A steel tube arch bridge arch construction method suitable for special terrain

Abstract

The present invention provides a method for constructing a steel tube arch bridge suitable for special terrain. The method comprises the following steps: dividing the arch ribs of the bridge into west arch ribs and east arch ribs, dividing both the west arch ribs and the east arch ribs into a plurality of arch rib segments, rotating the west arch ribs into position by vertical assembly and vertical rotation, and hoisting the east arch ribs into position by a bracket method. The present invention adopts different arch rib installation methods in a targeted manner according to the different geographical locations of the west arch ribs and the east arch ribs. Since the west arch ribs are located in a valley area and it is difficult to build brackets, a method for vertically rotating the arch ribs without building brackets is adopted. Since the east arch ribs are located in a narrow hillside area, a safer bracket method is adopted for erection, thereby reducing construction risks as a whole and improving construction efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of bridge construction, in particular to an arch construction method for a steel tube arch bridge suitable for special terrain. Background Art

[0002] Concrete-filled steel tube arch bridges are constructed by filling steel tubes with concrete. The radial constraints of the tubes limit the expansion of the compressed concrete, placing it under three-dimensional compression. This significantly increases the concrete's compressive strength. Furthermore, the steel tubes serve as both longitudinal reinforcement and transverse hoops, acting as formwork for easier concrete pouring. During construction, the steel tubes act as a rigid, heavy-duty skeleton, simplifying welding and reducing the weight required for hoisting. This simplifies the construction process and shortens the construction period.

[0003] The construction of steel tube arch ribs is the core link in the construction of steel tube concrete arch bridges. There are many construction methods for steel tube arch ribs, such as the bracket method, cable hoisting method and rotation construction method. Among them: the bracket method is to build the arch rib bracket in advance, and then hoist the arch rib onto the arch rib bracket for assembly and alignment. This construction method is easy to operate and relatively low in cost. It can achieve better control of the installation accuracy of the horizontal and diagonal braces and the arch axis shape. However, its disadvantage is that it has high requirements on the terrain and foundation conditions under the bridge, requires a large number of bracket systems and a certain number of templates, and consumes a lot of construction materials. If it is located above the river, it will occupy the waterway for a long time; the cable hoisting method is to use a crane to hoist the steel tube arch rib in sections, and Anchoring with cables and guy ropes at any time, this construction method does not require the construction of scaffolding, reducing the occupation of the waterway, but the cable force must be adjusted repeatedly, the construction is difficult, the arch axis shape control is cumbersome, and the construction period is long; the rotation construction method is implemented by first prefabricating and splicing the half bridge, and then using the bridge structure itself as the rotating body, using some machinery and equipment, the two half bridges are rotated to the bridge axis position to form a bridge. This construction method has the advantage of no scaffolding or less scaffolding, which can reduce the occupation of the waterway, but if the traditional horizontal splicing and vertical lifting method is adopted, the horizontal splicing scaffolding still needs to be pre-erected during assembly. However, if the bridge site happens to be located in a valley area, there will still be a problem of the scaffolding being too high, making it difficult to erect.

[0004] The above analysis shows that the method for arch rib construction must be considered in conjunction with geographical factors, construction time, and construction costs. During the Pinglu Canal project, the site was narrow on one side and valley-like on the other. How to quickly and safely construct the bridge arch ribs in this intertwined area became a pressing challenge. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a steel tube arch bridge arch construction method suitable for special terrain.

[0006] To achieve the above object, the technical solution of the present invention is:

[0007] A method for constructing a steel tube arch bridge suitable for special terrain comprises the following steps:

[0008] (1) The bridge arch ribs are divided into west arch ribs and east arch ribs. The west arch ribs and east arch ribs are divided into multiple arch rib segments. The west arch ribs are rotated into place by vertical rotation, and the east arch ribs are hoisted into place by bracket method. The construction of the west arch seat and the east arch seat is completed. The tower foundation of the lowering cable fixing foundation is completed behind the west arch seat. The arch rib bracket foundation is completed below the designed position of the east arch rib.

[0009] (2) Complete the construction of the vertical rotating tower in the cable-fixing foundation and the arch rib support. The arch rib support closest to the west arch seat is located below the joint position of the west arch rib and the east arch rib;

[0010] (3) The west arch rib and the east arch rib are assembled at the same time. The construction of the west arch rib includes: installing a rotatable structure at the lower end of the arch rib segment closest to the arch seat and connecting it to the west arch seat, and then assembling the arch rib segments vertically upwards in sequence until the west arch rib reaches the designed length. At the same time, installing a lowering cable at the back of the arch rib segment and connecting it to the vertical rotation tower, and installing a cable wind cable at the front of the arch rib segment and connecting it to the arch rib support foundation closest to the west arch seat; the construction of the east arch rib includes: hoisting the arch rib segments in sequence from the easternmost side of the arch rib to the middle, wherein the first and second arch rib segments on the easternmost side are not connected for the time being, and the other arch rib segments are connected together after the alignment is completed;

[0011] (4) Pre-tighten the lowering cables and guy cables, and coordinate and adjust the lengths of the lowering cables and guy cables so that the lower end of the west arch rib rotates downward with the rotatable structure as the axis until it reaches the designed position and is fixed to the east arch rib;

[0012] (5) Complete the connection between the first and second arch rib sections on the easternmost side, as well as the connection between the arch foot of the western arch rib and the western arch seat, and remove the guy wires, arch rib supports and lowering wires.

[0013] Preferably, in step (1), while completing the construction of the tower foundation in the lowering cable fixing foundation, the construction of the rear anchor device is also completed behind the lowering cable fixing foundation;

[0014] In step (2), after the construction of the vertical rotation tower is completed, the top of the vertical rotation tower and the rear anchor device are connected by an anchor cable.

[0015] More preferably, a rear anchoring jack is installed on the top of the rear anchoring device, the rear anchoring jack is connected to one end of an anchoring cable, and the other end of the anchoring cable is connected to the top of the vertical rotation tower;

[0016] A tensioning jack is provided on the top of the vertical tower, one end of the lowering cable is connected to the tensioning jack, and the other end is connected to the rear of the arch rib segment;

[0017] A front anchoring jack is provided on the arch rib support foundation closest to the west arch seat, one end of the wind cable is connected to the front anchoring jack, and the other end is connected to the front of the arch rib segment.

[0018] Preferably, in step (3), in the process of vertically assembling the arch rib segments in sequence upward until the west arch rib reaches the designed length, the alignment assembly between the arch rib segments includes the following steps:

[0019] S1. Install horse plates and pulling devices on all sides of the top of the installed arch rib segment. The horse plates extend upward from the top of the installed arch rib segment, and fixed ear plates are installed at the bottom of the arch rib segment to be installed.

