, disconnection from the tunneling process, and even safety hazards such as surrounding rock instability. Traditional tunnel initial support concrete construction mainly uses manual shotcreting or robotic shotcreting operations. Manual shotcreting suffers from problems such as high labor intensity, harsh working environment, low shotcreting efficiency, high material rebound rate, and unstable spraying quality. It heavily relies on the operator's experience and makes it difficult to guarantee the uniformity and density of the shotcrete layer. In recent years, the use of hydraulic mechanical shotcreting has reduced the labor intensity and improved efficiency to some extent, but it is still essentially still in the category of "spraying". During operation, the concrete rebound loss of such equipment is still relatively large, which not only wastes materials but also exacerbates dust pollution inside the tunnel. Meanwhile, the surface of the sprayed concrete is not smooth, often requiring a lot of manual leveling, making it impossible to achieve integrated spraying and molding, which restricts further improvement of construction efficiency.

[0003] Chinese patent document 202211260812.0 discloses a tunnel shotcrete method, which includes the following steps: S1, making a preliminary determination of the type of shotcrete to be used; S2, driving into different shotcrete trucks according to actual needs, the top of the shotcrete trucks being equipped with robotic arms, and selecting the corresponding concrete filter screens according to different shotcrete types and needs; S3, first connecting the shotcrete pipe to the water supply pipe to spray water to wet the area to be shotcreted, and roughening overly smooth parts to increase friction.

[0004] However, the above-mentioned solutions have at least the following technical problems in implementation: traditional research methods mostly rely on field tests or simple devices, which cannot repeatedly simulate various complex working conditions of shotcrete on tunnel walls under controlled environments. Furthermore, the test devices often only allow for fixed tests on a specific cross-section, making adjustments difficult and failing to meet the research needs of multiple test variables, including tunnel diameter, spraying angle, and spraying position. Therefore, there is an urgent need to propose a shotcrete test device and method for tunnel wall support. Summary of the Invention

[0005] In view of the above technical problems, this disclosure provides a mold spraying test device and method for tunnel wall support, which solves the problems that traditional research methods in the prior art mostly rely on field tests or simple devices, which cannot repeatedly simulate various complex working conditions of spraying concrete on the inner wall of the tunnel in a controlled environment. Moreover, the test devices can often only conduct fixed tests on a specific cross section, which is difficult to adjust and cannot meet the research needs of multiple test variables, including tunnel diameter, spraying angle, spraying position, etc.

[0006] According to one aspect of this disclosure, a spraying test device for tunnel wall support is provided, comprising a poured concrete foundation, a tunnel-type steel arch fixedly mounted on the concrete foundation, the outside of the tunnel-type steel arch wrapped with a rubber sheet, a spraying mechanism disposed inside the tunnel-type steel arch, a power supply device disposed outside the tunnel-type steel arch, the spraying mechanism being mounted on a sliding rail to adjust the axial position of the spraying mechanism, the sliding rail being fixed to the concrete foundation; the spraying mechanism includes a rotary telescopic mechanism, a belt-type template is mounted above the rotary telescopic mechanism to adjust the circumferential position and angle of the belt-type template, the rotary telescopic mechanism includes a rotating structure, a telescopic structure is mounted on the rotating structure, a front support is rotatably mounted on one side of the rotating structure via a support column, and the other side is mounted on the sliding rail via a triangular support mechanism.

[0007] In some embodiments of this disclosure, the input port of the spraying mechanism is connected to a wet spraying machine and an air compressor.

[0008] In some embodiments of this disclosure, a support structure is provided on both sides below the tunnel-type steel arch frame.

[0009] In some embodiments of this disclosure, the front support includes a support bracket and a quick-release structure. The support bracket has pre-drilled roller mounting holes at its bottom. The quick-release structure includes an upper mounting bracket and a lower mounting bracket. The quick-release structure has a hollow structure in the middle to accommodate the support column, and multiple circular bearings are spaced around the support column. The upper and lower mounting brackets have corresponding bolt through holes on their right sides and are installed via upper and lower bracket connecting plates. A handle is provided on the left side of the quick-release structure to lift the upper mounting bracket.

[0010] In some embodiments of this disclosure, baffles are installed on both sides of the sliding track.

