Construction method of large-span through bolt-welding combined system steel box tied arch bridge with first beam and second arch

Abstract

The invention relates to a beam-first and arch-second construction method for a large-span through bolt-welding combined system steel box tied arch bridge, which comprises the following steps of: obtaining an under-bridge construction platform based on a preset bridge way system of the steel box tied arch bridge; on the basis of the under-bridge construction platform, sequentially completing suspended assembly of one straining beam, longitudinal and transverse beams and the other straining beam which are in bridge joint with piers at the two ends of the steel box tied-arch bridge, and after suspended assembly, completing fixed connection between the straining beams and the longitudinal and transverse beams in an auxiliary mode through the wedge-shaped lifting platform to obtain a spandrel girder structure; based on the bearing beam structure, laying of a temporary bridge deck system is completed, arch span structure construction is completed, and bridge deck system construction of the steel box tied-arch bridge is completed. According to the invention, the number of high-altitude supports is reduced, the cost of construction measures is saved, temporary construction measures are reduced, and the method has the advantages of improving the construction efficiency and reducing the cost.

Description

Technical Field

[0001] The invention relates to the technical field of arch bridge construction, in particular to a construction method of a large-span bottom-supported bolt-welded composite steel box tied arch bridge with a beam-first and arch-later construction. Background Art

[0002] In the construction of urban roads and highways, the construction of bolted and welded composite steel box tied arch bridges is a high-tech project. Since the span of this type of bridge is large, the height of the arch ribs also increases, so some special construction methods need to be adopted during the construction process. The following are some traditional construction methods, each with its own advantages and disadvantages: (1) Building a full-bridge support system to construct the entire bridge structure: This method involves building a complete support system on the ground, with its foundation completely set on the ground. Since the distance from the highest point of the arch bridge to the original ground elevation is large, the overall structural height of the support will also be correspondingly high. The advantage of this method is that it can provide a stable platform for construction, but the disadvantage is that the overall structural height of the support is high, requiring a large amount of materials and labor, thereby increasing the project cost. (2) In-situ lifting technology: This method involves lifting the arch ribs directly at the construction site. Since the arch ribs need to be lifted to a higher position, a large amount of temporary measures costs are required. The advantage of this method is that it can reduce the workload of ground construction, but the disadvantage is that the risk during the lifting process is greater and requires precise control and monitoring. (3) Using the tower construction method: This method involves building a tower at the construction site and then constructing the arch ribs through the tower. The advantage of this method is that it can provide a stable construction platform, but the disadvantage is that it requires a lot of temporary measures and the construction and dismantling of the tower is relatively complicated. (4) Using concrete bridge deck system to build full-bridge support: First, build full-bridge support on the ground, and then construct the concrete bridge deck system; after the construction of the concrete bridge deck system is completed, a stable structure is formed, and then support is built on it to construct the arch ribs; due to the heavy weight of the concrete bridge deck itself, the strength requirements of the support under the bridge are very high, and it requires more than 28 days of maintenance time, so the construction period is relatively long; the advantage of this method is that it can ensure the quality of the bridge deck system, but the disadvantage is that the construction period is relatively long and requires a large amount of materials and labor.

[0003] The above construction methods have the following deficiencies and defects: 1) The construction process is complicated and the construction period is long; 2) Traditional lifting methods such as arch rib segmented support method and cable lifting are greatly restricted by terrain factors, which is not conducive to construction organization and has high construction costs. These deficiencies and defects have led to certain limitations of traditional construction methods in practical applications, which require continuous exploration and improvement to improve construction efficiency and reduce costs. Summary of the invention

[0004] The problem to be solved by the present invention is to provide a construction method for a large-span bottom-supported bolt-welded composite steel box tie arch bridge, which first installs the beam and then the arch, in response to the above-mentioned deficiencies in the prior art. After the tie beams and longitudinal and transverse beams are installed and combined with the construction platform under the bridge into an integral force-bearing system, a temporary bridge deck and an on-bridge construction platform are laid thereon to form a temporary bridge road system, which is then used as a temporary bridge deck system, thereby reducing the number of high-altitude support projects and saving construction measures costs. A truck crane is used to install arch ribs, wind braces, hangers, and bridge deck systems, thereby shortening the arch bridge erection period and reducing temporary construction measures. The method has the advantages of improving construction efficiency and reducing costs.

