Mountainous area cable-stayed bridge steel box girder efficient and rapid construction method

Abstract

The present application belongs to the technical field of cable-stayed bridge construction method, and discloses a kind of mountainous area cable-stayed bridge steel box girder efficient and fast construction method, first section steel box girder is positioned and installed on steel and concrete combined section at bridge tower;The steel box girder on the bank is hoisted to the first section steel box girder midspan side cantilever end for positioning and is connected with the first section steel box girder bridge tower side temporary connecting piece matching connection, and then the cable force of the cable on the bank steel box girder is tensioned to T1;Hoist the steel box girder on the opposite bank, and install it by the same method as the steel box girder on the bank;Connect the ring seam of the steel box girder on the bank, and then remove the temporary connecting piece completed at the bridge tower end of the steel box girder on the bank;The cable force of the cable on the steel box girder on the bank is tensioned to the preset value T, and the installation of the steel box girder on the bank is completed;According to the above steps, the remaining girder segment construction is completed, until the main bridge closure is completed.The present application cooperates with cable crane system, successfully solves the problem of terrain restriction and slow construction progress of steel box girder hoisting in mountainous area, and further reduces the construction cost, and the comprehensive benefit is remarkable.

Description

Technical Field

[0001] This invention belongs to the technical field of cable-stayed bridge construction methods, and particularly relates to an efficient and rapid construction method for steel box girders of cable-stayed bridges in mountainous areas. Background Technology

[0002] Due to the complex terrain and poor installation conditions of long-span cable-stayed bridges in mountainous areas, conventional construction methods for steel box girders typically require significant time and expense. Current technology primarily involves transporting the steel box girders by ship or using storage scaffolds on the beach area to hold them below the installation location. Then, bridge cranes or large-tonnage floating cranes are used for vertical lifting and positioning. Only after the cables of this segment are tensioned can the lifting points be released, allowing for the installation of the next segment. This method is costly in terms of storage scaffolds and large-tonnage floating cranes, requires vertical lifting of the steel box girders, is significantly constrained by the terrain at the bridge site, impacts construction convenience, and results in a long installation cycle for each individual steel box girder segment.

[0003] Therefore, this application proposes an efficient and rapid construction method for steel box girders of cable-stayed bridges in mountainous areas to solve the aforementioned technical problems. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes an efficient and rapid construction method for steel box girders of cable-stayed bridges in mountainous areas.

[0005] To achieve the above objectives, this invention provides an efficient and rapid construction method for steel box girders of cable-stayed bridges in mountainous areas, comprising the following steps:

[0006] The initial tension value T1 of the stay cable is determined based on the weight of each segment of the steel box girder, and the structure, location, and quantity of temporary connectors are also determined.

[0007] Erect a cable lifting system and install temporary external flanges and temporary matching parts at the ends of the prefabricated steel box girders in the factory;

[0008] The first segment of the steel box girder was positioned and installed on the steel-concrete composite section at the bridge tower.

[0009] The steel box girder on this bank is hoisted to the cantilever end of the first steel box girder at the mid-span for positioning. Then, the first steel box girder is matched and connected to the temporary outer flange and temporary matching parts on the bridge tower side of the steel box girder on this bank to form temporary connecting parts. Then, the cable force of the cable stays of the steel box girder on this bank is tensioned to T1.

[0010] The cable-stayed crane system was withdrawn from the installation of the steel box girder on this bank and moved to the opposite bank to lift the steel box girder on the opposite bank. The girder segments were then installed using the same construction method as the steel box girder on this bank.

[0011] The circumferential joint connecting the end of the steel box girder bridge tower on this bank and the first segment of the steel box girder;

[0012] Remove the temporary connectors that have been completed at the bridge tower end of the steel box girder on this bank, and then tension the cable tension of the stay cables on the steel box girder on this bank to the preset value T, thus completing the installation of the steel box girder on this bank;

[0013] Repeat the above installation steps to complete the construction of the remaining beam segments until the main bridge is closed.

