Open excavation hidden arch formwork fixing method

Abstract

The invention provides an open excavation concealed arch template fixing method, which relates to the technical field of underground engineering construction, and comprises the following steps of: calibrating a reference positioning point on an open excavation concealed arch bottom plate in a construction area; the formwork trolley is moved to a construction area, the position of the formwork trolley is adjusted according to the reference positioning point, and after adjustment is completed, the formwork trolley works to form an inner formwork assembly; a steel reinforcement framework is built on the outer side of the inner formwork assembly; an outer formwork assembly is arranged on the outer side of the steel bar framework, and annular fixing steel bars are arranged on the outer side of the outer formwork assembly; a vertical formwork is arranged on the outer side of the vertical section of the outer formwork assembly, and a supporting mechanism is arranged between the vertical formwork and the slope of the construction area. According to the method, the special formwork trolley for the tunnel is adopted as the inner formwork assembly, extra purchasing and renting of a special trolley for open excavation and hidden arch are not needed, repeated investment of two sets of equipment is avoided, meanwhile, the equipment transportation, installation, debugging and maintenance cost is reduced, and then the overall construction cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of underground engineering construction technology, and in particular to a method for fixing formwork in open-cut and concealed arch construction. Background Technology

[0002] Currently, in the fields of urban underground space development, traffic tunnels, water conservancy culverts and integrated pipe corridors, when the overlying soil layer is shallow, the geological conditions are complex (such as soft strata) or the ground environment is limited (such as proximity to important buildings or main traffic arteries), full-section cut-and-cover excavation is risky and slow, while full-cut slope excavation or support is too costly. In such cases, the cut-and-cover arch method is often adopted for construction.

[0003] Currently, the most common reinforcement method in open-cut arch construction is the "standard arch frame + tie rod" system. This involves prefabricating or assembling an arc-shaped steel arch frame (usually made of bent or segmented steel) that matches the inner contour of the arch, serving as the main load-bearing skeleton of the formwork. The arch frames are fixed together by longitudinal connections, and then steel formwork or plywood panels are laid on top. A key reinforcement measure is to install tie rods such as high-strength threaded steel bars or bolts at the two ends or specific locations of the arch frame, anchoring them to solid foundations such as the side pit support piles, diaphragm walls, or pre-cast base plates, forming a "self-balancing system." However, this system has significant limitations. It is only suitable for short-length open-cut arch construction. For long-distance, large-scale open-cut arch projects, the erection and dismantling process is cumbersome, significantly reducing construction efficiency and making it difficult to meet schedule requirements.

[0004] For long-distance cut-and-cover arch construction, the industry typically adopts customized formwork trolley solutions. These trolleys integrate inner and outer formwork, enabling overall mechanized construction and effectively improving the efficiency of long-distance construction. However, in integrated "cut-and-cover arch + tunnel" projects, the cross-sectional dimensions of the cut-and-cover arch and the tunnel are often consistent. If two sets of dedicated formwork trolleys are deployed separately according to traditional methods (one set containing both inner and outer formwork for cut-and-cover arch construction; the other set containing only inner formwork for tunnel construction), the following problems will arise: First, a large amount of additional capital is required to purchase or lease a second set of formwork trolleys, significantly increasing the upfront costs of equipment purchase, transportation, and deployment. Second, the two sets of trolleys cannot be reused during the tunnel construction phase. The dedicated cut-and-cover arch trolley is idle for a long time, while the tunnel trolley is stationary during the cut-and-cover arch construction phase, resulting in a significant reduction in the utilization rate of expensive equipment assets, low equipment turnover efficiency, and a substantial increase in construction costs. Summary of the Invention

[0005] This invention provides a method for fixing formwork in open-cut tunnel arches, which solves the technical problem that in current projects integrating open-cut tunnel arches and tunnels, the cross-sectional dimensions of the two are the same, but two sets of special formwork trolleys are required, resulting in a significant increase in construction costs.

[0006] To solve the above-mentioned technical problems, this invention discloses a method for fixing formwork in open-cut and concealed arch construction, comprising the following steps: Mark the benchmark positioning points on the bottom slab of the open-cut and concealed arch in the construction area; Move the formwork trolley to the construction area, adjust the position of the formwork trolley according to the benchmark positioning point, and after the adjustment is completed, the formwork trolley works to form the inner formwork assembly; A steel reinforcement frame is erected on the outside of the inner formwork assembly; An outer formwork assembly is installed on the outside of the steel reinforcement cage, and circumferential fixing steel bars are installed on the outside of the outer formwork assembly; Vertical formwork is installed on the outside of the vertical section of the outer formwork assembly, and a support mechanism is installed between the vertical formwork and the slope of the construction area.

