Installation Method of Cable Hoisting for Full-Section Welded Steel Box Girder of Main Span of Long-Span Cable-Stayed Bridge

Abstract

The present invention provides a cable hoisting and installation method for a full-section welded steel box girder of the main span of a long-span cable-stayed bridge, which comprises the following steps: S1 cable hoisting system layout, S2 transporting the steel box girder, S3 hoisting in place, S4 installing temporary matching parts, S5 partial calibration, S6 installing code plates, S7 circumferential gap welding, S8 inclined tensioning and fixing, S9 installing U ribs and I ribs, and S10 cable hoisting system layout. The present invention can provide a quick and safe installation method applicable to the full-section welded steel box girder of the main span of a long-span cable-stayed bridge.

Description

[Technical field]

[0001] The invention relates to the technical field of bridge construction, and in particular to a cable hoisting and installation method for a full-section welded steel box girder of a main span of a large-span cable-stayed bridge. [Background technology]

[0002] A cable-stayed bridge, also known as a cable-stayed bridge, is a bridge in which the main beam is directly pulled on the bridge tower by many cables. It is a structural system composed of a pressure-bearing tower, tensioned cables and a bending beam. In the construction process of a large-span cable-stayed bridge, the installation of a full-section welded steel box girder for the main span is an indispensable link. For a cross-sectional diagram of a full-section welded steel box girder for the main span, see Figure 1 ,from Figure 1 It can be known that the main span full-section welded steel box girder is a symmetrical box girder structure with the bridge centerline 105, and it is symmetrically provided with two left and right side boxes 111 with the bridge centerline 105, and the top surfaces of the two side boxes 111 are connected by the top plate 110, and the end of the side box 111 away from the top plate 110 is a phoenix mouth 112, wherein the side box 111 also includes a middle web 1111, a bottom plate 1112, an inclined bottom plate 1113, a side web 1114 and a transverse diaphragm 1115, and one end of the middle web 1111 is connected to the middle part of the top plate 110 and faces the width direction of the side box 111 The bottom plate 1112 is extended, one end of the bottom plate 1112 is connected to the other end of the middle web 1111 and the bottom plate 1112 is parallel to the top plate 110, the bottom plate 1112 extends toward the direction of the mouth 112, one end of the inclined bottom plate 1113 is connected to the other end of the bottom plate 1112, the other end of the inclined bottom plate 1113 is connected to the corresponding mouth 112, and the opposite ends of the side web 1114 are connected to the other end of the inclined bottom plate 1113 and the other end of the top plate 110; in addition, the middle web 1111 is connected to a plurality of transverse diaphragms 1115 along the width direction of the main span full-section welded steel box girder. In the prior art, the installation method of the main span full-section welded steel box girder and the corresponding shortcomings are as follows:

[0003] Method 1: Use large-scale lifting equipment to lift and assemble the entire section. Large-scale lifting equipment is expensive and heavy, and imposes a large load on the deck of the cable-stayed bridge. The heavy weight of the lifting equipment makes it difficult to control the line shape of the completed bridge. At the same time, vertical lifting is required, and high transportation conditions are required, which limits the construction of cable-stayed bridges in shallow areas, mountainous areas, canyons, etc.

[0004] Method 2: Decompose the steel structure segments of the bridge deck into small components, and use the bridge deck full-revolving crane bridge position scattered assembly method to continuously assemble and assemble to form the cable-stayed bridge deck structure. This method is mainly used in steel-concrete composite beam bridge deck structures and is installed through high-strength bolts. When used for the installation of full-section welded steel box girders, since the full-section welded steel box girders have more welding points than the steel box girders of other bridge bodies, the welding points need to be repeatedly positioned before welding can be carried out during scattered assembly installation, which is not only time-consuming but also has high safety and quality risks.

[0005] In the prior art, methods for constructing the deck of a cable-stayed bridge using a cable hoisting system have been studied. However, since the fully welded steel box girder uses a full welding process, there are many differences compared to the deck structures of other cable-stayed bridges that use high-strength bolt matching connections (such as I-beams or truss girders). When using existing hoisting methods, many problems often occur in construction safety, quality control, and installation accuracy. Therefore, designing a fast and safe installation method suitable for the main span fully welded steel box girder of a long-span cable-stayed bridge is an urgent problem to be solved.