[0014] Preferably, in the step of determining the initial tension value T1 of the stay cable, the resultant force of the vertical component of the tension value T1 is equal to the self-weight of the steel box girder of the main beam segment.

[0015] Preferably, in the step of determining the structure, location and quantity of temporary connectors, the temporary connectors include temporary matching parts and temporary outer flanges. The temporary outer flanges are set at the junction of the top plate, web plate and bottom plate of the box girder where the local stiffness is relatively large. The temporary matching parts are evenly distributed on the top plate, web plate and bottom plate of the steel box girder, which also serves the positioning function of the steel box girder.

[0016] Preferably, in the step of positioning and installing the first segment of the steel box girder on the steel-concrete composite section at the bridge tower, the first segment of the steel box girder is only equipped with a temporary outer flange and a temporary matching component at the cantilever end on the mid-span side.

[0017] Preferably, in the hoisting step of the steel box girder on the shore, a cable lifting system is used to connect the lifting lugs on the steel box girder on the shore, and the steel box girder is hoisted to the cantilever end of the first segment of the steel box girder for positioning.

[0018] Preferably, in the hoisting step of the steel box girder on the bank, after the steel box girder on the bank is positioned, the temporary outer flange and temporary matching parts of the cantilever end of the first segment of the steel box girder on the mid-span side are matched and connected with the temporary outer flange and temporary matching parts on the bridge tower side of the steel box girder on the bank, respectively, to form temporary connecting parts.

[0019] Preferably, in the step of tensioning the stay cables of the steel box girder on the bank to T1, the stay cables of the steel box girder on the bank are gradually and symmetrically tensioned to the cable force T1, so that the self-weight of the steel box girder is gradually converted from being borne by the cable lifting system to being balanced by the vertical component force of the stay cables. The horizontal component force generated by the cable force T1 is transmitted to the first segment of the steel box girder through the temporary connector.

[0020] Preferably, in the step of connecting the circumferential joint between the steel box girder on this bank and the first segment of the steel box girder, after the cable lifting system withdraws from the work of this segment, the bridge tower end of the steel box girder on this bank and the first segment of the steel box girder are connected by welding and bolting, so that the steel box girder on this bank and the first segment of the steel box girder are connected into a whole.

[0021] Preferably, in the step of removing the temporary connecting parts on the side of the steel box girder bridge tower, the temporary connecting parts on the side of the steel box girder bridge tower are removed, so that the horizontal component of the cable force T1 generated by the cable stay is transferred to the first segment of the steel box girder through the circumferential joint of the steel box girder.

[0022] Preferably, during the process of repeating the above installation steps to complete the construction of the remaining beam segments until the main bridge is closed, after the stay cables of this beam segment are tensioned to the cable force T1, before the circumferential joint connection of this beam segment is carried out, the connection between the cable lifting system and the lifting lugs is loosened, the cable lifting system is moved, and the steel box girder on the opposite bank is lifted, thereby achieving the purpose of loosening the lifting points of the cable system earlier and improving construction efficiency.

[0023] Compared with the prior art, the present invention has the following advantages and technical effects: The present invention discloses an efficient and rapid construction method for steel box girders of cable-stayed bridges in mountainous areas. Compared with the traditional steel box girder hoisting construction, by setting temporary connectors on the steel box girder, the cable lifting system can be released from its lifting points earlier, thus withdrawing from the installation work of the steel box girder on this bank and allowing for earlier commencement of the hoisting work of the steel box girder on the opposite bank. This method, in conjunction with the cable lifting system, successfully solves the problems of terrain limitations and slow construction progress in the hoisting of steel box girders in mountainous areas, thereby reducing construction costs and achieving significant comprehensive benefits. Attached Figure Description

[0024] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0025] Figure 1 This is a flowchart illustrating the efficient and rapid construction method for steel box girders of cable-stayed bridges in mountainous areas, as described in this invention.

