A pressure steel pipe fixing device and fixing method

Abstract

The application belongs to the technical field of installation of pressure steel pipe of hydropower station, and particularly discloses a pressure steel pipe fixing device and fixing method, which comprises a locking fixing support pier, a locking fixing hinge, a locking movable hinge and a limiting unit; the locking fixing hinge and the locking fixing support pier are pre-buried in concrete, and the locking movable hinge is rotationally connected with the locking fixing hinge; the locking fixing support pier is used for limiting the downstream rotation of the locking movable hinge; the limiting unit is used for limiting the angle of the upstream rotation of the locking movable hinge, and when the locking movable hinge rotates to a preset angle, the limiting unit can abut against the locking movable hinge; the locking movable hinge has two working surfaces, when the pressure steel pipe is in a locking position, the locking fixing support pier abuts against one of the working surfaces of the locking movable hinge, and the stiffening ring of the pressure steel pipe abuts against the other working surface of the locking movable hinge. The application can temporarily fix the pressure steel pipe during installation, and ensures the construction safety.

Description

Technical Field

[0001] This invention relates to the field of pressure steel pipe installation technology in hydropower stations, specifically to a pressure steel pipe fixing device and fixing method. Background Technology

[0002] Currently, there are three main methods for installing pressure steel pipes in the downward bend of hydropower stations. The first method involves processing the pressure steel pipe into tile-like shapes, assembling them into circular sections and welding the longitudinal seams inside the tunnel, and then sequentially lowering them through the upper horizontal tunnel, upper bend, and vertical shaft to the downward bend installation position, proceeding from downstream to upstream. The second method involves using steel strands and a hydraulic cylinder for overall lifting and installation. Specific steps include setting anchor points at the front end of the downward bend pressure steel pipe and configuring multiple movable stress points at the front end, while installing tracks within the downward bend section. Steel wheels or slippers are installed on corresponding parts of the steel pipe, and a large-tonnage hydraulic hoist and corresponding steel strands are used inside the tunnel to connect the anchor points and movable stress points. When the hydraulic hoist operates, the length of the steel strands shortens, thus pulling the steel pipe forward. As the steel pipe moves forward, it is assembled and welded section by section at the starting point until it is lifted into position and the welding is completed. This method has been applied in the installation of pressure steel pipes at the Huangjinping Hydropower Station and was published on September 22, 2014, in the proceedings of the 8th National Conference on Pressure Pipelines for Hydropower Stations, entitled "Application of Hydraulic Overall Lifting Technology in the Installation of Pressure Steel Pipes in Hydropower Stations". The third method is hydraulic jacking technology, which involves transporting the bend from the installation bay to the powerhouse and using a bridge crane to lift it onto a lower horizontal section transport trolley, then transporting it to the bend location. At this location, a stepping hydraulic device is used to advance the entire bend section from bottom to top. This technology was applied in the installation of pressure steel pipes in the water diversion tunnel of the Ertan Hydropower Station and was published in the first issue of "Hydropower Station Electromechanical Technology" in 2001, entitled "Construction of Pressure Steel Pipes at Ertan Hydropower Station".

[0003] In the above methods, when using hydraulic jacking technology to install downward-bending pressure steel pipes, external support and fixation can only be carried out after the entire pipe section has been installed. During installation, the steel pipe needs to be temporarily fixed: small pressure steel pipes can be fixed with wedges or rail clamps, however, such fixing methods cannot guarantee construction safety for large pressure steel pipes. Therefore, for the installation of downward-bending pressure steel pipes using hydraulic jacking technology, there is an urgent need to invent a pressure steel pipe fixing device to temporarily fix the pressure steel pipe during installation and ensure construction safety. Summary of the Invention

[0004] This invention provides a pressure steel pipe fixing device and fixing method, which aims to temporarily fix the pressure steel pipe during the installation process to ensure construction safety.

[0005] This invention is achieved through the following technical solution: a pressure steel pipe fixing device, comprising a locking fixing support, a locking fixing hinge, a locking movable hinge, and a limiting unit;

[0006] Both the locking hinge and the locking support are embedded in concrete, and the locking hinge is rotatably connected to the locking hinge.

[0007] The locking fixed support is used to restrict the downstream rotation of the locking movable hinge;

[0008] The limiting unit is used to limit the angle of the locking hinge rotating upstream. When the locking hinge rotates to a preset angle, the limiting unit can abut against the locking hinge.

[0009] The locking hinge has two working surfaces. When the pressure steel pipe is in the locked position, the locking fixed support abuts against one of the working surfaces of the locking hinge, and the stiffening ring of the pressure steel pipe abuts against the other working surface of the locking hinge.