[0007] Preferably, a number of positioning bars are provided inside the steel reinforcement cage. The end of the positioning bar away from the inner formwork assembly extends to the outside of the steel reinforcement cage and is provided with supporting bars. The supporting bars are provided along the outer contour of the steel reinforcement cage.

[0008] Preferably, the outer formwork assembly includes several transverse formwork groups arranged along the axis of the reinforcing steel skeleton. Each transverse formwork group includes several transverse formwork bodies, which are arranged along the outer contour of the reinforcing steel skeleton. The inner side of each transverse formwork body is in contact with the supporting reinforcing steel.

[0009] Preferably, a number of connecting steel bars are provided between the circumferential fixed steel bars and the steel cage. The connecting steel bars are arranged at intervals along the circumferential direction of the steel cage. One end of the connecting steel bar is fixedly connected to the steel cage, and the other end of the connecting steel bar is fixedly connected to the circumferential fixed steel bar.

[0010] Preferably, several gap-filling strips are provided between the circumferential fixed reinforcing bars and the outer formwork assembly, and the gap-filling strips are provided along the axial direction of the outer formwork assembly.

[0011] Preferably, the support mechanism includes several support tubes, each with a first threaded hole at both ends. A first screw is installed in each of the two first threaded holes. The outer wall of the first screw is threadedly connected to the inner wall of the first threaded hole via an external thread. One end of the first screw extends to the outside of the support tube and is rotatably connected to a connecting block. A pressure block is installed at the end of the connecting block away from the first screw. The pressure block is hinged to the connecting block. A contact pad is installed at the end of the pressure block away from the connecting block. The contact pad is made of an elastic material.

[0012] Preferably, the support mechanism further includes a support column, the front end of the support tube is rotatably connected to the support column via a rotating shaft, the rotating shaft is evenly spaced along the axial direction of the support column, a support seat is provided at the lower end of the support column, and the support column is perpendicular to the support seat.

[0013] Preferably, a lifting lug is provided at the upper end of the support column.

[0014] Preferably, a sliding cavity is provided inside the support column, and the sliding cavity is arranged along the axial direction of the support column. A rack is slidably arranged inside the sliding cavity, and one side wall of the rack is slidably connected to the inner wall of the sliding cavity. The upper end of the rack is connected to the top wall of the sliding cavity through a connecting spring. The front end of the rotating shaft extends into the sliding cavity and is provided with a gear. The gear meshes with the side wall of the rack. A second threaded hole is provided at the lower end of the rack, and a second screw is provided inside the second threaded hole. The outer wall of the second screw is threadedly connected to the inner wall of the second threaded hole. A groove is provided on the bottom wall of the support base. The upper end of the groove is connected to the bottom wall of the sliding cavity through a connecting hole. The lower end of the second screw passes through the connecting hole and is provided with a movable seat.

[0015] Preferably, an air pump and controller are installed on the side wall of the support column, and a cavity is provided inside the contact pad. The output end of the air pump is connected to the inside of the cavity through an air pipe, and a solenoid valve is installed on the air pipe. A pressure sensor is installed inside the cavity to collect the pressure inside the cavity in real time and transmit it to the controller. The controller is electrically connected to the air pump, the solenoid valve and the pressure sensor respectively. The controller has a preset pressure threshold. When the pressure collected by the pressure sensor is lower than the lower limit of the preset pressure threshold, the controller controls the air pump to start and the solenoid valve to open to inflate the cavity. When the pressure collected by the pressure sensor is higher than the upper limit of the preset pressure threshold, the controller controls the solenoid valve to open to release the gas in the cavity. When the pressure is within the preset pressure threshold range, the controller controls the air pump to stop and the solenoid valve to close, so as to maintain the stable support pressure of the contact pad.

[0016] The technical solution of this invention has the following advantages: This invention provides a method for fixing formwork in open-cut and concealed arch tunnels, relating to the field of underground engineering construction technology, including the following steps: marking reference positioning points on the bottom slab of the open-cut and concealed arch tunnel in the construction area; moving the formwork trolley to the construction area, adjusting the position of the formwork trolley according to the reference positioning points, and after adjustment, the formwork trolley operates to form an inner formwork assembly; building a steel reinforcement frame on the outside of the inner formwork assembly; setting an outer formwork assembly on the outside of the steel reinforcement frame, and setting circumferential fixing steel bars on the outside of the outer formwork assembly; setting a vertical formwork on the outside of the vertical section of the outer formwork assembly, and setting a support mechanism between the vertical formwork and the slope of the construction area. In this invention, a tunnel-specific formwork trolley is used as the inner formwork assembly, eliminating the need for additional purchase or rental of open-cut and concealed arch tunnel-specific trolleys, avoiding redundant investment in two sets of equipment, and reducing equipment transportation, installation, commissioning, and maintenance costs, thereby reducing the overall construction cost.

