A whole-segment steel box girder sliding on-ship-lifting integrated construction method without floating crane intervention

Abstract

The application discloses a whole-segment steel box girder sliding on-ship-lifting integrated construction method without floating crane intervention, a whole-segment steel box girder assembling and sliding platform is arranged on the land area of the bank side of a bridge to be built, and two groups of sliding tracks are arranged in parallel on the assembling and sliding platform; a deck barge with an adaptive tonnage is selected, and ship-borne sliding tracks with the same specification and spacing as the sliding tracks on the bank side are arranged on the deck of the barge; the application greatly reduces the approach and operation of large lifting equipment, reduces fuel consumption and carbon emission of mechanical equipment, shifts the main construction operation to the land area to reduce the water operation time, effectively avoids water pollution caused by construction sewage, welding slag, waste and the like entering a river, dust and noise in land operation can be effectively controlled through conventional protection measures, the influence of construction operation on surrounding residential areas, crops and ecological environment is greatly reduced, and the application meets the relevant requirements of green construction and ecological environment protection.

Description

Technical Field

[0001] This invention relates to the field of steel structure construction technology for bridge engineering, and particularly to a method for the transfer and installation of whole-segment steel box girders for long-span bridges. Specifically, it is an integrated construction method for sliding whole-segment steel box girders onto a ship and hoisting them without the intervention of a floating crane. Background Technology

[0002] With the rapid advancement of transportation infrastructure construction in my country, long-span cable-stayed bridges and continuous steel structure bridges are widely used in cross-river, cross-sea, and cross-channel projects. Steel box girder structures, due to their advantages such as light weight, strong spanning capacity, high degree of industrial prefabrication, and short construction period, have become one of the preferred forms of main girder structures for long-span bridges. In recent years, to further improve construction efficiency and control on-site welding quality, the prefabrication and assembly process of whole-segment, large-tonnage steel box girders has become the mainstream development direction in the industry. The weight of a single steel box girder generally reaches over 200 tons, and its length exceeds 12 meters. The transfer from land to water and the high-altitude installation at the bridge site have become core technical constraints on project safety, quality, schedule, and cost.

[0003] Currently, the mainstream transportation and installation processes used in the construction of long-span steel box girder bridges in China are mainly divided into two categories, both of which have insurmountable technical defects: 1. This process uses large floating cranes to directly lift entire steel box girder segments transported by water to the bridge site to the design elevation for installation. However, in practical engineering applications, this process has significant drawbacks: First, it is extremely dependent on large-tonnage floating cranes, which are expensive to lease. Furthermore, in inland waterways, large-tonnage floating cranes are often unable to operate due to limitations such as water depth, navigation clearance, and bridge span. Second, construction is greatly affected by hydrological and meteorological conditions. Fluctuations in water level, wind, waves, and rainfall can all cause floating crane operations to stop, resulting in significant risks of uncontrollable project timelines. Third, floating crane operations require prolonged occupation of the main waterway, severely impacting normal navigation, especially in busy inland waterway sections where waterway coordination is difficult and navigation safety risks are high. Fourth, the high-altitude lifting of large-tonnage components on the water is high-risk, with difficulty in controlling the component's attitude during lifting, increasing the risk of collisions, overturning, and other safety accidents.

[0004] 2. This process breaks down the steel box girder into multiple smaller segments, which are transported to the bridge site using small transport equipment, and then assembled and welded segment by segment using a bridge deck crane. While this process reduces reliance on large lifting equipment, it also has significant drawbacks: First, the amount of work at height is extremely large, and workers spend long periods of time working near the edge at height, posing significant safety risks such as falls from heights and being struck by objects. Second, the on-site high-altitude welding workload is large, the welding working environment is poor, and the welding quality and flaw detection are difficult, making welding defects more likely and affecting the long-term service life of the structure. Third, multiple hoisting and segment-by-segment assembly can easily lead to cumulative errors, making it difficult to control the alignment of the steel box girder and ensuring the accuracy of the closure segment. Fourth, the efficiency of process connection is low, high-altitude operations are greatly affected by weather, and the overall construction period is significantly extended.