[0010] Compared with existing technologies, this solution has the following advantages and beneficial effects:

[0011] During the installation of pressure steel pipes, especially in the downward bend section, there is a tendency for the pipe to slide downstream due to gravity and slope. In this solution, the locking fixed support and the locking movable hinge work together. The locking fixed support restricts the downstream rotation of the locking movable hinge, while when the stiffening ring of the pressure steel pipe abuts against one working surface of the locking movable hinge, and the locking fixed support abuts against the other working surface of the locking movable hinge, a bidirectional restraint is formed on the pressure steel pipe. The stiffening ring, as a reinforcing structure of the steel pipe, can withstand a large load. Clamped by the locking movable hinge and the locking fixed support, it effectively prevents the steel pipe from sliding down during jacking gaps, welding, and other construction stages, providing a safe working environment for construction personnel and significantly reducing safety risks during construction.

[0012] Compared to traditional methods that rely on a single support point or simple constraints to fix pressure steel pipes, the bidirectional limiting structure in this solution offers greater stability. In existing technologies, in some similar projects, ordinary support blocks are used to fix pressure steel pipes. However, under complex geological conditions or construction vibrations, the support blocks are prone to displacement, causing the steel pipe to slide down. In contrast, this solution, through the tight cooperation between the locking fixed support and the locking movable hinge, effectively fixes the steel pipe under various complex working conditions, ensuring construction safety.

[0013] Furthermore, as the stiffening ring of the pressure steel pipe passes through the locking hinge, it will push the locking hinge to rotate counterclockwise upstream, and cause one of the working surfaces of the locking hinge to abut against the limiting unit. After the stiffening ring of the pressure steel pipe has completely passed through the locking hinge, the locking hinge can rotate clockwise downstream under its own gravity, causing the two working surfaces of the locking hinge to abut against the locking fixed block and the limiting unit, respectively.

[0014] Beneficial effects: When the stiffening ring passes through, it pushes the upstream locking hinge to rotate counterclockwise. This process is not a forced hard contact, but rather utilizes the forward momentum of the stiffening ring and the rotational characteristics of the hinge to achieve flexible avoidance—the hinge rotates gradually as the stiffening ring advances, avoiding a rigid impact between the stiffening ring and the device, effectively preventing structural damage such as stiffening ring deformation and hinge breakage. Simultaneously, when the hinge rotates to abut against the limiting unit, the limiting unit precisely restricts its maximum rotation angle, preventing the hinge from exceeding the structural bearing capacity due to excessive counterclockwise rotation, which could lead to safety hazards such as locking shaft bending or limiting unit failure. This ensures that the device remains in a safe operating state throughout the dynamic avoidance phase.

[0015] After the stiffening ring has completely passed, the locking hinge rotates clockwise downstream under gravity. Eventually, the two working surfaces abut against the locking fixed support and the limiting unit, respectively. This reset state creates a double limit: the locking fixed support restricts the hinge from continuing to rotate downstream, and the limiting unit restricts its upstream retraction. The locking hinge is firmly clamped between the locking fixed support and the limiting unit, preventing any displacement. At this point, the locking hinge and the stiffening ring are tightly fitted, effectively providing a rigid support point for the pressure steel pipe. This effectively resists the downstream sliding force generated by gravity and jacking inertia in the downward-bending section of the steel pipe, preventing displacement of the steel pipe during welding, inspection, and other construction gaps. Compared to traditional devices without reset locking, this significantly reduces the safety risks of steel pipe slippage and overturning, providing a stable and safe working environment for construction personnel.

[0016] Furthermore, the center of gravity of the locking hinge is offset from its rotation center, and the center of gravity of the locking hinge is located downstream of its rotation center. When the stiffening ring thrust disappears, the locking hinge rotates downstream around the rotation center under the action of gravitational torque until it fits against the locking fixed support.

[0017] Beneficial effects: Since the center of gravity of the locking movable hinge is located downstream of the rotation center, after the stiffening ring thrust disappears, the offset between the center of gravity and the rotation center will naturally form a clockwise gravitational torque. This torque does not require any external intervention and always acts on the movable hinge, driving it to rotate around the downstream of the rotation center. This means that the locking movable hinge does not require external power or auxiliary reset components such as hydraulic cylinders, motors, and springs. The device structure only needs to lock the movable hinge to achieve the reset function.

[0018] Furthermore, both ends of the locking hinge are provided with oblique cut surfaces in the thickness direction, and the oblique cut surfaces match the outer arc cut surface of the pressure steel pipe section.

[0019] Beneficial effects: The cross-section of the pressure steel pipe is an arc-shaped structure. The inclined surface of the locking hinge in this solution matches the outer arc-shaped surface of the steel pipe. When the two come into contact, they form a surface contact, which can avoid radial shaking of the steel pipe caused by gaps and ensure that the steel pipe always maintains the preset position during welding and inspection, thus effectively improving the locking stability.