[0005] The above-mentioned object of the present invention is achieved through the following technical solutions: A construction method for a large-span bottom-supported bolt-welded composite steel box tied arch bridge, comprising the following steps: S1 determines the center lines of the two tie beams and the center lines of the longitudinal and transverse beams based on the preset bridge system of the steel box tied arch bridge, and then establishes multiple underbridge supports with wedge-shaped lifting platforms at intervals along the three center lines on the foundation to obtain the underbridge construction platform; S2, based on the under-bridge construction platform, sequentially completes the suspended assembly between one of the tie beams, the longitudinal and transverse beams, and the other tie beam of the piers at both ends of the steel box tie-bar arch bridge, and after the suspended assembly, completes the fixed connection between the tie beam and the longitudinal and transverse beams with the assistance of the wedge-shaped lifting platform to obtain a load-bearing beam structure; S3 completes the laying of the temporary bridge deck system based on the load-bearing beam structure, and then builds a bridge construction platform on the temporary bridge deck system and completes the construction of the arch span structure. Then, the hangers are tensioned, the bridge construction platform and the temporary bridge deck system are dismantled, the bridge deck system construction of the steel box tied arch bridge is completed, and the construction platform under the bridge is dismantled.

[0006] Furthermore, in S1, the wedge-shaped lifting platform is composed of a screw pair and at least two stacked wedge-shaped steel plates, the fixed end of the screw pair is set on one of the wedge-shaped steel plates, and the tensioning end is in contact with the other wedge-shaped steel plates; the nut of the tensioning end of the screw pair is twisted by a torque wrench, and through the secondary effect of the torque (lifting force = torque × screw pair diameter ÷ thread pitch), the screw at the fixed end of the screw pair drives one of the wedge-shaped steel plates to move relative to the wedge surface of the other wedge-shaped steel plates, thereby adjusting the height of the wedge-shaped lifting platform.

[0007] Further, in said S2, the following steps are included: S21 hoist one of the tie beams to the construction platform under the bridge, and pre-fix it on the corresponding bracket under the bridge, and release the sling on one of the tie beams; S22 hoist two end beams and multiple middle beams above the construction platform under the bridge, and assemble them in mid-air on one of the tie beams through fasteners; S23, after connecting the end cross beams and the middle cross beams with the secondary longitudinal beams to form longitudinal and transverse beams, adjusting the height of the wedge-shaped lifting platform in the longitudinal and transverse beam area until the top of the wedge-shaped lifting platform contacts the bottom surface of the end cross beams and / or the middle cross beams, and releasing the slings on the end cross beams and the middle cross beams; S24 installs another tie beam hoist above the construction platform under the bridge and suspends it on these end beams and middle beams through fasteners. During this process, the height of the wedge-shaped lifting platform in the longitudinal and transverse beam area is adjusted to complete the alignment of the tie beam and the longitudinal and transverse beams; S25 adjusts the height of the wedge-shaped lifting platform in the tie beam area until the top of the wedge-shaped lifting platform contacts the bottom surface of another tie beam, thereby releasing the sling on the other tie beam.

[0008] Furthermore, in the S21, a crawler crane working platform is preliminarily established on a side of the under-bridge construction platform away from another tie beam.

[0009] Furthermore, in S22 and S24, the fasteners are configured as high-strength bolts.

[0010] Furthermore, in S2, the tie beam and the end cross beam are respectively set as box-type steel beams, and the middle cross beam and the secondary longitudinal beam are respectively set as I-beams.

[0011] Further, in said S3, the following steps are included: S31: Multiple temporary light bridge decks are laid on the longitudinal and transverse beams to obtain a temporary bridge deck system for automobile crane hoisting operations, beam transport vehicle movement and aerial platform operations; S32 determines the side lines on both sides of the steel truss arch based on the preset arch span of the steel box tied arch bridge, and then establishes a plurality of bridge supports along the two side lines on the temporary bridge deck system to obtain a construction platform on the bridge; S33 hoisted the steel truss arch components including arch ribs and wind bracing to the construction platform on the bridge in sequence and used a climbing vehicle to weld and fix them; S34 tensioned the suspender rod for the first time and dismantled the construction platform on the bridge; S35 tensioned the suspenders for the second time and removed the temporary bridge deck system; S36 laid the formal bridge deck on the longitudinal and transverse beams and dismantled the construction platform under the bridge.