Summary of the Invention

[0006] The present invention aims to solve at least one of the above-mentioned technical problems, and provides a cable hoisting installation method for the main span fully welded steel box girder of a long-span cable-stayed bridge, which provides a fast and safe installation method suitable for the main span fully welded steel box girder of a long-span cable-stayed bridge.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] A cable hoisting installation method for the main span fully welded steel box girder of a long-span cable-stayed bridge, comprising the following steps:

[0009] S1 Cable hoisting system layout: Install the cable hoisting system;

[0010] S2 Transport the steel box girder: Transport the prefabricated fully welded steel box girder to the bridge site hoisting point and connect it to the cable hoisting system;

[0011] S3 Hoist in place: Use the cable hoisting system to hoist the prefabricated fully welded steel box girder to the preset installation position, and the preset installation position is the pre-welding joint with the already installed steel box girder;

[0012] S4 Install temporary matching parts: Pre-install several temporary matching parts at the preset positions of the pre-welding joint between the prefabricated fully welded steel box girder and the already installed steel box girder. The several temporary matching parts can preliminarily position and connect the pre-welding joint between the prefabricated fully welded steel box girder and the already installed steel box girder;

[0013] S5 Local calibration: Conduct local precise calibration and adjustment on the pre-welding joint between the prefabricated fully welded steel box girder and the already installed steel box girder. When it is confirmed that the misalignment deviation value at the local pre-welding joint between the prefabricated fully welded steel box girder and the already installed steel box girder is within the allowable error range, and the line elevation of the prefabricated fully welded steel box girder meets the design requirements, fix and install the several temporary matching parts;

[0014] S6 Install code plates: Weld several code plates at intervals between two adjacent temporary matching parts. The opposite ends of the code plates are connected to both the prefabricated fully welded steel box girder and the already installed steel box girder;

[0015] S7 Annular gap welding: welding the annular gaps of the pre-installed full-section welded steel box girder and the installed steel box girder;

[0016] S8: Tilt tensioning and fixing: arranging a tilt pulling component on the pre-installed full-section welded steel box girder, using the tilt pulling component to tilt and pull the pre-installed full-section welded steel box girder, so that the pre-installed full-section welded steel box girder is fixed relative to the bridge pier, and then releasing the lifting point of the pre-installed full-section welded steel box girder by the cable lifting system;

[0017] S9 U-rib and I-rib installation: installing the U-rib and I-rib of the pre-installed full-section welded steel box girder and the survey and repair section between the installed steel box girder;

[0018] S10 Cable hoisting system layout: The pre-installed full-section welded steel box girder is subjected to a second tilt tensioning. When the tensioning force reaches the design target value, the elevation and line shape of the pre-installed full-section welded steel box girder are remeasured, and the tilt tensioning force is adjusted at the same time. When the installation requirements of the pre-installed full-section welded steel box girder are met, the installation of the pre-installed full-section welded steel box girder is completed.

[0019] Furthermore, the step S2 of transporting the steel box girder comprises the following steps:

[0020] S2.1 loading the pre-assembled full-section welded steel box girder onto a transport device;

[0021] S2.2 The transport device transports the pre-assembled full-section welded steel box girder to a convenient position for lifting;

[0022] S2.3 Connect the cable lifting system to the lifting points on the pre-installed full-section welded steel box girder.

[0023] Furthermore, the number of the lifting points is two groups, and the two groups of lifting points are symmetrically distributed on the middle webs corresponding to the opposite sides of the top plate with the center line of the bridge, and each group of the lifting points includes two pairs of the lifting points, and the two pairs of the lifting points are arranged on the opposite sides of the top plate along the length direction of the middle web, and each pair of the lifting points corresponds to the connection between the middle web and the diaphragm.