[0020] Furthermore, the locking hinge has a right-angled triangular structure, and the two working surfaces of the locking hinge are two mutually perpendicular right-angled surfaces.

[0021] Beneficial effects: The two right-angled faces of the right triangle serve as working surfaces, which are perpendicularly fitted to the locking and fixing support and the pressure steel pipe stiffening ring, respectively. The supporting force of the locking and fixing support on the movable hinge is transmitted perpendicularly along one of the right-angled faces, and the pressure of the stiffening ring on the movable hinge is acted perpendicularly along the other right-angled face. The forces in the two perpendicular directions form an orthogonal constraint, preventing the locking movable hinge from shifting in the horizontal or vertical direction.

[0022] Furthermore, the top surface of the locking fixed support is adapted to the working surface of the locking movable hinge.

[0023] Beneficial effects: This configuration ensures that the working surface of the locking hinge is completely in contact with the top surface of the locking fixed support. The force transmitted from the pressure steel pipe to the locking fixed support through the locking hinge is conducted in a straight line and acts directly on the steel reinforcement skeleton and concrete foundation inside the support, making the support formed by the pressure steel pipe more stable.

[0024] Furthermore, the locking and fixing support includes an upper flange plate, a web plate, stiffening plates, and a lower flange plate. The two ends of the web plate are respectively connected to the upper flange plate and the lower flange plate. Multiple stiffening plates and web plates are provided. Multiple stiffening plates and multiple web plates are connected between the upper flange plate and the lower flange plate at intervals, and the stiffening plates and web plates are arranged perpendicular to each other.

[0025] Beneficial effects: The vertically spaced web plates and stiffeners form a three-dimensional support frame, which has a strong load-distribution capacity, can resist the impact and sliding force transmitted by the pressure steel pipe, avoid the deformation or breakage of the support, and improve the overall strength of the locked and fixed support.

[0026] Furthermore, the locking hinge includes a reinforcing plate, a web plate, a flange plate, and a stiffening plate. The flange plate is provided with bolt connection holes for connecting with anchor bars in concrete. There are two reinforcing plates and two web plates. The two web plates are respectively connected to the two reinforcing plates. The two reinforcing plates are perpendicularly connected to the flange plate. The two ends of the stiffening plate are respectively connected to the two reinforcing plates and the two web plates.

[0027] Beneficial effects: The double web plates and double reinforcing plates are vertically and symmetrically distributed, and together with the cross-connection of the stiffening plates, they form a three-dimensional load-bearing frame. This can evenly distribute the loads (such as thrust and sliding force) transmitted by the pressure steel pipe to the flange plate, avoid component deformation caused by local stress concentration, and enhance the overall torsional and lateral bending resistance of the hinge. At the same time, the flange plate is firmly fixed to the concrete anchor bars through bolt connection holes to achieve stable force transmission and resist load impact.

[0028] Furthermore, the limiting unit is an irregular angle steel structure, and the limiting unit includes a first limiting plate, a second limiting plate and a stiffening plate. The stiffening plate is connected between the first limiting plate and the second limiting plate. The included angle between the first limiting plate and the second limiting plate is greater than 90 degrees. The second limiting plate is fixed on the side of the locking hinge away from the locking support.

[0029] Beneficial effects: The included angle between the first and second limit plates is greater than 90 degrees, which can accurately engage the locking hinge that has rotated to the preset angle, strictly limit its upstream excessive rotation, avoid the hinge from exceeding the working range and causing reset failure, ensure the consistency of each limit action, and lay a precise benchmark for the subsequent locking process.

[0030] A method for fixing pressure steel pipes includes setting the aforementioned pressure steel pipe fixing device at the upstream stiffening ring position of a preset segment of the pressure steel pipe to be installed, and numbering the pressure steel pipes sequentially from upstream to downstream as 1, 2, 3...N, comprising the following steps:

[0031] S1, complete the excavation and acceptance of the downward-bending pressure steel pipe tunnel;

[0032] S2, Install the pressure steel pipe fixing device and the arc-shaped track. Fix the pressure steel pipe fixing device to the corresponding position of the upstream stiffening ring of the N-1 section of the pressure steel pipe. After acceptance, pour the arc-shaped track and the second-stage concrete.

[0033] S3: When the upstream stiffening ring of the first section of pressure steel pipe passes the locking hinge, push the locking hinge to rotate counterclockwise upstream until it touches the limit unit and stops; after the upstream stiffening ring of the first section passes the locking hinge, the locking hinge rotates downstream to fit with the locking fixed support; then the first section of pressure steel pipe is retracted downstream so that the upstream stiffening ring of the first section fits with the locking hinge, thus locking the upstream stiffening ring of the first section.

[0034] S4: Weld the second section of pressure steel pipe to the first section of pressure steel pipe. After the weld passes the non-destructive testing, start the jacking operation.