[0012] Furthermore, in said S31, the temporary light bridge deck is composed of a pair of steel longitudinal beams, a plurality of steel cross beams, and a patterned steel plate, the two ends of the steel longitudinal beam are respectively arranged on the longitudinal and cross beams, these steel cross beams are arranged between the pair of steel longitudinal beams at intervals to form a steel structure frame, and the patterned steel plate is laid and fixed on the steel structure frame. Among them, the film effect of the patterned steel plate is used to transfer the load of the construction vehicle to the steel structure frame, and the patterned steel plate is simulated by plate unit through finite element software, and the steel cross beam and steel longitudinal beam are simulated by beam unit, and the force can meet the requirements.

[0013] Furthermore, in the S32, a plurality of wind ropes are arranged along the circumference of the bridge support, and the wind ropes are anchored on the gravity anchors of the foundation, and the gravity anchors are located in a preset foundation pit, and wooden sticks are supported under the gravity anchors; when the wind force exceeds the preset value, fuel is poured into the foundation pit to burn wooden sticks, and the wooden sticks break after burning, and the gravity anchors sink and tension the wind ropes. The bridge support is located on a large-span arch bridge, resulting in a high height of the bridge support, and the new bridge has not laid a formal bridge deck, resulting in a very flexible system. In order to meet the wind load once in 10 years, selectively tensioned wind ropes are arranged, and the structural stability is analyzed by finite element software, which can meet the requirements.

[0014] In summary, the beneficial technical effects of the present invention are: 1. The present invention provides a novel construction method, which effectively solves the construction problem of a large-span through-type arch bridge by first erecting a steel box girder and then constructing a tied arch; 2. The present invention not only improves the construction efficiency, but also reduces the construction cost, while ensuring the safety of the construction process; 3. The present invention significantly improves the stability of the arch bridge by constructing the beam first and then the arch, providing a solid foundation for subsequent construction; 4. The present invention can effectively control the deformation of the arch bridge during the construction process, thus ensuring the accuracy of the structure and the quality of the project; 5. The construction method of the present invention is applicable to the construction of various large-span arch bridges and has wide applicability and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a flow chart of the method provided in Example 1 of the present invention.

[0016] Figure 2 It is a structural schematic diagram of a steel box tied arch bridge according to Example 1 of the present invention.

[0017] Figure 3 It is a structural schematic diagram of the underbridge construction platform of Example 2 of the present invention.

[0018] Figure 4 It is a structural schematic diagram of the steel box tied arch bridge obtained in S1 of Example 2 of the present invention.

[0019] Figure 5 It is a flow chart of step S2 provided in Example 3 of the present invention.

[0020] Figure 6 It is a schematic structural diagram of the steel box tied arch bridge obtained by S2 of Example 3 of the present invention.

[0021] Figure 7 It is a schematic diagram of the connection relationship between the longitudinal and transverse beams and the temporary light bridge deck in Example 4 of the present invention.

[0022] Figure 8 It is a schematic diagram of the connection relationship between the bridge support and the guy rope in Example 4 of the present invention.

[0023] Fig. 9 It is a schematic structural diagram of the steel box tied arch bridge obtained in S32 of Example 4 of the present invention.

[0024] Fig.10 It is a schematic diagram of the connection relationship between the steel truss arch component and the construction platform on the bridge in Example 4 of the present invention.

[0025] Fig.11 It is a schematic structural diagram of the steel box tied arch bridge obtained in S33 of Example 4 of the present invention.

[0026] Fig.12 It is a stress distribution diagram of the steel box tied arch bridge of Example 5 of the present invention when various construction loads other than the crawler crane are considered.

[0027] Fig.13 It is a stress distribution and deformation diagram of the steel box tied arch bridge of Example 5 of the present invention when two truck cranes are operating.

[0028] Fig.14 It is a stress distribution and displacement diagram of the bridge support and the bridge support of Example 5 of the present invention under the action of level 6 wind load and construction load.

[0029] Fig.15 It is a stress distribution and displacement diagram of the bridge support and the bridge support of Example 5 of the present invention under the action of a wind load of once in ten years and a construction load.

[0030] Fig.16 It is the stress distribution and displacement diagram of the temporary lightweight bridge deck of Example 5 of the present invention. DETAILED DESCRIPTION

[0031] In order to make the technical means, creative features, objectives and functions achieved by the present invention clearer and easier to understand, the present invention is further explained below in conjunction with the accompanying drawings and specific implementation methods.

