Arching construction method of steel tube arch bridge suitable for special terrains

Abstract

The invention provides a steel tube arch bridge arching construction method suitable for special terrains. Comprising the following steps that a bridge arch rib is divided into a west-side arch rib and an east-side arch rib, the west-side arch rib and the east-side arch rib are each divided into a plurality of arch rib sections, the west-side arch rib is rotated in place in a vertical assembly and vertical rotation mode, and the east-side arch rib is hoisted in place in a support method. According to different geographic positions of the west side arch rib and the east side arch rib, different arch rib installation methods are adopted in a targeted mode, the arch rib vertical rotation construction method without erecting a support is adopted for the situation that the west side arch rib is located in a valley zone and the support is difficult to erect, and the arch rib vertical rotation construction method without erecting the support is adopted for the situation that the east side arch rib is located in a narrow hilly land zone. Therefore, a safer bracket method is adopted for erecting, so that the construction risk is integrally reduced, and the construction efficiency is improved.

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 terrains. Background Art

[0002] Steel tube concrete arch bridge is a bridge that fills steel tubes with concrete. The radial constraints of the steel tubes limit the expansion of the compressed concrete, which puts the concrete in a three-dimensional compression state, thus significantly improving the compressive strength of the concrete. In addition, the steel tubes have the functions of longitudinal main reinforcement and transverse hoops, and can be used as construction templates to facilitate concrete pouring. During the construction process, the steel tubes can be used as a rigid heavy skeleton, and the welding work is simple and the hoisting weight is light, which can simplify the construction process and shorten 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 has relatively low cost. It can achieve better installation accuracy control of the horizontal and diagonal braces and the arch axis line 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 axis position of the bridge to form a bridge. This construction method has the advantages of no scaffolding or less scaffolding, which can reduce the occupation of the waterway, but if the traditional horizontal assembly and vertical lifting method is adopted, the horizontal assembly 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] Combined with the above analysis, it can be seen that the method of arch rib construction must be combined with geographical factors, construction period and construction cost. During the construction of the Pinglu Canal project, one side of the site was a narrow site and the other side was a valley area. How to quickly and safely carry out bridge arch rib construction in the area where the narrow site and the valley area are combined has become an urgent problem to be solved. 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: A construction method for forming an arch of a steel pipe arch bridge applicable to special terrains, comprising the following steps: (1) Divide the bridge arch rib into a west arch rib and an east arch rib. Both the west arch rib and the east arch rib are divided into multiple arch rib segments. The west arch rib is rotated into place by the vertical rotation method, and the east arch rib is hoisted into place by the support method. Complete the construction of the west arch seat and the east arch seat. Complete the construction of the tower foundation of the fixed foundation of the lowering cable at the rear of the west arch seat, and complete the construction of the arch rib support foundation below the design position of the east arch rib; (2) Complete the construction of the vertical rotation tower in the fixed foundation of the lowering cable and the construction of the arch rib support. Among them, the arch rib support closest to the west arch seat is located below the closure position of the west arch rib and the east arch rib; (3) Assemble the west arch rib and the east arch rib simultaneously. Among them, the construction of the west arch rib includes: install a rotatable structure at the lower end of the arch rib segment closest to the arch seat and connect it to the west arch seat, and then sequentially vertically assemble the arch rib segments upward until the west arch rib reaches the design length. At the same time, install a lowering cable at the rear of the arch rib segment and connect it to the vertical rotation tower, and install a guy cable at the front of the arch rib segment and connect it to the arch rib support foundation closest to the west arch seat; The construction of the east arch rib includes: hoist the arch rib segments sequentially from the eastmost side of the arch rib to the middle. Among them, the first and second arch rib segments on the eastmost side are not connected temporarily, and the other arch rib segments are connected together after alignment; (4) Pre-tighten the lowering cable and the guy cable, coordinate and adjust the lengths of the lowering cable and the guy cable, so that the lower end of the west arch rib rotates downward with the rotatable structure as the axis until it reaches the design position and is closed and fixed with the east arch rib; (5) Complete the connection of the first and second arch rib segments on the eastmost side and the connection of the arch foot of the west arch rib and the west arch seat, and remove the guy cable, the arch rib support and the lowering cable.

[0007] Preferably, in step (1), while completing the construction of the tower foundation in the fixed foundation of the lowering cable, also complete the construction of the rear anchor device at the rear of the fixed foundation of the lowering cable; In step (2), after the construction of the vertical rotation tower is completed, connect the top of the vertical rotation tower and the rear anchor device through an anchor cable.

[0008] More preferably, a rear anchor jack is installed at the top of the rear anchor device. One end of the anchor cable is connected to the rear anchor jack, and the other end of the anchor cable is connected to the top of the vertical rotation tower; A tension jack is provided at the top of the vertical rotation tower. One end of the lowering cable is connected to the tension jack, and the other end is connected to the rear of the arch rib segment; A front anchor jack is provided on the arch rib support foundation closest to the west arch seat. One end of the guy cable is connected to the front anchor jack, and the other end is connected to the front of the arch rib segment.