[0035] S5: Referring to the operation of step S3, when the downstream stiffening ring of the first section of pressure steel pipe passes through the locking movable hinge, the locking of the downstream stiffening ring of the first section is completed.

[0036] S6: Referring to the operation of step S3, when the upstream stiffening ring of the second section of pressure steel pipe passes through the locking movable hinge, the locking of the upstream stiffening ring of the second section is completed;

[0037] S7: Repeat steps S3-S6 to complete the installation of pressure steel pipes from section 3 to section N-1 and the locking of the corresponding stiffening rings in sequence;

[0038] S8: Weld the Nth pressure steel pipe to the N-1th section. After the weld passes the non-destructive testing, install a support structure inside and outside the pressure steel pipe.

[0039] S9: After completing the installation and locking of all pressure steel pipes, pour concrete between the pressure steel pipes and the tunnel.

[0040] Beneficial effects: Through the sequential stiffening rings of S3, S5, and S6 (upstream + downstream dual-point locking), each section of steel pipe has stable support during the jacking and welding process, which can effectively resist the downstream sliding force caused by gravity in the downward bending section of the steel pipe and avoid the risk of displacement and overturning during construction gaps; at the same time, the non-destructive testing of the weld and the overall casting after temporary fixation further ensure structural safety and reduce potential risks in later operation.

[0041] In this solution, the position of the upstream stiffening ring of the N-1 section is used as a fixed reference. The standardized process of the stiffening ring pushing the locking hinge, the limiting unit controlling the angle, and the locking hinge retracting and fitting is used to ensure the accurate locking position of each steel pipe section. Furthermore, the standardized steps are repeated in S7 to avoid the accumulation of deviations in a single section. Ultimately, the overall installation accuracy of multiple steel pipe sections is controllable, solving the problem of cumulative deviation that is easy to occur when installing the downward bend section section by section.

[0042] The fixing method in this solution forms a closed loop (S3-S6) of locking the first section → welding the second section → jacking → locking the second section, allowing for the connection of multiple sections for installation without additional adjustments to the device position; the finishing method of internal and external support (S8) + overall casting (S9) avoids repeated disassembly of the device after fixing a single section, greatly reducing construction interruption time and improving the efficiency of continuous installation of multiple steel pipe sections, especially suitable for tunnel construction scenarios with long downward-bending pressure steel pipes. Attached Figure Description

[0043] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0044] Figure 1 Schematic diagram of track layout for installing bending pressure steel pipe;

[0045] Figure 2 A schematic diagram showing the layout after the downward-bent pressure steel pipe is installed;

[0046] Figure 3 Schematic diagram of the installation section of the downward-bending pressure steel pipe;

[0047] Figure 4 This is a front view of the pressure steel pipe fixing device;

[0048] Figure 5 This is a side view of the pressure steel pipe fixing device;

[0049] Figure 6 Main view showing the status of the stiffening ring of the pressure steel pipe fixing device;

[0050] Figure 7 The side view shows the locking stiffening ring of the pressure steel pipe fixing device.

[0051] Figure 8 To lock the main view of the fixed support;

[0052] Figure 9 Side view for locking the fixed support;

[0053] Figure 10 For locking the main view of the fixed hinge;

[0054] Figure 11 Side view for locking the fixed hinge;

[0055] Figure 12 To lock the main view of the active hinge;

[0056] Figure 13 Side view for locking the movable hinge;

[0057] Figure 14 The main view for locking the axis;

[0058] Figure 15 This is the front view of the limiting unit;

[0059] Figure 16 This is a side view of the limiting unit.

[0060] The attached diagram shows the markings and corresponding component names:

[0061] Arc track 100, tunnel center 300;

[0062] Pressure steel pipe 400, stiffening ring 402;

[0063] Pressure steel pipe fixing device 500, locking movable hinge 501, locking movable hinge center 5011, oblique cutting edge line 5012, first working surface 5013, second working surface 5014, oblique cutting surface 5015;

[0064] Locking shaft 502, locking shaft end baffle 503, limiting unit 504, first limiting plate 5041, rib plate 5042, second limiting plate 5043;

[0065] Locking hinge 505, upper flange plate 5051, web plate 5052, stiffening plate 5053, lower flange plate 5054;

[0066] Locking and fixing support 506, reinforcing plate 5061, web plate 5062, flange plate 5063, stiffening plate 5064. Detailed Implementation

[0067] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0068] As one embodiment of this application, such as Figures 1-16 As shown, this embodiment provides a pressure steel pipe fixing device 500, including a locking fixing support 506, a locking fixing hinge 505, a locking movable hinge 501, and a limiting unit 504.