[0011] In some embodiments of this disclosure, the triangular support mechanism includes a lower roller mounting bracket for fixing the rollers, and the triangular support mechanism also includes an upper vertical fixing plate and a back support bracket.

[0012] In some embodiments of this disclosure, the rotating mechanism is mounted on a cylindrical frame via bearings, the cylindrical frame is welded to a triangular support mechanism, a hydraulic motor is mounted above the triangular support mechanism, a driving gear is mounted on the hydraulic motor via a coupling, and a driven gear is arranged around the rotating mechanism near the position of the triangular support mechanism, with the driving gear and the driven gear meshing with each other.

[0013] In some embodiments of this disclosure, the rotary telescopic mechanism further includes a telescopic structure, which includes a fixed telescopic frame and a movable telescopic frame fitted inside it. A hydraulic cylinder connecting base is welded to the bottom inner side of the fixed telescopic frame, and the hydraulic cylinder connecting base is connected to a fixed hydraulic cylinder through a hydraulic cylinder base connecting hole. A hydraulic cylinder connecting base is welded to the upper inner side of the movable telescopic frame, and the hydraulic cylinder connecting base is connected to a movable hydraulic cylinder through an upper hydraulic cylinder connecting hole. Two hydraulic oil inlet and outlet holes are provided at the upper and lower ends of the fixed hydraulic cylinder. By discharging and releasing hydraulic oil, the hydraulic cylinder is driven to extend and retract, thereby pushing the mold spraying mechanism to change the spraying diameter.

[0014] According to another aspect of this disclosure, a method for testing sprayed concrete for tunnel wall support is provided, applicable to the aforementioned sprayed concrete testing apparatus for tunnel wall support, comprising the following steps: S1. Test preparation: A tunnel-type steel arch frame is fixedly installed on the poured concrete foundation, and a rubber plate is wrapped around its outside to simulate a tunnel wall; the spraying mechanism is installed on the sliding rail through the triangular support mechanism at its bottom and the front support, and the power supply equipment, wet spraying machine and air compressor are connected. S2. Axial position adjustment: Adjust the axial position of the spraying mechanism by sliding the rail to move it to the test section inside the tunnel-type steel arch frame; S3. Circumferential and radial adjustment: Start the rotary telescopic mechanism, and drive the active gear and the passive gear to mesh through the hydraulic motor, so as to drive the rotating structure and the belt-type template above to rotate circumferentially, and adjust the circumferential position and angle of the template. The hydraulic cylinder is extended and retracted by controlling the hydraulic oil circuit. The hydraulic oil enters the fixed cylinder of the hydraulic cylinder through the hydraulic oil inlet and outlet holes, which pushes the movable cylinder of the hydraulic cylinder to move, so that the movable telescopic frame extends or retracts along the fixed telescopic frame, thereby adjusting the spraying diameter of the mold spraying mechanism to adapt to different tunnel cross-section dimensions. S4. Disassembly and Support Adjustment: Adjust the front support, operate the quick-release structure, and pull the handle to lift the upper mounting bracket, separating it from the lower mounting bracket, thereby quickly disassembling or installing the support column; after adjustment, re-fix it through the upper and lower bracket connecting plates and bolt through holes; S5. Mold spraying test: Start the wet spraying machine and air compressor to deliver concrete slurry to the mold spraying mechanism through the inlet. The slurry is then evenly sprayed onto the tunnel wall simulated by the rubber plate through the belt-type template. If necessary, adjust the position of the mold spraying mechanism by sliding the track, or adjust the spraying angle and diameter by rotating the telescopic mechanism.

[0015] The beneficial effects of this invention are as follows: The purpose of this invention is to develop a rapid shotcrete test device for tunnel walls. A tunnel-type steel arch structure is installed on a concrete surface, and steel tracks are laid inside the tunnel-type steel arch structure. A rapid shotcrete device is then installed. The rapid shotcrete device uses a large hydraulic motor and hydraulic cylinder to drive and change the rotation speed and shotcrete diameter, thereby allowing the concrete to have a better setting time and better adhere to the tunnel wall for shotcreting. During shotcreting, sufficient concrete is first sprayed out using a spray nozzle, and then a belt-type template is used to slowly roll over the concrete surface to ultimately reduce the concrete rebound rate, reduce surface flatness errors, and improve the efficiency of concrete shotcreting.