[0009] Preferably, in step (3), during the process of vertically assembling the arch rib segments upward in sequence until the west arch rib reaches the designed length, the alignment and assembly between the arch rib segments include the following steps: S1. Install shoring plates and pulling devices on each side of the top of the installed topmost arch rib segment. The shoring plates protrude upward from the top of the installed topmost arch rib segment, and install fixed ear plates at the bottom of the arch rib segment to be installed. S2. Vertically turn over the arch rib segment to be installed with a hoisting device to lift it off the ground and hoist it into the area enclosed by the shoring plates, and conduct a preliminary docking with the installed topmost arch rib segment. S3. Install fine adjustment jacks inside the shoring plates, connect the movable ends of the pulling devices to the fixed ear plates on the same side of the arch rib segment to be installed, and adjust the lengths of the pulling devices on each side to make the arch rib segment to be installed as close as possible to the designed assembly posture. S4. Adjust the elongation lengths of the fine adjustment jacks on each side to align all the connecting bolt holes of the arch rib segment to be installed with those of the installed topmost arch rib segment, install connecting bolts, and release the pulling devices, fine adjustment jacks and hoisting device.

[0010] More preferably, in step S2, before hoisting the arch rib segment to be installed, pre-adjust the position of the top of the installed topmost arch rib segment. The specific steps include: measuring the position deviation of the top of the installed topmost arch rib segment with a total station, and using horizontal guy ropes and / or lowering cables to adjust its position to control the position deviation within the threshold range.

[0011] More preferably, in step S2, the process of vertically turning over the arch rib segment to be installed with a hoisting device includes: First, use the hoisting device in combination with a flexible sling to turn over the arch rib segment to be installed from a horizontal transverse posture to a horizontal longitudinal posture, and set a cushion block under the top of the arch rib segment to be installed and install a turning-over trolley under the bottom. Replace the flexible sling with a steel wire rope, and lift the top of the arch rib segment to be installed upward by the hoisting device to make it turn over vertically.

[0012] More preferably, the pulling devices and the fixed ear plates on the same side of the arch rib segment are respectively installed on different arch rib chords on both sides of this side. At least two shoring plates are provided on each side of the top of the installed topmost arch rib segment, and are respectively installed on the arch rib chords on both sides of each side. The shoring plates have shoring plate fixing parts protruding upward from the top of this arch rib segment, and fine adjustment jacks are fixed inside the shoring plate fixing parts.

[0013] More preferably, in step (2), after at least 2 arch rib brackets are installed, a thrust self-anchoring system is installed between the arch rib bracket and the arch rib bracket foundation adjacent to the arch rib bracket. The thrust self-anchoring system includes longitudinal guy ropes and guy rope adjusting devices. One end of the longitudinal guy rope is detachably connected to one side of the upper part of the arch rib bracket, and the other end is detachably connected to the arch rib bracket foundation through the guy rope adjusting device.

[0014] More preferably, a thrust self-anchoring system is provided on one side of each of the arch rib brackets that are not fixed on the east abutment and for which the corresponding supported arch rib segments are not connected by transverse guy ropes.

[0015] Preferably, an adjustable support system is provided at the top of the arch rib bracket closest to the west abutment. The adjustable support system includes a support cross beam, a top cushion, a vertical jack, and a lateral adjustment jack. The support cross beam is fixedly connected along the transverse direction of the bridge on the top surface of the arch rib bracket. The top cushion is fixed on the top surface of the support cross beam. The top cushion includes two top cushion units for matching the bottom sides of the corresponding supported arch rib chords. The vertical jack is installed between the two top cushion units. An adjustment reaction seat is fixed on the outer end top surface. The lateral adjustment jack is fixed on the inner side surface of the adjustment reaction seat. The movable end of the lateral 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. A spacing of 30 - 60 cm is maintained between the designed positions of the closure ends of the west arch rib and the east arch rib. Positioning plates are respectively connected to the outside of the chord cross braces, and bolt holes are provided in the positioning plates. In step (4), the process of fixing the closure of the west arch rib and the east arch rib includes: Adjust the vertical elevation of the west arch rib through the vertical jack, and combine the lateral adjustment jack and the lowering cable to adjust the horizontal position of the west arch rib. After the position adjustment is completed, take a pre-prepared splicing plate. The two ends of the splicing plate are respectively connected to the outer ends of the positioning plates of the west arch rib and the east arch rib through drift pins, and at the same time, the instantaneous closure of the closure opening is completed. After the instantaneous closure is completed, measure the actual size of the closure opening, determine the cutting lengths of the upper chord and lower chord filling segments, and perform the welding of the closure segment to complete the closure of the arch rib.

[0016] The above-mentioned construction method for forming an arch of a steel pipe arch bridge applicable to special terrains has the following advantages: (1) According to the different geographical locations of the west arch rib and the east arch rib, the present invention specifically adopts different installation methods for the arch ribs. For the west arch rib located in the valley area where it is difficult to erect a support, the vertical rotation construction method of the arch rib without erecting a support is adopted. For the east arch rib located in the narrow hillside area, the support erection method with a self-anchoring system is adopted, thereby reducing the construction risk as a whole and improving the construction efficiency.

[0017] (2) For the west arch rib, the arch rib segments are installed vertically without the need to erect a support in the water, which well solves the problem of difficult erection due to the excessive height of the support in the valley area. At the same time, it avoids the impact on the navigation of the waterway and flood discharge, and reduces the workload of high-altitude operation in the water, thus reducing the operation risk.

[0018] (3) For the east arch rib, since the east side is in the narrow hillside area on both the north and south sides and it is difficult to install horizontal guy cables to resist its load, the present invention sets a thrust self-anchoring 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 during the installation of the arch rib segments. In this way, the process of additionally erecting the horizontal guy cable foundation is also reduced, the construction time is shortened, and the construction progress is accelerated.

[0019] (4) For the vertical assembly of the west arch rib, the present invention further realizes the accurate alignment problem during the vertical assembly of the arch rib segments by the coordinated work of the pulling device, the horse plate and the fine-tuning jack.