[0026] Figure 2 This is a schematic diagram of the cable lifting system of the present invention;

[0027] Figure 3 This is a cross-sectional view of the steel box girder hoisting of the present invention;

[0028] Figure 4 This is a schematic cross-sectional view of the temporary connector of the present invention;

[0029] Figure 5 This is a side view of the steel box girder installation of the present invention;

[0030] Figure 6 This is a schematic diagram of the side view of the first segment of the steel box girder installed on the opposite bank and on this bank according to the present invention;

[0031] Figure 7 This is a schematic diagram of the side view of the steel box girder being lifted using a cable lifting system according to the present invention;

[0032] Figure 8 This is a side view of the temporary connector for the steel box girder connection of the present invention;

[0033] Figure 9 This is a side view of the first tensioning of the cable in the steel box girder of this invention;

[0034] Figure 10 This is a schematic diagram illustrating the circumferential joint connection of the steel box girder on the shore and the use of a cable lifting system to lift the side of the steel box girder on the opposite shore according to the present invention.

[0035] Figure 11 This is a schematic diagram showing the removal of the temporary connectors for the steel box girder on the same bank and the connection of the temporary connectors for the steel box girder on the opposite bank.

[0036] Figure 12 This is a schematic diagram of the tensioning of the stay cables of the steel box girder on the same bank to a preset value, and the side view of the stay cables during the first tensioning of the steel box girder on the opposite bank.

[0037] Figure 13 This is a schematic diagram of the lifting of the next segment of the steel box girder on this bank and the side view of the circumferential joint connection of the steel box girder on the opposite bank.

[0038] Figure 14 This invention relates to the connection of the temporary connector for the next segment of the steel box girder on this bank, and the intention to remove the temporary connector for the steel box girder on the opposite bank.

[0039] Figure 15 This is a side view of the first tensioning of the stay cables of the next segment of the steel box girder on this bank and the tensioning of the stay cables of the steel box girder on the opposite bank to the preset value.

[0040] In the diagram: 1. Cable system; 2. Cable lifting system; 3. Main cable saddle of the cable system; 4. Middle crossbeam of the bridge tower; 5. First segment of steel box girder; 6. Steel box girder on this bank; 7. Stay cable; 8. Lifting lug; 9. Temporary outer flange; 10. Temporary matching component; 11. Temporary connector; 12. Circumferential joint; 106. Steel box girder on the opposite bank; 107. Next segment of steel box girder. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] Reference Figures 1-15 As shown in the figure, this embodiment provides an efficient and rapid construction method for steel box girders of cable-stayed bridges in mountainous areas, including the following steps:

[0044] The initial tension value T1 of the cable system 1 and the stay cable 7 is determined based on the weight of each segment of the steel box girder, and the structure, location and quantity of the temporary outer flange 9 and the temporary matching parts 10 are determined.

[0045] Erect the cable lifting system 2, and install temporary outer flange 9 and temporary matching parts 10 at the ends of the prefabricated steel box girder in the factory;

[0046] The first segment of the steel box girder 5 was positioned and installed on the steel-concrete composite section at the bridge tower;

[0047] The steel box girder 6 on this bank is hoisted to the cantilever end of the first segment steel box girder 5 at the mid-span for positioning. Then, the temporary outer flange 9 and temporary matching parts 10 on the bridge tower side of the first segment steel box girder 5 and the steel box girder 6 on this bank are matched and connected to form a temporary connecting part 11. Then, the cable force of the inclined cable 7 of the steel box girder 6 on this bank is tensioned to T1.

[0048] Cable lifting system 2 is withdrawn from the installation of steel box girder 6 on this bank. The mobile cable lifting system 2 lifts steel box girder 106 on the opposite bank and installs the girder segments using the same construction method as steel box girder 6 on this bank.

[0049] Circumferential joint 12 connecting the end of the 6th bridge tower of the steel box girder on this bank and the first segment of the steel box girder 5;

[0050] Remove the temporary connector 11 that was connected to the bridge tower end of the steel box girder 6 on this bank, and then tension the cable force of the stay cable 7 on the steel box girder 6 on this bank to the preset value T, thus completing the installation of the steel box girder 6 on this bank.

[0051] Repeat the above installation steps to complete the construction of the remaining beam segments until the main bridge is closed.

