Splicing method and system for large-span steel arch frame with mast type buckle cable extruded into arch

Abstract

The invention discloses a large-span steel arch splicing method and system for extruding mast type buckle cables to form an arch, and belongs to the technical field of large-span steel arch splicing. The method comprises the steps that masts are erected on foundations on the two sides of an arch, the bottom ends of the masts are connected with the foundations through hinged supports, a plurality of wind cables are arranged on the tops of the masts, and pre-tension force is adjusted to form a temporary supporting system; according to the segment design space coordinates, the buckle cable material parameters and the construction temperature, the stress-free length of the buckle cable is calculated, the buckle cable is in a non-additional tension force state after being connected, and segment three-dimensional positioning is completed through at least two buckle cables; all the sections are spliced in a cantilever mode according to the sequence from the side span to the midspan, part of wind cable pretension force is adjusted before midspan closure, and cantilever structures on the two sides are guided to be in smooth butt joint under the self-weight effect of closure sections; after closure, the buckle cables are unloaded in a graded mode, stress and displacement are monitored synchronously, and system conversion is completed; the system is composed of a mast cable system, a stress-free control module and a structure monitoring and unloading module, and the section positioning precision and closure controllability can be improved.

Description

Technical Field

[0001] This invention relates to the field of large-span steel arch frame assembly technology, and in particular to a method for assembling large-span steel arch frames by extruding mast-type cable clamps into an arch. Background Technology

[0002] Large-span steel arch frames are widely used in bridges, hydraulic engineering, and municipal engineering, with typical spans reaching over 100 meters. For steel truss arch structures with spans ranging from 100m to 150m, segmented cantilever assembly is often adopted during construction, relying on tower systems, cable systems, or temporary support systems to complete segment positioning and overall arch formation.

[0003] Currently, the commonly used cantilever tower assembly method has some technical limitations in large-span projects.

[0004] Temporary support systems are large in scale, expensive, and lack adaptability. Traditional tower-laying systems typically require tall towers and large foundations, resulting in long construction periods, high concrete consumption, and low overall stability in areas with complex geological conditions or insufficient bearing capacity. Segment positioning and cable tension control rely on manual operation, which is not very accurate. Traditional tensioning methods mainly apply prestress manually or with hydraulic equipment, making it difficult to guarantee the consistency between measured and theoretical cable tension values. Significant deviations in segment spatial position control affect subsequent welding accuracy and arch alignment. For mid-span structures assembled from multiple segments using cantilever construction, installation efficiency and overall progress are also easily affected. The closure and unloading stages are risky. Forced closure may cause significant additional stress and alignment deviations in the arch ribs. If monitoring methods are insufficient, uneven stress redistribution during unloading can easily lead to structural instability, requiring additional temporary supports or repeated correction measures, further extending the construction period and increasing investment. Summary of the Invention

[0005] The purpose of this invention is to provide a method for assembling large-span steel arch frames by extruding mast-type cable clamps into an arch, so as to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A method for assembling a large-span steel arch frame formed by mast-type cable extrusion includes the following steps: S1. Erect masts at the foundations on both sides of the steel arch frame to be built, with the bottom of the masts hinged to the foundations; connect several wind cables arranged circumferentially to the top of the masts; by adjusting the preload of the wind cables, the masts and wind cables together form a mast-type temporary support system for positioning the arch frame segments; S2. For each arch segment to be hoisted, the cutting length L0 of the lashing cable is determined using a stress-free length calculation model based on its design spatial coordinates, the elastic modulus of the lashing cable material, the design temperature, and the construction temperature. One end of the lashing cable with a cutting length of L0 is connected to a pre-set hanging point at the top of the mast, and the other end is connected to the arch segment to be hoisted, ensuring that the lashing cable is in a state of no external tension after connection. At least two lashing cables are used for spatial positioning of the arch segment. A mast-type temporary support system positions the arch segment to its designed spatial location. The position of the arch segment is verified using a measuring device. S3. Following the sequence of advancing from both side spans towards the center, repeat S2 to complete the hoisting, positioning, and connection of each arch frame segment, forming a cantilever structure that gradually extends from both sides; S4. When the cantilever structures on both sides approach the design closure point at the mid-span, adjust the pretension of some wind cables to obtain the structural flexibility required for closure; hoist and position the closure section at the mid-span position, and guide the cantilever structures on both sides to move towards the mid-span under the self-weight of the closure section to complete the connection of the closure section; S5. After the closure connection is completed, the corresponding cables are unloaded in stages according to the reverse order of the arch frame segment installation, and the stress and mid-span displacement of key nodes are monitored simultaneously. When the monitored values ​​meet the structural stability requirements, the cables and wind cables are removed, so that the steel arch frame is transferred from the temporary support system to the completed bridge load-bearing system.