[0016] The poured concrete foundation provides a stable, robust, and level installation base, ensuring the structural stability and reliability of the entire test apparatus during the spraying process and avoiding test errors caused by foundation settlement or deformation. The tunnel-type steel arch accurately simulates the contour and support structure of a real tunnel, providing a realistic and reliable test environment for the spraying experiment, making the test results more instructive for engineering applications. The outer rubber-covered surface provides a smooth, easy-to-demold spraying interface, simulating the characteristics of the initial support rock surface and facilitating post-test cleaning of the sprayed concrete, protecting the steel arch from adhesion damage, and improving test efficiency and the reusability of the apparatus. The internally integrated spraying mechanism and external power supply equipment achieve integration of the core functions of spraying while separating the power source, ensuring operational safety and facilitating maintenance and operation of the spraying mechanism. The spraying mechanism, mounted on a sliding rail, allows for flexible and precise movement along the tunnel axis, facilitating continuous or repeated tests on different sections and greatly improving test flexibility and efficiency. The rotary telescopic mechanism integrates rotation and telescopic functions and is the core component for achieving multi-degree-of-freedom adjustment of the nozzle. A belt-type template mounted above the rotary telescopic mechanism enables circumferential rotation and angle adjustment of the template, accurately simulating different spraying angles and coverage areas, suitable for testing needs under various complex working conditions. The rotating structure features a front support mounted on one side via a support column and on the other side via a triangular support mechanism mounted on a sliding rail, providing stable and reliable primary and secondary support points. This ensures the stability of the rotary structure while allowing for flexible rotation within a certain range, balancing rigidity and flexibility. The input port of the spraying mechanism connects to the wet spraying machine and air compressor. The wet spraying equipment provides power and material supply, ensuring stable mix proportions and quality of the sprayed concrete, keeping test conditions consistent with actual construction, and improving the reliability of test data. Support structures are installed on both sides below the tunnel-type steel arch frame, further enhancing its rigidity and stability, preventing vibration or deformation during spraying operations, and ensuring a safe and accurate test environment. The quick-release structure of the front support allows for rapid disassembly and installation, greatly facilitating the entry, exit, maintenance, and position adjustment of the spraying mechanism, saving auxiliary work time and improving test efficiency. Baffles installed on both sides of the sliding track effectively prevent the spraying mechanism from derailing or slipping during movement, enhancing the safety and reliability of the equipment. The triangular support mechanism provides excellent stability and strong support for the entire rotary telescopic mechanism; integrated rollers enable smooth movement on the track. Gear meshing transmission ensures reliable and controllable 360-degree rotation of the belt-driven template with precise positioning. The telescopic structure, driven hydraulically, allows for stepless adjustment of the radial dimension of the spraying mechanism, enabling a single unit to adapt to the testing needs of tunnel cross-sections of different diameters, offering high versatility and reducing costs. Attached Figure Description

[0017] Figure 1A schematic diagram of a spraying test device used for tunnel wall support; Figure 2 A schematic diagram of the tunnel structure has been removed from the mold spraying test device used for tunnel wall support; Figure 3 A schematic diagram of the front support structure of the sprayed concrete test device used for tunnel wall support; Figure 4 A schematic diagram of the quick-release structure at the front of the sprayed concrete test device used for tunnel wall support; Figure 5 A schematic diagram of the triangular support mechanism of a spraying test device used for tunnel wall support; Figure 6 A schematic diagram of the rotating structure of a sprayed concrete test device used for tunnel wall support; Figure 7 A schematic diagram of the telescopic structure of a sprayed concrete test device used for tunnel wall support; Figure 8 for Figure 7 Enlarged view of a section of the telescopic frame; Component names in the diagram: 1. Concrete foundation; 2. Tunnel-type steel arch frame; 3. Rubber sheet; 4. Mold spraying mechanism; 5. Power supply equipment; 11. Front support; 12. Rotary telescopic mechanism; 13. Belt-type formwork; 14. Spraying nozzle; 15. Triangular support mechanism; 16. Sliding track; 21. Roller mounting hole; 22. Support bracket; 23. Connecting bolt; 24. Handle; 25. Upper mounting bracket; 26. Circular bearing; 27. Bolt through hole; 28. Upper and lower bracket connecting plate; 29. ​​Lower mounting bracket; 32. Baffle; 33. Roller mounting plate. 34. Mounting bracket; 35. Roller; 36. Locking mechanism; 37. Vertical fixing plate; 38. Back support bracket; 49. Track expansion bolt mounting hole; 40. Rotating mechanism; 41. Driven gear; 42. Driven gear; 43. Hydraulic motor; 44. Cylindrical frame; 55. Hydraulic cylinder connecting base; 56. Hydraulic cylinder base connecting hole; 57. Hydraulic oil inlet / outlet hole one; 58. Fixed hydraulic cylinder; 59. Movable hydraulic cylinder; 50. Hydraulic cylinder inlet / outlet hole two; 51. Upper connecting hole of hydraulic cylinder; 51. Fixed telescopic frame; 52. Movable telescopic frame. Detailed Implementation