[0020] (5) For the closure of the arch rib and the east arch rib, the present invention further adopts the combination of the jacking jack, the large-scale hoisting equipment and the lowering cable to adjust its position, and at the same time combines the splicing plate for rapid positioning, which greatly shortens the positioning time of the closure and accelerates the construction progress. Brief Description of the Drawings

[0021] Figure 1 is the structural schematic diagram of step (1).

[0022] Figure 2 is the structural schematic diagram of step (2).

[0023] Figure 3 is the structural schematic diagram of step (3).

[0024] Figure 4 is the structural schematic diagram at the initial stage of step (4).

[0025] Figure 5 is the structural schematic diagram at the end of step (4).

[0026] Figure 6 is the structural schematic diagram when the arch rib segment to be installed is in a horizontal transverse posture.

[0027] Figure 7 It is a schematic structural diagram when the arch rib segment to be installed is turned over to the horizontal longitudinal posture.

[0028] Figure 8 It is a schematic structural diagram when the arch rib segment to be installed is turned over to the vertical posture.

[0029] Figure 9 It is Figure 7 An enlarged schematic structural diagram when the arch rib segment to be installed is connected to the turnover trolley in

[0030] Figure 10 It is Figure 8 An enlarged schematic structural diagram when the turnover trolley assists the arch rib segment to be installed to turn over to the vertical posture in

[0031] Figure 11 It is a schematic structural diagram when the support pipe of the turnover trolley is placed horizontally.

[0032] Figure 12 It is a schematic structural diagram when the support pipe of the turnover trolley rotates to an inclined state.

[0033] Figure 13 It is a schematic structural diagram of the transverse guy rope.

[0034] Figure 14 It is a schematic structural diagram when the arch rib segment to be installed is aligned with the topmost installed arch rib segment.

[0035] Figure 15 It is a schematic structural diagram of the horse plate and the pulling device.

[0036] Figure 16 It is a schematic structural diagram when the pulling device is installed on the arch rib chord.

[0037] Figure 17 It is a schematic structural diagram when the horse plate and the fine-tuning jack are installed on the arch rib chord.

[0038] Figure 18 It is an enlarged schematic structural diagram when one of the fine-tuning jacks adjusts the arch rib chord.

[0039] Figure 19 It is an enlarged schematic structural diagram of the arch rib support, the arch rib support foundation and the thrust self-anchoring system.

[0040] Figure 20 It is Figure 19 The top view structural diagram of

[0041] Figure 21 It is a schematic structural diagram of an embodiment of the arch rib support foundation anchored in the mountainous area.

[0042] Figure 22 It isFigure 21 Top view structural schematic diagram.

[0043] Figure 23 Amplified structural schematic diagram of the uplift anchor rod.

[0044] Figure 24 Structural schematic diagram of an embodiment of the thrust self-anchoring system.

[0045] Figure 25 Structural schematic diagram of the closure of the west arch rib and the east arch rib.

[0046] Figure 26 Vertical sectional structural schematic diagram of the closure joint.

[0047] Figure 27 Amplified structural schematic diagram of the connection of the chord bracing through the positioning plate and the splicing plate.

[0048] Figure 28 Structural schematic diagram of the adjustable support system.

[0049] Figure 29 Is Figure 28 Left view structural schematic diagram (the lower chord of the arch rib is omitted).

[0050] In the figure, the rear anchor device 1, the lowering cable fixing foundation 2, the tower foundation 201, the vertical rotation tower 202, the west arch seat 3, the arch rib support foundation 4, the support enlarged foundation 410, the reinforcing steel bars 411, the uplift anchor rod 420, the uplift anchor rod body 421, the nut 422, the anchor plate 423, the grouting pipe 424, the east arch seat 5, the anchoring cable 6, the rotatable structure 7, the arch rib support 8, the support column 801, the west arch rib 9, the lowering cable 10, the guy cable 11, the east arch rib 12, the thrust self-anchoring system 13, the support column ear plate 1301, the shackle 1302, the longitudinal guy cable 1303, the guy cable adjusting device 1304, the foundation ear plate 1305, the arch rib segment to be installed 14, the hoisting device 15, the cushion block 16, the turning-over trolley 17, the support pipe 1701, the vehicle body mechanism 1702, the traveling mechanism 1703, the trolley ear plate 1704, the installed arch rib segment at the topmost part 18, the transverse guy cable 19, the horse plate 20, the pulling device 21, the fixed ear plate 22, the arch rib chord 23, the lower chord 2301, the upper chord 2302, the fine adjustment jack 16, the chord bracing 25, the positioning plate 26, the splicing plate 27, the drift pin 28, the positioning stiffening plate 29, the chord bracing stiffening plate 30, the adjustable support system 31, the vertical jacking jack 3101, the arc-shaped adjusting plate 3102, the transverse adjusting jack 3103, the adjusting reaction seat 3104, the top support 3105, the support cross beam 3106. Detailed implementation manners

[0051] The present invention will be further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited to the following embodiments.

[0052] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "front", "rear", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present invention is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0053] In this application, unless otherwise clearly specified and limited, the terms "installation", "connection", "connection", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0054] A construction method for forming an arch of a steel pipe arch bridge applicable to special terrains, comprising the following steps: (1) Divide the bridge arch rib into a west arch rib 9 and an east arch rib 12. Both the west arch rib 9 and the east arch rib 12 are divided into multiple arch rib segments. The west arch rib 9 is rotated and positioned by the vertical rotation method, and the east arch rib 12 is hoisted and positioned by the 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, and are set according to the terrain structure where the bridge is located. Taking the embodiment of the present invention as an example, as Figure 1 shown, below the designed position of the bridge, the river width is small while the area of the hillside is wide. Thus, the length of the west arch rib 9 is less than the length of the east arch rib 12; in combination with Figure 1 as shown, first complete the construction of the west arch seat 3 and the east arch seat 5, complete the construction of the tower foundation 201 of the lowering cable fixing foundation 2 behind the west arch seat 3, and complete the construction of the arch rib bracket foundation 4 below the designed position of the east arch rib 12.

