Asynchronous construction method, sling and system for cantilever assembly of mast type deck crane for hybrid beam of cable-stayed bridge

Abstract

The invention belongs to the field of cable-stayed bridge steel-concrete composite beam structure construction, and particularly relates to a cable-stayed bridge composite beam mast type deck crane cantilever assembly asynchronous construction method, a sling and a system. Comprising the following steps: (1) asynchronous hoisting and positioning of a steel beam; (2) asynchronous hoisting of a whole bridge deck in a framing manner; and (3) wet joint construction and integral connection: after the steel beam and the bridge deck are mounted, wet joint concrete is poured to form an integral structure of the steel-concrete composite beam. The construction efficiency is improved, the hoisting frequency is reduced through the whole hoisting technology, the construction period is shortened, and the construction efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the field of the construction of the steel-concrete composite beam structure of a cable-stayed bridge, and specifically relates to an asynchronous construction method, a lifting tool and a system for cantilever erection of a cable-stayed bridge hybrid beam mast-type deck crane. Background Art

[0002] In the field of the construction of the steel-concrete composite beam of a cable-stayed bridge, the composite structure of a steel beam and a precast concrete deck slab is widely used due to its excellent mechanical properties. The traditional steel-concrete composite beam consists of a steel beam main body, a precast deck slab and shear connectors between the two. Among them, the steel beam plays the role of tensile and local compressive resistance, while the concrete deck slab bears the main pressure load. However, for the long-span design of a multi-line bridge, the deck slab needs to be divided into multiple precast slabs (such as the left, middle and right spans). The single slab has a large area, a thin thickness and a high self-weight, resulting in extremely high requirements for the installation and positioning accuracy.

[0003] In the prior art, there are mainly two processes for the installation of the deck slab: Lifting each single slab independently: Using a large-tonnage floating crane or a land crane to lift the deck slab piece by piece. This method is limited by the water area conditions of the cross-river bridge and the equipment entry cost, and cumulative errors are likely to occur during the single-piece positioning, and repeated adjustments are required; Synchronous lifting of the deck slab and the steel beam: Pre-positioning the deck slab on the steel beam and lifting them together as a whole. Although this scheme reduces the number of positioning times, it greatly increases the rated lifting weight of the deck crane, resulting in a sharp increase in the structural transformation cost of the crane, and posing a risk to the transportation stability of the steel beam.

[0004] The core contradiction of the above processes lies in that it is difficult to balance the lightweight requirement of the deck slab and the requirement of lifting stability, and the traditional lifting tool cannot simultaneously meet the different lifting requirements of the steel beam and multiple deck slabs, especially lacking a dynamic center-of-gravity adjustment mechanism for synchronous lifting of multiple slabs. Therefore, there is an urgent need to develop a customized lifting tool with multi-component adaptability, center-of-gravity adjustability and synchronous lifting ability to break through the efficiency and cost bottlenecks in the construction of long-span steel-concrete composite beams. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides an asynchronous construction method, a lifting tool and a system for cantilever erection of a cable-stayed bridge hybrid beam mast-type deck crane.

[0006] The present invention adopts the following technical solutions: An asynchronous construction method for cantilever erection of a cable-stayed bridge hybrid beam mast-type deck crane, comprising the following steps: 1) Asynchronous hoisting and positioning of the steel beam: Transporting the whole segment of the steel beam to the bridge site by a deck barge, and using the mast-type deck crane equipped with a lifting tool to grab the steel beam; Adjust the gravity adjustment device of the spreader to longitudinally move the sliding reaction hook seat along the longitudinal beam to the preset position, lift the steel beam to the cantilever erection position, and after positioning, weld and fix it; After the installation of the steel beam is completed, conduct the initial tensioning of the stay cables; 2) Hoisting the bridge deck in whole-width and sub-width asynchronous manner: Assemble the left-width bridge deck, the middle-width bridge deck and the right-width bridge deck into a unit body on the transport ship through positioning fixtures and limit blocks, and transport it to the hoisting position by a deck barge; Adjust the working radius of the mast-type bridge deck crane, and sequentially hoist the bridge decks in order by using the sub-width lifting lugs of the adjustable spreader; Connect the left, middle and right lifting points of the crossbeam of the spreader to the embedded lifting rings of the bridge deck, and lift the bridge deck in sub-width to above the steel beam to complete accurate positioning; 3) Construction of the wet joint and integral connection: After the installation of the steel beam and the bridge deck is completed, pour the wet joint concrete to form the integral structure of the steel-concrete composite beam.