[0017] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the means particularly pointed out in the written description and the accompanying drawings.

[0018] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a flowchart illustrating a method for fixing formwork in an open-cut, concealed arch structure according to the present invention. Figure 2 This is a schematic diagram of the template trolley and outer template structure in this invention; Figure 3 For the present invention Figure 2 Enlarged view of the structure at point A in the middle; Figure 4 This is a schematic diagram of the overall structure of the support mechanism in this invention; Figure 5 This is a schematic diagram of the internal structure of the support tube in this invention.

[0020] In the diagram: 1. Template trolley; 2. Inner template assembly; 3. Reinforcing steel cage; 4. Outer template assembly; 5. Circumferential fixing reinforcement; 6. Vertical template; 7. Slope; 8. Support mechanism; 9. Supporting reinforcement; 10. Horizontal template body; 11. Connecting reinforcement; 12. Gap filler strip; 13. Support pipe; 14. First screw; 15. Connecting block; 16. Pressure block; 17. Contact pad; 18. Support column; 19. Rotating shaft; 20. Support seat; 21. Lifting lug; 22. Sliding cavity; 23. Rack; 24. Connecting spring; 25. Gear; 26. Second screw; 27. Groove; 28. Moving seat; 29. ​​Air pump; 30. Cavity; 31. Air pipe; 32. Positioning reinforcement. Detailed Implementation

[0021] 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.

[0022] Furthermore, in this invention, the use of terms such as "first" and "second" is for descriptive purposes only and does not specifically refer to any order or sequence, nor is it intended to limit the invention. They are merely used to distinguish components or operations described using the same technical terms and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions and features of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If a combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0023] Example 1: This embodiment of the invention provides a method for fixing the formwork of a cut-and-cover arch structure, such as... Figures 1-5 As shown, it includes the following steps: Mark the benchmark positioning points on the bottom slab of the open-cut and concealed arch in the construction area; Move the formwork trolley 1 to the construction area, adjust the position of the formwork trolley 1 according to the benchmark positioning point, and after the adjustment is completed, the formwork trolley 1 works to form the inner formwork component 2. A steel reinforcement frame 3 is erected on the outside of the inner formwork component 2; An outer formwork assembly 4 is installed on the outside of the steel reinforcement cage 3, and a circumferential fixing steel bar 5 is installed on the outside of the outer formwork assembly 4; A vertical formwork 6 is installed on the outside of the vertical section of the outer formwork assembly 4, and a support mechanism 8 is installed between the vertical formwork 6 and the slope 7 of the construction area; A number of positioning steel bars 32 are provided inside the steel reinforcement cage 3. The end of the positioning steel bar 32 away from the inner formwork component 2 extends to the outside of the steel reinforcement cage 3 and is provided with a supporting steel bar 9. The supporting steel bar 9 is provided along the outer contour of the steel reinforcement cage 3. The outer formwork assembly 4 includes several transverse formwork groups arranged along the axis of the steel reinforcement skeleton 3. Each transverse formwork group includes several transverse formwork bodies 10. The transverse formwork bodies 10 are arranged along the outer contour of the steel reinforcement skeleton 3, and the inner side of the transverse formwork bodies 10 contacts the supporting steel reinforcement 9. A number of connecting steel bars 11 are provided between the circumferential fixed steel bar 5 and the steel cage 3. The connecting steel bars 11 are arranged circumferentially along the steel cage 3. One end of the connecting steel bar 11 is fixedly connected to the steel cage 3, and the other end of the connecting steel bar 11 is fixedly connected to the circumferential fixed steel bar 5. Several gap-filling strips 12 are set between the circumferential fixed steel bar 5 and the outer formwork assembly 4, and the gap-filling strips 12 are set along the axial direction of the outer formwork assembly 4.