[0007] Preferably, in S1, a hinged support is provided between the bottom end of the mast and the foundation; the end of the wind cable is connected to the ground anchor through a hydraulic tensioner; and the number of wind cables at the top of the mast is not less than three.

[0008] Preferably, the expression for calculating the stress-free length L0 in S2 is: ; in, Design length for the buckle; ; , ; This is the difference between the construction temperature and the design temperature.

[0009] Preferably, in step S2, after the cable is connected, a total station or laser measuring device is used to verify the three-dimensional coordinates of the segment, and when the deviation exceeds the preset allowable value, it is corrected by adjusting the length of the cable, the cable hanging point, or the position of the temporary support of the segment; the method of fine-tuning the length of the cable is to adjust the travel of the cable tensioner.

[0010] Preferably, in step S4, when the cantilever structures on both sides are 40-60 cm away from the closure section, 50% of the pre-tension of the wind cable is first removed.

[0011] Preferably, the expression for the displacement of the cantilever structures on both sides towards the mid-span in S4 is: ; in, For the weight of the closure section; The free length of the cantilever; The bending stiffness of the arch frame section; displacement. ≤20mm.

[0012] Preferably, in step S4, after the cantilever structures on both sides are guided to move towards the mid-span and stabilize, the arch frame closure section is welded in layers, and the welding temperature is controlled at 180-240℃.

[0013] Preferably, in step S5, a preload of 1.2 times its own weight is applied to the formed circumferential arch before the staged unloading; 10% of the cable tension is released at each stage, with a stage interval of 20-30 minutes, and displacement gauges and strain sensors are used to monitor the stress of key nodes and mid-span displacement in real time.

[0014] Another object of the present invention is to provide a large-span steel arch frame assembly system for mast-type cable extrusion arching, comprising: The mast cable system, including the mast, hinged supports, cable anchors, and several wind cables, is used to form an adjustable and flexible temporary spatial support system. The stress-free control module includes a cable length calculation unit, a temperature measurement unit, a cable tensioner, and segment positioning marks, used to generate the stress-free length of the cable and achieve three-dimensional segment positioning; The structural monitoring and unloading module, including displacement gauges, strain sensors, data acquisition units, and over-limit alarm units, is used to monitor the structural response and provide safety control during the closure and staged unloading process.

[0015] Preferably, the wind cable has a specification of φ24-32 mm, is made of high-strength steel strand, and has an angle of 45°-60° with the horizontal.

[0016] The present invention discloses a method for assembling a large-span steel arch frame by extruding mast-type cable clamps into an arch, which has the following beneficial effects.

[0017] This method involves erecting masts on both sides of the foundation of the steel arch frame. The bottom of the mast is connected to the foundation through a hinged support. Several wind cables are arranged on the top of the mast, and a mast-type temporary support system is formed by adjusting the preload. This method can achieve precise positioning of the arch frame segments without the need for large-scale towers and extensive temporary supports, reducing the amount of foundation work and adapting to complex foundation conditions.

[0018] Based on the segment design spatial coordinates, cable material parameters, and construction temperature, a stress-free length calculation model is used to determine the cable cutting length, ensuring that the cable is in a state of no external tension after connection. The segment is three-dimensionally positioned using at least two cables, and its installation accuracy is verified by a measuring device. The cable participates in positioning in a stress-free state, making the segment spatial coordinates easier to control. Positional deviations between segments can be corrected in a timely manner through fine-tuning of the cable, resulting in more stable overall alignment control.

[0019] The hoisting and connection of each segment are completed in the order of advancing from the side spans to the center of the span, forming a symmetrical cantilever structure. When the cantilever structure approaches the center of the span, the required flexibility for closure is obtained by adjusting the pretension of some wind cables. The closure segment is positioned and its own weight is used to guide the structures on both sides to achieve compression arch formation. The adjustable flexibility of the mast system makes the displacement process during the closure stage more predictable. The closure segment's own weight can guide the cantilever structure to close, reducing the additional stress caused by forced closure.