[0055] (2) In combination with Figure 2As shown, the construction of the vertical turret 202 in the lowering cable fixing foundation 2 and the construction of the arch rib support 8 are completed. The vertical turret 202 is fixed on the turret 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 closure position of the west arch rib 9 and the east arch rib 12. This arch rib support 8 needs to support the closure ends of both the west arch rib 9 and the east arch rib 12 at the same time to assist in completing the closure of the west arch rib 9 and the east arch rib 12.

[0056] (3)The west arch rib 9 and the east arch rib 12 are assembled simultaneously. Combining Figure 3 As shown, among them, 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 sequentially assembling the arch rib segments vertically upward until the west arch rib 9 reaches the designed length. At the same time, a lowering cable 10 is installed behind the arch rib segment and connected to the vertical turret 202, and a guy cable 11 is installed in front of the arch rib segment and connected 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 sequentially from the east side of the arch rib to the middle. Among them, the first and second arch rib segments on the eastmost side are not connected temporarily, and the other arch rib segments are connected together after alignment.

[0057] (4)Combining Figure 4 As shown, first pre-tighten the lowering cable 10 and the guy cable 11, and then coordinate and adjust the lengths of the lowering cable 10 and the guy cable 11 so that the lower end of the west arch rib 9 rotates downward with the rotatable structure 7 as the axis until it reaches the designed position and is fixed to the east arch rib 12 in closure, that is, as Figure 5 shown.

[0058] (5)Complete the connection of the first and second arch rib segments on the eastmost side, and the connection of the arch foot of the west arch rib 9 to the west arch seat 3, and remove the guy cable 11, the arch rib support 8 and the lowering cable 10.

[0059] In this embodiment, according to the different geographical locations of the west arch rib 9 and the east arch rib 12, different arch rib installation methods are adopted specifically. For the west arch rib located in the valley area where it is difficult to build a support, the arch rib vertical rotation construction method without building a support is adopted. For the east arch rib located on the hillside area, the support method is safer and more reliable, so the support method is adopted for erection, thus overall reducing the construction risk and improving the construction efficiency.

[0060] For the west arch rib, the arch rib segments are installed vertically, so there is no need to build a support in the water, which well solves the problem of difficult erection due to excessive support height in the valley area. At the same time, it avoids the impact on the navigation of the waterway and flood discharge, and in addition, reduces the workload of high-altitude operation in the water and lowers the operation risk.

[0061] 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 rotation tower 202 is completed, the top of the vertical rotation tower 202 and the rear anchor device 1 are connected by the anchoring cable 6. The anchoring cable 6 can well maintain the force balance before and after the vertical rotation tower 202 and ensure the stability during the lowering process of the arch rib.

[0062] More preferably, a rear anchoring jack is installed at the top of the rear anchor device 1. One end of the anchoring cable 6 is connected to the rear anchoring jack, and the other end is connected to the top of the vertical rotation tower 202; a tensioning jack is provided at the top of the vertical rotation tower 202. One end of the lowering cable 10 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 4 closest to the west arch seat 3. One end of the guy cable 11 is connected to the front anchoring jack, and the other end is connected to the front of the arch rib segment. By respectively adjusting the lengths and cable forces of the anchoring cable 6, the lowering cable 10 and the guy cable 11 through the rear anchoring jack, the tensioning jack and the front anchoring jack, it is convenient, fast and highly safe.

[0063] In addition, it should be noted that when the west arch rib 9 is vertically assembled, after installing the rotatable structure 7, it is preferably 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 to the west arch seat 3 to ensure the stability of the vertical assembly process of the west arch rib 9, that is, in the direction as Figure 3 shown, on the left and right sides of the bottom end of the arch rib segment, the arch rib segment and the west arch seat 3 are generally fixed together by welding steel pipes. Of course, the arch seat 300 is provided with corresponding embedded parts for connecting with the steel pipes. The temporary fixing structure may include a rear-end temporary fixing structure and a front-end temporary fixing structure. The one connected to the upper chord 2302 of the arch rib is the rear-end temporary fixing structure, and the one connected to the lower chord 2301 of the arch rib is the front-end temporary fixing structure. Before the rotation construction, the temporary fixing structure is removed, that is, in the state as Figure 4 shown. This embodiment only lists one kind of temporary fixing structure that is convenient for installation, and other temporary fixing structures can also be adopted, as long as it can fix the arch rib segment.