[0024] The working principle and beneficial effects of the above technical solution are as follows: First, benchmark positioning points are marked on the bottom slab of the open-cut and hidden arch to provide a reference for the positioning of the formwork trolley 1 and the installation of the outer formwork assembly 4. The benchmark positioning points include the midpoint and the edge points, which can be marked by surveying and setting out. Surveyors are arranged to set out the midpoint and the edge points on the completed open-cut and hidden arch bottom slab. Then, the formwork trolley is positioned by moving the formwork trolley 1 to the construction area. The formwork trolley 1 can be a special type used for tunnel construction. The position of the formwork trolley 1 is adjusted according to the benchmark positioning points. After the adjustment is completed, the formwork trolley 1 works to form the inner formwork assembly 2. Specifically, the endpoint of the formwork trolley 1 can be checked against the midpoint marked out by using a plumb bob at the top of the arch. The formwork trolley 1 is adjusted by moving back and forth and swinging the top formwork left and right. Position the formwork trolley 1 until the plumb bob aligns with the midpoint, then lock the traveling mechanism of the formwork trolley 1. Next, adjust the hydraulic system of the formwork trolley 1 to unfold the side formwork. Lower the plumb bob at the arching point to adjust the verticality of the side formwork of the formwork trolley 1 and position it to the inner contour of the open-cut and hidden arch. After the formwork trolley 1 is positioned, tighten all the screw rods of the formwork trolley 1. At this point, the inner formwork assembly 2 is completed. Next, the reinforcement is tied. According to the design drawings, a reinforcement cage 3 is built on the outside of the inner formwork assembly 2. Several positioning reinforcement bars 32 are set inside the reinforcement cage 3. The positioning reinforcement bars 32 are circumferentially spaced along the outer wall of the reinforcement cage 3 corresponding to the designed thickness of the concrete protective layer, and several groups are equally spaced along the axial direction of the reinforcement cage 3. The positioning reinforcement bars 32 are welded to the reinforcement cage 3. The connection is made to form a stable connection structure, ensuring the installation accuracy and load-bearing stability of the positioning steel bar 32, thereby ensuring that the thickness of the concrete cover meets the design specifications. The positioning steel bar 32 can serve as the connection base for the 8mm diameter support steel bar 9. Then, the 8mm diameter support steel bar 9 is longitudinally welded to the positioning steel bar 32. The support steel bar 9 is set along the outer contour of the steel reinforcement skeleton 3. By setting several support steel bars 9, the support form is transformed from point support to line support, thereby supporting each transverse formwork body 10. Then, the outer formwork assembly 4 is set on the outside of the steel reinforcement skeleton 3. The outer formwork assembly 4 includes several transverse formwork groups set along the axial direction of the steel reinforcement skeleton 3. The transverse formwork groups include several transverse formwork bodies 10. The several transverse formwork bodies 10 are set along the axial direction of the steel reinforcement skeleton 3. The outer contour of the reinforcing steel frame 3 is set, with adjacent transverse formwork bodies 10 contacting each other. The inner side of the transverse formwork body 10 contacts the supporting reinforcing steel 9. Each transverse formwork body 10 corresponds to at least 3 supporting reinforcing steel 9, which can not only achieve stable support for the inner side of the transverse formwork body 10 by the supporting reinforcing steel 9, but also ensure that the thickness of the concrete protective layer is uniform. The transverse formwork body 10 can be made of lightweight wood. After the transverse formwork body 10 is laid, the outer formwork assembly 4 is completed. Then, several circumferential fixing reinforcing steel bars 5 are used to tighten the outer formwork assembly 4 to fix the outer formwork assembly 4 and resist the buoyancy of the concrete. The circumferential fixing reinforcing steel bars 5 are arranged circumferentially along the entire length of the outer formwork assembly 4 and welded closed at the top of the arch. The circumferential fixing reinforcing steel bars 5 can be made of steel bars with a diameter of 20mm.Along the outer wall of the reinforcing steel frame 3, a connecting steel bar 11 with a diameter of 14mm is installed every 1m axially (to ensure that each transverse formwork body 10 is fixed by 3 outer circumferential fixing steel bars 5) and every 90cm circumferentially (corresponding to three transverse formwork bodies 10). The inner side of the connecting steel bar 11 is welded to the open-cut arch reinforcing steel frame 3, and the outer side of the connecting steel bar 11 is welded to the circumferential fixing steel bars 5. The circumferential fixing steel bars 5 are installed at equal intervals of 1m along the axial direction of the reinforcing steel frame 3, and are arranged along the circumferential length of the open-cut arch, with one on each side of the open-cut arch, and welded at the arch top position to fix the outer formwork and resist the buoyancy of the concrete. Several gap-filling strips 12 are installed between the circumferential fixing steel bars 5 and the outer formwork assembly 4. The gap-filling strips 12 can be made of wooden wedges. The gap-filling strips 12 can eliminate the circumferential fixing The gap between the reinforcing bar 5 and the outer formwork assembly 4 is tightened from the outside to resist the buoyancy and lateral pressure during concrete pouring. Then, a vertical formwork 6 is added to the vertical section of the outer formwork assembly 4. The vertical formwork 6 is pressed against the slope 7 by the support mechanism 8 to form a lateral reinforcement structure that supports the vertical formwork 6 and the slope 7, preventing the formwork from bulging during concrete pouring. Finally, concrete is poured between the outer formwork assembly 4 and the inner formwork assembly 2. After the space between the outer formwork assembly 4 and the inner formwork assembly 2 is completely filled, the concrete pouring is completed. Subsequently, the side formwork and top formwork of the formwork trolley 1 are retrieved and can be moved to the next construction position. At the same time, the support mechanism 8, the vertical formwork 6, the circumferential fixing reinforcing bar 5 and the outer formwork assembly 4 are removed so that they can be installed at the next construction position for easy recycling. In this invention, a tunnel-specific formwork trolley 1 is used as the inner formwork component 2, eliminating the need for additional procurement or rental of special open-cut arch trolleys, avoiding redundant investment in two sets of equipment, and reducing equipment transportation, installation, commissioning, and maintenance costs, thereby lowering the overall construction cost. The outer formwork component 4 uses lightweight wooden formwork, which can be installed and dismantled manually without the need for cranes or other large machinery, saving on machinery rental and site leveling costs. Using the formwork trolley 1 eliminates the need for internal support frames; after positioning and adjustment, it can be quickly unfolded to form the inner formwork component 2. With the pre-bent circumferential fixing steel bars 5, the welding connection of the supporting steel bars 9 and the positioning steel bars 32, and the assembly of the connecting steel bars 11 and the circumferential fixing steel bars 5, all require no complex procedures. In long-distance open-cut arch construction, there is no need to repeatedly erect and dismantle scaffolding, improving construction progress.