[0024] Further, the temporary matching part comprises two L-shaped plates and an abutment plate, one side of the two L-shaped plates are parallel to each other, the abutment plate is clamped between one side of the two L-shaped plates, and the two L-shaped plates and the abutment plate are fixed by bolts; a reinforcing plate is mounted on the L-shaped plate;

[0025] In the installation of the temporary matching parts in step S4, the other side of one of the L-shaped plates contacts the top plate of the pre-installed full-section welded steel box girder, and the other side of the other L-shaped plate contacts the top plate of the installed steel box girder.

[0026] Furthermore, the code plate is plate-shaped, and a welding fusion interface is provided at the bottom of the code plate.

[0027] Furthermore, the inclined pulling member includes a pulling member, a stay cable steel strand, and an HPDE pipe. In the inclined tensioning and fixing in step S8, the pulling member is arranged on the pier, one end of the stay cable steel strand is connected to the pulling member, the other end of the stay cable steel strand is connected to the opposite ends of the pre-installed full-section welded steel box girder, and the HPDE pipe is sleeved outside the stay cable steel strand.

[0028] Furthermore, when the stay cable steel strand is arranged, the vertical component of the tension of the stay cable steel strand is equal to the weight of the pre-installed full-section welded steel box girder.

[0029] Furthermore, in the installation of the temporary matching parts in step S4:

[0030] When a plurality of the temporary matching parts are pre-installed, the plurality of temporary matching parts are evenly divided into two groups, and the two groups of temporary matching parts are pre-installed symmetrically about the bridge center line at the pre-welding position between the pre-installed full-section welded steel box girder and the installed steel box girder. Among them, the temporary matching parts corresponding to the center web, side web, and top plate at the bottom plate are fixedly installed.

[0031] Due to the adoption of the above technical solutions, the present invention has the following beneficial effects:

[0032] 1. The cable hoisting system uses the cable tower of the cable-stayed bridge as the tower, reducing the cost of separately setting up the tower of the cable hoisting system, and having great economic advantages;

[0033] 2. Using the cable hoisting system for the installation of the pre-installed full-section welded steel box girder, the lifting blind area of the cable hoisting system is small, avoiding the requirements of the conventional deck crane for vertical lifting, reducing the requirements for transportation conditions, and being applicable to the construction of cable-stayed bridges in areas such as shoals, mountains, and canyons;

[0034] 3. The cable hoisting system can achieve large-tonnage hoisting, avoiding the limitation of the deck full-rotation crane's in-situ splicing method on the deck structure type, and also reducing the impact of repeated welding on the overall safety and stability of the pre-installed full-section welded steel box girder;

[0035] 4. Since the prefabricated full-section welded steel box girder is installed after integral hoisting in this method, compared with the in-situ segmental erection method, the construction duration is greatly reduced. As temperature changes can affect the construction quality of welding operations and cable hoisting operations, the reduction in construction duration enables construction workers to schedule construction during stable temperatures, such as only during the day, rather than during the day-night alternation with large temperature differences. It can be seen that this method solves the problems of large deformation of the suspension points and unstable butt welds caused by large temperature differences between day and night in the cable hoisting system during the installation of the prefabricated full-section welded steel box girder, and further promotes the popularization of this installation construction technology and the construction of cable-stayed bridges in mountainous areas with traffic restrictions.

Description of the Drawings

[0036] Figure 1 It is a cross-sectional schematic diagram of the main span full-section welded steel box girder.

[0037] Figure 2 It is a rough schematic diagram of being hoisted in place in step S3.

[0038] Figure 3 It is a hoisting cross-sectional schematic diagram of the prefabricated full-section welded steel box girder.

[0039] Figure 4 It is a schematic diagram of the distribution of suspension points of the prefabricated full-section welded steel box girder.

[0040] Figure 5 It is a rough schematic diagram of inclined tensioning and fixing in step S8.

[0041] Figure 6 It is a structural schematic diagram of the temporary matching part.

[0042] Figure 7 It is a welding schematic diagram of the code plate.