[0069] like Figure 4 As shown, both the locking hinge 505 and the locking support 506 are embedded in concrete. The locking hinge 501 is rotatably connected to the locking hinge 505. Specifically, in this embodiment, the locking hinge 501 and the locking hinge 505 are rotatably connected through a locking shaft 502. The end of the locking shaft 502 is provided with a locking shaft end baffle 503, which is fixed on the locking hinge 505 and limits the end of the locking shaft 502 to prevent it from coming out and to ensure the stability of its position. The locking hinge 501 is connected to the locking hinge 505 as a whole through the locking shaft 502 and the locking shaft end baffle 503. Figure 14 As shown, the locking shaft 502 is made of round steel. A stop plate groove is provided on the locking shaft 502. One end of the locking shaft end baffle 503 is fixed on the locking fixing hinge 505, and the other end of the locking shaft end baffle 503 engages with the stop plate groove to limit and fix the locking shaft 502.

[0070] The locking fixed support 506 is located on one side of the locking fixed hinge 505. The locking fixed support 506 is used to restrict the locking movable hinge 501 from rotating downstream. The top surface of the locking fixed support 506 is adapted to the working surface of the locking movable hinge 501, thereby ensuring the stable support of the locking fixed support 506 for the locking movable hinge 501.

[0071] like Figure 4As shown, the limiting unit 504 is used to limit the angle of the locking hinge 501 rotating upstream. When the locking hinge 501 rotates to the preset angle, the limiting unit 504 can abut against the locking hinge 501, thereby limiting the locking hinge 501 and stopping its rotation.

[0072] The locking hinge 501 has two working surfaces. When the pressure steel pipe 400 is in the locked position, the locking fixed support 506 abuts against one of the working surfaces of the locking hinge 501, and the stiffening ring 402 of the pressure steel pipe 400 abuts against the other working surface of the locking hinge 501. In this embodiment, as shown... Figure 12 As shown, the locking hinge 501 has a right-angled triangular structure. The two working surfaces of the locking hinge 501 are two mutually perpendicular right-angled surfaces, and the two working surfaces of the locking hinge 501 are the first working surface 5013 and the second working surface 5014.

[0073] Combination Figure 1 After the excavation of the lower bend tunnel is completed and accepted, the curved track 100 needs to be laid before the installation of the lower bend pressure steel pipe 400.

[0074] Combination Figure 2 The downward-bending pressure steel pipe 400 is arranged along the center 300 of the tunnel. Its pipe sections are numbered 1, 2, 3...N from upstream to downstream according to the water flow direction. The installation sequence strictly follows the numbers 1, 2, 3...N.

[0075] Combination Figure 2 and Figure 3 In this embodiment, a pressure steel pipe fixing device 500 is arranged at the upstream stiffening ring 402 of the N-1th section. The first working surface 5013 of the locking movable hinge 501 is completely in contact with the upstream stiffening ring 402 of the N-1th section, and the second working surface 5014 is completely in contact with the top surface of the locking fixed support 506.

[0076] The locking and fixing support 506 and the locking and fixing hinge 505 are embedded in the secondary concrete. In this embodiment, there are two sets of pressure steel pipe fixing devices 500, and the two sets of pressure steel pipe fixing devices 500 are respectively arranged on both sides of the arc track 100.

[0077] In one embodiment, combined Figure 6 and Figure 7 As shown, when the stiffening ring 402 of the pressure steel pipe 400 passes through the locking hinge 501, it will push the locking hinge 501 to rotate counterclockwise upstream, and cause one of the working surfaces of the locking hinge 501 (i.e., the first working surface 5013) to abut against the limiting unit 504, thus combining... Figure 4 and Figure 5As shown, when the stiffening ring 402 of the pressure steel pipe 400 passes completely through the locking hinge 501, the locking hinge 501 can rotate clockwise downstream under its own gravity, so that the two working surfaces of the locking hinge 501 abut against the locking fixed block and the limiting unit 504 respectively.

[0078] In this embodiment, as Figure 12 and 13 As shown, the locking hinge 501 is made of thick steel plate. Both ends of the locking hinge 501, along its thickness direction, have beveled surfaces 5015. These beveled surfaces 5015 match the outer arc section of the pressure steel pipe 400, meaning they have an arc that matches the outer arc section of the pressure steel pipe 400. The beveled surfaces 5015 along the thickness direction of the locking hinge 501 are parallel to the outer arc section of the pressure steel pipe 400. When the locking hinge 501 is in the locked state, the distance between the beveled surfaces 5015 and the outer arc section of the pressure steel pipe 400 is 50mm. A through hole is provided at the rotation center of the locking hinge 501, with the axis of this through hole being the center 5011 of the locking hinge. The line connecting the two beveled surfaces 5015 at the ends of the locking hinge 501 is the edge line 5012 of the beveled surfaces.