[0018] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention. Example 1

[0019] This example discloses a spraying test apparatus for tunnel wall support, see [link to relevant documentation]. Figures 1 to 8The system includes a poured concrete foundation 1, a tunnel-type steel arch 2 fixedly installed on the concrete foundation 1, a rubber sheet 3 covering the outside of the tunnel-type steel arch 2, a molding and spraying mechanism 4 installed inside the tunnel-type steel arch 2, and a power supply device 5 installed on the outside of the tunnel-type steel arch 2. The molding and spraying mechanism 4 is installed on a sliding rail 16 to adjust the axial position of the molding and spraying mechanism 4. The sliding rail 16 is fixed on the concrete foundation 1. The molding and spraying mechanism 4 includes a rotary telescopic mechanism 12. A belt-type template 13 is installed above the rotary telescopic mechanism 12 to adjust the circumferential position and angle of the belt-type template 13. The rotary telescopic mechanism 12 includes a rotating structure. A telescopic structure is installed on the rotating structure 41. A front support 11 is installed on one side of the rotating structure via a support column, and the other side is installed on the sliding rail 16 via a triangular support mechanism 15.

[0020] The belt-type template 13 is installed at the spray nozzle 14.

[0021] The input port of the spraying mechanism 4 is connected to the wet spraying machine and the air compressor.

[0022] Support structures are installed on both sides below the tunnel-type steel arch frame 2.

[0023] The front support 11 includes a support bracket 22 and a quick-release structure. The quick-release structure is installed on the support bracket 22 via connecting bolts 23. The bottom of the support bracket 22 has pre-drilled roller mounting holes 21. The quick-release structure includes an upper mounting bracket 25 and a lower mounting bracket 29. The quick-release structure has a hollow structure in the middle to accommodate the support column, and multiple circular bearings 26 are arranged at intervals around the support column. The upper mounting bracket 25 and the lower mounting bracket 29 have corresponding bolt through holes 27 on their right sides, and are installed via upper and lower bracket connecting plates 28. A handle 24 is provided on the left side of the quick-release structure to lift the upper mounting bracket 25.

[0024] Baffles 32 are installed on both sides of the sliding track 16.

[0025] A locking mechanism 35 is installed at the end of the sliding track 16.

[0026] The sliding rail 16 is installed on the concrete foundation through the rail expansion bolt mounting holes 38.

[0027] The triangular support mechanism 15 includes a lower roller mounting bracket 33 for fixing the roller 34, and an upper vertical fixing plate 36 and a back support bracket 37.

[0028] The rotating mechanism 41 is mounted on the cylindrical frame 45 via bearings. The cylindrical frame 45 is welded to the triangular support mechanism 15. A hydraulic motor 44 is installed above the triangular support mechanism 15. The hydraulic motor 44 is equipped with a drive gear 43 via a coupling. A passive gear 42 is arranged around the rotating mechanism near the triangular support mechanism 15. The drive gear 43 and the passive gear 42 mesh with each other.