[0043] In the drawings, 100 - prefabricated full-section welded steel box girder, 101 - installed steel box girder, 102 - transporting device, 103 - river, 104 - pre-built bridge body, 105 - bridge center line, 110 - top plate, 111 - side box, 1111 - middle web, 1112 - bottom plate, 1113 - inclined bottom plate, 1114 - side web, 1115 - diaphragm plate, 112 - wind nose, 106 - bridge pier, 200 - preset installation position, 201 - cable-stayed cable suspension point, 202 - hoisting point, 1 - cable hoisting system, 2 - temporary matching part, 21 - L-shaped plate, 22 - abutting plate, 23 - reinforcing plate, 24 - bolt, 3 - code plate, 31 - welding fusion interface, 4 - inclined pulling component, 41 - cable-stayed cable HPDE pipe, 42 - steel strand.

Detailed Implementation Modes

[0044] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0045] It should be noted that when a component is referred to as "fixed to" another component, it can be directly on the other component or there may also be an intermediate component. When a component is considered to be "disposed on" another component, it can be directly disposed on the other component or there may be an intermediate component at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for the purpose of illustration.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and do not limit the present invention alone. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0047] As Figures 2 to 7 shown, a cable-suspended erection method for the full-section welded steel box girder of the main span of a long-span cable-stayed bridge is provided in a preferred embodiment of the present invention, which is used for the installation of the full-section welded steel box girder of the main span during the construction of a long-span cable-stayed bridge, and includes the following steps:

[0048] S1 Cable-suspended erection system layout: Install the cable-suspended erection system 1. The tower used for the installation of the cable-suspended erection system 1 is the cable tower for building the cable-stayed bridge, that is, the cable-suspended erection system 1 is a cable tower suitable for the hoisting of the full-section welded steel box girder of the main span. For its specific structure, please refer to a high pier or cable tower crossbeam construction platform and construction method disclosed in the Chinese patent application with the publication number CN115928596A; in addition to the cable tower, hoisting cables are also installed. The installation of the hoisting cables is well known to those skilled in the art and will not be elaborated herein;

[0049] S2 Transport the steel box girder: Transport the prefabricated full-section welded steel box girder 100 to the bridge site hoisting point and connect it to the cable-suspended erection system 1. Specifically, when the location for building the cable-stayed bridge is in areas such as shoals, mountains, canyons, etc., the selection of the bridge site hoisting point can be made according to the actual construction site conditions. Compared with the vertical hoisting required for the integral segment hoisting using large lifting equipment, the use of the cable-suspended erection system 1 for hoisting can make the selection of the construction site more flexible;

[0050] S3: hoisting in place: using the cable hoisting system 1, hoisting the pre-installed full-section welded steel box girder 100 to the preset installation position 200, the preset installation position 200 is the pre-welding position with the installed steel box girder 101, wherein the installation method of the installed steel box girder 101 can be the installation method of the existing technology, which will not be described in detail here;

[0051] S4 temporary matching parts 2 installation: pre-install a plurality of temporary matching parts 2 at the preset positions of the pre-welded parts of the pre-installed full-section welded steel box girder 100 and the installed steel box girder 101, and the plurality of temporary matching parts 2 can enable the pre-welded parts of the pre-installed full-section welded steel box girder 100 and the installed steel box girder 101 to be initially positioned and connected;

[0052] S5 local calibration: perform local precise calibration and adjustment on the pre-welded portion of the pre-installed full-section welded steel box girder 100 and the installed steel box girder 101. After confirming that the misalignment deviation value of the pre-installed full-section welded steel box girder 100 and the installed steel box girder 101 at the local pre-welded portion is within the allowable error range, a number of temporary matching parts 2 are fixedly installed;

[0053] S6: installing the yard plates: welding a plurality of yard plates 3 between two adjacent temporary matching parts 2, and connecting the opposite ends of the yard plates 3 to the pre-installed full-section welded steel box beam 100 and the installed steel box beam 101;

[0054] S7 Annular gap welding: welding the annular gaps of the pre-installed full-section welded steel box girder 100 and the installed steel box girder 101;

[0055] S8: Tilt tensioning and fixing: Arrange the tilt pulling component 4 on the pre-installed full-section welded steel box girder 100, use the tilt pulling component 4 to tilt and pull the pre-installed full-section welded steel box girder 100, fix the pre-installed full-section welded steel box girder 100 relative to the bridge pier 106, and then release the cable lifting system 1 on the lifting point of the pre-installed full-section welded steel box girder 100;

[0056] S9 U-rib and I-rib installation: installing the U-rib and I-rib of the survey and repair section between the pre-installed full-section welded steel box girder 100 and the installed steel box girder 101. This step is a common technical means used by those skilled in the art and will not be described in detail here.