[0020] S2. The arch rib segment to be installed is turned vertically with a lifting device to lift it off the ground and hoisted to the area surrounded by the horse board, and is initially docked with the installed arch rib segment at the top;

[0021] S3. Install a fine-tuning jack on the inside of the horse plate, connect the active end of the pulling device to the fixed ear plate on the same side of the arch rib segment to be installed, and adjust the length of the pulling device on each side so that the arch rib segment to be installed is as close to the designed assembly posture as possible;

[0022] S4. Adjust the extension length of the fine-adjustment jacks on each side so that the connecting bolt holes of the arch rib segment to be installed are all aligned with the connecting bolt holes of the installed arch rib segment at the top. Install the connecting bolts and release the pulling device, fine-adjustment jacks and lifting device.

[0023] More preferably, in step S2, before hoisting the arch rib segment to be installed, the position of the top of the installed arch rib segment at the top is pre-adjusted, and the specific steps include: measuring the position deviation of the top of the installed arch rib segment at the top by a total station, and using a transverse guy rope and / or a lowering rope to adjust its position so that its position deviation is controlled within a threshold range.

[0024] More preferably, in step S2, the process of vertically turning over the arch rib segment to be installed using a hoisting device includes:

[0025] First, use a lifting device combined with a flexible sling to flip the arch rib segment to be installed from a horizontal transverse posture to a horizontal longitudinal posture, set a pad under the top of the arch rib segment to be installed, install a turning trolley under the bottom, replace the flexible sling with a steel wire rope, and use the lifting device to pull up the top of the arch rib segment to be installed to flip it vertically.

[0026] More preferably, the pulling device and the fixing lug located on the same side of the arch rib segment are respectively installed on different arch rib chords located on both sides of the side;

[0027] Each side surface of the top of the installed arch rib segment at the top is provided with at least two horse plates, which are respectively installed on the arch rib chords on both sides of each side surface. The horse plates have a horse plate fixing portion extending upward from the top of the arch rib segment, and a fine-tuning jack is fixed on the inner side of the horse plate fixing portion.

[0028] More preferably, in step (2), after at least two arch rib supports are installed, a thrust self-anchoring system is installed between the arch rib support and the arch rib support foundation adjacent to the arch rib support, wherein the thrust self-anchoring system includes a longitudinal guy rope and a guy rope adjusting device, wherein one end of the longitudinal guy rope is detachably connected to one side of the upper portion of the arch rib support, and the other end is detachably connected to the arch rib support foundation via the guy rope adjusting device.

[0029] More preferably, a thrust self-anchoring system is provided on one side of the arch rib support that is not fixed on the east arch seat and to which the corresponding supported arch rib segment is not connected with a transverse guy rope.

[0030] Preferably, an adjustable support system is provided on the top of the arch rib bracket closest to the west arch seat, the adjustable support system includes a supporting crossbeam, a top support pad, a vertical lifting jack and a transverse adjustment jack, the top surface of the arch rib bracket is fixedly connected to the supporting crossbeam along the transverse bridge direction, the top surface of the supporting crossbeam is fixed to the top surface of the supporting crossbeam, the top support pad includes two top support pad units for matching the bottom two sides of the corresponding supporting arch rib chord, the vertical lifting jack is installed between the two top support pad units, an adjustment reaction seat is fixed on the top surface of the outer end, a transverse adjustment jack is fixed on the inner side surface of the adjustment reaction seat, the movable end of the transverse adjustment jack faces the designed position of the arch rib chord, and is connected to an arc-shaped adjustment plate of the arch rib chord;

[0031] The closure ends of the west arch rib and the east arch rib are designed to be spaced 30 to 60 cm apart, and are respectively connected to the outside of the chord cross brace with a positioning plate, which is provided with a bolt hole;

[0032] In step (4), the process of joining and fixing the west arch rib and the east arch rib includes:

[0033] The vertical elevation of the west arch rib is adjusted by a vertical lifting jack, and the horizontal position of the west arch rib is adjusted by a lateral adjustment jack and a lowering rope. After the position adjustment is completed, a pre-prepared splicing plate is taken, and the outer ends of the positioning plates of the west arch rib and the east arch rib are connected together by punching nails at both ends of the splicing plate, thereby completing the instantaneous closure of the closure mouth.

[0034] After the instantaneous closure is completed, the actual size of the closure mouth is measured, the cutting length of the upper chord and lower chord patching sections is determined, the closure sections are welded, and the arch rib closure is completed.

[0035] The above-mentioned method for the construction of a steel tube arch bridge suitable for special terrain has the following advantages:

[0036] (1) The present invention adopts different arch rib installation methods according to the different geographical locations of the west arch rib and the east arch rib. Since the west arch rib is located in a valley area and it is difficult to build a bracket, a vertical rotation construction method of the arch rib without building a bracket is adopted. Since the east arch rib is located in a narrow hillside area, a bracket with a self-anchoring system is used for bracket erection, thereby reducing the overall construction risk and improving the construction efficiency.

[0037] (2) For the west arch rib, the arch rib segments are installed vertically without the need to erect supports in the water. This effectively solves the problem of difficult installation due to the high height of the supports in the valley area, while avoiding the impact on the passage of the waterway and flood discharge. In addition, the amount of high-altitude operations in the water is reduced, thereby reducing the operational risks.

[0038] (3) As for the east side arch rib, it is located in a narrow hillside area on the north and south sides, and it is difficult to install a transverse cable to resist its load. However, the present invention sets a thrust self-anchor system between the arch rib support and the arch rib support foundation adjacent to the arch rib support, which can achieve the purpose of resisting the horizontal force generated when the arch rib segment is installed. This also reduces the process of additionally building a transverse cable foundation, shortens the construction time, and speeds up the construction process.

[0039] (4) For the vertical assembly of the west arch rib, the present invention further realizes the problem of precise alignment of the arch rib segments during the vertical assembly by setting up a pulling device, a horse plate and a fine-tuning jack to coordinate their work.

[0040] (5) For the closure of the arch rib and the east side arch rib, the present invention further adopts a combination of jacking jacks, large hoisting equipment and lowering ropes to adjust their positions, and at the same time combines splicing plates for rapid positioning, which greatly shortens the positioning time of the closure and speeds up the construction progress. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a schematic diagram of the structure of step (1).

[0042] Figure 2 It is a structural diagram of step (2).

[0043] Figure 3 It is a structural diagram of step (3).

[0044] Figure 4 This is a schematic diagram of the structure at the beginning of step (4).

[0045] Figure 5 This is a schematic diagram of the structure at the end of step (4).