[0007] In some embodiments, the spreader includes: A "well"-shaped structure composed of longitudinal beams and crossbeams, with steel beam lifting lugs provided at both ends of the longitudinal beams, and bridge deck lifting lugs provided at the left, middle and right of the crossbeams; The sliding reaction hook seat is slidably connected to the longitudinal beam, and the gravity of the spreader is adjusted by precision rolled threaded steel to ensure the balanced hoisting of the steel beam and the bridge deck.

[0008] In some embodiments, the sub-width hoisting of the bridge deck specifically includes: Preferentially hoist the left-width bridge deck and the right-width bridge deck to the position of the steel beam and fix them; After releasing the spreaders of the left-width bridge deck and the right-width bridge deck, adjust the cantilever length of the crane, hoist the middle-width bridge deck and complete the positioning.

[0009] The rated lifting capacity of the mast-type bridge deck crane is 140 tons, the weight of a single segment of the steel beam is 130 tons, and the weight of a single bridge deck is 40 tons.

[0010] The welding of the steel beam adopts the symmetric welding process from the middle to both sides, and after the welding is completed, conduct the secondary tensioning of the stay cables.

[0011] The positioning fixture is processed from I-beams and fixed on the transport ship, and the distance between the bridge decks is accurately controlled by limit blocks.

[0012] The sliding reaction hook seat is linked by precision rolled threaded steel, and the operator twists the threaded steel to drive the longitudinal displacement of the sliding seat to dynamically match the hoisting gravity center.

[0013] A spreader for the construction method, including: Longitudinal beams and crossbeams, with steel beam lifting lugs provided at both ends of the longitudinal beams, and bridge deck lifting lugs provided at the left, middle and right of the crossbeams; The sliding reaction force hook seat is slidably connected to the longitudinal beam, and the center of gravity of the lifting appliance is adjusted by the precision rolled threaded steel; The cross beam and the longitudinal beam are connected by bolts.

[0014] Vertical stiffening plates are arranged inside the longitudinal beam, and the widened section of the upper wing plate serves as the fixed position of the sliding reaction force hook seat.

[0015] A construction system for a hybrid girder cable-stayed bridge includes: A mast-type deck crane, a lifting appliance, a deck barge and a transport ship; The system realizes the cantilever assembly of the steel girder, the left-side bridge deck, the middle bridge deck and the right-side bridge deck through the asynchronous sectional hoisting construction method, and completes the casting of the wet joint.

[0016] Compared with the prior art, the present invention has the following beneficial effects: In the present invention, the whole-section steel box girder is first transported to the bridge site by water. The deck crane completes the welding and installation work of the steel box girder section through a customized lifting appliance. Then, the precast bridge deck is transported to the ship by land and water transportation. The bridge deck positioning tooling is installed on the ship in advance, and multiple bridge decks are pre-positioned on the ship in advance. After the ship transports the bridge deck to the bridge site, the deck crane adjusts the amplitude of the crane, crosses the position of the assembled steel girder, uses the lifting appliance to lift the three bridge decks under the bridge to a height above the bridge deck, adjusts the amplitude of the deck crane, moves the bridge deck backward, and uses the fixture tooling to complete the fine adjustment of the bridge deck and then complete the placement of the bridge deck after the formwork is removed.