[0020] After the closure is completed, the cable-stayed structure is unloaded in stages according to the reverse sequence of segmental installation. Stress and displacement at key nodes are monitored. Once stability requirements are met, the cable-stayed structure and wind cables are removed, allowing the structure to transition from a temporary support system to the completed bridge load-bearing system. Cable force, stress, and displacement monitoring are maintained throughout the entire assembly process. Unloading is carried out in reverse sequence segment by segment, gradually and smoothly transferring the load from the temporary system to the completed bridge state, thereby reducing the risk of structural abrupt changes and improving construction safety and closure accuracy. This overall method reduces reliance on large equipment, accelerates the segmental installation pace, and is suitable for efficient arch construction of large-span steel arches of hundreds of meters. Attached Figure Description

[0021] Figure 1 This is a flowchart of a method for assembling a large-span steel arch frame by extruding mast-type cable clamps into an arch.

[0022] Figure 2 This is a schematic diagram of the mast cable system structure of the present invention.

[0023] Figure 3 This is a schematic diagram of the mast structure of the present invention.

[0024] Figure 4 This is another schematic diagram of the mast structure of the present invention.

[0025] Figure 5 This is a schematic diagram of the hoisting unit structure of the present invention.

[0026] Figure 6 This is a schematic diagram of the steel arch frame after it has been closed according to the present invention.

[0027] Figure 7 This is a schematic diagram illustrating the application of a preload of 1.2 times its own weight to the formed circumferential arch ring according to the present invention.

[0028] Figure 8This is a schematic diagram of the hinge support structure of the present invention.

[0029] In the diagram: 1. Mast cable system; 101. Mast; 102. Hinge support; 103. Cable anchor point; 104. Wind cable; 2. Cable; 201. Cable tensioner; 3. Sandbag; 4. Water tank; 5. Steel arch frame; 501. Standard segment; 502. Adjustable segment; 503. Arch foot segment; 504. Closure segment. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0031] In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not 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 limiting this invention.

[0032] Example 1 In this embodiment, an aqueduct spanning a gully with a terrain slope of 15° and strata consisting of Jurassic Penglaizhen Formation silty mudstone interbedded with sandstone is used as an example, with a 108m span arched aqueduct steel arch frame 5 assembled. In this embodiment, the steel arch frame 5 is a "five-rib four-connection" structure (total width 6.428m), with a total of 29 segments (10 standard segments 501, 15 adjustable segments 502, 2 arch foot segments 503, and 2 closure segments 504), and a total weight of 243.14t.

[0033] like Figure 1 As shown, this invention proposes a method for assembling a large-span steel arch frame 5 formed by compressing mast 101 type fasteners 2 into an arch, including the following steps: S1. Erect masts 101 at the foundations on both sides of the steel arch frame 5 to be constructed. The bottom end of the mast 101 is hinged to the foundation. Several wind cables 104 arranged circumferentially are connected to the top of the mast 101. By adjusting the preload of the wind cables 104, the mast 101 and the wind cables 104 together form a mast 101-type temporary support system for positioning the arch frame segments. Preferably, in this embodiment, such as Figures 2 to 4 , Figure 8 As shown, a hinge support 102 is provided between the bottom end of the mast 101 and the foundation in S1; the end of the wind cable 104 is connected to the ground anchor through a hydraulic tensioner; there are no less than three wind cables 104 at the top of the mast 101.

[0034] In this embodiment, the foundation of the central mast 101 is 4m×4m×1.5m C30 concrete with a 20mm thick steel plate embedded (flatness error 1.2mm); the mast 101 is 36.3m high, the column is φ820×12mm steel pipe, and there are 3 60cm×100cm connecting beams; the side mast 101 is 24.2m high, the column is φ630×10mm steel pipe, and there are 2 connecting beams; it is hoisted in 3 sections using a 25t truck crane, with a verticality deviation of 0.8‰; the wind cable 104 uses 4 φ28-6×36WS-IWRC-1770 cables, and the wind cable 104 is at a 50° angle to the horizontal.

[0035] S2. For each arch segment to be hoisted, based on its design spatial coordinates, the elastic modulus of the ligature 2 material, the design temperature, and the construction temperature, the cutting length L0 of the ligature 2 is determined using a stress-free length calculation model. One end of the ligature 2 with a cutting length of L0 is connected to a pre-set hanging point at the top of the mast 101, and the other end is connected to the arch segment to be hoisted, ensuring that the ligature 2 is in a state of no external tension after connection. At least two ligatures 2 are used to spatially position the arch segment. The temporary support system of the mast 101 positions the arch segment to the design spatial location. The position of the arch segment is verified using a measuring device. like Figure 5 As shown, in this embodiment, based on the type and weight of the 5 segments of the steel arch frame, the 5 segments of the steel arch frame are divided into Class A units (arch foot segment 503+1 basic segment, weighing 14.51t), Class B units (basic segment, weighing 7.36t), and Class C units (adjustment segment 502, weighing 4.31t). An 80t truck crane (ZTC800V6-1) is used for lifting, with an operating radius of 12-18m, a lifting height of 36-54m, and a preliminary GPS positioning deviation of 7mm.