[0046] Figure 6 It is a structural diagram when the arch rib segment to be installed is in a horizontal transverse posture.

[0047] Figure 7 It is a structural diagram of the arch rib segment to be installed when it is turned over to a horizontal longitudinal posture.

[0048] Figure 8 It is a structural diagram of the arch rib segment to be installed when it is turned over to a vertical position.

[0049] Figure 9 yes Figure 7 An enlarged structural diagram of the arch rib segment to be installed when connected to the tipping trolley.

[0050] Figure 10 yes Figure 8 An enlarged structural diagram of the middle turning trolley assisting the arch rib segment to be installed to turn to a vertical position.

[0051] Figure 11 It is a structural diagram of the tipping trolley when the support tube is placed horizontally.

[0052] Figure 12 It is a structural diagram of the tipping trolley when the support tube is rotated to an oblique state.

[0053] Figure 13 It is a schematic diagram of the structure of the horizontal guy rope.

[0054] Figure 14 It is a structural diagram when the arch rib segment to be installed is aligned with the installed arch rib segment at the top.

[0055] Figure 15 It is a structural diagram of the horse board and pulling device.

[0056] Figure 16 It is a structural diagram of the pulling device installed on the arch rib chord.

[0057] Figure 17 It is a structural diagram of the installation of the horse plate and fine-tuning jack on the arch rib chord.

[0058] Figure 18 It is an enlarged structural diagram of one of the fine-tuning jacks adjusting the arch rib chord.

[0059] Figure 19It is an enlarged structural diagram of the arch rib support, arch rib support foundation and thrust self-anchor system.

[0060] Figure 20 yes Figure 19 Schematic diagram of the top view structure.

[0061] Figure 21 It is a structural schematic diagram of an embodiment of an arch rib support foundation anchored in a hillside area.

[0062] Figure 22 yes Figure 21 Schematic diagram of the top view structure.

[0063] Figure 23 It is an enlarged structural diagram of the pull-out anchor.

[0064] Figure 24 It is a structural diagram of an embodiment of a thrust self-anchoring system.

[0065] Figure 25 It is a structural diagram of the joint of the west arch rib and the east arch rib.

[0066] Figure 26 It is a schematic diagram of the vertical cross-section structure of the closure.

[0067] Figure 27 It is an enlarged structural diagram of the chord cross brace connected by the positioning plate and the splicing plate.

[0068] Figure 28 It is a structural diagram of the adjustable support system.

[0069] Figure 29 yes Figure 28 Schematic diagram of the left side structure (omitting the lower chord of the arch rib).

[0070] In the figure, rear anchor device 1, lowering cable fixing foundation 2, tower foundation 201, vertical tower 202, west arch seat 3, arch rib support foundation 4, support expansion foundation 410, reinforcing steel bar 411, pull-out anchor rod 420, pull-out anchor rod body 421, nut 422, anchor plate 423, grouting pipe 424, east arch seat 5, anchor cable 6, rotatable structure 7, arch rib support 8, support column 801, west arch rib 9, lowering cable 10, cable wind rope 11, east arch rib 12, thrust self-anchor system 13, support column ear plate 1301, shackle 1302, longitudinal cable wind rope 1303, cable wind rope adjustment device 1304, foundation ear plate 1305, arch rib segment to be installed 14, lifting device 15 , pad 16, turning trolley 17, support tube 1701, car body mechanism 1702, walking mechanism 1703, trolley ear plate 1704, installed arch rib segment 18 at the top, transverse guy rope 19, horse plate 20, pulling device 21, fixed ear plate 22, arch rib chord 23, lower chord 2301, upper chord 2302, fine-tuning jack 24, chord cross brace 25, positioning plate 26, splicing plate 27, punching nail 28, positioning stiffening plate 29, chord cross brace stiffening plate 30, adjustable support system 31, vertical lifting jack 3101, arc adjustment plate 3102, transverse adjustment jack 3103, adjustment reaction seat 3104, top support pad 3105, support beam 3106. DETAILED DESCRIPTION

[0071] The present invention will be further described below with reference to specific examples, but the protection scope of the present invention is not limited to the following examples.

[0072] In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper", "lower", "left", "right", "front", "back", etc. are based on the directions or positional relationships shown in the accompanying drawings, or are the directions or positional relationships in which the inventive product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the present invention.

[0073] In this application, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components or interactions between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on specific circumstances.

[0074] A method for constructing a steel tube arch bridge suitable for special terrain comprises the following steps:

[0075] (1) The arch ribs of the bridge are divided into a west arch rib 9 and an east arch rib 12. The west arch rib 9 and the east arch rib 12 are both divided into a plurality of arch rib segments. The west arch rib 9 is rotated into position by vertical rotation, and the east arch rib 12 is hoisted into position by a bracket method. It should be noted that the lengths of the west arch rib 9 and the east arch rib 12 can be equal or unequal, depending on the terrain structure of the bridge. Taking the embodiment of the present invention as an example, Figure 1 In the figure, below the design position of the bridge, the river width is small and the hillside area is wide, so the length of the west arch rib 9 is smaller than the length of the east arch rib 12; Figure 1 As shown, the construction of the west arch seat 3 and the east arch seat 5 is completed first, the construction of the tower foundation 201 in the lowering cable fixing foundation 2 is completed behind the west arch seat 3, and the construction of the arch rib support foundation 4 is completed below the designed position of the east arch rib 12.

[0076] (2) Combination Figure 2 As shown, the construction of the vertical rotating tower 202 in the lowering cable fixing foundation 2 and the construction of the arch rib support 8 are completed. The vertical rotating tower 202 is fixed on the tower foundation 201, and the arch rib support 8 is fixed on the arch rib support foundation 4. Among them, the arch rib support 8 closest to the west arch seat 3 is located below the joint position of the west arch rib 9 and the east arch rib 12. The arch rib support 8 needs to support the joint ends of the west arch rib 9 and the east arch rib 12 at the same time to assist in completing the joint of the west arch rib 9 and the east arch rib 12.

[0077] (3) The west arch rib 9 and the east arch rib 12 are assembled at the same time, combined with Figure 3 As shown, the construction of the west arch rib 9 includes: installing a rotatable structure 7 at the lower end of the arch rib segment closest to the arch seat and connecting it to the west arch seat 3, and then vertically assembling the arch rib segments upward in sequence until the west arch rib 9 reaches the designed length, and at the same time installing a lowering cable 10 at the back of the arch rib segment and connecting it to the vertical rotation tower 202, and installing a cable wind cable 11 in front of the arch rib segment and connecting it to the arch rib support foundation 4 closest to the west arch seat 3; the construction of the east arch rib 12 includes: hoisting the arch rib segments in sequence from the easternmost side of the arch rib to the middle, wherein the first and second arch rib segments on the easternmost side are not connected for the time being, and the other arch rib segments are connected together after the alignment is completed.