[0005] In addition, some technologies for sliding steel box girders onto ships have emerged in the industry, but the existing sliding process still faces many technical bottlenecks: 1. It cannot effectively solve the problem of dynamic seamless docking of ship and shore tracks under the fluctuation of water level in inland waterways. The track docking accuracy is low, the risk of misalignment is high, and it is easy to cause component jamming and deformation during the sliding process. 2. The ship's dynamic balance control capability is insufficient during the sliding process. As the load of the steel box girder is gradually transferred to the barge, the change in the ship's draft can easily cause sudden changes in the track elevation, posing a safety hazard of component overturning and track collapse. 3. The existing process can only achieve the sliding and transfer of steel box girders onto ships, and has not formed an integrated set of technologies with the subsequent high-altitude hoisting and installation process at the bridge site. The process is disconnected, and the improvement of construction efficiency is limited. 4. Most skid-slip processes still require floating cranes to complete the final hoisting and installation, and the dependence on floating cranes has not been completely eliminated, thus failing to fundamentally solve the problems of cost, construction period and navigation impact caused by floating crane processes.

[0006] In summary, there is a lack of existing technologies that can completely eliminate reliance on large floating cranes, adapt to the complex hydrology and restricted operating environment of inland waterways, and simultaneously ensure construction safety, quality, efficiency, and cost. There is an urgent need to develop a fully integrated construction method to address the many pain points of existing technologies and promote the upgrading of large-span steel structure bridge construction technology. Summary of the Invention

[0007] In order to overcome the shortcomings of the existing technology, one of the objectives of this invention is to provide an integrated construction method for sliding and hoisting whole-section steel box girder onto a ship without the intervention of a floating crane.

[0008] One of the objectives of this invention is achieved through the following technical solution: A method for integrated construction of whole-segment steel box girder sliding onto a ship and hoisting without the intervention of a floating crane includes the following steps: S1: Construction preparation and temporary support system construction: A whole-section steel box girder assembly and sliding platform is set up on the land side of the bridge to be built, and two sets of sliding tracks are laid in parallel on the assembly and sliding platform; a deck barge of suitable tonnage is selected, and ship-mounted sliding tracks of the same specifications and spacing as the shore-side sliding tracks are laid on the barge deck; a jacking system, a lifting system, a ballast water control system and a monitoring system are set up in conjunction with the project; S2: Integral assembly of whole steel box girder segments on land: The steel box girder segments are assembled, welded, inspected and inspected on the assembly and sliding platform to form an integral large steel box girder segment; S3: Sliding and positioning of steel box girder and dynamic docking of ship and shore track: The whole large-segment steel box girder that has passed the acceptance is simultaneously lifted by the jacking system. After the sliding bearing device is set up at the bottom of the steel box girder, the girder is lowered so that the sliding bearing device is embedded in the sliding groove of the sliding track. The ballast water system of the barge is adjusted to make the elevation and flatness of the ship-mounted sliding track consistent with the shore sliding track, and the rigid anchoring docking of the ship and shore track is completed. S4: Synchronous jacking and sliding with dynamic balance control of the hull: The synchronous jacking system is used to push the steel box girder along the sliding track to slide towards the barge at a set speed. During the sliding process, the water injection and discharge of the barge's ballast tanks are dynamically adjusted in real time through the ballast water control system to compensate for the changes in the hull's draft caused by the load transfer of the steel box girder. The horizontal docking accuracy of the ship-shore track is maintained throughout the process until the steel box girder slides to the preset position of the barge. S5: Steel box girder hull fixing and water transport: After the steel box girder is slid into place, the ballast water of the barge is adjusted to raise the hull, the anchoring connection of the ship-shore track is released, and the steel box girder is rigidly fixed to the barge deck to form an integral transport unit; the steel box girder is transported to the bridge site water area corresponding to the bridge design axis by tugboat towing the barge. S6: In-situ hoisting and precision installation of bridge deck cranes: Self-propelled bridge deck cranes are deployed on the already erected beam segments of the bridge to be built. The bridge deck cranes vertically lift the entire steel box girder segment from the barge to the design elevation. After the attitude is adjusted, the girder is precisely aligned and connected with the already erected beam segment, realizing the integrated construction of the entire steel box girder segment from land assembly to water transfer and high-altitude installation without floating cranes.