[0029] The rotary telescopic mechanism also includes a telescopic structure, which includes a fixed telescopic frame 58 and a movable telescopic frame 59 fitted inside it. A hydraulic cylinder connecting base 51 is welded to the bottom inner side of the fixed telescopic frame 58. The hydraulic cylinder connecting base 51 is connected to the fixed hydraulic cylinder 54 through the hydraulic cylinder base connecting hole 52. A hydraulic cylinder connecting base 51 is welded to the upper inner side of the movable telescopic frame 59. The hydraulic cylinder connecting base 51 is connected to the movable hydraulic cylinder 55 through the upper hydraulic cylinder connecting hole 57. A hydraulic oil inlet / outlet hole 1 53 and a hydraulic cylinder inlet / outlet hole 2 56 are provided at the upper and lower ends of the fixed hydraulic cylinder 54. By discharging and discharging hydraulic oil, the hydraulic cylinder is driven to extend and retract, thereby pushing the mold spraying mechanism to change the spraying diameter.

[0030] A method for test spraying for tunnel wall support, applicable to the aforementioned test apparatus for spraying for tunnel wall support, includes the following steps: S1. Test preparation: A tunnel-type steel arch frame is fixedly installed on the poured concrete foundation, and a rubber plate is wrapped around its outside to simulate a tunnel wall; the spraying mechanism is installed on the sliding rail through the triangular support mechanism at its bottom and the front support, and the power supply equipment, wet spraying machine and air compressor are connected. S2. Axial position adjustment: Adjust the axial position of the spraying mechanism by sliding the rail to move it to the test section inside the tunnel-type steel arch frame; S3. Circumferential and radial adjustment: Start the rotary telescopic mechanism, and drive the active gear and the passive gear to mesh through the hydraulic motor, so as to drive the rotating structure and the belt-type template above to rotate circumferentially, and adjust the circumferential position and angle of the template. The hydraulic cylinder is extended and retracted by controlling the hydraulic oil circuit. The hydraulic oil enters the fixed cylinder of the hydraulic cylinder through the hydraulic oil inlet and outlet holes, which pushes the movable cylinder of the hydraulic cylinder to move, so that the movable telescopic frame extends or retracts along the fixed telescopic frame, thereby adjusting the spraying diameter of the mold spraying mechanism to adapt to different tunnel cross-section dimensions. S4. Disassembly and Support Adjustment: Adjust the front support, operate the quick-release structure, and pull the handle to lift the upper mounting bracket, separating it from the lower mounting bracket, thereby quickly disassembling or installing the support column; after adjustment, re-fix it through the upper and lower bracket connecting plates and bolt through holes; S5. Mold spraying test: Start the wet spraying machine and air compressor to deliver concrete slurry to the mold spraying mechanism through the inlet. The slurry is then evenly sprayed onto the tunnel wall simulated by the rubber plate through the belt-type template. If necessary, adjust the position of the mold spraying mechanism by sliding the track, or adjust the spraying angle and diameter by rotating the telescopic mechanism.

[0031] Although some preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the invention.

[0032] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this application and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A test device for sprayed concrete for tunnel wall support, characterized in that: The system includes a poured concrete foundation, on which a tunnel-type steel arch frame is fixedly installed. The outside of the tunnel-type steel arch frame is covered with a rubber sheet. A spraying mechanism is installed inside the tunnel-type steel arch frame, and power supply equipment is installed on the outside of the tunnel-type steel arch frame. The spraying mechanism is mounted on a sliding rail to adjust its axial position, and the sliding rail is fixed to the concrete foundation. The spraying mechanism includes a rotary telescopic mechanism, above which a belt-type template is installed to adjust its circumferential position and angle. The rotary telescopic mechanism includes a rotating structure, on which a telescopic structure is installed. One side of the rotating structure has a front support mounted via a support column, and the other side is mounted on the sliding rail via a triangular support mechanism.

2. The spraying test device for tunnel wall support as described in claim 1, characterized in that: The input port of the spraying mechanism is connected to the wet spraying machine and the air compressor.

3. The spraying test device for tunnel wall support as described in claim 1, characterized in that: Support structures are installed on both sides below the tunnel-type steel arch frame.