[0032] Example 1: Reference Figure 1and Figure 2 , a construction method for a large-span bottom-supported bolt-welded composite steel box tied arch bridge, first beam and then arch, disclosed by the present invention, comprises the following steps: S1 determines the center lines of the two tie beams and the center lines of the longitudinal and transverse beams based on the preset bridge system of the steel box tied arch bridge, and then establishes multiple underbridge supports with wedge-shaped lifting platforms at intervals along the three center lines on the foundation to obtain the underbridge construction platform; S2, based on the construction platform under the bridge, sequentially completes the suspended assembly between one of the tie beams, the longitudinal and transverse beams, and the other tie beam of the bridge piers at both ends of the steel box tie arch bridge. After the suspended assembly, the fixed connection between the tie beam and the longitudinal and transverse beams is completed with the assistance of a wedge-shaped lifting platform to obtain a load-bearing beam structure. Based on the load-bearing beam structure, S3 completes the laying of the temporary bridge deck system, and then builds a bridge construction platform on the temporary bridge deck system and completes the arch span structure construction. Then, the hangers are tensioned, the bridge construction platform, the temporary bridge deck system and the underbridge construction platform are dismantled, and the bridge deck system construction of the steel box tied arch bridge is completed.

[0033] Example 2: Reference Figure 3 , is a construction method of a large-span bottom-supported bolt-welded composite steel box tie-arch bridge of the present invention, which is different from Example 1 in that S1 is specifically implemented by driving multiple groups of steel pipe piles in sequence along the center lines of the two tie beams and the center lines of the longitudinal and transverse beams based on the preset bridge system of the steel box tie-arch bridge, and installing a wedge-shaped lifting platform on the top of the steel pipe piles to form multiple under-bridge supports to obtain an under-bridge construction platform; wherein, Reference Figure 4 The wedge-shaped lifting platform is composed of a screw pair and at least two stacked wedge-shaped steel plates. The fixed end of the screw pair is set on one of the wedge-shaped steel plates, and the tensioning end is in contact with the other wedge-shaped steel plates. The nut of the tensioning end of the screw pair is twisted by a torque wrench, and through the secondary effect of the torque, the screw at the fixed end of the screw pair drives one of the wedge-shaped steel plates to move relative to the wedge-shaped surface of the other wedge-shaped steel plates, thereby adjusting the height of the wedge-shaped lifting platform.

[0034] Example 3: Reference Figure 5 and Figure 6 , is a construction method of a large-span bottom-supported bolt-welded composite steel box tied arch bridge with beams first and arches later disclosed in the present invention, which is different from Example 1 in that the specific implementation method of S2 is, S21 pre-build a crawler crane working platform on the side of the underbridge construction platform away from the other tie beam, hoist one of the tie beams onto the underbridge construction platform, and pre-fix it on the corresponding underbridge bracket, and release the sling on one of the tie beams; S22 hoists two end cross beams and multiple middle cross beams above the construction platform under the bridge respectively, and assembles them in mid-air on one of the tie beams through fasteners, and the fasteners are set as high-strength bolts; S23, after connecting the end cross beams and the middle cross beams with the secondary longitudinal beams to form longitudinal and transverse beams, adjusting the height of the wedge-shaped lifting platform in the longitudinal and transverse beam area until the top of the wedge-shaped lifting platform contacts the bottom surface of the end cross beams and / or the middle cross beams, and releasing the slings on the end cross beams and the middle cross beams; S24 installs another tie beam hoist above the construction platform under the bridge, and suspends and assembles it on these end beams and middle beams through fasteners. The fasteners are set as high-strength bolts. During this process, the height of the wedge-shaped lifting platform in the longitudinal and transverse beam area is adjusted to complete the alignment of the tie beam and the longitudinal and transverse beams; S25: adjusting the height of the wedge-shaped lifting platform in the tie beam area until the top of the wedge-shaped lifting platform contacts the bottom surface of another tie beam, and releasing the sling on the other tie beam; Among them, the tie beam and the end cross beam are respectively set as box-type steel beams, and the middle cross beam and the secondary longitudinal beam are respectively set as I-beams.