[0057] S10 cable hoisting system layout: The pre-installed full-section welded steel box girder 100 is subjected to a second tilt tensioning. When the tensioning force reaches the design target value, the elevation and line shape of the pre-installed full-section welded steel box girder 100 are remeasured, and the tilt tensioning force is adjusted at the same time. When the installation requirements of the pre-installed full-section welded steel box girder 100 are met, the installation of the pre-installed full-section welded steel box girder 100 is completed.

[0058] In this embodiment, step S2 of transporting the steel box beam includes the following steps:

[0059] S2.1 Load the prefabricated full-section welded steel box girder 100 onto the transportation device 102. In this embodiment, taking the construction of a cable-stayed bridge over a river as an example, the transportation device 102 is selected as a ship.

[0060] S2.2 The transportation device 102 transports the prefabricated full-section welded steel box girder 100 to a position convenient for hoisting. In this embodiment, the "position convenient for hoisting" is the position in the middle of the pre-built bridge body 104 corresponding to the river 103.

[0061] S2.3 Connect the cable hoisting system 1 to the hoisting points 202 on the prefabricated full-section welded steel box girder 100.

[0062] When the cable-stayed bridge to be built is located in areas such as shoals, mountains, and canyons, the "position convenient for hoisting" is no longer the "position in the middle of the pre-built bridge body 104". Construction workers can select a suitable position for transporting the prefabricated full-section welded steel box girder 100 according to the terrain to connect and install the hoisting points 202.

[0063] In this embodiment, mainly referring to Figure 4 , the number of hoisting points 202 is two groups. The two groups of hoisting points 202 are symmetrically distributed on the corresponding middle webs 1111 on the opposite sides of the top plate 110 with the bridge center line 105 as the symmetry axis. Each group of hoisting points 202 includes two pairs of hoisting points 202. The two pairs of hoisting points 202 are arranged on the opposite sides of the top plate 110 along the length direction of the middle web 1111, and each pair of hoisting points 202 corresponds to the connection between the middle web 1111 and the diaphragm 1115. Since the main structure of the prefabricated full-section welded steel box girder 100 is fixed by welding, different from the selection of hoisting points of the rest of the steel box girder structure, the hoisting points of the rest of the steel box girder structure are selected based on the center of gravity of the whole steel box girder. When selecting the hoisting points of the prefabricated full-section welded steel box girder 100, in addition to considering the overall self-weight and center of gravity, the firmness of the welding points also needs to be considered. Therefore, the position selection of the hoisting points 202 in this method can not only ensure that the prefabricated full-section welded steel box girder 100 is hoisted by the cable hoisting system 1, but also ensure the firmness and safety of the whole prefabricated full-section welded steel box girder 100 after hoisting the whole prefabricated full-section welded steel box girder 100.

[0064] In this embodiment, the temporary matching part 2 includes two L-shaped plates 21 and a butting plate 22. One side surfaces of the two L-shaped plates 21 are parallel and opposite to each other. The butting plate 22 is clamped between one side surfaces of the two L-shaped plates 21. The two L-shaped plates 21 and the butting plate 22 are fixed by bolts 24; a reinforcing plate 23 is assembled on the L-shaped plate 21.