[0017] The present invention adopts the full-section hoisting technology to complete the hoisting of multiple bridge decks. Compared with the traditional single-block hoisting using a separate hoisting device, this method can greatly improve the construction efficiency, reduce the number of hoistings, and reduce the construction cost. The hoisting device is optimized in design to ensure the stability and safety during the hoisting process. Through precise hoisting control and adjustment, the precise placement of the bridge deck can be achieved.

[0018] The present invention improves the construction efficiency. The full-section hoisting technology reduces the number of hoistings, shortens the construction period, and improves the construction efficiency. By reducing the number of hoistings and the equipment usage cost, this construction method can significantly reduce the construction cost. The optimized hoisting device and precise hoisting control can ensure the stability and safety during the hoisting process and reduce the construction risk. Description of the Drawings

[0019] Figure 1 Schematic diagram of the steel-concrete composite girder structure; Figure 2 Schematic diagram of the bridge deck transport ship; Figure 3 Bridge deck positioning fixture on the ship; Figure 4 Schematic cross-sectional view of the customized lifting appliance; Figure 5 Schematic diagram of the longitudinal section of a customized sling; Figure 6 Cross-sectional view of the gravity center adjusting device of the customized sling; Figure 7 Longitudinal section view of the gravity center adjusting device of the customized sling; Figure 8 Schematic diagram for the hoisting construction of the steel beam segment of the cable-stayed bridge; Figure 9 Schematic diagram for the integral hoisting of the bridge deck of the cable-stayed bridge; Figure 10 Schematic diagram for the cantilever erection construction of the steel beam segment of the cable-stayed bridge; Figure 11 Schematic diagram for the construction of the integral hoisting and positioning of the bridge deck of the cable-stayed bridge; Figure 12 Schematic diagram of the longitudinal beam of the sling; Figure 13 Top view of the longitudinal beam of the sling; Figure 14 Cross-sectional view of the 1-1 longitudinal beam of the sling; Figure 15 Cross-sectional view of the 2-2 longitudinal beam of the sling; Figure 16 Schematic diagram for the connection between the steel beam sling and the longitudinal beam; Figure 17 Schematic diagram of the cross beam of the sling; Figure 18 Cross-sectional view of the cross beam of the sling; Figure 19 Transmission principle diagram I of the sliding hanger seat; Figure 20 Transmission principle diagram II of the sliding hanger seat; In the figure, 1 - steel beam, 2 - left bridge deck, 3 - middle bridge deck, 4 - right bridge deck, 5 - cast-in-place wet joint, 6 - on-board positioning fixture, 7 - limit block, 8 - cross beam, 9 - longitudinal beam, 11 - steel beam lifting lug, 12 - bridge deck crane lifting lug, 13 - gravity center adjusting device, 14 - reaction hook seat, 15 - longitudinal movement limit fine-threaded steel bar, 16 - constructed steel beam segment, 17 - hoisting steel beam segment, 18 - bridge deck embedded lifting ring, 19 - steel beam embedded lifting lug, 20 - mast-type luffing deck crane, 21 - hoisting bridge deck, 8-1 - lifting lug, 8-2 - shackle sling, 8-3 - stiffening plate inside the cross beam, 8-4 - connecting bolt between the cross beam and the longitudinal beam, 8-5 - triangular stiffening plate, 9-1 - connecting hole, 9-2 - vertical stiffening plate inside the longitudinal beam, 9-3 - stiffening plate outside the sliding hanger seat, 9-6 - stiffening rib under the upper wing plate, 9-7 - widened section of the upper wing plate, 9-8 - sliding section, 9-9 - stiffening rib, 14-1 - bolt, 14-2 - reaction seat, 14-3 - sliding hanger seat, 14-4 - threaded steel connector, 14-5 - limit fixing nut. Specific implementation method

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Apparently, the described embodiments are some, rather than all, of the embodiments of the present invention. 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 scope of protection of the present invention.