[0009] As a further improvement to the above technical solution: In step S1, the assembled sliding platform uses Φ630×8mm steel pipe piles as lattice columns, and the columns are reinforced with straight and diagonal braces made of 16# channel steel. Double-segmented 40a I-beam distribution beams are set on the top of the columns. The sliding track and the ship-mounted sliding track are both made of three-segmented HN700×300×13×24mm H-beams. C28 channel steel is fixed on the top of the track as a sliding chute. The parallelism deviation of the two sets of sliding tracks is ≤2mm, and the top surface elevation deviation is ≤1mm.

[0010] In step S1, the lifting system uses four hydraulic jacks with a single lifting force ≥100t and a stroke ≥200mm; the jacking system uses a synchronous hydraulic jacking device with an adjustable jacking speed range of 3-8m / h; the ballast water control system uses two parallel 100CBZ-18 self-priming ballast water pumps with a single pump flow rate ≥100m³ / h and a total displacement ≥200m³ / h; the monitoring system includes a hull tilt monitoring unit, a track displacement monitoring unit, a steel box girder stress monitoring unit, and a water level monitoring unit.

[0011] In step S2, the overall large segment steel box girder is a steel box girder segment with a single section length ≥12m and a weight ≥200t. During the assembly process, circumferential welding, non-destructive testing and anti-corrosion coating are completed between the segments. After the assembly is completed, the axial deviation of the steel box girder is ≤3mm and the elevation deviation of the top surface of the beam segment is ≤2mm.

[0012] In step S3, the sliding bearing device uses four mobile transport tanks with a rated load capacity of ≥100t each. The four transport tanks are symmetrically arranged at the web position at the bottom of the steel box girder. The steel wheels of the transport tanks are embedded in the grooves of the sliding track, and the gap between the steel wheel and the groove on one side is ≤0.5mm. After the ship-shore track is connected, rigid connectors are used to anchor the ship-mounted sliding track to the shore-side sliding track and the steel pipe piles of the assembly platform. After anchoring, the misalignment at the track connection point is ≤1mm.

[0013] In step S4, the uniform speed of the jacking and sliding is set to 6 m / h. The sliding process adopts segmented jacking, and the stroke of each segment is matched with the rated stroke of the hydraulic jack. After each segment of jacking is completed, anti-impact safety wedges are set between the sliding track and the steel box girder. During the sliding process, based on the real-time data of the ship's draft, tilt, and track elevation collected by the monitoring system, the ballast water control system is used to synchronously inject and drain water in real time to maintain the ship's heel ≤0.1°, trim ≤0.05°, and the elevation deviation at the docking point of the ship and shore track is always ≤1 mm.

[0014] In step S4, after the steel box girder is slid to the preset position on the barge, the steel box girder is temporarily locked laterally and longitudinally by the limiting baffle. In step S5, the barge ballast water is discharged to raise the hull by ≥40cm. After the anchoring of the ship-shore track is released, the bottom of the steel box girder is welded and fixed to the support structure of the barge deck using rigid welded parts. The welding and fixing points are symmetrically arranged along the longitudinal direction of the steel box girder and there are no less than 4 sets.

[0015] In step S6, the rated lifting capacity of the self-propelled bridge deck crane is ≥350t. The bridge deck crane is fixed to the front end of the bridge beam segment that has been erected through an anchoring system. The lifting points are symmetrically arranged with the center of gravity of the steel box girder. During the lifting process, a steel strand hydraulic synchronous lifting system is used for vertical lifting. The horizontal deviation of the steel box girder during the lifting process is ≤2mm. After being lifted to the design elevation, the posture of the steel box girder is finely adjusted by a three-dimensional adjustment device. The axial deviation and elevation deviation during the connection are ≤1mm.

[0016] The quality control throughout the construction process complies with the requirements of the "Technical Specification for Construction of Highway Bridges and Culverts" JTG / TF50-2020, the "Code for Acceptance of Construction Quality of Steel Structures" GB50205-2020, and the "Code for Manufacturing and Installation of Highway Steel Structure Bridges" JTG / T3651-2022; the first-time pass rate for welding of steel box girders is ≥92%, the first-time pass rate for unit assembly is ≥93%, and the first-time pass rate for inspection is ≥98%.