[0078] (4) Combination Figure 4 As shown, first pre-tighten the lowering cable 10 and the cable 11, and then coordinate and adjust the length of the lowering cable 10 and the cable 11 so that the lower end of the west arch rib 9 is axially centered on the rotatable structure 7, and the upper part rotates downward to reach the designed position, and is fixed to the east arch rib 12, that is, Figure 5 shown.

[0079] (5) Complete the connection between the first and second arch rib segments on the easternmost side, as well as the connection between the arch foot of the west arch rib 9 and the west arch seat 3, and remove the cable 11, arch rib support 8 and lowering cable 10.

[0080] This embodiment adopts different arch rib installation methods according to the different geographical locations of the west arch rib 9 and the east arch rib 12. As the west arch rib is located in a valley area and it is difficult to build a scaffold, a vertical rotation construction method of the arch rib without building a scaffold is adopted. As the east arch rib is located in a hillside area, the scaffolding method is safer and more reliable, so the scaffolding method is adopted to reduce the overall construction risk and improve the construction efficiency.

[0081] For the west arch rib, the arch rib segments are installed vertically, so there is no need to set up supports in the water. This effectively solves the problem of difficult installation due to the high height of the supports in the valley area, while avoiding the impact on waterway navigation and flood discharge. It also reduces the amount of high-altitude operations in the water and reduces operational risks.

[0082] Preferably, in step (1), while completing the construction of the tower foundation 201 in the lowering cable fixing foundation 2, the construction of the rear anchor device 1 is also completed behind the lowering cable fixing foundation 2; in step (2), after the construction of the vertical tower 202 is completed, the top of the vertical tower 202 and the rear anchor device 1 are connected by the anchor cable 6, and the anchor cable 6 can well maintain the force balance before and after the vertical tower 202, thereby ensuring the stability during the lowering process of the arch rib.

[0083] More preferably, a rear anchor jack is mounted on the top of the rear anchor device 1, connected to one end of the anchor cable 6, the other end of which is connected to the top of the vertical turret 202. A tensioning jack is mounted on the top of the vertical turret 202, with one end of the lowering cable 10 connected to the tensioning jack and the other end connected to the rear of the arch rib segment. A front anchor jack is mounted on the arch rib support foundation 4 closest to the west arch seat 3, with one end of the wind cable 11 connected to the front anchor jack and the other end connected to the front of the arch rib segment. The length and cable force of the anchor cable 6, lowering cable 10, and wind cable 11 can be adjusted respectively by the rear anchor jack, tensioning jack, and front anchor jack, which is convenient, fast, and highly safe.

[0084] It should also be noted that when the west arch rib 9 is vertically assembled, after the rotatable structure 7 is installed, it is preferred to install temporary fixing structures at the front and rear of the lower end of the arch rib segment closest to the west arch seat 3 to fix the arch rib segment closest to the west arch seat 3 together to ensure the stability of the vertical assembly process of the west arch rib 9, that is, Figure 3In the direction shown, the left and right sides of the bottom end of the arch rib segment are generally fixed to the west arch seat 3 by welding steel pipes. Of course, the west arch seat 3 is provided with corresponding embedded parts to connect with the steel pipes. The temporary fixing structure may include a rear temporary fixing structure and a front temporary fixing structure. The rear temporary fixing structure is connected to the arch rib upper chord 2302, and the front temporary fixing structure is connected to the arch rib lower chord 2301. Before the rotation construction, the temporary fixing structure is removed, as shown in FIG. Figure 4 This embodiment only lists one temporary fixing structure that is convenient for installation. Other temporary fixing structures can also be used, as long as they can fix the arch rib segments.

[0085] To control the assembly and rotation position of the west arch rib 9, a monitoring system is used to monitor the position and line shape of the arch rib during the assembly and rotation of the arch rib segments. The monitoring system of this embodiment includes a 4D laser point cloud acquisition device and a lowering control system. The lowering control system is electrically connected to the 4D laser point cloud acquisition device, the lowering cable 10, and the cable wind cable 11. The 4D laser point cloud acquisition device is installed in front of and behind the west arch rib 9 to collect data including the position coordinates and line shape of the arch rib segments and transmit it to the lowering control system. The lowering control system transmits lowering instructions, controls the length and cable force of the lowering cable 10 and the cable wind cable 11, and controls the installation and lowering positions of the arch rib segments within an error range. During the assembly of the arch rib segments, the 4D laser point cloud acquisition device can be used to understand the hoisting position of the arch rib segments to assist in adjusting the hoisting position. During the rotation construction process, based on the feedback from the 4D laser point cloud acquisition device, the lowering control system controls the tension of the lowering cable 10 and the cable wind cable 11 by controlling the tensioning jack and the front anchoring jack to adjust the position of the west arch rib 9. In this embodiment, the west arch rib 9 is rotated and lowered in multiple times. After each rotation to a certain angle, it is necessary to adjust the tension and length of the lowering cable 10 and the cable wind cable 11 so that the rotation position of the west arch rib 9 does not exceed the deviation control range. Of course, in order to facilitate the stable vertical rotation of the tower, the rear anchoring jack is also connected to the lowering control system, and the tension of the anchoring cable 6 can also be controlled by the lowering control system. The 4D laser point cloud acquisition device can be installed on both sides of the river. The images collected by the 4D laser point cloud acquisition device need to be converted to the coordinate system after collection to obtain the position coordinates of the arch rib segment.

[0086] Preferably, in step (3), in the process of vertically assembling the arch rib segments in sequence upward until the west arch rib 9 reaches the designed length, the alignment assembly between the arch rib segments includes the following steps:

[0087] S1. Install a horse plate 20 and a pulling device 21 on each side of the top of the installed arch rib segment 18 at the top. The horse plate 20 extends upward from the top of the installed arch rib segment 18 at the top. Install a fixing ear plate 22 at the bottom of the arch rib segment 14 to be installed.

[0088] S2. Combination Figure 6-8 As shown, the arch rib segment 14 to be installed is vertically turned over by a hoisting device, lifted off the ground and hoisted into the area surrounded by the horse plate 20, and preliminarily docked with the installed arch rib segment 18 at the top; the horse plate 20 extends from the top of the installed arch rib segment 18 at the top to the height range of the designed position of the arch rib segment 14 to be installed, providing preliminary positioning for the hoisting of the arch rib segment 14 to be installed.