[0064] For the control of the assembly and rotation position of the west side arch rib 9, during the process of assembling the arch rib segments and the rotation construction, a monitoring system is used to monitor the position and line type of the arch rib. 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 guy cable 11. The 4D laser point cloud acquisition device is installed in front of and behind the east side arch rib 9, and is used to collect data including the position coordinates and line type of the arch rib segments, and transmit it to the lowering control system. The lowering control system transmits a lowering instruction to control the length and cable force of the lowering cable 10 and the guy cable 11, so that the installation position and lowering position of the arch rib segments are controlled within the error range. During the process of assembling the arch rib segments, the hoisting position of the arch rib segments can be understood through the 4D laser point cloud acquisition device to assist in adjusting the hoisting position. During the rotation construction process, according to the feedback of the 4D laser point cloud acquisition device, the lowering control system controls the cable force of the lowering cable 1300 and the guy cable 1400 by controlling the tensioning jack 1000 and the front anchoring jack 1200 to adjust the position of the east side arch rib 9. In this embodiment, the east side arch rib 9 is lowered by rotation in multiple times. After each rotation by a certain angle, it is necessary to pay attention to adjusting the cable force and length of the lowering cable 10 and the guy cable 11 so that the rotation position of the east side arch rib 9 does not exceed the deviation control range. Of course, for the convenience of stabilizing the vertical rotation tower, the rear anchoring jack is also connected to the lowering control system, and the cable force of the anchoring cable 6 can also be controlled through the lowering control system. For the 4D laser point cloud acquisition device, it can be installed on both banks of the river. The images collected by the 4D laser point cloud acquisition device need to be subjected to coordinate system conversion after collection to obtain the position coordinates of the arch rib segments.

[0065] Preferably, in step (3), during the process of sequentially vertically assembling the arch rib segments upwards until the west side arch rib 9 reaches the designed length, the alignment and assembly between the arch rib segments include the following steps: S1. Install shoring plates 20 and pulling devices 21 on each side of the top of the already installed topmost arch rib segment 18. The shoring plates 20 protrude upwards from the top of the already installed topmost arch rib segment 18, and install fixed ear plates 22 at the bottom of the arch rib segment 14 to be installed.

[0066] S2. As shown in Figures 6 - 8 , use a hoisting device to vertically turn over the arch rib segment 14 to be installed, so that it is lifted off the ground and hoisted into the area surrounded by the shoring plates 20, and perform a preliminary docking with the already installed topmost arch rib segment 18; the shoring plates 20 protrude from the top of the already installed topmost arch rib segment 18 and extend to the height range of the designed position of the arch rib segment 14 to be installed, providing a preliminary positioning for the hoisting of the arch rib segment 14 to be installed.

[0067] S3. Install fine-tuning jacks 16 on the inner side of the horse plate 20. 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 lengths of the pulling devices 21 on each side to make the arch rib segment 14 to be installed as close as possible to the designed assembly posture, and complete the rough adjustment of the posture of the arch rib segment.

[0068] S4. Adjust the elongation lengths of the fine-tuning jacks 16 on each side to align all the connection bolt holes of the arch rib segment 14 to be installed with those of the topmost installed arch rib segment 18. Install the connection bolts, and release the pulling device 21, the fine-tuning jacks 16 and the hoisting device 15.

[0069] In this embodiment, by setting the pulling device 21, the horse plate 20 and the fine-tuning jacks 16 to work in coordination, the problem of accurate alignment during the vertical assembly of the arch rib segments is solved.

[0070] More preferably, in step S2, considering that the arch rib segment may be offset due to the influence of the external environment after installation, before hoisting the arch rib segment 14 to be installed, the position of the top of the topmost installed arch rib segment 18 is pre-adjusted. The specific steps include: measuring the position deviation of the top of the topmost installed arch rib segment 18 with a total station, and combining Figure 13 As shown, use the transverse guy wire 19 and / or the lowering cable 10 to adjust its position so that the position deviation is controlled within the threshold range. The left-right direction of the arch rib segment can be conveniently adjusted through the transverse guy wire 19, and the front-back direction of the arch rib segment can be conveniently adjusted through the lowering cable 10. If the lowering cable 10 has not been installed on the lower arch rib segment, the position adjustment mainly relies on the tension of the transverse guy wire 19. Before hoisting the arch rib segment, pre-adjust the position of the top of the topmost installed arch rib segment 18, so as to better solve the problem of accurate positioning of the arch rib segment 14 to be installed. In addition, the installation of the transverse guy wire 19 can refer to the installation method of the transverse guy wire of a general bridge.

[0071] More preferably, to better protect the arch rib segment, in step S2, the process of vertically turning over the arch rib segment 14 to be installed with the hoisting device 15 includes: combining Figure 6 As shown, the arch rib segment 14 to be installed first presents a horizontal transverse posture. First, use the hoisting device 15 in combination with a flexible sling, combining Figure 7 and Figure 9As shown, the arch rib segment 14 to be installed is turned over from a horizontal transverse posture to a horizontal longitudinal posture. A cushion block 16 is arranged below the top of the arch rib segment 14 to be installed, and a turnover trolley 17 is installed below the bottom. The flexible sling is replaced with a steel wire rope. The hoisting device 15 pulls up the top of the arch rib segment 14 to be installed vertically to turn it over. After the vertical turnover is completed as Figure 8 and Figure 10 shown. During the process of turning the arch rib segment from a horizontal transverse posture to a horizontal longitudinal posture, using a flexible sling can prevent it from rubbing against the arch rib segment and causing damage to the arch rib coating. After completing the horizontal longitudinal turnover, it is replaced with a steel wire rope because at this time, the steel wire rope pulls the top of the arch rib segment 14 to be installed, with less contact and a lower probability of rubbing against the arch rib segment. Moreover, the steel wire rope can better meet the mechanical strength requirements during the hoisting process. In addition, by setting the turnover trolley 17, the problem that the arch rib chord 23 is damaged due to rubbing against the ground or even deformed when only a single crane can be set for turnover in a narrow site is effectively solved.