[0025] Example 2: Based on Example 1 above, the support mechanism 8 includes several support tubes 13. The two ends of the support tubes 13 are provided with first threaded holes. The two first threaded holes are respectively provided with first screws 14. The outer wall of the first screw 14 is connected to the inner wall of the first threaded hole through external thread. One end of the first screw 14 extends to the outside of the support tube 13 and is rotatably provided with a connecting block 15. The end of the connecting block 15 away from the first screw 14 is provided with a pressure block 16. The pressure block 16 is hinged to the connecting block 15. The end of the pressure block 16 away from the connecting block 15 is provided with a contact pad 17. The contact pad 17 is made of elastic material.

[0026] The working principle and beneficial effects of the above technical solution are as follows: A support mechanism 8 is arranged between the outer side of the vertical template 6 and the slope 7. The support pipe 13 serves as the core load-bearing carrier. The first screws 14 at both ends form a threaded transmission engagement with the first threaded holes on the inner wall of the support pipe 13, constituting an adjustable-length support body. When the first screws 14 are rotated, the extension length of the first screws 14 at both ends of the support pipe 13 can be precisely adjusted by utilizing the threaded transmission between the outer wall of the first screws 14 and the first threaded holes, thereby adapting to different distances between the vertical template 6 and the slope 7, until one contact pad 17 contacts the vertical template 6 and the other contact pad 17 contacts the slope 7, ensuring that the support mechanism 8 can tightly support between the two and avoid gaps. The connecting block 15 and the pressure block 16 at the end of the screw are hinged, allowing the pressure block 16 to rotate flexibly around the connecting block 15, which can adapt to the slope. The tilt angle of 7 and the flatness of the outer wall of the vertical template 6 enable the pressure block 16 to make surface contact with the vertical template 6 and the slope 7, thereby improving the stability of the support. At the same time, the elastic material contact pad 17 at the end of the pressure block 16 can undergo elastic deformation, further filling the tiny gaps on the contact surface, improving the tightness of the fit, and increasing the friction of the contact surface to prevent the support mechanism 8 from slipping off. It can also play a buffering role when instantaneous lateral pressure is generated during concrete pouring, reducing the impact damage of pressure on the vertical template 6 and the slope 7, and preventing soil detachment from the slope 7 or local damage to the template. During concrete pouring, the support mechanism 8 can provide continuous and stable lateral support force. The lateral pressure on the vertical template 6 is transmitted to the slope 7 through the pressure block 16, connecting block 15, first screw 14, and support pipe 13. The bearing capacity of the slope 7 is used to offset the lateral pressure and strengthen the anti-bulging ability of the vertical template 6.