4. The spraying test device for tunnel wall support as described in claim 1, characterized in that: The front support includes a support bracket and a quick-release structure. The bottom of the support bracket has pre-drilled roller mounting holes. The quick-release structure includes an upper mounting bracket and a lower mounting bracket. The quick-release structure has a hollow structure in the middle to accommodate the support column, and multiple circular bearings are arranged at intervals around the support column. The upper mounting bracket and the lower mounting bracket have corresponding bolt through holes on their right sides and are installed via the upper and lower bracket connecting plates. A handle is provided on the left side of the quick-release structure to lift the upper mounting bracket.

5. The spraying test device for tunnel wall support as described in claim 1, characterized in that: Baffles are installed on both sides of the sliding track.

6. The spraying test device for tunnel wall support as described in claim 1, characterized in that: The triangular support mechanism includes a lower roller mounting bracket for fixing the rollers, and an upper vertical fixing plate and a back support bracket.

7. The spraying test device for tunnel wall support as described in claim 1, characterized in that: The rotating mechanism is mounted on a cylindrical frame via bearings. The cylindrical frame is welded to a triangular support mechanism. A hydraulic motor is installed above the triangular support mechanism. The hydraulic motor is equipped with a drive gear via a coupling. A driven gear is arranged around the rotating mechanism near the triangular support mechanism. The drive gear and the driven gear mesh with each other.

8. The spraying test device for tunnel wall support as described in claim 1, characterized in that: The rotary telescopic mechanism also includes a telescopic structure, which includes a fixed telescopic frame and a movable telescopic frame fitted inside it. A hydraulic cylinder connecting base is welded to the bottom inner side of the fixed telescopic frame. The hydraulic cylinder connecting base is connected to the fixed hydraulic cylinder through a hydraulic cylinder base connecting hole. A hydraulic cylinder connecting base is welded to the upper inner side of the movable telescopic frame. The hydraulic cylinder connecting base is connected to the movable hydraulic cylinder through an upper hydraulic cylinder connecting hole. Two hydraulic oil inlet and outlet holes are provided at the upper and lower ends of the fixed hydraulic cylinder. By discharging and releasing hydraulic oil, the hydraulic cylinder is driven to extend and retract, thereby pushing the mold spraying mechanism to change the spraying diameter.

9. A method for test spraying for tunnel wall support, applicable to the spraying test apparatus for tunnel wall support as described in any one of claims 1 to 8, characterized in that, Includes the following steps: S1. Test preparation: A tunnel-type steel arch frame is fixedly installed on the poured concrete foundation, and a rubber plate is wrapped around its outside to simulate a tunnel wall; the spraying mechanism is installed on the sliding rail through the triangular support mechanism at its bottom and the front support, and the power supply equipment, wet spraying machine and air compressor are connected. S2. Axial position adjustment: Adjust the axial position of the spraying mechanism by sliding the rail to move it to the test section inside the tunnel-type steel arch frame; S3. Circumferential and radial adjustment: Start the rotary telescopic mechanism, and drive the active gear and the passive gear to mesh through the hydraulic motor, so as to drive the rotating structure and the belt-type template above to rotate circumferentially, and adjust the circumferential position and angle of the template. The hydraulic cylinder is extended and retracted by controlling the hydraulic oil circuit. The hydraulic oil enters the fixed cylinder of the hydraulic cylinder through the hydraulic oil inlet and outlet holes, which pushes the movable cylinder of the hydraulic cylinder to move, so that the movable telescopic frame extends or retracts along the fixed telescopic frame, thereby adjusting the spraying diameter of the mold spraying mechanism to adapt to different tunnel cross-section dimensions. S4. Disassembly and Support Adjustment: Adjust the front support, operate the quick-release structure, and pull the handle to lift the upper mounting bracket, separating it from the lower mounting bracket, thereby quickly disassembling or installing the support column; after adjustment, re-fix it through the upper and lower bracket connecting plates and bolt through holes; S5. Mold spraying test: Start the wet spraying machine and air compressor to deliver concrete slurry to the mold spraying mechanism through the inlet. The slurry is then evenly sprayed onto the tunnel wall simulated by the rubber plate through the belt-type template. If necessary, adjust the position of the mold spraying mechanism by sliding the track, or adjust the spraying angle and diameter by rotating the telescopic mechanism.

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