[0036] Preferably, in this embodiment, the expression for calculating the stress-free length L0 in S2 is: ; in, Design length for the buckle; ; , ; This is the difference between the construction temperature and the design temperature.

[0037] Preferably, in this embodiment, after the buckle 2 is connected, a total station or laser measuring device is used to verify the three-dimensional coordinates of the segment in S2, and when the deviation exceeds the preset allowable value, it is corrected by adjusting the length of the buckle 2, the buckle hanging point 103, or the position of the temporary support of the segment; the way to fine-tune the length of the buckle 2 is to adjust the travel of the tensioner of the buckle 2.

[0038] S3, such as Figure 2As shown, following the sequence of advancing from both side spans towards the center, S2 is repeated to complete the hoisting, positioning, and connection of each arch frame segment, forming a cantilever structure that gradually extends from both sides; In this embodiment, the closure segment is made of 504 stainless steel and weighs 80t. The interface is ground to a flatness of 0.4mm. It is lifted by an 80t truck crane. The alignment deviation is 4mm. A 3mm thick stainless steel sheet is used to level it.

[0039] S4, such as Figure 6 As shown, when the cantilever structures on both sides approach the design closure point at the mid-span, the pretension of some wind cables 104 is adjusted to obtain the structural flexibility required for closure; the closure section is hoisted and positioned at the mid-span position, and under the self-weight of the closure section, the cantilever structures on both sides are guided to move towards the mid-span to complete the connection of the closure section; Preferably, in this embodiment, when the cantilever structures on both sides are 40-60 cm away from the closure section in S4, the 10450% pre-tension of the wind cable is first removed.

[0040] Preferably, in this embodiment, the expression for the displacement of the cantilever structures on both sides towards the mid-span in S4 is: ; in, For the weight of the closure section; The free length of the cantilever; The bending stiffness of the arch frame section; displacement. ≤20mm.

[0041] It should be noted that in this embodiment, due to the large span, the arch frame can be approximated as a straight beam for displacement calculation.

[0042] Preferably, in this embodiment, after the cantilever structures on both sides are guided to move towards the mid-span and stabilize in S4, the arch frame closure section is welded in layers, and the welding temperature is controlled at 180-240℃.

[0043] In this embodiment, the arch frame closure section is welded in layers, with the first layer at 200°C and the second layer at 220°C. The stress after welding is tested at 26MPa (≤28MPa).

[0044] S5. After the closure connection is completed, the corresponding fasteners 2 are unloaded in stages according to the reverse order of the arch frame segment installation, and the stress and mid-span displacement of key nodes are monitored simultaneously. When the monitored values ​​meet the structural stability requirements, the fasteners 2 and wind cables 104 are removed, so that the steel arch frame 5 is transferred from the temporary support system to the completed bridge force system.

[0045] Preferably, in this embodiment, such as Figure 7As shown, in S5, a preload of 1.2 times its own weight is applied to the formed circumferential arch before the staged unloading; 10% of the cable tension is released at each stage, with a stage interval of 20-30 minutes, and displacement gauges and strain sensors are used to monitor the stress of key nodes and mid-span displacement in real time.

[0046] As shown in the figure, in this embodiment, the load is 1.2 times the self-weight of the circumferential arch ring (17369.76kN×1.2). The arch foot section uses 1.8t / bag sandbags 3 (88 bags / side), and the arch crown section uses water tank 4 (water height 1.15-3.3m). After preloading, the inelastic deformation is measured to be 7mm and the elastic deformation to be 11mm. During the staged unloading, the ties 2 are released in reverse order of the arch frame segment installation, releasing 80kN (10% of the maximum cable force) at each stage, and monitoring is carried out at 30-minute intervals. The mid-span displacement increases by 2-3mm at each stage, and the stress change is ≤5MPa. After all ties 2 are released, continuous monitoring is carried out for 1 hour. The mid-span deflection is 22mm (≤27mm=L / 4000, L=108m), and the maximum stress at the node is 205MPa (≤213MPa=355MPa×60%), which meets the requirements.