[0021] As Figure 1 shown, the main girder of the cable-stayed bridge adopts a steel-concrete composite girder structure design. The steel girder 1 adopts an open trough-shaped steel girder design. The deck slab uses three precast bridge slabs, namely the left-side bridge slab 2, the middle bridge slab 3, and the right-side bridge slab 4. The connection within the wet joint 5 forms a force synergy through the stub bars at both ends of the bridge slab and the shear studs on the top surface of the steel girder. The three precast bridge slabs and the steel girder are post-cast through the cast-in-place wet joint 5 to form an integral body.

[0022] After the construction of the cast-in-place section at the pier top is completed and the cable-stayed cables are hung and tensioned, the traveling and positioning of the bridge slab crane can be carried out.

[0023] A method for asynchronous construction of cantilever erection of a cable-stayed bridge with a hybrid girder mast-type bridge deck crane includes the following steps: 1) Asynchronous hoisting and positioning of the steel girder: In the steel structure processing factory, the whole-section steel girder 1 is transported to the bridge site by a deck barge, and the mast-type bridge deck crane 20 is used to carry a lifting tool to grab the steel girder 1; Adjust the gravity adjustment device 13 of the lifting tool to move the sliding reaction hook seat 14 longitudinally along the longitudinal beam 9 to a preset position, lift the steel girder 1 to the cantilever erection position, and weld and fix it after positioning; After the installation of the steel girder 1 is completed, the initial tensioning of the cable-stayed cables is carried out.

[0024] Specifically, as Figure 2 、 Figure 3 shown, the three bridge slabs 2, 3, and 4 are transported to the bridge site by ship. To ensure that the bridge slabs match the position of the lifting tool and can be accurately positioned on the steel girder after lifting, positioning fixtures 6 are erected on the ship in advance according to the designed spacing positions. The positioning fixtures 6 are fabricated from 20 I-beam materials. The left, middle, and right bridge slabs 2, 3, and 4 are placed according to the designed positions, and limit blocks 7 are installed on both the left and right sides of each bridge slab to ensure that there is no large displacement during transportation and hoisting.

[0025] According to the gravity center position of the steel girder of this segment, the operator first operates to adjust the sliding reaction hook seat to the corresponding position according to the designed gravity center position. The operator connects the front and rear end lifting lugs of the adjusting sling to the embedded lifting lugs on the steel girder through buckles and steel wires. After the bridge deck crane operator confirms that it is correct, the operator of the bridge deck crane slowly lifts the entire segment of the steel girder to the height of the bridge deck. After the inspector confirms that the bridge deck crane is operating normally, the operator of the bridge deck crane continues to operate the bridge deck crane for the luffing action, slowly horizontally moves the entire segment of the steel girder to the cantilever erection position of the steel girder, and then slowly performs the lowering action to complete the butt joint positioning of this segment with the constructed segment. After the surveyor accurately positions the cantilever erected steel girder, the welding operator can proceed with the next welding and fixing work, and thus complete the cantilever erection work of the steel girder.

[0026] 2) Asynchronous hoisting of the entire bridge deck in sections: Assemble the left bridge deck 2, the middle bridge deck 3, and the right bridge deck 4 into a unit body on the transport ship through the positioning fixture 6 and the limit block 7, and transport it to the hoisting position by the deck barge; Adjust the working radius of the mast-type bridge deck crane 20, and sequentially hoist the bridge deck in order using the sectional lifting lugs 10 of the adjustable sling; Connect the left, middle, and right lifting points of the crossbeam 8 of the sling to the embedded lifting rings 18 of the bridge deck, and lift the bridge deck in sections above the steel girder 1 to complete the accurate positioning.