[0072] More preferably, this embodiment provides a turnover trolley 17 that is convenient to operate. Combining Figures 11 - 12 shown, the turnover trolley 17 includes a traveling mechanism 1703, a vehicle body mechanism 1702, a trolley ear plate 1704, and a support pipe 1701. The bottom of the vehicle body mechanism 1702 is rollingly connected to the traveling mechanism 1703. The traveling mechanism 1703 is generally a roller. The top surface of the vehicle body mechanism 1702 is fixedly connected to the trolley ear plate 1704. The trolley ear plate 1704 is rotatably connected to the support pipe 1701. This rotatable connection can be achieved by inserting a pin shaft into the ear hole of the trolley ear plate 1704 and the pin hole at the lower end of the support pipe 1701. The support pipe 1701 can be inserted into the upper chord 2302 / lower chord 2301 of the arch rib segment or can be fitted around the bottom periphery of the upper chord 2302 / lower chord 2301 of the arch rib segment. The above connection method between the support pipe 1701 and the arch rib segment can better prevent the arch rib segment from detaching from the support of the turnover trolley 17. Figure 9 and Figure 10 The schematic diagram in

[0073] shows the support pipe 1701 inserted into the lower chord 2301. Figure 16 More preferably, as shown in Figure 16 , the pulling device 21 and the fixed ear plate 22 located on the same side of the arch rib segment are respectively installed on different arch rib chords 23 on both sides of this side; taking the pulling device 21 installed at the frontmost position in

[0074] Combined with Figure 15 and 17 As shown, on each side of the top of the installed topmost arch rib segment 18, at least two yokes 20 are provided, which are respectively installed on the arch rib chords 23 on both sides of each side. The yoke 20 has a yoke fixing part extending upward from the top of the arch rib segment. Inside the yoke fixing part, a fine adjustment jack 16 is fixed. Combined with Figure 18 As shown, the yoke 20 has a yoke fixing part extending upward from the top of the arch rib segment. Inside the yoke fixing part, a fine adjustment jack 16 is fixed. The yoke 20 may include a yoke support part and a yoke fixing part. One end of the yoke support part is connected to the arch rib chord 23 of the topmost arch rib segment 8, and the yoke fixing part is fixed on it. The yoke fixing part keeps a distance from the arch rib chord 23 of the arch rib segment 14 to be installed to install the fine adjustment jack 16.

[0075] Preferably, the pulling device 21 selected in this embodiment is a chain block, which has a low cost and is convenient for length adjustment.

[0076] Preferably, the hoisting device 15 for hoisting the west side arch rib 12 in this embodiment is a crawler crane or a truck crane. When the arch rib span is large, the crawler crane can better meet the hoisting height requirements during assembly.

[0077] More preferably, in the traditional support method construction, considering that the arch rib supports are generally high and narrow structures and are greatly affected by the lateral wind load, horizontal guy wires are usually installed to resist the load. However, considering that the east bank is in a mountainous area and the space on the north and south sides is narrow, it is difficult to set the anchoring foundation for the horizontal guy wires. Combined with Figure 19 and Figure 20 As shown, in step (2), after at least 2 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 wire and a guy wire adjusting device. One end of the longitudinal guy wire is detachably connected to the upper side of the arch rib support 8, and the other end is detachably connected to the arch rib support foundation 4 through the guy wire adjusting device. A guy wire adjusting device 1304 is provided between the arch rib support foundation 4 and the longitudinal guy wire 1303. The guy wire adjusting device 1304 can adjust the overall length of the longitudinal guy wire 1303 and the guy wire adjusting device 1304 to tension the longitudinal guy wire 1303, so as to better resist the wind load and the horizontal force for installing the arch rib segment.

[0078] 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 ropes, eliminating the need to install the anchoring foundation for the lateral guy ropes. Thus, the problem of being unable to set up the anchoring foundation for the lateral guy ropes to resist wind loads in a narrow site is effectively solved, and the construction period is also effectively shortened. Moreover, by setting up a thrust self-anchoring system 13 between the arch rib support 8 and the arch rib support foundation 4 adjacent to the arch rib support 8, the purpose of resisting the horizontal force generated during the installation of the arch rib segments can be achieved, thereby avoiding the installation of longitudinal connections between the arch rib supports 8 and preventing material waste. In this embodiment, the arch rib support foundation 4 closest to the west side arch seat 4 also serves as the fixed foundation for the guy ropes 11, further reducing the material cost and shortening the construction period.

[0079] More preferably, to reduce the construction cost and take into account the safety and accuracy of construction at the same time, the number of settings of the thrust self-anchoring system 13 is fully considered in this embodiment. Among them, the thrust self-anchoring system 13 is provided on one side of the arch rib support 8 that is not fixed on the east side arch seat 5 and whose corresponding supported arch rib segment is not connected by a lateral guy rope 19. Figure 19 To illustrate the above settings, the easternmost arch rib support foundation 4 is installed on the east side arch seat 5 (the arch rib support foundation 4 shown in the figure is the rightmost one). Since the arch rib of the arch seat is relatively stable, the arch rib support 8 installed on the east side arch seat 5 is not provided with a longitudinal guy rope connected to one side of its top. The westernmost arch rib support foundation 4 (the arch rib support foundation 4 shown in the figure is the leftmost one), the arch rib segment supported by its upper part also includes the closure end of the east side arch rib 3, and the east side arch rib 3 is tensioned by a lateral guy rope 19. Therefore, the arch rib support 8 is not provided with a longitudinal guy rope connected to one side of its top.