[0017] The sliding operation in step S4 and the hoisting operation in step S6 both avoid adverse working conditions such as strong winds, rain, strong sunlight and excessive water level fluctuations. During the sliding operation, the waterway is temporarily controlled, and warning signs and warning vessels are set up in the operation area. Safety nets and fall protection devices are set up throughout the high-altitude assembly and hoisting operation areas, and all special operation personnel are certified to work.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention requires no large floating crane equipment throughout the entire process. The assembly and welding of the entire steel box girder segment is completed through a land-based assembly platform. The steel box girder is smoothly transferred from the land to the barge using a track sliding system. Finally, the in-situ precise hoisting is completed by a bridge crane, which fundamentally solves the problem of the traditional process's strong dependence on large-tonnage floating cranes.

[0019] 2. This invention innovatively employs ballast water dynamic balance control technology. Through a dual-pump linked ballast water regulation system, it compensates in real time for changes in the ship's draft caused by the load transfer of the steel box girder, maintaining the horizontal docking accuracy of the ship-shore track throughout the entire process. Simultaneously, through the coordinated operation of a high-precision sliding track system, a synchronous jacking system, and a multi-dimensional monitoring system, the entire sliding process is fully controllable. On one hand, all welding operations of the steel box girder are transferred to a fixed land platform, significantly reducing the time and workload of high-altitude operations on the water, thus mitigating safety risks such as falls from heights and being struck by objects. On the other hand, it completely avoids the risks of collisions and capsizing during the lifting and attitude adjustment of large-tonnage components on the water, as well as the navigation safety risks caused by waterway obstruction, inherent in traditional floating crane lifting operations. During the sliding process, multiple protections, including limit devices, anti-impact wedges, and a real-time monitoring and early warning system, eliminate safety hazards such as component displacement, deformation, and capsizing, resulting in a qualitative improvement in construction safety assurance capabilities.

[0020] 3. This invention achieves full-process quality control of the entire steel box girder segment from assembly to closure through a multi-stage precision control system: First, the overall assembly of the fixed land platform ensures a stable working environment, enabling high-precision control of steel box girder welding. The welding working environment is excellent, and flaw detection is fully covered, effectively guaranteeing welding quality. Secondly, the high-precision sliding track system works in conjunction with the synchronous jacking system, ensuring that the deviation of the steel box girder axis is ≤3mm during the sliding process, thus avoiding structural deformation during the sliding process; Third, the hydraulic synchronous lifting system of the bridge deck crane, in conjunction with the three-dimensional adjustment device, can achieve millimeter-level fine-tuning of the steel box girder's high-altitude posture. The deviation of the docking axis of the closure section is ≤1mm and the elevation deviation is ≤1mm, which greatly improves the accuracy of the steel box girder's alignment control and the quality of closure. At the same time, it significantly reduces on-site high-altitude welding operations, reduces the impact of environmental factors on welding quality, and effectively ensures the long-term service life of the bridge structure.

[0021] 4. This invention enables parallel operation of multiple processes. The assembly of whole sections of steel box girders on land can be carried out simultaneously with the construction of the bridge substructure, without waiting for the substructure and girder erection equipment to be in place, which greatly reduces the critical path construction period. The sliding of a single steel box girder onto the ship can be completed in just 2 hours, and the temporary control time of the waterway is extremely short. Unlike the traditional floating crane process, it does not occupy the main waterway for a long time, which minimizes the interference of construction operations on the normal navigation of inland waterways, greatly reduces the difficulty of waterway coordination and navigation safety risks, and is especially suitable for bridge projects in busy navigable river sections.

[0022] 5. This invention is not limited by waterway depth, navigation clearance, or work site conditions, and can be widely applied to the construction of whole-segment steel box girders for long-span cable-stayed bridges and continuous beam bridges. It is especially suitable for construction scenarios with large water level fluctuations, limited work space, and complex navigation conditions in inland waterways. It can meet the construction needs of large-tonnage, large-size whole-segment steel box girders of 250t and above and lengths exceeding 12m. It is suitable for projects with sufficient work space on the bank, and can also be adapted to construction environments with limited space by optimizing the size of the assembly platform. It has extremely strong engineering adaptability and solves the pain points of traditional processes being "unusable, inefficient, and costly" in complex inland waterway environments.