[0027] Such as Figure 10 、 Figure 11 As shown, the bridge deck crane is a variable luffing mast-type bridge deck crane 20. The steel girder 17 is transported to the bridge site by the transport ship. The mast-type bridge deck crane 20 extends the luffing out of the bridge deck to the position of the ship, lowers the steel wire rope, connects the sling to the steel girder, and gradually lifts it to the height of the bridge deck. Then, continue to luff backward to the constructed steel girder segment 16. After the subsequent welding of the steel girder 17 and the steel girder 16 is completed, the stay cable is tensioned, and then the next bridge deck installation process can be entered. The 3 integral bridge decks 20 are transported to the bridge site by the transport ship. After the stay cable is tensioned, disconnect the connection between the mast-type bridge deck crane 20 and the steel girder 17. Operate the bridge deck crane 20 as described above, complete the connection between the sling and the bridge deck 20, and match the gravity center position of the bridge deck 20 through the gravity center adjustment device so that the bridge deck 20 can be lifted balancedly. Operate the bridge deck crane to complete the installation work of the three bridge decks 20 at one time through vertical and luffing actions, and thus complete the hoisting work of the steel-concrete composite girder.

[0028] 3) Construction of the wet joint and overall connection: After the installation of the steel girder and the bridge deck is completed, pour the concrete of the wet joint 5 to form the overall structure of the steel-concrete composite girder.

[0029] The sectional hoisting of the bridge deck specifically includes: Prioritize lifting the left - hand bridge deck 2 and the right - hand bridge deck 4 to the steel - beam position and fix them; After removing the lifting appliances of the left - hand bridge deck 2 and the right - hand bridge deck 4, adjust the cantilever length of the crane, lift the middle - hand bridge deck 3 and complete the positioning.

[0030] The rated lifting capacity of the mast - type bridge deck crane 20 is 140 tons, the weight of a single - segment steel beam is 130 tons, and the weight of a single bridge deck is 40 tons.

[0031] For the steel - beam welding, adopt the symmetric welding process from the middle to both sides. After welding is completed, conduct the secondary tensioning of the stay cables.

[0032] The positioning fixture 6 is made of I - beam and fixed on the transport ship. The distance between the bridge decks is accurately controlled by the limit block 7.

[0033] Specifically, the lifting appliance includes: A "well" - shaped structure composed of longitudinal beams 9 and cross - beams 8. Steel - beam lifting lugs 11 are arranged at both ends of the longitudinal beam 9, and bridge - deck lifting lugs are arranged on the left, middle, and right of the cross - beam 8; The sliding reaction hook seat 14 is slidably connected to the longitudinal beam 9. The center of gravity of the lifting appliance is adjusted by the high - strength precision - rolled threaded steel 15 to ensure the balanced lifting of the steel beam and the bridge deck.

[0034] The sliding reaction hook seat 14 is linked by the high - strength precision - rolled threaded steel 15. The operator twists the threaded steel to drive the longitudinal displacement of the sliding seat, dynamically matching the lifting center of gravity.

[0035] Specifically, the lifting appliance includes: A cross - beam 8, on which at least three lifting lugs 8 - 1 are provided, corresponding to the embedded lifting rings 18 on the left - hand bridge deck 2, the middle - hand bridge deck 3, and the right - hand bridge deck 4 respectively; A longitudinal beam 9, which is perpendicularly connected to the cross - beam 8. A center - of - gravity adjusting device 13 that can move longitudinally is provided at the center - of - gravity position of the longitudinal beam 9, and a bridge - deck crane lifting lug 12 is arranged on the center - of - gravity adjusting device 13; Steel - beam lifting lugs 11 are arranged at both ends of the longitudinal beam 9 for connecting with the embedded lifting lugs 19 on the steel beam 1 through pin shafts; The cross - beam 8 and the longitudinal beam 9 are connected by bolts.

[0036] As Figures 17 - 18 shown, specifically, the lifting lugs 8 - 1 on the cross - beam 8 are welded to the cross - beam 8, and shackle lifting appliances 8 - 2 are installed on the lifting lugs 8 - 1. The shackle lifting appliances 8 - 2 are connected to the embedded lifting rings 18 on the bridge deck through steel wires.

[0037] Specifically, the cross - beam 8 is welded by steel plates with a thickness of 20 mm, and cross - beam internal stiffening plates 8 - 3 are provided inside the cross - beam 8 to disperse the lifting load.