[0052] Furthermore, in this embodiment, T represents the final tension of the cable during the installation of this beam segment, and T1 represents the initial tension of the cable during the installation of this beam segment.

[0053] This invention discloses an efficient and rapid construction method for steel box girders of cable-stayed bridges in mountainous areas. Compared with traditional steel box girder hoisting construction, this method uses a temporary connector 11 consisting of a temporary outer flange 9 and a temporary matching part 10 on the steel box girder to allow the cable lifting system 2 to release its lifting points earlier and withdraw from the work on the steel box girder segment 6 on this bank. This allows for earlier commencement of the hoisting work on the steel box girder 106 on the opposite bank. This method, in conjunction with the cable lifting system 2, successfully solves the problems of terrain limitations and slow construction progress in the hoisting of steel box girders in mountainous areas, thereby reducing construction costs and achieving significant overall benefits.

[0054] Furthermore, in the design of the cable system 1, the main cable saddle 3 of the cable system can be installed on the crossbeam 4 in the bridge tower.

[0055] Further optimization of the scheme: in the step of determining the initial tension value T1 of the stay cable 7, the resultant force of the vertical component of the tension value T1 is equal to the self-weight of the steel box girder 6 on the bank.

[0056] Further optimization of the scheme: In determining the structure, location, and quantity of temporary connectors 11, the temporary connectors 11 include temporary matching parts 10 and temporary outer flanges 9. The temporary outer flanges 9 are placed at locations with high local stiffness where the top plate, web plate, and bottom plate of the box girder intersect. The temporary matching parts 10 are evenly distributed on the top plate, web plate, and bottom plate of the steel box girder. The temporary connectors 11, composed of these two components, are used for positioning the steel box girder and for the rapid connection of adjacent steel box girders. This reduces construction difficulty and effectively accelerates the construction progress.

[0057] Further optimizing the scheme, in the step of positioning and installing the first segment of the steel box girder 5 on the steel-concrete composite section at the bridge tower, the first segment of the steel box girder 5 is only equipped with a temporary outer flange 9 and a temporary matching component 10 at the cantilever end on the mid-span side. The first segment of the steel box girder 5 is positioned by matching and connecting with the steel box girder 6 on the same bank using the temporary matching component 10.

[0058] To further optimize the plan, during the hoisting of the steel box girder 6 on this bank, a cable lifting system 2 is used to connect the lifting lugs 8 on the steel box girder 6 to the cantilever end at the mid-span of the first segment steel box girder 5 for positioning. The lifting lugs 8 on the steel box girder are used to connect with the cable lifting system 2, facilitating the hoisting construction of the steel box girder.

[0059] Further optimize the scheme. In the hoisting step of the steel box girder 6 on this bank, after the steel box girder 6 on this bank is positioned, the temporary outer flange 9 and temporary matching part 10 on the cantilever end of the first segment steel box girder 5 at the mid-span are matched and connected with the temporary outer flange 9 and temporary matching part 10 on the bridge tower side of the steel box girder 6 on this bank, respectively, to form a temporary connecting part 11.

[0060] To further optimize the scheme, in the step of tensioning the cable force of the stay cable 7 of the steel box girder 6 on the bank to T1, the stay cable 7 of the steel box girder 6 on the bank is gradually and symmetrically tensioned to the cable force T1. The self-weight of the steel box girder 6 on the bank is gradually converted from being borne by the cable lifting system 2 to being balanced by the vertical component force through the stay cable 7. The horizontal component force generated by the cable force T1 is transmitted to the first segment of the steel box girder 5 through the temporary connector 11.

[0061] Furthermore, in the step of tensioning the cable tension of the stay cable 7 of the steel box girder 6 on the bank to T1, after being pulled into place, the connection between the cable lifting system 2 and the lifting lug 8 on the steel box girder 6 on the bank is disconnected, the cable lifting system 2 is withdrawn from the installation work of the steel box girder 6 on the bank, and the moving cable lifting system 2 lifts the steel box girder 106 on the opposite bank.