[0023] 6. This invention significantly reduces the need for large lifting equipment to enter the site and operate, thereby reducing fuel consumption and carbon emissions of machinery and equipment; by transferring the main processing operations to land, the time spent on water operations is reduced, effectively preventing water pollution caused by construction wastewater, welding slag, and waste entering waterways; dust and noise from land operations can be effectively controlled through conventional protective measures, significantly reducing the impact of construction operations on surrounding residential areas, crops, and the ecological environment, and meeting the relevant requirements of green construction and ecological environmental protection.

[0024] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0025] Figure 1 This is a flowchart of the method in this embodiment. Detailed Implementation

[0026] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0027] It should be noted that when a component is described as "fixed to" another component, it can be directly on the other component or may have a component in between. When a component is considered "connected to" another component, it can be directly connected to the other component or may have a component in between. When a component is considered "set on" another component, it can be directly set on the other component or may have a component in between. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0029] This embodiment is based on the Dongfeihe Bridge project of the Shouxian Liugang to Baoyi section of the S16 Hefei-Zhoukou Expressway. The main bridge adopts a 95m+175m single-tower double-cable-stayed bridge structure. The main span steel box girder has a total length of 161m (excluding the 3m steel-concrete composite section), a total width of 32.5m for the top plate of the bridge deck, a standard beam height of 3.0m at the center line of the beam, and transverse diaphragms arranged at equal intervals of 3m. The entire steel box girder is divided into 13 precast segments, with a standard segment length of 12m. Among them, the large segments D1-D9 are constructed using this method. The maximum weight of a single segment is 253t, and the maximum length is 12m. This is a typical construction scenario of large-tonnage, large-size whole-segment steel box girder.

[0030] The Dongfei River, where the project is located, is an inland navigable waterway with large fluctuations in water level and limited operating space. Traditional large-scale floating crane operations suffer from problems such as significant interference with waterway navigation, high rental costs, and uncontrollable construction period due to weather and water level fluctuations.

[0031] This embodiment adopts the integrated construction method of the present invention without the intervention of floating cranes. The entire process does not require large floating crane equipment and completes the entire construction process of land assembly, sliding onto ship, water transfer and high-altitude hoisting and closure of 9 large steel box girder segments.

[0032] Step 1: Construction preparation and temporary support system construction (1) Erection of the assembled sliding platform On the land side of the bridge adjacent to the waterway, a 24m×32.5m integral steel box girder assembly and sliding platform was constructed. The platform foundation uses Φ630×8mm Q235B steel pipe piles as lattice-type columns, with a minimum penetration depth of 12m and a pile top elevation deviation controlled within ±1mm. The columns are reinforced with 16# channel steel for transverse straight bracing and diagonal scissor bracing to form a stable lattice system. Double 40a I-beams are installed at the top of the columns as distribution beams, which are fully welded to the top of the steel pipe piles with a weld height of not less than 10mm.

[0033] Two sets of sliding tracks are laid parallel to each other on the top of the distribution beam. The center-to-center spacing of the tracks is consistent with the spacing of the web plates of the steel box girder. Each set of tracks is formed by welding three HN700×300×13×24mm H-beams. C28 channel steel is fixed upright on the top of the track as a sliding chute, with the chute opening upward. After the tracks are laid, they are finely adjusted using a total station and a level to control the parallelism deviation of the two sets of tracks to ≤2mm, the elevation deviation of the track top surface to ≤1mm, the misalignment at the track joint to ≤0.5mm, and the joint welds to be ground smooth.

[0034] (2) Barge selection and onboard track layout A 1,000-ton deck barge was selected as the transfer carrier. The barge's core parameters are: waterline length 60m, beam 11.5m, effective working area length of the mid-deck 48m, depth 2.7m, average draft when unloaded 0.7m, and design draft of 1.2m after being equipped with a 253t steel box girder. It has 4 independent ballast tanks and can realize zoned injection and drainage control.