[0079] When the locking hinge 501 rotates 45° upstream, its oblique edge 5012 is perpendicular to the line connecting the center of the locking hinge 501 and the center of the downward-bent pressure steel pipe 400. The included angle between the two working surfaces of the locking hinge 501 is 90°, and the working surface that contacts the stiffening ring 402 has a vertically downstream angle. When the hinge rotates 45° upstream, its limiting unit 504 will restrict its continued rotation, and the center of the locking hinge 501 remains on the downstream side, rotating downstream by its own weight. Specifically:

[0080] In this embodiment, the center of gravity of the locking hinge 501 is offset from its rotation center, meaning the center of gravity of the locking hinge 501 does not coincide with its rotation center (i.e., the locking shaft 502), and the center of gravity of the locking hinge 501 is located downstream of its rotation center. When the thrust of the stiffening ring 402 disappears, the locking hinge 501 rotates downstream around its rotation center under the action of gravitational torque until it comes into contact with the locking fixed support 506. In this embodiment, after the first working surface 5013 of the locking hinge 501 comes into contact with the stiffening ring 402, there is a vertical deflection angle downstream, meaning that the first working surface 5013 is tilted downstream rather than vertically or upstream.

[0081] In this embodiment, the center of gravity of the locking hinge 501 is not coincident with the rotation center (the axis of the locking shaft 502) due to the asymmetry of the structure, but is offset downstream. That is, the projection position of the center of gravity in space is always located downstream of the rotation center (the axis of the locking shaft 502).

[0082] Whether the locking hinge 501 is in the initial contact state (contact with the locking fixed support 506) or is pushed to a 45° rotation state by the stiffening ring 402 (touching the limit unit 504), the relative position of the center of gravity downstream of the rotation center remains unchanged (because the locking hinge 501 has a fixed structure and only rotates around the rotation center, the relative offset direction and offset distance between the center of gravity and the rotation center are constant).

[0083] When the stiffening ring 402 passes over the locking hinge 501, the thrust on the locking hinge 501 disappears, and the locking hinge 501 is only supported by gravity and the center of rotation: because the center of gravity is located downstream of the center of rotation, gravity will generate a clockwise torque on the center of rotation (with the center of rotation as the fulcrum, the downstream center of gravity is subjected to gravity and generates a downward force, driving the hinge to rotate clockwise around the center of rotation).

[0084] The clockwise rotation direction is exactly the downstream rotation direction, which eventually causes the locking hinge 501 to rotate from the 45° limit state to the initial state of being in contact with the locking fixed support 506, thus achieving automatic reset.

[0085] In one embodiment, such as Figure 8 and Figure 9 As shown, the locking and fixing support 506 includes an upper flange plate 5051, a web plate 5052, a stiffening plate 5053, and a lower flange plate 5054. The two ends of the web plate 5052 are welded to the upper flange plate 5051 and the lower flange plate 5054, respectively. Multiple stiffening plates 5053 and multiple web plates 5052 are provided. Multiple stiffening plates 5053 and multiple web plates 5052 are spaced apart and connected between the upper flange plate 5051 and the lower flange plate 5054. The stiffening plates 5053 and the web plate 5052 are arranged perpendicular to each other and are welded to each other.

[0086] There is an included angle between the upper flange 5051 and the lower flange 5054, that is, the upper flange 5051 is inclined and the lower flange 5054 is horizontal. Figure 4 As shown, the upper flange plate 5051 of the locking fixed support 506 is inclined, which facilitates close contact with the second working surface 5014 of the locking movable hinge 501. In this embodiment, the lower flange plate 5054 is cast in concrete.

[0087] In one embodiment, such as Figure 10 and Figure 11 As shown, the locking hinge 505 includes a reinforcing plate 5061, a web plate 5062, a flange plate 5063, and a stiffening plate 5064. The flange plate 5063 is provided with bolt holes for connecting to anchor bars in the concrete, such as... Figure 11As shown, there are two reinforcing plates 5061 and two web plates 5062. The two web plates 5062 are respectively welded to the two reinforcing plates 5061, integrally formed or connected in other ways. The two reinforcing plates 5061 are respectively vertically welded to the flange plate 5063, or screwed or connected in other ways. The two ends of the stiffening plate 5064 are respectively welded to the two reinforcing plates 5061 and the two web plates 5062, or screwed or connected in other ways.

[0088] The reinforcing plate 5061 has through holes for easy installation of the locking shaft 502. Figure 5 As shown, in this embodiment, bolts are used to connect the locking hinge 505 to the anchor bars of the first-stage concrete, and the locking hinge 505 and the locking hinge 501 are connected by a locking shaft 502 (including a shaft end baffle and fasteners). When the locking hinge 501 is in the locked state, one of its working surfaces is in contact with the stiffening ring 402, and the other working surface is in contact with the top surface of the locking support 506.