[0047] Compared with the traditional cantilever tower method, the key performance indicators of this embodiment are improved as follows: Example 2 This embodiment provides a large-span steel arch frame 5 assembly system for mast 101 type fastener 2 extruded into an arch, including: The mast cable system 1 includes a mast 101, a hinge support 102, a cable attachment point 103, and several wind cables 104, which are used to form an adjustable and flexible temporary spatial support system. In this embodiment, the mast 101 adopts a steel pipe mast 101 structure, preferably a high-strength steel pipe with a diameter of φ630-820×10-14 mm, which is processed and hoisted in sections. The height of the mast 101 is generally 20-40 m, which can be determined according to the span and the site terrain. Two to three connecting beams are set on the outer perimeter of the mast 101 to improve the overall lateral stiffness.

[0048] like Figure 8 As shown, the mast 101 is connected to the foundation at the bottom by a hinged support 102, giving the mast 101 a certain degree of rotational freedom. The thickness of the steel plate embedded below the hinged support 102 is 16-25 mm, and the flatness error is controlled within 1.0-1.5 mm.

[0049] The buckle attachment points 103 are arranged on the stiffening steel ring plate arranged circumferentially at the top of the mast 101, preferably 8-12 attachment points. Each attachment point is made of 30-40 mm thick steel plate welded into an ear plate structure with a hole diameter of 45-55 mm, and is connected to the end of the buckle 2 by a pin shaft, so that the buckle 2 can be quickly disassembled and adjusted.

[0050] The wind cable 104 is used to control the spatial attitude and stability of the mast 101, and the flexibility of the mast 101 can be adjusted by adjusting the preload of the wind cable 104. In this embodiment, the wind cable 104 is a φ24-32 mm high-strength steel strand with a tensile strength of 1670-1770 MPa. The angle between the wind cable 104 and the horizontal is 45°-60°, which can take into account the reasonable distribution of horizontal and vertical forces. The end of the wind cable 104 is connected to the ground anchor via a hydraulic tensioner. The tensioner has a stroke of 200-400 mm and can adjust the preload of the wind cable 104 in stages to meet the stiffness requirements of the mast 101 under different working conditions.

[0051] The stress-free control module includes a length calculation unit for the buckle 2, a temperature measurement unit, a buckle tensioner 201, and segment positioning marks. It is used to generate the stress-free length of the buckle 2 and achieve three-dimensional segment positioning. The length calculation unit can output the required cutting length by inputting the segment number, design coordinates, and the current measured temperature, enabling rapid on-site calculation and verification. The temperature measurement unit includes an infrared thermometer and an ambient temperature sensor to obtain the actual temperature effect ΔT on the buckle 2. Figure 6 As shown, each of the 201 ties is equipped with a tensioner with a stroke of 50-100 mm at the end of each 2 tie, which is used for: fine-tuning the length error of the 2 tie; adjusting the segment posture and three-dimensional coordinates; and providing flexibility release control before closure.

[0052] The structural monitoring and unloading module, including displacement gauges, strain sensors, data acquisition units, and over-limit alarm units, is used to monitor the structural response and provide safety control during the closure and staged unloading process.

[0053] In this embodiment, 3-5 resistance or fiber optic displacement gauges are installed at the top of mast 101, both sides of the closure section, and the cantilever ends to monitor: lateral displacement of the top of mast 101; relative displacement of the cantilever ends near the closure point; and structural springback during unloading. 8-12 strain gauges are installed on the lower edge plate, web plate, or closure section of key segments to monitor stress changes during the arching process and prevent local over-limits. A data acquisition unit, with a multi-channel data acquisition instrument, receives signals from the displacement gauges and strain gauges in real time and transmits them to the field control terminal via 4G / 5G or wireless LAN. An over-limit alarm unit automatically issues an audible and visual alarm when displacement or strain exceeds a preset threshold, and displays the over-limit location and value on the control terminal interface, guiding construction personnel to suspend related operations.