[0027] Example 3: Based on Example 2, the support mechanism 8 further includes a support column 18. The front end of the support tube 13 is rotatably connected to the support column 18 through a rotating shaft 19. The rotating shaft 19 is evenly spaced along the axial direction of the support column 18. A support seat 20 is provided at the lower end of the support column 18. The support column 18 is perpendicular to the support seat 20. A lifting lug 21 is provided at the upper end of the support column 18.

[0028] The working principle and beneficial effects of the above technical solution are as follows: After the vertical formwork 6 is installed, the support base 20 is placed flat on the ground of the construction area and compacted and fixed. The support column 18 is set perpendicular to the support base 20. The support base 20 can provide a stable force carrier for the support pipe 13, avoiding tilting or settlement caused by the support pipe 13 directly contacting the ground. The front end of the support pipe 13 is rotatably connected to the support column 18 through the rotating shaft 19, and the rotating shaft 19 is evenly spaced along the axial direction of the support column 18. By rotating the support pipe 13, the angle between the support pipe 13 and the vertical formwork 6 and the slope 7 can be precisely adjusted, thereby adapting to different slope 7 inclination angles. After the inclination angle of the support pipe 13 is adjusted... Then, the first screw 14 can be rotated until the contact pad 17 is tightly fitted with the vertical template 6 and the slope 7. The lifting lug 21 at the upper end of the support column 18 provides a force point for the overall transfer of the support mechanism 8. It can be quickly moved and deployed in the construction area by small lifting equipment or manual lifting, without the need for manual handling and assembly of each part, thereby improving construction efficiency and reducing construction intensity. The support column 18 and the support base 20 form a vertical stable benchmark, providing rigid support for the support pipe 13, avoiding the tilting and displacement of the support pipe 13 due to uneven force, improving the anti-overturning ability of the support mechanism 8, and further strengthening the anti-bulging effect of the vertical template 6.

[0029] Example 4: Based on Example 3, a sliding cavity 22 is provided inside the support column 18. The sliding cavity 22 is arranged along the axial direction of the support column 18. A rack 23 is slidably arranged inside the sliding cavity 22. One side wall of the rack 23 is slidably connected to the inner wall of the sliding cavity 22. The upper end of the rack 23 is connected to the top wall of the sliding cavity 22 through a connecting spring 24. The front end of the rotating shaft 19 extends into the sliding cavity 22 and is provided with a gear 25. The gear 25 meshes with the side wall of the rack 23. A second threaded hole is provided at the lower end of the rack 23. A second screw 26 is provided in the second threaded hole. The outer wall of the second screw 26 is threadedly connected to the inner wall of the second threaded hole. A groove 27 is provided on the bottom wall of the support seat 20. The upper end of the groove 27 is connected to the bottom wall of the sliding cavity 22 through a connecting hole. The lower end of the second screw 26 passes through the connecting hole and is provided with a movable seat 28.

[0030] The working principle and beneficial effects of the above technical solution are as follows: When the support base 20 is placed, the movable base 28 first contacts the ground. As the support base 20 is lowered, the movable base 28 moves towards the groove 27 and drives the rack 23 to slide upward along the sliding cavity 22 via the second screw 26. The connecting spring 24 is gradually compressed, and the rack 23 meshes with the gear 25 to drive the rotating shaft 19 to rotate. The rotation of the rotating shaft 19 drives the support tube 13 to rotate, thereby adjusting the inclination angle of the support tube 13. After the support base 20 is fully in contact with the ground, the movable base 28 is located in the groove 27. At this time, the inclination angle of the support tube 13 is fixed, and the position of the contact pad 17 can be adjusted by rotating the first screw 14. Through the above solution, the inclination angle of the support tube 13 can be automatically adjusted without manual adjustment, further improving construction efficiency. In addition, the movable base 28 moves towards the groove 27 via the second screw 26 and the rack 28. 3. The lower end is connected, and rotating the second screw 26 can adjust the extension length of the second screw 26, thereby adjusting the inclination angle of the support pipe 13 according to the construction scene, so as to achieve precise control of the angle of the support pipe 13. During the dismantling process, only small lifting equipment or manual lifting lugs are needed. During the upward lifting process, the contact pad 17 gradually separates from the contact surface of the vertical template 6 or slope 7. Under the action of gravity, the moving seat 28 moves downward and separates from the groove 27. The moving seat 28 drives the rack 23 to slide downward through the second screw 26. The rack 23 drives the rotating shaft to rotate in the opposite direction through the meshing with the gear 25, so that the inclination angle of the support pipe 13 gradually decreases and tends to be vertical, thereby reducing the overall storage volume of the support mechanism 8 and the support column 18, making it easier to transport multiple support mechanisms 8 as a whole to the next construction area, improving the handling efficiency, and further improving the construction efficiency.