[0089] In one embodiment, Figure 15 and Figure 16 As shown, the limiting unit 504 is an irregular angle steel structure. The limiting unit 504 includes a first limiting plate 5041, a second limiting plate 5043, and a stiffening plate 5042. The stiffening plate 5042 connects the first limiting plate 5041 and the second limiting plate 5043. The included angle between the first limiting plate 5041 and the second limiting plate 5043 is greater than 90 degrees. Figure 4 As shown, the second limiting plate 5043 is fixed (e.g., welded) on the side of the locking hinge 505 away from the locking support 506.

[0090] In one embodiment, a method for fixing a pressure steel pipe is also disclosed, wherein the aforementioned pressure steel pipe fixing device is positioned at the upstream stiffening ring position of a preset segment in the pressure steel pipe to be installed, and the position of the upstream stiffening ring of the segment to be installed is locked each time. Using the aforementioned pressure steel pipe fixing device, the pressure steel pipes are sequentially numbered 1, 2, 3...N from upstream to downstream, including the following steps:

[0091] S1, complete the excavation and acceptance of the downward-bending pressure steel pipe tunnel;

[0092] S2, Install the pressure steel pipe fixing device and the arc-shaped track. Fix the pressure steel pipe fixing device to the corresponding position of the upstream stiffening ring of the N-1 section of the pressure steel pipe. After acceptance, pour the arc-shaped track and the second-stage concrete.

[0093] S3: When the upstream stiffening ring of the first section of the pressure steel pipe passes the locking hinge, it will push the locking hinge to rotate counterclockwise upstream until it touches the limit unit and stops; after the upstream stiffening ring 402 of the first section passes the locking hinge 501, the locking hinge 501 rotates downstream under the action of gravity until it is in contact with the locking fixed support; then the first section of the pressure steel pipe 400 is retracted downstream, so that the upstream stiffening ring 402 of the first section is in contact with the first working surface of the locking hinge 501, and the second working surface of the locking hinge is in contact with the upper flange plate 5051 of the locking fixed support 506, thus locking the upstream stiffening ring of the first section; specifically:

[0094] The first section of pressure steel pipe 400 is pushed upstream. When its upstream stiffening ring 402 reaches the locking hinge 501, the pressure steel pipe 400 drives the locking hinge 501 to rotate around its center 5011. The locking hinge 501 rotates until its first working surface 5013 is in contact with the first limiting plate 5041 of the limiting unit 504. At this point, the first section of pressure steel pipe 400 stops advancing, and the locking hinge 501 rotates downstream by its own weight until its second working surface 5014 is completely in contact with the upper flange plate 5051 of the locking fixed support 505. Subsequently, the first section of pressure steel pipe 400 retracts downstream until its upstream stiffening ring 402 is in contact with the first working surface 5013 of the locking hinge 501, thus completing the locking of the first section of pressure steel pipe 400.

[0095] S4: Weld the second section of pressure steel pipe to the first section of pressure steel pipe. After the weld passes the non-destructive testing, start the jacking operation.

[0096] S5: Referring to the operation of step S3, when the downstream stiffening ring of the first section of pressure steel pipe passes through the locking movable hinge, the locking of the downstream stiffening ring of the first section is completed.

[0097] S6: Referring to the operation of step S3, when the upstream stiffening ring of the second section of the pressure steel pipe passes through the locking movable hinge, the locking of the upstream stiffening ring 402 of the second section is completed;

[0098] S7: Repeat steps S3-S6 to complete the installation of pressure steel pipes from section 3 to section N-1 and the locking of the corresponding stiffening rings in sequence;

[0099] S8: Weld the Nth section of the pressure steel pipe to the N-1th section. After the weld passes the non-destructive testing, inspect the installation status of the entire downward-bent pressure steel pipe. After the inspection is passed, install a support structure inside and outside the pressure steel pipe 400mm. Also, support and fix the downward-bent pressure steel pipe to the rock mass.

[0100] S9: After completing the installation and locking of all pressure steel pipes, hand them over to the civil engineering unit to pour concrete between the pressure steel pipes and the tunnel.

[0101] It should be noted that the above description of the disclosed embodiments enables those skilled in the art to implement or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A pressure steel pipe fixing device, characterized in that, Includes a locking fixed support, a locking fixed hinge, a locking movable hinge, and a limiting unit; Both the locking hinge and the locking support are embedded in concrete, and the locking hinge is rotatably connected to the locking hinge. The locking fixed support is used to restrict the downstream rotation of the locking movable hinge; The limiting unit is used to limit the angle of the locking hinge rotating upstream. When the locking hinge rotates to a preset angle, the limiting unit can abut against the locking hinge. The locking hinge has two working surfaces. When the pressure steel pipe is in the locked position, the locking fixed support abuts against one of the working surfaces of the locking hinge, and the stiffening ring of the pressure steel pipe abuts against the other working surface of the locking hinge. As the stiffening ring of the pressure steel pipe passes through the locking hinge, it pushes the locking hinge to rotate counterclockwise upstream, causing one of the working surfaces of the locking hinge to abut against the limiting unit. After the stiffening ring of the pressure steel pipe has completely passed through the locking hinge, the locking hinge can rotate clockwise downstream, causing the two working surfaces of the locking hinge to abut against the locking fixed support and the limiting unit, respectively.