[0038] Specifically, the bolt connection between the cross beam 8 and the longitudinal beam 9 is connected by the cross-longitudinal beam connection bolt 8-4, and transverse stiffening plates 8-3 and triangular stiffening plates 8-5 are welded around the connection position to enhance the shear resistance of the connection part.

[0039] The cross beam 8 is reinforced with a 2 cm thick steel beam. Lifting lugs 8-1 are welded at corresponding positions with the steel beam bridge deck respectively, and shackle lifting tools 8-2 are installed. The shackle lifting tool 8-2 is connected with the embedded lifting rings on the bridge deck through steel wires. The cross beam 8 and the longitudinal beam 9 are connected by bolts. To ensure its stiffness at the bolt connection, it is strengthened by adding triangular stiffening plates 8-5.

[0040] As Figures 12 - 16 shown, vertical stiffening plates 9-2 are provided inside the longitudinal beam 9, and stiffening ribs 9-9 are added below the upper flange of the longitudinal beam 9 to improve the bending strength and stability of the longitudinal beam 9; Connection holes 9-1 are provided at both ends of the longitudinal beam 9 and are connected with the steel beam lifting lugs 11 through pin shafts to form a detachable rigid connection structure. Sliding hanger outer stiffening plates 9-3 are provided around the connection holes 9-1 to enhance the local stiffness; The upper flanges at both ends of the longitudinal beam 9 are provided with widened sections 9-7, and the reaction hook seats 14 are fixed to the widened sections 9-7 by bolts.

[0041] The longitudinal beam 9 is welded with steel with a thickness of 2 cm. The beam end is rectangular. Inside, vertical stiffening plates 9-2 of the longitudinal beam are adopted. As Figure 14 shown, stiffening ribs 9-9 are added below the upper flange 9-6. The widened section 9-7 is provided at the upper flange position as the fixed position of the reaction hook seat 14 of the center of gravity adjustment device. The sliding section 9-8 is the sliding contact surface between the reaction hook seat 14 of the center of gravity adjustment device and the longitudinal beam 9.

[0042] The steel beam lifting tool 11 and the longitudinal beam 9 are fixedly connected through the connection hole 9-1 at the front end of the longitudinal beam 9 by using a pin shaft. The lifting lug 11 of the steel beam lifting tool is connected with the embedded lifting lug on the steel beam through a pin shaft.

[0043] As Figures 19 - 20 shown, the center of gravity adjustment device 13 includes: A reaction hook seat 14, and the reaction hook seat 14 is buckled on the widened section 9-7 of the upper flange of the longitudinal beam 9; A longitudinally moving limit fine-threaded steel bar 15, and the longitudinally moving limit fine-threaded steel bar 15 is arranged below the widened section 9-7 of the upper flange. One side of the reaction hook seat 14 is sleeved on the longitudinally moving limit fine-threaded steel bar 15 and slides along the longitudinally moving limit fine-threaded steel bar 15. The displacement range of the longitudinally moving fine-threaded steel bar 15 is restricted by a limit fixing nut.

[0044] Specifically, a sliding suspension seat 14-3 is arranged inside the reaction force hook seat 14, and a threaded steel connector 14-4 is installed at the bottom of the sliding suspension seat 14-3 for sliding connection with the longitudinal displacement limiting fine threaded steel 15.

[0045] Both ends of the longitudinal displacement limiting fine threaded steel 15 are installed on the reaction force seat 14-2, and the reaction force seat 14-2 is fixedly connected to the longitudinal beam 9 through bolts 14-1. Limit fixing nuts 14-5 are fixedly installed at the front and rear ends of the threaded steel connector 14-4 on the screw rod 15 respectively to ensure that the screw rod cannot have longitudinal displacement.