[0062] To further optimize the scheme, in step 12 of connecting the circumferential joint between the main bank steel box girder 6 and the first segment steel box girder 5, welding and bolting are used to connect the bridge tower end of the main bank steel box girder 6 and the first segment steel box girder 5, so that the main bank steel box girder 6 and the first segment steel box girder 5 are connected into a whole.

[0063] Further optimize the plan by removing the temporary connecting piece 11 on the side of the bridge tower of the steel box girder 6 on the same bank. This will allow the horizontal component of the cable force T1 generated by the cable stay 7 to be transferred to the first segment of the steel box girder 5 through the circumferential joint 12 of the steel box girder.

[0064] To further optimize the plan, after repeating the above installation steps to complete the construction of the remaining beam segments until the main bridge is closed, when the stay cable 7 of this beam segment is tensioned to the cable force T1, before connecting the circumferential joint 12 of this beam segment, the connection between the cable lifting system 2 and the lifting lug 8 is loosened, the cable lifting system 2 is moved, and the steel box girder 106 on the opposite bank is lifted, thereby achieving the purpose of loosening the lifting point of the cable system 1 earlier and improving construction efficiency.

[0065] The construction steps involved are as follows:

[0066] S1, such as Figure 2 and Figure 3 As shown, based on the maximum self-weight of the entire bridge's steel box girder segments, the design lifting weight of cable system 1 was determined. Through calculation and analysis, the main cable saddle 3 of the cable system was positioned on the middle crossbeam 4 of the bridge tower. The structural dimensions of the middle crossbeam 4 of the bridge tower were sufficient to withstand the vertical and horizontal unbalanced forces generated by the main cable saddle 3 of the cable system. After the design was completed, cable system 1 was erected and commissioned.

[0067] S2. Determine the tension value T1 of the stay cables for each beam segment based on the lifting weight of each beam segment, so that the resultant force of the vertical component of the cable force T1 is equal to the lifting weight of each segment of the steel box girder.

[0068] S3, such as Figure 4 and Figure 5 As shown, the structure, quantity, and location distribution of the temporary connectors 11 (including temporary matching parts 10 and temporary outer flanges 9) are determined based on the tension value T1 of the stay cable 7. The temporary connectors 11 should ensure the structural safety of themselves and the steel box girder under the action of cable force T1. The temporary matching parts 10 are evenly distributed on the top plate, web plate, and bottom plate of the steel box girder; the temporary outer flanges 9 are located at the junction of the top plate, web plate, and bottom plate of the box girder.

[0069] S4, such as Figure 6 As shown, the first steel box girder segment 5 was transported by ship to a suitable location below the cable system 1. Then, the cable lifting system 2 was used to lift the first steel box girder segments 5 on both banks and position them at the steel-concrete composite section of the bridge tower.

[0070] S5, such as Figure 7 As shown, the cable system 1 lowers the cable lifting system 2 to connect with the lifting lug 8 of the steel box girder 6 on the bank, and lifts the steel box girder 6 on the bank to the cantilever end of the first segment of the steel box girder 5 for positioning.

[0071] S6, such as Figure 8As shown, the temporary outer flange 9 and temporary matching part 10 on the side of the bridge tower of the steel box girder 6 on this bank are respectively matched and connected with the temporary outer flange 9 and temporary matching part 10 at the cantilever end of the first segment of the steel box girder 5 on this bank to form a temporary connecting part 11.

[0072] S7, such as Figure 9 As shown, the cable force of the stay cables 7 of the steel box girder 6 on the bank is symmetrically tensioned to T1, so that the self-weight of the steel box girder 6 on the bank is gradually converted from being borne by the cable lifting system 2 to being balanced by the vertical component force of the stay cables 7.

[0073] S8, such as Figure 10 As shown, the connection between the cable lifting system 2 and the lifting lug 8 at point 6 of the steel box girder on this bank is loosened, and the cable lifting system 2 is moved to lift the steel box girder 106 on the opposite bank to the cantilever end of the first segment of the steel box girder 5 on the opposite bank for positioning. Then, the circumferential joint between the steel box girders on this bank 6 is welded and bolted.