[0065] In the installation of the temporary matching member 2 in step S4, the other side of one L-shaped plate 21 contacts the top plate 110 of the pre-installed full-section welded steel box girder 100, and the side of the clamping abutting plate 22 is flush with the pre-welding surface of the pre-installed full-section welded steel box girder 100. The other side of the other L-shaped plate 21 contacts the top plate 110 of the installed steel box girder 101, and the side of the clamping abutting plate 22 is flush with the pre-welding surface of the installed steel box girder 101. Specifically:

[0066] When pre-installing several temporary matching members 2, specifically refer to Figure 3 , several temporary matching members 2 are evenly divided into two groups. The two groups of temporary matching members 2 are symmetrically pre-installed at the pre-welding joints of the pre-installed full-section welded steel box girder 100 and the installed steel box girder 101 with respect to the bridge center line 105. Among them, the temporary matching members 2 corresponding to the center web 1111, the side web 1114, and the bottom plate 1112 corresponding to the top plate 110 are fixedly installed. The operation of the fixed installation is to tighten the bolts 24 of the corresponding temporary matching members 2, while the bolts 24 of the remaining temporary matching members 2 are only pre-installed on the L-shaped plate 21 and the abutting plate 22.

[0067] In step S5 of local calibration, after confirming that the misalignment deviation value at the local pre-welding joint of the pre-installed full-section welded steel box girder 100 and the installed steel box girder 101 is within the allowable error range, then tighten and fix the bolts 24 of the remaining temporary matching members 2 with the L-shaped plate 21 and the abutting plate 22.

[0068] The setting of several temporary matching members 2 can roughly match the contours of the pre-installed full-section welded steel box girder 100 and the installed steel box girder 101. First, fixedly install the temporary matching members 2 corresponding to the center web 1111, the side web 1114, and the bottom plate 1112 corresponding to the top plate 110, which can prevent the pre-installed full-section welded steel box girder 100 and the installed steel box girder 101 from having a large range of relative movement, and can also facilitate the precise calibration and adjustment of the local parts of the two steel box girders. And the setting of the abutting plate 22 can reserve a welding space for the welding operation.

[0069] In this embodiment, the code plate 3 is a plate-shaped. A welding melting interface 31 is opened at the bottom of the code plate 3. The welding melting interface 31 and the abutting plate 22 both correspond to the circumferential gap of the pre-installed full-section welded steel box girder 100 and the installed steel box girder 101. The ends of the code plate 3 on both sides of the welding melting interface 31 are connected to the corresponding top plate 110.

[0070] In this embodiment, the inclined pulling member 4 includes a stay cable strand 42, an HPDE pipe 41 and a pulling member. In the inclined tensioning and fixing step S8, the pulling member is arranged on the pier 106. Specifically, the pulling member is not shown in the figure. The pulling member adopts a drum strand threading machine in the prior art, and its specific arrangement method is well known to those skilled in the art and will not be elaborated here. One end of the stay cable strand 42 is connected to the pulling member, and the other end of the stay cable strand 42 is connected to the opposite ends of the prefabricated full-section welded steel box girder 100. Specifically, refer to Figure 4 and Figure 5 , near the connection between the top plate 110 and the wind mouths 112 at both ends, a stay cable suspension point 201 is provided. The other end of the stay cable strand 42 is fixed to the stay cable suspension point 201. During actual construction, the stay cable strand 42 fixed to the stay cable suspension point 201 is the main stay cable. Near the stay cable suspension point 201, other auxiliary stay cable suspension points are also provided, and auxiliary stay cables are connected to the other auxiliary stay cable suspension points. Both ends of the auxiliary stay cables are also connected to the pier 106 and the top plate 110. The HPDE pipe 41 is sleeved outside the stay cable strand 42, and the arrangement of the HPDE pipe 41 is a commonly used technical means in the art and will not be elaborated here.

[0071] Under the inclined tensioning and fixing of the inclined pulling member 4, the prefabricated full-section welded steel box girder 100 is in a pre-fixed position. At this time, the connection of the suspension point of the cable hoisting system 1 to the prefabricated full-section welded steel box girder 100 is released. Not only will the position of the prefabricated full-section welded steel box girder 100 not change, but the cable hoisting system 1 can also perform the hoisting operation of the next prefabricated full-section welded steel box girder 100. Compared with the prior art where the U-ribs and I-ribs are installed first and then the connection of the suspension point of the cable hoisting system 1 is released, the construction time can be greatly saved and the efficiency can be improved.