[0089] S3. Install the fine-adjustment jack 24 on the inner side of the horse plate 20. The fine-adjustment jack 24 is within the height range of the designed position of the arch rib segment 14 to be installed. Connect the movable end of the pulling device 21 to the fixed ear plate 22 on the same side of the arch rib segment 14 to be installed. Adjust the length of the pulling device 21 on each side so that the arch rib segment 14 to be installed is as close to the designed assembly posture as possible, completing the rough adjustment of the arch rib segment posture.

[0090] S4. Adjust the extension length of the fine-tuning jacks 24 on each side so that the connecting bolt holes of the arch rib segment 14 to be installed are all aligned with the connecting bolt holes of the installed arch rib segment 18 at the top, install the connecting bolts, and release the pulling device 21, the fine-tuning jacks 24 and the lifting device 15.

[0091] In this embodiment, the pulling device 21, the horse plate 20 and the fine adjustment jack 24 are arranged to work in coordination, thereby achieving the problem of precise alignment during the vertical assembly of the arch rib segments.

[0092] More preferably, in step S2, considering that the arch rib segment may be affected by the external environment and may be offset after installation, the position of the top of the installed arch rib segment 18 at the top is pre-adjusted before the arch rib segment 14 to be installed is hoisted. The specific steps include: measuring the position deviation of the top of the installed arch rib segment 18 at the top by a total station, and combining the position deviation of the top of the arch rib segment 18 at the top with the total station. Figure 13As shown, transverse guy cables 19 and / or lowering cables 10 are used to adjust their positions so that their positional deviations are controlled within a threshold range. The transverse guy cables 19 facilitate adjustment of the left-right direction of the arch rib segments, while the lowering cables 10 facilitate adjustment of the front-back direction of the arch rib segments. If the lower arch rib segments have not yet been installed with lowering cables 10, position adjustment is primarily achieved by tensioning the transverse guy cables 19. Before hoisting the arch rib segments, the position of the top of the already installed arch rib segment 18 is pre-adjusted, thereby better solving the problem of precise positioning of the arch rib segments 14 to be installed. Furthermore, the installation of the transverse guy cables 19 can be referred to the installation method of transverse guy cables on conventional bridges.

[0093] More preferably, in order to better protect the arch rib segment, in step S2, the process of vertically turning over the arch rib segment 14 to be installed using the hoisting device 15 includes: combining Figure 6 As shown, the arch rib segment 14 to be installed is first in a horizontal horizontal posture, and the lifting device 15 is first used in combination with the flexible lifting belt, and then the lifting device 15 is used in combination with the flexible lifting belt. Figure 7 and Figure 9 As shown, the arch rib segment 14 to be installed is turned over from a horizontal transverse posture to a horizontal longitudinal posture, and a pad 16 is set under the top of the arch rib segment 14 to be installed, and a turning trolley 17 is installed under the bottom. The flexible lifting belt is replaced with a steel wire rope, and the top of the arch rib segment 14 to be installed is pulled upward by the lifting device 15 to make it turn vertically. The vertical turning is completed as shown in FIG. Figure 8 and Figure 10 As shown. During the process of turning the arch rib segment from a horizontal transverse position to a horizontal longitudinal position, the use of a flexible sling prevents friction with the arch rib segment and damage to the arch rib coating. After the horizontal longitudinal turning is completed, it is replaced with a steel wire rope. This is because the steel wire rope is now pulling the top of the arch rib segment 14 to be installed, with less contact and less probability of friction with the arch rib segment. The steel wire rope can also better meet the mechanical strength requirements of the lifting process. In addition, the provision of a turning trolley 17 effectively solves the problem of arch rib chords 23 rubbing against the ground when turning the arch rib in a narrow space where only a single crane can be installed, which can cause damage to the arch rib coating and even deformation of the arch rib chords 23.

[0094] More preferably, this embodiment provides a convenient operation turning trolley 17, combined with Figure 11-12As shown, the turning trolley 17 includes a walking mechanism 1703, a car body mechanism 1702, a trolley ear plate 1704 and a support tube 1701. The bottom of the car body mechanism 1702 is rollingly connected to the walking mechanism 1703. The walking mechanism 1703 is generally a roller. The top surface of the car body mechanism 1702 is fixedly connected to the trolley ear plate 1704. The trolley ear plate 1704 is rotatably connected to the support tube 1701. The rotatable connection can be achieved by inserting a pin into the ear hole of the trolley ear plate 1704 and the pin hole at the lower end of the support tube 1701. The support tube 1701 can be matched and inserted into the upper chord rod 2302 / lower chord rod 2301 of the arch rib segment or can be matched and sleeved on the outer periphery of the bottom end of the upper chord rod 2302 / lower chord rod 2301 of the arch rib segment. The above-mentioned connection method of the support tube 1701 and the arch rib segment can better prevent the arch rib segment from being separated from the support of the turning trolley 17. Figure 9 and Figure 10 The figure shows that the support tube 1701 is matched and inserted into the lower chord 2301.

[0095] More preferably, combined Figure 16 As shown, the pulling device 21 and the fixing lug 22 located on the same side of the arch rib segment are respectively installed on different arch rib chords 23 located on both sides of the side; Figure 16 Taking the front pulling device 21 as an example, the pulling device 21 is first installed on the lower chord 2301 of the installed arch rib segment 18 at the top, and then its movable end is connected to the upper chord 2302 on the same side of the arch rib segment 14 to be installed. The same applies to the others, so that the force applied to the entire arch rib segment can be better adjusted.

[0096] Combine Figure 15 and 17 As shown, each side of the top of the installed arch rib segment 18 is provided with at least two horse plates 20, which are respectively installed on the arch rib chords 23 on both sides of each side. The horse plates 20 have a horse plate 20 fixing portion extending upward from the top of the arch rib segment, and a fine adjustment jack 24 is fixed inside the horse plate 20 fixing portion. Figure 18 As shown, the saddle 20 has a saddle fixing portion extending upward from the top of the arch rib segment, and a fine adjustment jack 24 is fixed inside the saddle fixing portion. The saddle 20 may include a saddle support portion and a saddle fixing portion. One end of the saddle support portion is connected to the arch rib chord 23 of the installed arch rib segment 18 at the top, and the saddle fixing portion is fixed thereto. The saddle fixing portion is spaced apart from the arch rib chord 23 of the arch rib segment 14 to be installed to facilitate the installation of the fine adjustment jack 24.

[0097] Preferably, the pulling device 21 selected in this embodiment is a hand chain hoist, which is low in cost and convenient for length adjustment.

[0098] Preferably, the hoisting device 15 selected in this embodiment for hoisting the west arch rib 9 is a crawler crane or a truck crane. When the span of the arch rib is large, the crawler crane can better meet the hoisting height requirement during assembly.