[0035] Example 4: Reference Figures 7 to 11 , is a construction method of a large-span bottom-supported bolt-welded composite steel box tied arch bridge with beams first and arches later disclosed in the present invention, which is different from Example 1 in that the specific implementation method of S3 is, S31 lays multiple temporary light bridge slabs on the longitudinal and transverse beams to obtain a temporary bridge deck system for automobile crane hoisting operations, beam transport vehicles and aerial work vehicles; The temporary light bridge deck is composed of a pair of steel longitudinal beams, multiple steel cross beams, and patterned steel plates. The two ends of the steel longitudinal beams are respectively arranged on the longitudinal and cross beams. These steel cross beams are arranged between the pair of steel longitudinal beams at intervals to form a steel structure frame. The patterned steel plates are laid and fixed on the steel structure frame. Through finite element software, the patterned steel plates are simulated by plate units, and the steel cross beams and steel longitudinal beams are simulated by beam units. The force can meet the requirements. S32 determines the side lines on both sides of the steel truss arch based on the preset arch span of the steel box tied arch bridge, and then establishes multiple bridge supports along the two side lines on the temporary bridge deck system to obtain a bridge construction platform; wherein, The bridge support is located on a long-span arch bridge, resulting in a high height of the bridge support. In addition, the new bridge has not been paved with a formal bridge deck, resulting in a very weak system. In order to meet the wind load of once in 10 years, multiple cables and wind ropes are set along the circumference of the bridge support. The cables and wind ropes are anchored to the gravity anchors of the foundation. The gravity anchors are located in the preset foundation pit, and wooden sticks are supported under the gravity anchors. When the wind force exceeds the preset value, fuel is poured into the foundation pit to burn the wooden sticks. The wooden sticks break after burning, and the gravity anchors sink and tension the cables and wind ropes. After the structural stability is analyzed by finite element software, it can meet the requirements. S33 hoisted the steel truss arch components including arch ribs and wind bracing to the construction platform on the bridge in sequence and used a climbing vehicle to weld and fix them; S34 tensioned the suspender rod for the first time and dismantled the construction platform on the bridge; S35 tensioned the suspenders for the second time and removed the temporary bridge deck system; S36 laid the formal bridge deck on the longitudinal and transverse beams and dismantled the construction platform under the bridge.

[0036] Example 5: A construction method for a large-span bottom-supported bolt-welded composite steel box tied arch bridge of the present invention, which is different from Example 1 in that the structural stability of the steel box tied arch bridge and its components during the construction process is analyzed. The results are as follows: Figures 12 to 16 shown.

[0037] from Fig.12 It can be seen that after the bridge system is formed, the steel structure bridge slab is fully paved. Under various construction loads, the combined structure composed of the underbridge construction platform and the steel bridge system, the stress and the bearing capacity of the steel pipe foundation can meet the requirements; from Fig.13 It can be seen that under the load operation of two large truck cranes (each fully loaded with 260 tons), the stress and deformation of the beams of the steel structure bridge system can meet the requirements; from Fig.14 It can be seen that under the combined effect of force 6 wind and construction load, the stress, deformation and bearing capacity of the steel pipe foundation of the structure can meet the requirements; from Fig.15 It can be seen that under the wind speed load of 10 years, the stress, deformation and stability of the structure can meet the requirements; from Fig.16 It can be seen that for temporary light bridge slabs, under the action of vehicle loads, the stress of beam units meets the requirements, and the calculated stress of plate units meets the requirements.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A construction method for a large-span bottom-supported bolt-welded composite steel box tied arch bridge with beams first and arches second, characterized in that: The following steps are included: S1 determines the center lines of the two tie beams and the center lines of the longitudinal and transverse beams based on the preset bridge system of the steel box tied arch bridge, and then establishes multiple underbridge supports with wedge-shaped lifting platforms at intervals along the three center lines on the foundation to obtain the underbridge construction platform; S2, based on the under-bridge construction platform, sequentially completes the suspended assembly between one of the tie beams, the longitudinal and transverse beams, and the other tie beam of the piers at both ends of the steel box tie-bar arch bridge, and after the suspended assembly, completes the fixed connection between the tie beam and the longitudinal and transverse beams with the assistance of the wedge-shaped lifting platform to obtain a load-bearing beam structure; S3 completes the laying of the temporary bridge deck system based on the load-bearing beam structure, and then builds a bridge construction platform on the temporary bridge deck system and completes the arch span structure construction, then tensions the hangers, dismantles the bridge construction platform, the temporary bridge deck system and the underbridge construction platform, and then completes the bridge deck system construction of the steel box tie arch bridge.

2. The construction method of a large-span bottom-supported bolt-welded composite steel box tied arch bridge of claim 1, characterized in that: In S1, the wedge-shaped lifting platform is composed of a screw pair and at least two stacked wedge-shaped steel plates, the fixed end of the screw pair is set on one of the wedge-shaped steel plates, and the tensioning end is in contact with the other wedge-shaped steel plates; the nut of the tensioning end of the screw pair is twisted by a torque wrench, and through the secondary effect of the torque, the screw at the fixed end of the screw pair drives one of the wedge-shaped steel plates to move relative to the wedge surface of the other wedge-shaped steel plates, thereby adjusting the height of the wedge-shaped lifting platform.