2. The pressure steel pipe fixing device according to claim 1, characterized in that, The locking hinge is able to rotate clockwise downstream under its own weight.

3. The pressure steel pipe fixing device according to claim 2, characterized in that, The center of gravity of the locking hinge is offset from its rotation center, and the center of gravity of the locking hinge is located downstream of its rotation center. When the stiffening ring thrust disappears, the locking hinge rotates downstream around the rotation center under the action of gravitational torque until it fits against the locking fixed support.

4. The pressure steel pipe fixing device according to claim 1, characterized in that, Both ends of the locking hinge are provided with oblique cut surfaces in the thickness direction, and the oblique cut surfaces match the outer arc cut surface of the pressure steel pipe section.

5. A pressure steel pipe fixing device according to claim 1, characterized in that, The locking hinge has a right-angled triangular structure, and the two working surfaces of the locking hinge are two mutually perpendicular right-angled surfaces.

6. The pressure steel pipe fixing device according to claim 1, characterized in that, The top surface of the locking fixed support is adapted to the working surface of the locking movable hinge.

7. A pressure steel pipe fixing device according to claim 6, characterized in that, The locking and fixing support includes an upper flange plate, a web plate, a stiffening plate, and a lower flange plate. The two ends of the web plate are respectively connected to the upper flange plate and the lower flange plate. Multiple stiffening plates and web plates are provided. Multiple stiffening plates and multiple web plates are connected between the upper flange plate and the lower flange plate at intervals, and the stiffening plates and web plates are arranged perpendicular to each other.

8. A pressure steel pipe fixing device according to claim 1, characterized in that, The locking hinge includes a reinforcing plate, a web plate, a flange plate, and a stiffening plate. The flange plate is provided with bolt holes for connecting with anchor bars in concrete. There are two reinforcing plates and two web plates. The two web plates are respectively connected to the two reinforcing plates. The two reinforcing plates are perpendicularly connected to the flange plate. The two ends of the stiffening plate are respectively connected to the two reinforcing plates and the two web plates.

9. A pressure steel pipe fixing device according to claim 1, characterized in that, The limiting unit is an irregular angle steel structure. The limiting unit includes a first limiting plate, a second limiting plate, and a stiffening plate. The stiffening plate is connected between the first limiting plate and the second limiting plate. The included angle between the first limiting plate and the second limiting plate is greater than 90 degrees. The second limiting plate is fixed on the side of the locking hinge away from the locking support.

10. A method for fixing a pressure steel pipe, characterized in that, The pressure steel pipe fixing device according to any one of claims 1-9 is installed at the upstream stiffening ring position of a preset segment in the pressure steel pipe to be installed, and the pressure steel pipes are sequentially numbered 1, 2, 3...N from upstream to downstream, including the following steps: S1, complete the excavation and acceptance of the downward-bending pressure steel pipe tunnel; S2, Install the pressure steel pipe fixing device and the arc-shaped track. Fix the pressure steel pipe fixing device to the corresponding position of the upstream stiffening ring of the N-1 section of the pressure steel pipe. After acceptance, pour the arc-shaped track and the second-stage concrete. S3: When the upstream stiffening ring of the first section of pressure steel pipe passes the locking hinge, push the locking hinge to rotate counterclockwise upstream until it touches the limit unit and stops; after the upstream stiffening ring of the first section passes the locking hinge, the locking hinge rotates downstream to fit with the locking fixed support; then the first section of pressure steel pipe is retracted downstream so that the upstream stiffening ring of the first section fits with the locking hinge, thus locking the upstream stiffening ring of the first section. S4: Weld the second section of pressure steel pipe to the first section of pressure steel pipe. After the weld passes the non-destructive testing, start the jacking operation. S5: Referring to the operation of step S3, when the downstream stiffening ring of the first section of pressure steel pipe passes through the locking movable hinge, the locking of the downstream stiffening ring of the first section is completed. S6: Referring to the operation of step S3, when the upstream stiffening ring of the second section of the pressure steel pipe passes through the locking movable hinge, the locking of the upstream stiffening ring of the second section is completed; S7: Repeat steps S3-S6 to complete the installation of pressure steel pipes from section 3 to section N-1 and lock the corresponding stiffening rings in sequence; S8: Weld the Nth pressure steel pipe to the N-1th section. After the weld passes the non-destructive testing, install a support structure inside and outside the pressure steel pipe. S9: After completing the installation and locking of all pressure steel pipes, pour concrete between the pressure steel pipes and the tunnel.

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