[0099] More preferably, in the traditional support construction method, considering that the arch rib support is generally a high and narrow structure, it is greatly affected by the lateral wind load, and a lateral cable is usually installed to resist the load. However, considering that the east bank is in a hillside area and the space on the north and south sides is narrow, it is difficult to set the anchor foundation of the lateral cable. Figure 19 and Figure 20 As shown, in step (2), after at least two arch rib supports 8 are installed, a thrust self-anchoring system 13 is installed between the arch rib support 8 and the arch rib support foundation 4 adjacent to the arch rib support 8. The thrust self-anchoring system 13 includes a longitudinal guy rope and a guy rope adjusting device. One end of the longitudinal guy rope is detachably connected to one side of the upper portion of the arch rib support 8, and the other end is detachably connected to the arch rib support foundation 4 through the guy rope adjusting device. A guy rope adjusting device 1304 is provided between the arch rib support foundation 4 and the longitudinal guy rope 1303. The guy rope adjusting device 1304 can adjust the overall length of the longitudinal guy rope 1303 and the guy rope adjusting device 1304, and tighten the longitudinal guy rope 1303, thereby better resisting wind loads and the horizontal force of installing the arch rib segment.

[0100] In this embodiment, the arch rib support foundation 4 serves as the anchoring foundation for both the arch rib support 8 and the longitudinal guy rope, eliminating the need for installing a transverse guy rope anchoring foundation. This effectively addresses the issue of narrow sites being unable to install a transverse guy rope anchoring foundation to resist wind loads, while also effectively shortening the construction period. Furthermore, by providing a thrust self-anchoring system 13 between the arch rib support 8 and the adjacent arch rib support foundation 4, the horizontal force generated during the installation of the arch rib segments can be resisted, thereby avoiding the need to install longitudinal connections between the arch rib supports 8 and preventing material waste. Furthermore, in this embodiment, the arch rib support foundation 4 closest to the west arch seat 3 also serves as the fixed foundation for the guy rope 11, further reducing material costs and shortening the construction period.

[0101] More preferably, in order to reduce construction costs while taking into account construction safety and accuracy, this embodiment fully considers the number of thrust self-anchor systems 13, wherein each side of the arch rib bracket 8 that is not fixed on the east side arch seat 5 and whose corresponding supported arch rib segment is not connected to the transverse cable 19 is provided with a thrust self-anchor system 13. Figure 19To explain the above settings, the easternmost arch rib support foundation 4 is installed on the eastern arch seat 5 (the rightmost arch rib support foundation 4 is shown in the figure). Since the arch seat arch ribs are relatively stable, the arch rib support 8 installed on the eastern arch seat 5 is not provided with a longitudinal guy rope connected to its top side. The westernmost arch rib support foundation 4 (the leftmost arch rib support foundation 4 is shown in the figure) supports the arch rib segment on its upper part, and also includes the joint end of the eastern arch rib 12. The eastern arch rib 12 is tensioned by a transverse guy rope 19, so the arch rib support 8 is not provided with a longitudinal guy rope connected to its top side.

[0102] For the arch rib support foundation 4, if it is on water, a combination of cast-in-place piles and expanded foundations is used. For example, the westernmost arch rib support foundation 4 in this embodiment, if it is located on land, in addition to supporting the arch rib support 8, it also needs to withstand the upward pull of the thrust self-anchor system 13. Therefore, this embodiment also provides an arch rib support foundation 4 with good pull-out resistance, combined with Figure 21-23 As shown, it includes a support expansion foundation 410 and multiple anti-pull anchors 420. The lower and middle parts of the anti-pull anchors 420 are deeply embedded in the ground foundation, and the upper parts pass through the support expansion foundation 410 and are fixed together. In this embodiment, the support expansion foundation 410 is a reinforced concrete foundation. The construction steps include: the pull-out anchor rod 420 includes a pull-out anchor rod body 421, a hole is drilled downward in the ground foundation, the pull-out anchor rod body 421 is vertically placed in the hole and positioned, grouting is performed from bottom to top through the grouting pipe 424, and after reaching a certain strength, the bracket expansion foundation 410 is poured to ensure that the top end of the pull-out anchor rod body 421 passes through the bracket expansion foundation 410, and reinforcing steel bars 411 are pre-buried in the bracket expansion foundation 410 near its top surface and close to the pull-out anchor rod body 421 to increase the compressive capacity of the bracket expansion foundation 410, after the bracket expansion foundation 410 is consolidated, an anchor plate 423 with a through hole is placed from the top end of the pull-out anchor rod body 421, and finally a nut 422 is screwed in to press against the top surface of the anchor plate 423 and the anchor plate 423 is pressed against the top surface of the bracket expansion foundation 410; in addition, the construction steps can also be: Drill a hole downward in the ground foundation, reserve an anchor channel in the template of the bracket expanded foundation 410 (the anchor channel can be reserved by inserting a PVC pipe in the template), then cast the bracket expanded foundation 410, and embed reinforcing steel bars 411 in the expanded foundation near its top surface and close to the anchor channel. After the bracket expanded foundation 410 is consolidated to a certain strength, the pull-out anchor body 421 is passed through the anchor channel and penetrated into the hole of the ground foundation. Grouting is performed from bottom to top through the grouting pipe 424, and the slurry overflows from the top of the bracket expanded foundation 410. The slurry consolidates the pull-out anchor 420 to the ground foundation and the bracket expanded foundation 410. Then, the anchor plate 423 is placed from the top of the pull-out anchor body 421, and finally the nut 422 is screwed in to press against the top surface of the anchor plate 423 and the anchor plate 423 is pressed against the top surface of the bracket expanded foundation 410.

[0103] Preferably, this embodiment provides a thrust self-anchoring system 13, combined with Figure 24 As shown, each thrust self-anchoring system 13 also includes a support column ear plate 1301 and a base ear plate 1305. The support column ear plate 1301 is fixed to one side of the upper portion of the arch rib support 8, and the base ear plate 1305 is fixed to one side of the top surface of the support expanded foundation 410. Then, one end of the longitudinal guy rope 1303 is connected to the support column ear plate 1301, and the other end is connected to the movable end of the guy rope adjustment device 1304. The fixed end of the guy rope adjustment device 1304 is connected to the support expanded foundation 410 through the base ear plate 1305. The longitudinal guy rope 1303 can be kept in a tensioned state by adjusting the length of the guy rope adjustment device 1304. This embodiment uses an ear plate structure for connection. The ear plate is provided with corresponding ear holes to facilitate the tying of the longitudinal guy rope 1303. The ear plate is connected to the corresponding guy rope adjustment device 1304 via a pin shaft or a hook body, which is easy to operate and can better improve construction efficiency. One end of the longitudinal guy rope 1303 is connected to a shackle 1302, which is detachably connected to the bracket column ear plate 1301 through the shackle 1302. Before installing the longitudinal guy rope 1303, the shackle 1302 is pre-connected to one end of the longitudinal guy rope 1303. Then, when installing the thrust self-anchoring system 13, the shackle 1302 is directly hung on the bracket column ear plate 1301 to quickly realize the connection between the longitudinal guy rope 1303 and the arch rib bracket 8.