[0080] For the arch rib support foundation 4, if it is in water, the form of combining bored piles and enlarged foundations is adopted. For example, the westernmost arch rib support foundation 4 in this embodiment. If it is located on land, since it not only supports the arch rib support 8 but also needs to bear the uplift force of the thrust self-anchoring system 13, therefore, this embodiment also provides an arch rib support foundation 4 with better uplift resistance. Figures 21 - 23As shown, it includes a support expansion foundation 410 and a plurality of pull-out anchors 420. The lower and middle parts of the pull-out anchors 420 penetrate into the ground foundation, and the upper parts pass through the support expansion foundation 410 and are fixed together. The support expansion foundation 410 of this embodiment is a reinforced concrete foundation. The construction steps include: the pull-out anchor 420 includes a pull-out anchor body 421, a hole is drilled downward in the ground foundation, the pull-out anchor body 421 is vertically placed in the hole and positioned, grouting is performed from bottom to top through a grouting pipe 424, and after reaching a certain strength, the support expansion foundation 410 is poured to ensure that the top of the pull-out anchor body 421 passes through the support expansion foundation 410, and reinforcing steel bars 411 are pre-buried in the support expansion foundation 410 near its top surface and near the pull-out anchor body 421 to increase the compressive capacity of the support expansion foundation 410, and after the support expansion foundation 410 is consolidated, an anchor plate 423 with a through hole is placed from the top of the pull-out anchor body 421, and finally a nut 422 is screwed in to resist the top surface of the anchor plate 423 and the anchor plate 423 is pressed against the top surface of the support expansion foundation 410; in addition, the construction steps can also be: A hole is drilled downward in the ground foundation, and an anchor channel is reserved in the template of the support expansion foundation 410 (the anchor channel can be reserved by inserting a PVC pipe in the template), and then the support expansion foundation 410 is cast, and reinforcing steel bars 411 are embedded in the expanded foundation near its top surface and close to the anchor channel. After the support expansion 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, and grouting is performed from bottom to top through the grouting pipe 424. The slurry overflows from the top of the support expansion foundation 410. The slurry is consolidated to consolidate the pull-out anchor 420 with the ground foundation and the support expansion foundation 410, and then the anchor plate 423 is inserted from the top of the pull-out anchor body 421, and finally the nut 422 is screwed in to resist the top surface of the anchor plate 423 and the anchor plate 423 is pressed against the top surface of the support expansion foundation 410.

[0081] Preferably, this embodiment provides a thrust self-anchoring system 13, combined with Figure 24As shown in the figure, each set of thrust self-anchoring system 13 further includes a bracket column ear plate 1301 and a foundation ear plate 1305. The bracket column ear plate 1301 is fixed on one side of the upper part of the arch rib bracket 8, and the foundation ear plate 1305 is fixed on one side of the top surface of the bracket enlarged foundation 410. Then, one end of the longitudinal guy rope 1303 is connected to the bracket column ear plate 1301, and the other end is connected to the movable end of the guy rope adjusting device 1304. The fixed end of the guy rope adjusting device 1304 is connected to the bracket enlarged foundation 410 through the foundation ear plate 1305. By adjusting the length of the guy rope adjusting device 1304, the longitudinal guy rope 1303 can be kept in a tensioned state. In this embodiment, the ear plate structure is adopted for connection. The ear plate is provided with corresponding ear holes, which can facilitate the binding of the longitudinal guy rope 1303 and the connection with the corresponding guy rope adjusting device 1304 through structures such as a pin shaft or a hook body. The operation is convenient, and the construction efficiency can be better improved. One end of the longitudinal guy rope 1303 is connected with a shackle 1302, and 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 can be 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.

[0082] Preferably, for the closure of the west side arch rib 9 and the east side arch rib 12, this embodiment provides a preferred solution. As shown in combination with Figures 28 - 29 the figure, an adjustable support system 31 is provided at the top of the bracket column 801 of the arch rib bracket 8 closest to the west side arch seat. The adjustable support system 31 includes a support cross beam 3106, a top cushion 3105, a vertical jack 3101, and a lateral adjustment jack 3103. The top surface of the arch rib bracket is fixedly connected with a support cross beam 3106 along the transverse bridge direction. The top cushion 3105 is fixedly arranged on the top surface of the support cross beam 3106. The top cushion 3105 includes two top cushion 3105 units, which are used to match the bottom sides of the corresponding support arch rib chords 23. As Figure 28As shown, it is arranged along the transverse bridge direction. The top includes arc-shaped cushion blocks that match and support the lower chord 2301 of the arch rib. A vertical jack 3101 is installed between the two top cushion units. The outer end top surface is fixed with an adjusting reaction seat 3104. The inner side of the adjusting reaction seat 3104 is fixed with a transverse adjusting jack 3103. The movable end of the transverse adjusting jack 3103 faces the designed position of the arch rib chord, and is connected with an arc-shaped adjusting plate 3102 of the arch rib chord. The arc-shaped adjusting plate 3102 can match the radian of the lower chord 2301 of the arch rib. In addition, to better fix the transverse adjusting jack 3103, a support rod can also be set below the middle of the transverse adjusting jack 3103. The bottom end of the support rod is fixed on the top cushion 3105. The transverse adjusting jack 3103 can adopt a screw jack for more precise adjustment. There is a spacing of 30 - 60 cm between the designed positions of the closure ends of the west arch rib 9 and the east arch rib 12. Combining Figures 25 - 27 As shown, positioning plates 26 are respectively connected to the outside of the chord cross braces 25. 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, and are located at positions close to both ends of the chord cross brace 25. The side of the positioning plate 26 close to the chord cross brace 25 is semi-circular and is connected to the half circular arc line of the chord cross brace 25. The side far from the chord cross brace 25 extends outwards. The designed positions of the positioning plates 26 at the corresponding positions of the west arch rib 9 and the east arch rib 12 only need to maintain a spacing of 5 - 10 mm to avoid overlapping and affecting the installation of the splicing plate 27.