[0046] As Figure 4 shown, a front and rear reaction force seat device is installed at the middle position of the longitudinal beam 9. The reaction force seat 14-2 is fixedly connected to the longitudinal beam 9 through bolts. A connector 14-4 is used to connect the sliding suspension seat 14-3 and the transmission screw rod 15. The threaded steel connector 14-4 is fixedly connected to the sliding suspension seat by welding and cannot rotate relative to each other. Limit fixing nuts are fixedly installed at the front and rear ends of the screw rod 15 on the reaction force seat 14-2 respectively to ensure that the screw rod cannot have longitudinal displacement. When it is necessary to adjust the position of the sliding suspension seat on the longitudinal beam, the operator twists the fine threaded steel 15, so that the fine threaded steel connector 14-4 makes longitudinal displacement along the screw rod, driving the sliding seat to displace on the longitudinal beam, and the center position of the lifting point can be adjusted according to different objects.

[0047] This lifting tool is a customized lifting tool for the integral installation of precast bridge decks of steel-concrete composite girders of cable-stayed bridges. While this lifting tool can hoist steel girders, through the gravity center adjusting device 13, it can also match and hoist the left, middle, and right bridge decks. This lifting tool has 2 cross beams 8, and a lifting ear 8-1 is installed at each of the left, middle, and right positions of the cross beam 8, corresponding to the left, middle, and right bridge decks one by one. 2 longitudinal beams 9 are installed below the cross beam, and the longitudinal beams are mainly used for hoisting the steel girder structure. The steel girder lifting ears 11 correspond to the steel girder hoisting positions one by one. The gravity center adjusting device is arranged at the gravity center position of the longitudinal beam of the lifting tool, and the gravity center of the lifting tool can be moved back and forth to adjust the balance of the hoisted object, effectively solving the problem of different gravity centers of the lifting tool when hoisting bridge decks and steel girders.

[0048] The gravity center adjusting device of the customized lifting tool uses the reaction force hook seat 14 to buckle on the longitudinal beam 8 of the lifting tool, and the longitudinal displacement limiting fine threaded steel 15 is installed on both sides of the longitudinal beam. The operator can make the reaction force hook seat 14 move longitudinally on the longitudinal beam 8 by twisting the fine threaded steel, so that the hoisted object can be balanced and lifted according to the gravity center of different hoisted heavy objects.

[0049] The steel girder lifting ears 11 of the customized lifting tool are connected to the pre-embedded lifting ears of the steel girder through pin shafts. After the steel girder hoisting is completed, through amplitude adjustment, the bridge deck crane lifting ears 12 of the customized lifting tool are reconnected to the pre-embedded lifting rings 18 of the bridge deck through steel wires, and three integral bridge decks are hoisted at one time.

[0050] A construction system for a hybrid girder cable-stayed bridge, comprising: A mast-type deck crane 20, a sling, a deck barge and a transport ship; The system realizes the cantilever erection of the steel girder 1, the left-side bridge deck 2, the middle bridge deck 3 and the right-side bridge deck 4 through an asynchronous sectional hoisting construction method, and completes the casting of the wet joint 5.

[0051] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for asynchronous construction of cantilever erection of a mast-type deck crane for a cable-stayed bridge with a hybrid girder, characterized in that, It includes the following steps: 1) Asynchronous hoisting and positioning of steel girders: Transport the whole-section steel girder (1) to the bridge site by a deck barge, and use the mast-type deck crane (20) equipped with a lifting tool to grab the steel girder; Adjust the gravity adjustment device (13) of the lifting tool to longitudinally move the sliding reaction hook seat (14) along the longitudinal girder (9) to a preset position, lift the steel girder (1) to the cantilever erection position, and weld and fix it after positioning; After the installation of the steel girder (1) is completed, conduct the initial tensioning of the stay cables; 2) Asynchronous hoisting of the entire bridge deck in sections: Assemble the left bridge deck (2), the middle bridge deck (3), and the right bridge deck (4) into a unit body on the transport ship through the positioning fixture (6) and the limit block (7), and transport it to the lifting position by a deck barge; Adjust the working radius of the mast-type deck crane (20), and use the sectional lifting lugs (10) of the adjustable lifting tool to sequentially lift the bridge decks in order; Connect the left, middle, and right lifting points of the cross beam (8) of the lifting tool to the embedded lifting rings (18) of the bridge deck, and lift the bridge deck in sections above the steel girder (1) to complete precise positioning; 3) Construction of the wet joint and integral connection: After the installation of the steel girder and the bridge deck is completed, pour the concrete of the wet joint (5) to form the integral structure of the steel-concrete composite girder.