[0074] S9, such as Figure 11 As shown, the temporary connector 11 at the circumferential joint of the steel box girder 6 on this bank is removed. The temporary outer flange 9 and temporary matching part 10 on the bridge tower side of the steel box girder 106 on the opposite bank are respectively matched and connected to the temporary outer flange 9 and temporary matching part 10 at the cantilever end of the first segment of the steel box girder 5 on the opposite bank to form the temporary connector 11.

[0075] S10, such as Figure 12 As shown, the cable tension of the stay cables 7 of the steel box girder 6 on this bank is symmetrically tensioned to the preset value T, completing the installation of the steel box girder 6 on this bank. The cable tension of the stay cables 7 of the steel box girder 106 on the opposite bank is then symmetrically tensioned to T1.

[0076] S11, such as Figure 13 As shown, the connection between the cable lifting system 2 and the lifting lug 8 at the steel box girder 106 on the opposite bank is loosened, and the cable lifting system 2 is moved to lift the next segment of steel box girder 107 to the cantilever end of the steel box girder 6 on this bank for positioning. Subsequently, the circumferential joint between the steel box girder 106 on the opposite bank and the first segment of steel box girder 5 is welded and bolted.

[0077] S12, such as Figure 14 As shown, the temporary connector 11 at the circumferential joint of the steel box girder 106 on the opposite bank and the first segment of the steel box girder 5 is removed. The temporary outer flange 9 and temporary matching part 10 on the bridge tower side of the next segment of the steel box girder 107 on this bank are respectively matched and connected to the temporary outer flange 9 and temporary matching part 10 at the cantilever end of the steel box girder 6 on this bank to form the temporary connector 11.

[0078] S13, such as Figure 15 As shown, the cable tension of the stay cables 7 of the steel box girder 106 on the opposite bank is symmetrically tensioned to the preset value T, completing the installation of the steel box girder 106 on the opposite bank. The cable tension of the stay cables 7 of the next segment of the steel box girder 107 on this bank is then symmetrically tensioned to T1.

[0079] S14. Repeat steps S8 to S13 until the main bridge is closed.

[0080] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0081] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A highly efficient and rapid construction method for steel box girders of cable-stayed bridges in mountainous areas, characterized in that... Includes the following steps: The initial tension value T1 of the stay cable (7) is determined based on the weight of each segment of the steel box girder, and the structure, location and quantity of the temporary connectors (11) are determined. Erect a cable lifting system (2), and install temporary outer flanges (9) and temporary matching parts (10) at the ends of the prefabricated steel box girder in the factory; The first section of the steel box girder (5) is positioned and installed on the steel-concrete composite section at the bridge tower; The steel box girder (6) on this bank is hoisted to the cantilever end of the first segment steel box girder (5) at the mid-span for positioning. Then, the first segment steel box girder (5) is matched and connected to the temporary outer flange (9) and temporary matching parts (10) on the bridge tower side of the steel box girder (6) on this bank to form a temporary connecting part (11). Then, the cable force of the cable stay (7) of the steel box girder (6) on this bank is tensioned to T1. The cable lifting system (2) was erected and the steel box girder (6) on this bank was removed from the installation work. The steel box girder (106) on the opposite bank was lifted and the beam segments were installed using the same construction method as the steel box girder (6) on this bank. The circumferential joint (12) connecting the end of the bridge tower of the steel box girder (6) on this bank and the first segment of the steel box girder (5); Remove the temporary connector (11) that was completed at the bridge tower end of the steel box girder (6) on this bank, and then tension the cable force of the stay cable (7) on the steel box girder (6) on this bank to the preset value T, and complete the installation of the steel box girder (6) on this bank; Repeat the above installation steps to complete the construction of the remaining beam segments until the main bridge is closed.

2. The efficient and rapid construction method for steel box girders of cable-stayed bridges in mountainous areas according to claim 1, characterized in that: In the step of determining the initial tension value T1 of the stay cable (7), the resultant force of the vertical component of the tension value T1 is equal to the self-weight of the steel box girder (6) on the bank.