[0054] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for assembling a large-span steel arch frame formed by extruding mast-type cable clamps, characterized in that... This includes the following steps: S1. Erect masts at the foundations on both sides of the steel arch frame to be built, with the bottom of the masts hinged to the foundations; connect several wind cables arranged circumferentially to the top of the masts; by adjusting the preload of the wind cables, the masts and wind cables together form a mast-type temporary support system for positioning the arch frame segments; S2. For each arch segment to be hoisted, the cutting length L0 of the lashing cable is determined using a stress-free length calculation model based on its design spatial coordinates, the elastic modulus of the lashing cable material, the design temperature, and the construction temperature. One end of the lashing cable with a cutting length of L0 is connected to a pre-set hanging point at the top of the mast, and the other end is connected to the arch segment to be hoisted, ensuring that the lashing cable is in a state of no external tension after connection. At least two lashing cables are used for spatial positioning of the arch segment. A mast-type temporary support system positions the arch segment to its designed spatial location. The position of the arch segment is verified using a measuring device. S3. Following the sequence of advancing from both side spans towards the center, repeat S2 to complete the hoisting, positioning, and connection of each arch frame segment, forming a cantilever structure that gradually extends from both sides; S4. When the cantilever structures on both sides approach the design closure point at the mid-span, adjust the pretension of some wind cables to obtain the structural flexibility required for closure; hoist and position the closure section at the mid-span position, and guide the cantilever structures on both sides to move towards the mid-span under the self-weight of the closure section to complete the connection of the closure section; S5. After the closure connection is completed, the corresponding cables are unloaded in stages according to the reverse order of the arch frame segment installation, and the stress and mid-span displacement of key nodes are monitored simultaneously. When the monitored values ​​meet the structural stability requirements, the cables and wind cables are removed, so that the steel arch frame is transferred from the temporary support system to the completed bridge load-bearing system.

2. The method for assembling a large-span steel arch frame formed by extruding mast-type cable clamps according to claim 1, characterized in that... In S1, a hinged support is provided between the bottom end of the mast and the foundation; the end of the wind cable is connected to the ground anchor through a hydraulic tensioner; the number of wind cables at the top of the mast is not less than three.

3. The method for assembling a large-span steel arch frame formed by extruding mast-type cable clamps according to claim 1, characterized in that... The expression for calculating the stress-free length L0 in S2 is: ; in, Design length for the buckle; ; , ; This is the difference between the construction temperature and the design temperature.

4. The method for assembling a large-span steel arch frame formed by extruding mast-type cable clamps according to claim 3, characterized in that... In step S2, after the cable is connected, a total station or laser measuring device is used to verify the three-dimensional coordinates of the segment, and when the deviation exceeds the preset allowable value, it is corrected by adjusting the length of the cable, the cable hanging point, or the position of the temporary support of the segment; the method of fine-tuning the length of the cable is to adjust the travel of the cable tensioner.

5. The method for assembling a large-span steel arch frame formed by extruding mast-type cable clamps according to claim 1, characterized in that... In S4, when the cantilever structures on both sides are 40-60 cm away from the closure section, 50% of the pre-tension of the wind cable is first removed.

6. The method for assembling a large-span steel arch frame formed by extruding mast-type cable clamps according to claim 5, characterized in that... The expression for the displacement of the cantilever structures on both sides towards the mid-span in S4 is: ; in, For the weight of the closure section; The free length of the cantilever; The bending stiffness of the arch frame section; displacement. ≤20mm.

7. The method for assembling a large-span steel arch frame formed by extruding mast-type cable clamps according to claim 6, characterized in that... In step S4, after the cantilever structures on both sides are guided to move towards the mid-span and stabilize, the arch frame closure section is welded in layers, and the welding temperature is controlled at 180-240℃.

8. The method for assembling a large-span steel arch frame formed by extruding mast-type cable clamps according to claim 1, characterized in that... Before the staged unloading in S5, a preload of 1.2 times its own weight is applied to the formed circumferential arch; 10% of the cable tension is released at each stage, with a stage interval of 20-30 minutes, and displacement gauges and strain sensors are used to monitor the stress of key nodes and mid-span displacement in real time.

9. A large-span steel arch frame assembly system for mast-type cable extrusion arching, characterized in that... ,include: The mast cable system, including the mast, hinged supports, cable anchors, and several wind cables, is used to form an adjustable and flexible temporary spatial support system. The stress-free control module includes a cable length calculation unit, a temperature measurement unit, a cable tensioner, and segment positioning marks, used to generate the stress-free length of the cable and achieve three-dimensional segment positioning; The structural monitoring and unloading module, including displacement gauges, strain sensors, data acquisition units, and over-limit alarm units, is used to monitor the structural response and provide safety control during the closure and staged unloading process.

10. The large-span steel arch frame assembly system for mast-type cable extrusion arching as described in claim 9, characterized in that... The wind cable has a specification of φ24-32 mm, is made of high-strength steel strand, and has an angle of 45°-60° with the horizontal.

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