[0072] In this embodiment, when the stay cable strand 42 is arranged, the vertical tension component of the stay cable strand 42 is equal to the weight of the prefabricated full-section welded steel box girder 100, so that the stay cable strand 42 can stably pull the prefabricated full-section welded steel box girder 100.

[0073] It can be seen that the cable hoisting installation method for the main span full-section welded steel box girder of the long-span cable-stayed bridge has the following technical effects:

[0074] 1. The cable hoisting system 1 uses the cable tower of the cable-stayed bridge as the tower, reducing the cost of separately setting up the tower for the cable hoisting system 1, and having great economic advantages;

[0075] 2. The cable hoisting system 1 is used to install the prefabricated full-section welded steel box girder 100. The cable hoisting system 1 has a small hoisting blind area, avoiding the requirements of conventional deck cranes for vertical hoisting, reducing the requirements for transportation conditions, and being applicable to the construction of cable-stayed bridges in areas such as shoals, mountains, and canyons;

[0076] 3. The cable hoisting system 1 can achieve large-tonnage hoisting, avoiding the limitations of the deck full-rotation crane's in-situ splicing method on the deck structure type, and also reducing the impact of repeated welding on the overall safety and stability of the prefabricated full-section welded steel box girder 100;

[0077] 4. Since the prefabricated full-section welded steel box girder 100 is installed after overall hoisting in this method, compared with the in-situ splicing method, the construction duration is greatly reduced. Since temperature changes will affect the construction quality of welding operations and cable hoisting operations, the reduction of the construction duration enables construction personnel to arrange the construction time when the temperature is stable, such as only constructing during the day instead of during the day-night alternation with large temperature differences. It can be seen that this method solves the problems of large deformation of the hoisting points and unstable butt welds caused by the large temperature difference between day and night of the cable hoisting system 1 during the installation of the prefabricated full-section welded steel box girder 100, and further promotes the popularization of this installation construction technology and the construction of cable-stayed bridges in mountainous areas with traffic restrictions.

[0078] The above description is a detailed description of the preferred feasible embodiment of the present invention, but the embodiment is not used to limit the patent application scope of the present invention. Any equivalent changes or modified changes completed under the technical spirit disclosed by the present invention shall fall within the patent scope covered by the present invention.