[0035] On the barge deck, two sets of identical shipboard sliding tracks are laid, corresponding to the spacing and specifications of the shore-side sliding tracks. The bottom of the tracks uses 32a I-beams as distribution beams and is rigidly welded to the barge deck. The main body of the tracks also uses three-section HN700×300×13×24mm H-beams, with C28 channel steel grooves on the top to ensure that the width of the grooves and the top elevation of the top surface of the shipboard tracks and the shore-side tracks are completely compatible.

[0036] (3) Layout of supporting systems Lifting system: Four FCD-100-200 double-acting hydraulic jacks are selected, each with a rated lifting force of 100t and a stroke of 200mm. They are equipped with a synchronous hydraulic pump station, which can realize the synchronous lifting / lowering of the four jacks with a synchronization error of ≤0.5mm. The jacking system consists of two synchronous hydraulic jacking cylinders with a rated jacking force of 200t, equipped with stroke sensors and a synchronous control system. The jacking speed is infinitely adjustable, and the set operating speed is 6m / h. Ballast water control system: Two 100CBZ-18 self-priming ballast water pumps are selected, with a rated flow of 100m³ / h and a head of 21m per unit, and a total drainage capacity of 200m³ / h. They are equipped with electric control valves and can realize independent / interlocked injection and drainage of four ballast tanks. Monitoring system: Deploys hull tilt monitoring instruments (accuracy 0.01°), track displacement sensors (accuracy 0.1mm), steel box girder stress and strain monitoring plates, and real-time water level monitoring instruments, along with a central control system, to achieve real-time data acquisition and early warning throughout the entire process.

[0037] Step 2: Integral assembly of the entire steel box girder segment on land The steel box girder segments were prefabricated by Wuhu Steel Structure Plant, transported to the construction site by road, unloaded in sections using a 320-ton crawler crane, and assembled into whole segments on an assembly and sliding platform.

[0038] First, set up adjustment pipe supports on the platform, and use the adjustment pipes to finely adjust the elevation and axis of a single steel box girder to ensure that the positioning axis deviation of a single segment is ≤1mm and the top surface elevation deviation is ≤0.5mm. Complete the inter-segment circumferential joint assembly, and use a CO2 gas shielded welding machine for welding. After welding, perform 100% ultrasonic testing + 20% X-ray testing. The first-time inspection pass rate of welding is ≥92%. Parts that fail the testing are reworked and re-inspected. After the welding, flaw detection, and anti-corrosion coating of the entire steel box girder segment are completed, an overall acceptance test is conducted. The deviation of the entire segment axis is controlled to be ≤3mm, the elevation deviation of the top surface of the beam is ≤2mm, and the verticality deviation of the web is ≤1 / 1000. After the acceptance test is passed, the next process begins.

[0039] Step 3: Sliding the steel box girder into position and dynamically connecting it with the ship-shore track. Installation of the steel box girder lifting and sliding bearing device: Four 100t hydraulic jacks are installed at corresponding positions on the web of the steel box girder. The entire steel box girder segment is lifted synchronously and smoothly by 10cm through a synchronous control system. The stress and synchronicity of the beam are monitored throughout the lifting process to avoid beam deformation. After the lifting is completed, the bottom adjusting pipe is removed. At each of the four symmetrical support points at the bottom of the steel box girder, one CRM100 type 100t mobile transport tank (sliding bearing device) is installed. The four tanks are arranged in a rectangular symmetrical pattern, with their centers coinciding with the center of gravity of the steel box girder. The jacks are slowly and synchronously lowered to smoothly place the steel box girder onto the tanks, ensuring that the steel wheels of the tanks are fully embedded in the C28 channel steel groove of the sliding track, with a single-sided gap between the steel wheel and the groove ≤0.5mm. After the beam is lowered, it is checked that the force on each support point is uniform and there is no suspension.