[0031] Example 5: Based on Example 4, an air pump 29 and a controller are installed on the side wall of the support column 18, and a cavity 30 is provided inside the contact pad 17. The output end of the air pump 29 is connected to the inside of the cavity 30 through an air pipe 31. A solenoid valve is installed on the air pipe 31, and a pressure sensor is installed inside the cavity 30. The pressure sensor is used to collect the pressure inside the cavity 30 in real time and transmit it to the controller. The controller is electrically connected to the air pump 29, the solenoid valve, and the pressure sensor. The controller has a preset pressure threshold. When the pressure collected by the pressure sensor is lower than the lower limit of the preset pressure threshold, the controller controls the air pump 29 to start and the solenoid valve to open to inflate the cavity 30. When the pressure collected by the pressure sensor is higher than the upper limit of the preset pressure threshold, the controller controls the solenoid valve to open to release the gas inside the cavity 30. When the pressure is within the preset pressure threshold range, the controller controls the air pump 29 to stop and the solenoid valve to close, maintaining the stable support pressure of the contact pad 17.

[0032] The working principle and beneficial effects of the above technical solution are as follows: The pressure sensor inside the contact pad 17 collects the pressure data of the contact surface between the contact pad 17 and the vertical template 6 or slope 7 in real time, and converts the pressure signal into an electrical signal and transmits it to the controller. The controller has a preset pressure threshold, such as 20~30kN. When the collected pressure is less than the minimum value of the preset pressure threshold, the controller controls the air pump 29 to start and the solenoid valve to open, inflating the cavity 30 of the contact pad 17 through the air pipe 31, causing the contact pad 17 to expand elastically and fill the tiny gaps in the contact surface until the pressure reaches the preset pressure threshold, at which point the air pump 29 stops and the solenoid valve closes. When the pressure collected by the pressure sensor is greater than the maximum value of the preset pressure threshold, the controller instructs the solenoid valve to open, releasing some of the gas in the cavity 30. The contact pad 17 contracts moderately, and the solenoid valve closes after the pressure drops to the preset pressure threshold range. A mobile power supply is also installed on the support column 18, which is electrically connected to the controller, air pump, pressure sensor and solenoid valve respectively, thereby supplying power to the controller, air pump, pressure sensor and solenoid valve. Through the above scheme, the pressure of the contact pad 17 can be automatically adjusted, avoiding the problem of uneven pressure caused by manual adjustment, improving the contact surface fit, effectively preventing the support mechanism 8 from slipping or local stress concentration. During the concrete pouring process, the lateral pressure fluctuates dynamically. The rapid response of the air pump 29 and the solenoid valve can compensate for pressure changes in real time. The contact pad 17 absorbs instantaneous impact loads by inflating or deflating, improving the buffer performance and reducing the risk of damage to the vertical formwork 6 and soil detachment from the slope 7.

[0033] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0034] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0035] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. Other modifications can be easily made by those skilled in the art. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A method of fixing a template for a cut-and-cover arch, characterized by, The method comprises the following steps: Marking a reference positioning point on a open-cut hidden-arch bottom plate of a construction area; Moving a formwork trolley (1) to the construction area, adjusting the position of the formwork trolley (1) according to the reference positioning point, and after the adjustment is completed, the formwork trolley (1) works to form an inner formwork assembly (2); Building a steel reinforcement cage (3) outside the inner formwork assembly (2); Setting an outer formwork assembly (4) outside the steel reinforcement cage (3) and setting a circumferential fixing steel bar (5) outside the outer formwork assembly (4); Setting a vertical formwork (6) outside the vertical section of the outer formwork assembly (4), and setting a support mechanism (8) between the vertical formwork (6) and a slope (7) of the construction area.

2. The method of claim 1, wherein, The steel reinforcement cage (3) is provided with a plurality of positioning steel bars (32), one end of the positioning steel bars (32) extending to the outside of the steel reinforcement cage (3) away from the inner formwork assembly (2) and being provided with a support steel bar (9), and the support steel bar (9) is arranged along the outer contour of the steel reinforcement cage (3).