[0083] In step (4), the process of closing and fixing the west arch rib 9 and the east arch rib 12 includes: adjusting the vertical elevation of the west arch rib 9 through the vertical jack 3101, and combining the transverse adjusting jack 3103 and the lowering cable 10 to adjust the horizontal position of the west arch rib 9. After the position adjustment is completed, take 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 through drift pins 28, and the instantaneous closure of the closure opening is completed at the same time. After the instantaneous closure is completed, measure the actual size of the closure opening, determine the cutting lengths of the inlay segments of the upper chord 2302 and the lower chord 2301, and perform the welding of the closure section to complete the closure of the arch rib.

[0084] It should be noted that the positioning plates 26 are pre-drilled with screw holes to facilitate the installation of the drift pins 28. The splicing plate 27 does not need to be drilled, and the drift pins 28 are directly driven in during closure to allow for a certain deviation but still control it within a reasonable range. To ensure the stability of the connection, a chord cross brace stiffening plate 30 is welded at the connection between the chord cross brace 25 and the arch rib chord 23. A positioning stiffening plate 29 is welded at the connection between the positioning plate 26 and the chord cross brace 25. The positioning stiffening plate 29 is preferably symmetrically arranged relative to the center line of the chord cross brace 25 and is provided on both sides of the designed position of the splicing plate 27.

[0085] The above method for closing the west arch rib 9 and the east arch rib 12 adjusts their positions by combining the use of jacks for lifting, large-scale hoisting equipment and the lowering cable 10, and at the same time combines the splicing plate 27 for rapid positioning, greatly shortening the positioning time for closing and accelerating the construction progress.

[0086] The foregoing description of specific exemplary embodiments of the invention has been presented for purposes of illustration and example. These descriptions are not intended to limit the invention to the precise forms disclosed, and it is apparent that, in light of the above teaching, many modifications and variations are possible. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the invention and its practical application so that those skilled in the art can implement and utilize the various different exemplary embodiments of the invention, as well as various different selections 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 arch rib of the bridge is divided into the west arch rib and the east arch rib. The west arch rib and the east arch rib are divided into multiple arch rib segments. The west arch rib is rotated into place by vertical rotation, and the east arch rib is hoisted into place by the 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 upward in sequence until the west arch rib reaches the designed length. At the same time, installing a lowering cable behind the arch rib segment and connecting it to the vertical rotation tower, and installing a cable wind cable in 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, among which the first and second sections of the easternmost arch rib segments 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 the guy cables, and coordinate and adjust the lengths of the lowering cables and the guy cables so that the lower end of the west arch rib rotates downward with the rotatable structure as the axis to reach the designed position, and is then fixed with the east arch rib; (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 western arch rib and the western arch seat, and remove the wind cables, arch rib brackets and lowering cables.

2. The method for constructing a steel tube arch bridge suitable for special terrain according to claim 1 is 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 is characterized in that: A rear anchor jack is installed on the top of the rear anchor device, the rear anchor jack is connected to one end of the anchor cable, and the other end of the anchor cable is connected to the top of the vertical rotation tower; A tensioning jack is arranged on the top of the vertical rotating 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 arranged 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 is 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 a horse plate and a pulling device on each side of the top of the installed arch rib segment at the top, the horse plate extends upward from the top of the installed arch rib segment at the top, and install a fixed ear plate at the bottom of the arch rib segment to be installed; S2. The arch rib segment to be installed is turned vertically by a lifting device, so that it is lifted 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 inner side of the horse plate, connect the movable 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-adjusting jacks on each side so that the connecting bolt holes of the arch rib segment to be installed and the already installed arch rib segment at the top are all aligned, install the connecting bolts, and release the pulling device, fine-adjusting jacks and lifting device.

5. The method for constructing a steel tube arch bridge suitable for special terrain according to claim 4 is 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 is 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 cushion block under the top of the arch rib segment to be installed, install a turning trolley under the bottom, replace the flexible sling with a 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 is 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; At least two horse plates are provided on each side of the top of the installed arch rib segment at the top, respectively installed on the arch rib chords on both sides of each side. The horse plate has a horse plate fixing part 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 part.

8. The method for constructing a steel tube arch bridge suitable for special terrain according to claim 1 is 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 comprises 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.

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

10. The method for constructing a steel tube arch bridge suitable for special terrain according to claim 1 is characterized in that: An adjustable support system is provided on the top of the arch rib support closest to the west arch seat, and the adjustable support system includes a supporting crossbeam, 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 crossbeam along the transverse bridge direction, and the top support pad is fixed to the top surface of the supporting crossbeam. The top support pad includes two top support pad units for matching the bottom sides of the corresponding supporting arch rib chord rods. The vertical lifting jack is installed between the two top support pad units, and an adjustable jack is fixed to the top surface of the outer end. A reaction seat is provided, 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 positions of the joint ends of the west arch rib and the east arch rib are kept at a spacing of 30 to 60 cm, and positioning plates are respectively connected to the outer sides of the chord cross braces closest to the joint ends, and the positioning plates are penetrated with bolt holes; in step (4), the process of jointing and fixing the west arch rib and the east arch rib comprises: 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 two ends of the splicing plate are respectively connected to the outer ends of the positioning plates of the west arch rib and the east arch rib by punching nails, and the instantaneous closure of the closure mouth is completed at the same time; 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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