Claims

1. A cable hoisting and installation method for a full-section welded steel box girder of a main span of a large-span cable-stayed bridge, characterized in that: The following steps are involved: S1 Cable lifting system layout: Install the cable lifting system (1); S2 Transporting the steel box girder: transporting the pre-assembled full-section welded steel box girder (100) to the bridge site lifting point and connecting it to the cable lifting system (1), including the following steps: S2.1 Loading the pre-assembled full-section welded steel box girder (100) onto a transport device (102); S2.2 The transport device (102) transports the pre-assembled full-section welded steel box girder (100) to a convenient position for lifting; S2.3 Connecting the cable hoisting system (1) to the hoisting points (202) on the pre-assembled full-section welded steel box girder (100), wherein the number of the hoisting points (202) is two groups, and the two groups of hoisting points (202) are symmetrically distributed on the middle webs (1111) corresponding to the opposite sides of the top plate (110) with the bridge centerline (105), and each group of the hoisting points (202) includes two pairs of the hoisting points (202), and the two pairs of the hoisting points (202) are arranged on the opposite sides of the top plate (110) along the length direction of the middle web (1111), and each pair of the hoisting points (202) corresponds to the connection between the middle web (1111) and the diaphragm (1115); S3: hoisting in place: using the cable hoisting system (1), hoisting the pre-installed full-section welded steel box girder (100) to a preset installation position (200), wherein the preset installation position (200) is a pre-welded position with the installed steel box girder (101); S4 temporary matching parts (2) installation: pre-installing a plurality of temporary matching parts (2) at preset positions of the pre-welded joints between the pre-installed full-section welded steel box girder (100) and the installed steel box girder (101), wherein the plurality of temporary matching parts (2) can enable the pre-welded joints between the pre-installed full-section welded steel box girder (100) and the installed steel box girder (101) to be initially positioned and connected; When pre-installing a plurality of the temporary matching parts (2), the plurality of the temporary matching parts (2) are divided into two groups, and the two groups of the temporary matching parts (2) are symmetrically pre-installed at the pre-welding position of the pre-installed full-section welded steel box girder (100) and the installed steel box girder (101) with the bridge centerline (105), wherein the temporary matching parts (2) at the center web (1111), the side web (1114), and the top plate (110) corresponding to the bottom plate (1112) are fixedly installed; The temporary matching component (2) comprises two L-shaped plates (21) and an abutting plate (22), one side of the two L-shaped plates (21) are parallel to each other, the abutting plate (22) is clamped between one side of the two L-shaped plates (21), and the two L-shaped plates (21) and the abutting plate (22) are fixed by bolts (24); a reinforcing plate (23) is mounted on the L-shaped plate (21); In step S4, during the installation of the temporary matching part (2), the other side surface of one of the L-shaped plates (21) contacts the top plate (110) of the pre-installed full-section welded steel box girder (100), and the other side surface of the other L-shaped plate (21) contacts the top plate (110) of the installed steel box girder (101); S5 local calibration: performing local precise calibration and adjustment on the pre-welding portion of the pre-installed full-section welded steel box girder (100) and the installed steel box girder (101); after confirming that the misalignment deviation value of the local pre-welding portion of the pre-installed full-section welded steel box girder (100) and the installed steel box girder (101) is within the allowable error range, and the linear elevation of the pre-installed full-section welded steel box girder (100) meets the design requirements, a plurality of the temporary matching parts (2) are fixedly installed; S6 Installing the yard plates: welding a plurality of yard plates (3) at intervals between two adjacent temporary matching parts (2), wherein opposite ends of the yard plates (3) are connected to the pre-installed full-section welded steel box girder (100) and the installed steel box girder (101); S7: Annular gap welding: welding the annular gaps of the pre-installed full-section welded steel box girder (100) and the installed steel box girder (101); S8: Tilt tensioning and fixing: arranging a tilt pulling component (4) on the pre-installed full-section welded steel box girder (100), using the tilt pulling component (4) to tilt and pull the pre-installed full-section welded steel box girder (100), so that the pre-installed full-section welded steel box girder (100) is fixed relative to the bridge pier (106), and then releasing the lifting point of the pre-installed full-section welded steel box girder (100) by the cable lifting system (1); S9 U-rib and I-rib installation: installing the U-rib and I-rib of the inspection and repair section between the pre-installed full-section welded steel box girder (100) and the installed steel box girder (101); S10 Cable hoisting system arrangement: The pre-installed full-section welded steel box girder (100) is subjected to a second tilt tensioning. When the tensioning force reaches the design target value, the elevation and line shape of the pre-installed full-section welded steel box girder (100) are re-measured, and the tilt tensioning force is adjusted at the same time. When the installation requirements of the pre-installed full-section welded steel box girder (100) are met, the installation of the pre-installed full-section welded steel box girder (100) is completed.

2. The cable hoisting and installation method for the full-section welded steel box girder of the main span of a long-span cable-stayed bridge according to claim 1 is characterized in that: The code plate (3) is in the shape of a plate, and a welding interface (31) is provided at the bottom of the code plate (3).

3. The cable hoisting and installation method for the full-section welded steel box girder of the main span of a long-span cable-stayed bridge according to claim 1 is characterized in that: The inclined pulling component (4) comprises a pulling member, a cable-stayed steel strand (42) and a HPDE tube (41). In the inclined tensioning and fixing step S8, the pulling member is arranged on the bridge pier (106), one end of the cable-stayed steel strand (42) is connected to the pulling member, the other end of the cable-stayed steel strand (42) is connected to the opposite ends of the pre-assembled full-section welded steel box girder (100), and the HPDE tube (41) is sheathed on the cable-stayed steel strand (42).

4. The cable hoisting and installation method for the full-section welded steel box girder of the main span of a long-span cable-stayed bridge as claimed in claim 3 is characterized by: When the inclined cable steel strands (42) are arranged, the vertical component of tensioning force of the inclined cable steel strands (42) is equal to the weight of the pre-assembled full-section welded steel box girder (100).

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