3. The method of claim 2, wherein, The outer formwork assembly (4) comprises a plurality of transverse formwork assemblies arranged along the axis direction of the steel reinforcement cage (3), each transverse formwork assembly comprises a plurality of transverse formwork bodies (10), the plurality of transverse formwork bodies (10) are arranged along the outer contour of the steel reinforcement cage (3), and the inner side of each transverse formwork body (10) is in contact with the support steel bar (9).

4. The method of claim 3, wherein, A plurality of connecting steel bars (11) are arranged between the circumferential fixing steel bar (5) and the steel reinforcement cage (3), the connecting steel bars (11) are arranged at intervals along the circumferential direction of the steel reinforcement cage (3), one end of each connecting steel bar (11) is fixedly connected with the steel reinforcement cage (3), and the other end of each connecting steel bar (11) is fixedly connected with the circumferential fixing steel bar (5).

5. The method of claim 1, wherein, A plurality of gap-filling strips (12) are arranged between the circumferential fixing steel bar (5) and the outer formwork assembly (4), and the gap-filling strips (12) are arranged along the axis direction of the outer formwork assembly (4).

6. The method of claim 1, wherein, The support mechanism (8) comprises a plurality of support pipes (13), the two ends of each support pipe (13) are provided with first threaded holes, a first screw rod (14) is arranged in each first threaded hole, the outer wall of the first screw rod (14) is in threaded transmission connection with the inner wall of the first threaded hole through external threads, one end of the first screw rod (14) extends to the outside of the support pipe (13) and is rotatably provided with a connecting block (15), a pressing block (16) is arranged at the end of the connecting block (15) away from the first screw rod (14), the pressing block (16) is hingedly connected with the connecting block (15), a contact pad (17) is arranged at the end of the pressing block (16) away from the connecting block (15), and the contact pad (17) is made of elastic material.

7. The method of claim 6, wherein, The support mechanism (8) further comprises a support column (18), the front end of each support pipe (13) is rotatably connected with the support column (18) through a rotating shaft (19), the rotating shafts (19) are arranged at intervals along the axis direction of the support column (18), the lower end of the support column (18) is provided with a support base (20), and the support column (18) is perpendicular to the support base (20).

8. The method of claim 7, wherein, A lifting lug (21) is arranged at the upper end of the support column (18).

9. The method of claim 7, wherein, A sliding cavity (22) is arranged in the support column (18), the sliding cavity (22) is arranged axially along the support column (18), a rack (23) is arranged in the sliding cavity (22) and slides, one side wall of the rack (23) is connected to the upper and lower inner walls of the sliding cavity (22), the upper end of the rack (23) is connected to the top wall of the sliding cavity (22) through a connecting spring (24), the front end of the rotating shaft (19) extends into the sliding cavity (22) and a gear (25) is arranged, the gear (25) is engaged with the side wall of the rack (23), the lower end of the rack (23) is provided with a second threaded hole, a second screw rod (26) is arranged in the second threaded hole, the outer wall of the second screw rod (26) is threadedly connected to the inner wall of the second threaded hole, the bottom wall of the support base (20) is provided with a groove (27), the upper end of the groove (27) is communicated with the bottom wall of the sliding cavity (22) through a communication hole, and the lower end of the second screw rod (26) penetrates through the communication hole and is provided with a moving seat (28).

10. The method of claim 9, wherein, A gas pump (29) and a controller are arranged on the side wall of the support column (18), a cavity (30) is arranged in the contact pad (17), the output end of the gas pump (29) is communicated with the inside of the cavity (30) through a gas pipe (31), an electromagnetic valve is arranged on the gas pipe (31), a pressure sensor is arranged in the cavity (30), the pressure sensor is used for collecting the pressure in the cavity (30) in real time and transmitting to the controller, the controller is electrically connected with the gas pump (29), the electromagnetic valve and the pressure sensor, a preset pressure threshold is arranged in the controller, when the pressure collected by the pressure sensor is lower than the lower limit of the preset pressure threshold, the controller controls the gas pump (29) to start and the electromagnetic valve to open to inflate the cavity (30); when the pressure collected by the pressure sensor is higher than the upper limit of the preset pressure threshold, the controller controls the electromagnetic valve to open to release the gas in the cavity (30); when the pressure is within the preset pressure threshold range, the gas pump (29) is stopped and the electromagnetic valve is closed to maintain the stable support pressure of the contact pad (17).

Images