2. The asynchronous construction method for cantilever erection of a cable-stayed bridge hybrid girder mast-type deck crane according to claim 1, characterized in that, The lifting tool includes: A "well"-shaped structure composed of a longitudinal girder (9) and a cross beam (8). Steel girder lifting lugs (11) are provided at both ends of the longitudinal girder (9), and bridge deck lifting lugs are provided on the left, middle, and right of the cross beam (8); The sliding reaction hook seat (14) is slidably connected to the longitudinal girder (9), and the gravity of the lifting tool is adjusted by the precision rolled threaded steel (15) to ensure the balanced hoisting of the steel girder and the bridge deck.

3. The asynchronous construction method for cantilever erection of a cable-stayed bridge hybrid girder mast-type deck crane according to claim 1, wherein The specific process of the sectional hoisting of the bridge deck includes: Preferentially lift the left bridge deck (2) and the right bridge deck (4) to the position of the steel girder and fix them; After removing the lifting tools of the left bridge deck (2) and the right bridge deck (4), adjust the cantilever length of the crane, lift the middle bridge deck (3) and complete the positioning.

4. The asynchronous construction method for cantilever erection of the cable-stayed bridge hybrid beam mast-type deck crane according to claim 1, characterized in that The rated lifting capacity of the mast-type deck crane (20) is 140 tons, the weight of a single section of the steel girder is 130 tons, and the weight of a single bridge deck is 40 tons.

5. The asynchronous construction method for cantilever erection of a cable-stayed bridge with a hybrid girder mast-type deck crane according to claim 1, characterized in that The welding of the steel girder adopts the symmetric welding process from the middle to both sides, and the secondary tensioning of the stay cables is carried out after the welding is completed.

6. The asynchronous construction method for cantilever erection of the cable-stayed bridge hybrid girder mast-type deck crane according to claim 1, characterized in that The positioning fixture (6) is processed from an I-beam and fixed on the transport ship, and the distance between the bridge decks is accurately controlled by the limit block (7).

7. The asynchronous construction method for cantilever erection of the cable-stayed bridge hybrid girder mast-type deck crane according to claim 1, characterized in that The sliding reaction hook seat (14) is linked by the precision rolled threaded steel (15), and the operator twists the threaded steel to drive the longitudinal displacement of the sliding seat to dynamically match the hoisting gravity center.

8. A lifting device for the construction method according to any one of claims 1-7, characterized in that, It includes: A longitudinal girder (9) and a cross beam (8). Steel girder lifting lugs (11) are provided at both ends of the longitudinal girder (9), and bridge deck lifting lugs (8-1) are provided on the left, middle, and right of the cross beam; The sliding reaction hook seat (14) is slidably connected to the longitudinal girder (9), and the gravity of the lifting tool is adjusted by the precision rolled threaded steel (15); The cross beam (8) is connected to the longitudinal girder (9) by bolts.

9. The spreader according to claim 8, characterized in that Vertical stiffening plates (9-2) are arranged inside the longitudinal girder (9), and the widened section (9-7) of the upper wing plate serves as the fixed position of the sliding reaction hook seat (14).

10. A construction system for a hybrid girder cable-stayed bridge, characterized in that, It includes: A mast-type deck crane (20), the lifting tool described in claims 8-9, a deck barge, and a transport ship; The system realizes the cantilever assembly of the steel beam (1) with the left bridge deck (2), the middle bridge deck (3) and the right bridge deck (4) through the asynchronous sectional hoisting construction method, and completes the casting of the wet joint (5).

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