[0104] Preferably, this embodiment provides a preferred solution for the closure of the west arch rib 9 and the east arch rib 12. Figures 28-29 As shown, an adjustable support system 31 is provided on the top of the support column 801 of the arch rib support 8 closest to the west arch seat. The adjustable support system 31 includes a support beam 3106, a top support pad 3105, a vertical lifting jack 3101 and a transverse adjustment jack 3103. The top surface of the arch rib support is fixedly connected to the support beam 3106 along the transverse bridge direction. The top support pad 3105 is fixed to the top surface of the support beam 3106. The top support pad 3105 includes two top support pad units for matching the bottom sides of the corresponding supporting arch rib chord 23, as shown in FIG. Figure 28As shown, it is arranged along the transverse direction of the bridge, with a curved pad at the top to match and support the arch rib lower chord 2301. A vertical lifting jack 3101 is installed between the two top support pad units. An adjustment reaction seat 3104 is fixed to the top surface of the outer end, and a transverse adjustment jack 3103 is fixed to the inner side of the adjustment reaction seat 3104. The movable end of the transverse adjustment jack 3103 faces the designed position of the arch rib chord and is connected to a curved adjustment plate 3102 of the arch rib chord. This curved adjustment plate 3102 can match the curvature of the arch rib lower chord 2301. In addition, to better fix the transverse adjustment jack 3103, a support rod can be installed below the middle of the transverse adjustment jack 3103, and the bottom end of the support rod is fixed to the top support pad 3105. The transverse adjustment jack 3103 can use a screw jack for more precise adjustment. The closure ends of the west arch rib 9 and the east arch rib 12 are designed to be 30 to 60 cm apart. Figures 25-27 As shown, positioning plates 26 are connected to the outside of the chord cross braces 25, and the positioning plates 26 are provided with bolt holes. In this embodiment, two positioning plates 26 are fixedly connected to each chord cross brace 25, located near the ends of the chord cross brace 25. The positioning plates 26 are semicircular on the side near the chord cross brace 25, connected to the half-circular arc line of the chord cross brace 25, and extend outward away from the side near the chord cross brace 25. The positioning plates 26 are designed to maintain a spacing of 5 to 10 mm at the corresponding positions of the west arch rib 9 and the east arch rib 12 to avoid overlapping and affecting the installation of the splicing plate 27.

[0105] In step (4), the process of merging and fixing the west arch rib 9 and the east arch rib 12 includes: adjusting the vertical elevation of the west arch rib 9 by means of the vertical lifting jack 3101, adjusting the horizontal position of the west arch rib 9 by means of the lateral adjustment jack 3103 and the lowering rope 10, after the position adjustment is completed, taking the pre-prepared splicing plate 27, the two ends of the splicing plate 27 are respectively connected to the outer ends of the positioning plates 26 of the west arch rib 9 and the east arch rib 12 by means of the punching nails 28, and completing the instantaneous merging of the merging mouth at the same time; after the instantaneous merging is completed, measuring the actual size of the merging mouth, determining the blanking length of the patching section of the upper chord 2302 and the lower chord 2301, welding the merging section, and completing the merging of the arch ribs.

[0106] It should be noted that screw holes are pre-drilled in the positioning plate 26 to facilitate the installation of the rivets 28. The splicing plate 27 does not require drilling; the rivets 28 are driven directly into the splicing plate 27 during closure, allowing for a certain degree of deviation while remaining within a reasonable range. To ensure the stability of the connection, a chord brace stiffener 30 is welded to the connection between the chord brace 25 and the arch rib chord 23. A positioning stiffener 29 is welded to the connection between the positioning plate 26 and the chord brace 25. These positioning stiffeners 29 are preferably symmetrically arranged relative to the centerline of the chord brace 25, and are provided on both sides of the designed position of the splicing plate 27.

[0107] The method for joining the west arch rib 9 and the east arch rib 12 is to adjust their positions by combining a lifting jack, a large hoisting device and a lowering rope 10, and to quickly position them by combining a splicing plate 27, which greatly shortens the positioning time of the joint and speeds up the construction progress.

[0108] The foregoing descriptions of specific exemplary embodiments of the present invention are for purposes of illustration and description. These descriptions are not intended to limit the invention to the precise forms disclosed, and it is apparent that many variations and modifications are possible in light of the foregoing teachings. The exemplary embodiments have been selected and described for the purpose of explaining the specific principles of the invention and their practical application, thereby enabling those skilled in the art to realize and utilize a variety of exemplary embodiments of the invention and various options and modifications. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A method for constructing a steel tube arch bridge suitable for special terrain, characterized in that The following steps are involved: (1) The bridge arch ribs are divided into west arch ribs and east arch ribs. The west arch ribs and east arch ribs are divided into multiple arch rib segments. The west arch ribs are rotated into place by vertical rotation, and the east arch ribs are hoisted into place by bracket method. The construction of the west arch seat and the east arch seat is completed. The tower foundation of the lowering cable fixing foundation is completed behind the west arch seat. The arch rib bracket foundation is completed below the designed position of the east arch rib. (2) Complete the construction of the vertical rotating tower in the cable-fixing foundation and the arch rib support. The arch rib support closest to the west arch seat is located below the joint position of the west arch rib and the east arch rib; (3) The west arch rib and the east arch rib are assembled at the same time. The construction of the west arch rib includes: installing a rotatable structure at the lower end of the arch rib segment closest to the arch seat and connecting it to the west arch seat, and then assembling the arch rib segments vertically upwards in sequence until the west arch rib reaches the designed length. At the same time, installing a lowering cable at the back of the arch rib segment and connecting it to the vertical rotation tower, and installing a cable wind cable at the front of the arch rib segment and connecting it to the arch rib support foundation closest to the west arch seat; the construction of the east arch rib includes: hoisting the arch rib segments in sequence from the easternmost side of the arch rib to the middle, wherein the first and second arch rib segments on the easternmost side are not connected for the time being, and the other arch rib segments are connected together after the alignment is completed; (4) Pre-tighten the lowering cables and guy cables, and coordinate and adjust the lengths of the lowering cables and guy cables so that the lower end of the west arch rib rotates downward with the rotatable structure as the axis until it reaches the designed position and is fixed to the east arch rib; (5) Complete the connection between the first and second arch rib sections on the easternmost side, as well as the connection between the arch foot of the western arch rib and the western arch seat, and remove the guy wires, arch rib supports and lowering wires.