3. The construction method of a large-span bottom-supported bolt-welded composite steel box tied arch bridge of claim 1, characterized in that: In said S2, the following steps are included: S21 hoist one of the tie beams to the construction platform under the bridge, and pre-fix it on the corresponding bracket under the bridge, and release the sling on one of the tie beams; S22 hoist two end beams and multiple middle beams above the construction platform under the bridge, and assemble them in mid-air on one of the tie beams through fasteners; S23, after connecting the end cross beams and the middle cross beams with the secondary longitudinal beams to form longitudinal and transverse beams, adjusting the height of the wedge-shaped lifting platform in the longitudinal and transverse beam area until the top of the wedge-shaped lifting platform contacts the bottom surface of the end cross beams and / or the middle cross beams, and releasing the slings on the end cross beams and the middle cross beams; S24 installs another tie beam hoist above the construction platform under the bridge and suspends it on these end beams and middle beams through fasteners. During this process, the height of the wedge-shaped lifting platform in the longitudinal and transverse beam area is adjusted to complete the alignment of the tie beam and the longitudinal and transverse beams; S25 adjusts the height of the wedge-shaped lifting platform in the tie beam area until the top of the wedge-shaped lifting platform contacts the bottom surface of another tie beam, thereby releasing the sling on the other tie beam.

4. The construction method of a large-span bottom-supported bolted-welded composite steel box tied arch bridge of claim 3, characterized in that: In the step S21, a crawler crane working platform is preliminarily established on a side of the under-bridge construction platform away from another tie beam.

5. The construction method of a large-span bottom-supported bolt-welded composite steel box tied arch bridge of claim 3, characterized in that: In S22 and S24, the fasteners are configured as high-strength bolts.

6. The construction method of a large-span bottom-supported bolt-welded composite steel box tied arch bridge of claim 3, characterized in that: In the S2, the tie beam and the end cross beam are respectively configured as box-type steel beams.

7. The construction method of a large-span bottom-supported bolt-welded composite steel box tied arch bridge of claim 3, characterized in that: In the above S2, the middle cross beam and the secondary longitudinal beam are respectively set as I-beams.

8. The construction method of a large-span bottom-supported bolt-welded composite steel box tied arch bridge of claim 1, characterized in that: In said S3, the following steps are included: S31: Multiple temporary light bridge decks are laid on the longitudinal and transverse beams to obtain a temporary bridge deck system for automobile crane hoisting operations, beam transport vehicle movement and aerial platform operations; S32 determines the side lines on both sides of the steel truss arch based on the preset arch span of the steel box tied arch bridge, and then establishes a plurality of bridge supports along the two side lines on the temporary bridge deck system to obtain a construction platform on the bridge; S33 hoisted the steel truss arch components including arch ribs and wind bracing to the construction platform on the bridge in sequence and used a climbing vehicle to weld and fix them; S34 tensioned the suspender rod for the first time and dismantled the construction platform on the bridge; S35 tensioned the suspenders for the second time, dismantled the temporary bridge deck system, and removed the construction platform under the bridge; S36 lays the formal bridge deck on the longitudinal and transverse beams.

9. The construction method of a large-span bottom-supported bolt-welded composite steel box tied arch bridge of claim 8, characterized in that: In the S31, the temporary light bridge slab is composed of a pair of steel longitudinal beams, a plurality of steel transverse beams, and patterned steel plates. The two ends of the steel longitudinal beams are respectively arranged on the longitudinal and transverse beams. The steel transverse beams are arranged at intervals between the pair of steel longitudinal beams to form a steel structure frame. The patterned steel plates are laid and fixed on the steel structure frame.

10. The construction method of a large-span bottom-supported bolt-welded composite steel box tied arch bridge of claim 8, characterized in that: In the S32, a plurality of wind ropes are arranged along the circumference of the bridge support, and the wind ropes are anchored on the gravity anchors of the foundation. The gravity anchors are located in a preset foundation pit, and wooden sticks are supported under the gravity anchors. When the wind force exceeds a preset value, fuel is poured into the foundation pit to burn the wooden sticks, and the wooden sticks break after burning, and the gravity anchors sink and tension the wind ropes.

Images