3. The efficient and rapid construction method for steel box girders of cable-stayed bridges in mountainous areas according to claim 1, characterized in that: In the step of determining the structure, location and quantity of temporary connectors (11), the temporary connectors (11) include temporary matching parts (10) and temporary outer flanges (9). The temporary outer flanges (9) are set at the junction of the top plate, web plate and bottom plate of the box girder where the local stiffness is relatively large. The temporary matching parts (10) are evenly arranged on the top plate, web plate and bottom plate of the steel box girder, taking into account the positioning function of the steel box girder.

4. The efficient and rapid construction method for steel box girders of cable-stayed bridges in mountainous areas according to claim 1, characterized in that: In the step of positioning and installing the first segment of the steel box girder (5) on the steel-concrete composite section at the bridge tower, the first segment of the steel box girder (5) is only equipped with a temporary outer flange (9) and a temporary matching part (10) at the cantilever end on the mid-span side.

5. The efficient and rapid construction method for steel box girders of cable-stayed bridges in mountainous areas according to claim 1, characterized in that: In the hoisting process of the steel box girder (6) on this bank, the cable lifting system (2) is used to connect the lifting lugs (8) on the steel box girder (6) on this bank, and the steel box girder is hoisted to the cantilever end of the first segment steel box girder (5) for positioning.

6. The efficient and rapid construction method for steel box girders of cable-stayed bridges in mountainous areas according to claim 1, characterized in that: In the hoisting process of the steel box girder (6) on this bank, after the steel box girder (6) on this bank is positioned, the temporary outer flange (9) and temporary matching part (10) on the cantilever end of the first segment steel box girder (5) on the middle span are matched and connected with the temporary outer flange (9) and temporary matching part (10) on the bridge tower side of the steel box girder (6) on this bank to form a temporary connecting part (11).

7. The efficient and rapid construction method for steel box girders of cable-stayed bridges in mountainous areas according to claim 1, characterized in that: In the step of tensioning the cable force of the stay cable (7) of the steel box girder (6) on the bank to T1, the stay cable (7) of the steel box girder (6) on the bank is gradually tensioned symmetrically to the cable force T1, so that the self-weight of the steel box girder (6) on the bank is gradually converted from the load-bearing of the cable lifting system (2) to the vertical component force balance through the stay cable (7). The horizontal component force generated by the cable force T1 is transmitted to the first segment of the steel box girder (5) through the temporary connector (11).

8. The efficient and rapid construction method for steel box girders of cable-stayed bridges in mountainous areas according to claim 1, characterized in that: In the step of connecting the circumferential joint (12) between the steel box girder (6) on the bank and the first segment steel box girder (5), the bridge tower end of the steel box girder (6) on the bank and the first segment steel box girder (5) are connected by welding and bolting, so that the steel box girder (6) on the bank and the first segment steel box girder (5) are connected into a whole.

9. The efficient and rapid construction method for steel box girders of cable-stayed bridges in mountainous areas according to claim 1, characterized in that: In the step of removing the temporary connecting piece (11) on the side of the bridge tower of the steel box girder (6) on this bank, the temporary connecting piece (11) on the side of the bridge tower of the steel box girder (6) on this bank is removed, so that the horizontal component of the cable force T1 generated by the cable (7) is transferred to the first segment of the steel box girder (5) through the circumferential joint (12) of the steel box girder.

10. The efficient and rapid construction method for steel box girders of cable-stayed bridges in mountainous areas according to claim 1, characterized in that: In the process of repeating the above installation steps to complete the construction of the remaining beam segments until the main bridge is closed, after the stay cable (7) of this beam segment is tensioned to the cable force T1, before connecting the circumferential joint (12) of this beam segment, loosen the connection between the cable lifting system (2) and the lifting lug (8), move the cable lifting system (2), and lift the steel box girder on the opposite bank, so as to achieve the purpose of loosening the lifting point of the cable lifting system (2) earlier and improving the construction efficiency.

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