2. The method for constructing a steel tube arch bridge suitable for special terrain according to claim 1, characterized in that: In step (1), while completing the construction of the tower foundation in the lowering cable fixing foundation, the construction of the rear anchor device is also completed behind the lowering cable fixing foundation; In step (2), after the construction of the vertical rotation tower is completed, the top of the vertical rotation tower and the rear anchor device are connected by an anchor cable.

3. The method for constructing a steel tube arch bridge suitable for special terrain according to claim 2, characterized in that: A rear anchoring jack is installed on the top of the rear anchor device, the rear anchoring jack is connected to one end of the anchoring cable, and the other end of the anchoring cable is connected to the top of the vertical rotation tower; A tensioning jack is provided on the top of the vertical tower, one end of the lowering cable is connected to the tensioning jack, and the other end is connected to the rear of the arch rib segment; A front anchoring jack is provided on the arch rib support foundation closest to the west arch seat, one end of the wind cable is connected to the front anchoring jack, and the other end is connected to the front of the arch rib segment.

4. The method for constructing a steel tube arch bridge suitable for special terrain according to claim 1, characterized in that: In step (3), in the process of vertically assembling the arch rib segments upwards in sequence until the west arch rib reaches the designed length, the alignment assembly between the arch rib segments includes the following steps: S1. Install horse plates and pulling devices on all sides of the top of the installed arch rib segment. The horse plates extend upward from the top of the installed arch rib segment, and fixed ear plates are installed at the bottom of the arch rib segment to be installed. S2. The arch rib segment to be installed is turned vertically with a lifting device to lift it off the ground and hoisted to the area surrounded by the horse board, and is initially docked with the installed arch rib segment at the top; S3. Install a fine-tuning jack on the inside of the horse plate, connect the active end of the pulling device to the fixed ear plate on the same side of the arch rib segment to be installed, and adjust the length of the pulling device on each side so that the arch rib segment to be installed is as close to the designed assembly posture as possible; S4. Adjust the extension length of the fine-adjustment jacks on each side so that the connecting bolt holes of the arch rib segment to be installed are all aligned with the connecting bolt holes of the installed arch rib segment at the top. Install the connecting bolts and release the pulling device, fine-adjustment jacks and lifting device.

5. The method for constructing a steel tube arch bridge suitable for special terrain according to claim 4, characterized in that: In step S2, before hoisting the arch rib segment to be installed, the position of the top of the installed arch rib segment at the top is pre-adjusted. The specific steps include: measuring the position deviation of the top of the installed arch rib segment at the top by a total station, and using transverse guy ropes and / or lowering ropes to adjust its position so that its position deviation is controlled within a threshold range.

6. The method for constructing a steel tube arch bridge suitable for special terrain according to claim 4, characterized in that: In step S2, the process of vertically turning over the arch rib segment to be installed using a hoisting device includes: First, use a lifting device combined with a flexible sling to flip the arch rib segment to be installed from a horizontal transverse posture to a horizontal longitudinal posture, set a pad under the top of the arch rib segment to be installed, install a turning trolley under the bottom, replace the flexible sling with a steel wire rope, and use the lifting device to pull up the top of the arch rib segment to be installed to flip it vertically.

7. The method for constructing a steel tube arch bridge suitable for special terrain according to claim 4, characterized in that: The pulling device and the fixing lug located on the same side of the arch rib segment are respectively installed on different arch rib chords located on both sides of the side; Each side surface of the top of the installed arch rib segment at the top is provided with at least two horse plates, which are respectively installed on the arch rib chords on both sides of each side surface. The horse plates have a horse plate fixing portion extending upward from the top of the arch rib segment, and a fine-tuning jack is fixed on the inner side of the horse plate fixing portion.

8. The method for constructing a steel tube arch bridge suitable for special terrain according to claim 1, characterized in that: In step (2), after at least two arch rib supports are installed, a thrust self-anchoring system is installed between the arch rib support and the arch rib support foundation adjacent to the arch rib support, wherein the thrust self-anchoring system includes a longitudinal guy rope and a guy rope adjusting device, wherein one end of the longitudinal guy rope is detachably connected to one side of the upper portion of the arch rib support, and the other end is detachably connected to the arch rib support foundation through the guy rope adjusting device.

9. The method for constructing a steel tube arch bridge suitable for special terrain according to claim 8, characterized in that: One side of the arch rib support that is not fixed on the east side arch seat and to which the corresponding supported arch rib segment is not connected with a transverse guy rope is provided with a thrust self-anchoring system.

10. The method for constructing a steel tube arch bridge suitable for special terrain according to claim 1, characterized in that: The top of the arch rib support closest to the west arch seat is provided with an adjustable support system, which includes a supporting beam, a top support pad, a vertical lifting jack and a lateral adjustment jack. The top surface of the arch rib support is fixedly connected to the supporting beam along the transverse bridge direction, and the top surface of the supporting beam is fixed with the top support pad. The top support pad includes two top support pad units for matching the bottom sides of the corresponding supporting arch rib chords. The vertical lifting jack is installed between the two top support pad units, and an adjustable jack is fixed on the top surface of the outer end. The reaction seat is a joint, and a lateral adjustment jack is fixed on the inner side of the adjustment reaction seat, the movable end of the lateral adjustment jack faces the design position of the arch rib chord, and is connected to an arc-shaped adjustment plate with the arch rib chord; the design position of the joint end of the west arch rib and the east arch rib is kept at a distance of 30 to 60 cm, and a positioning plate is connected to the outer side of the chord cross brace closest to the joint end, and the positioning plate is penetrated with a bolt hole; in step (4), the process of jointing and fixing the west arch rib and the east arch rib includes: The vertical elevation of the west arch rib is adjusted by a vertical lifting jack, and the horizontal position of the west arch rib is adjusted by a lateral adjustment jack and a lowering rope. After the position adjustment is completed, a pre-prepared splicing plate is taken, and the outer ends of the positioning plates of the west arch rib and the east arch rib are connected together by punching nails at both ends of the splicing plate, thereby completing the instantaneous closure of the closure mouth. After the instantaneous closure is completed, the actual size of the closure mouth is measured, the cutting length of the upper chord and lower chord patching sections is determined, the closure sections are welded, and the arch rib closure is completed.

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