[0040] Dynamic leveling and anchoring of the ship-shore track: First, the barge is towed to the corresponding channel position of the assembly platform and initially positioned using the anchoring system. Water is simultaneously injected into the four ballast tanks of the barge to bring the barge's draft to 1.2m. The elevation of the top surface of the ship-mounted track is monitored in real time using a level instrument, and the water injection volume of each ballast tank is finely adjusted to ensure that the elevation difference between the top surface of the ship-mounted track and the shore-side sliding track is ≤1mm, and the alignment deviation of the track centerline is ≤1mm. After the track is aligned, rigid connecting plates and high-strength bolts are used to rigidly connect the ends of the ship-mounted track and the shore-side track. At the same time, the barge track is auxiliaryly anchored to the platform's steel pipe piles to complete the seamless docking of the ship-shore track. After docking, the smoothness of the track is checked to ensure that there are no misalignments or steps in the chute.

[0041] Step 4: Synchronous jacking and sliding with dynamic hull balance control Preparations before sliding: Weld and fix the jack reaction frame and rear baffle at the end of the sliding track, set the front baffle at the front end of the steel box girder, install limit devices along the entire track, and set anti-impact wedges and travel limit baffles at the front end of the track; conduct joint commissioning and testing of the jacking system, ballast water control system and monitoring system, and start the sliding operation after confirming that all equipment is normal.

[0042] Segmented synchronous jacking and sliding: The steel box girder is pushed along the sliding track towards the barge at a uniform speed of 6m / h through the synchronous hydraulic jacking system. The jacking process adopts segmented operation, and the jacking stroke of each segment is matched with the rated stroke of the jack. After each segment is completed, the operation is paused, and anti-impact safety wedges are set between the steel box girder and the track. After confirming that there is no displacement or deviation, the next segment is jacked.

[0043] Real-time dynamic balance control of the hull: During the sliding process, the load of the steel box girder is gradually transferred from the shore to the barge. For every 12m of sliding, the barge load increases by about 125t, and the hull draft changes. The monitoring system collects data on the hull tilt, track elevation, and draft in real time. The central control system is linked with the ballast water control system, which dynamically adjusts the water injection and drainage of each ballast tank in real time through two ballast water pumps to compensate for the changes in hull attitude caused by load changes. Throughout the process, the hull tilt is maintained at ≤0.1° and longitudinal tilt at ≤0.05°, and the elevation deviation at the docking point between the ship and the shore is always ≤1mm, ensuring smooth track and stable girder throughout the sliding process.

[0044] Sliding into position and locking: After the steel box girder has slid completely to the preset position on the barge deck, the jacking operation is stopped. The steel box girder is temporarily locked by the limiting baffle at the end of the track and the lateral limiting device at both ends of the steel box girder to ensure that the girder has no lateral or longitudinal displacement on the barge.

[0045] Step 5: Secure the steel box girder hull and transfer it by water Hull attitude adjustment and anchor release: Simultaneously drain water into the barge's ballast tanks to raise the hull by 40cm. After verifying that the ship's onboard rails and shore rails are completely separated, release the rigid connection and auxiliary anchoring of the ship's shore rails, and simultaneously release the preliminary preparations for temporary channel control.

[0046] Rigid fixing of steel box girder: Rigid welded components are used to weld and fix the bottom web of the steel box girder to the track distribution beam of the barge deck. The fixing points are symmetrically arranged along the longitudinal direction of the steel box girder, with a total of 8 sets of welding fixing points. The weld length of each set is not less than 30cm, ensuring that the steel box girder and the barge form an integral transportation unit and avoiding displacement or overturning during the transfer process.

[0047] Water transport: Two high-powered tugboats are used to tow and escort the barge from the bow and stern respectively. The transport route is planned in advance and navigation is reported to the waterway management department. The barge carrying the steel box girder is smoothly towed to the waters corresponding to the bridge design axis. After arriving at the designated position, the barge is accurately positioned by the anchoring system with a positioning deviation of ≤50cm.

[0048] Step 6: In-situ hoisting and precise installation of the bridge deck crane Bridge deck crane deployment: Two combined self-propelled bridge deck cranes with a rated lifting capacity of 336t are deployed at the front end of the already erected concrete beam / steel box girder segments of the bridge. The cranes are rigidly fixed to the beam body through the anchoring system. The cranes are tested and loaded to confirm that the lifting system and synchronous lifting system are operating normally.

[0049] Vertical lifting of the entire steel box girder segment: Four symmetrical lifting points are set on the top of the steel box girder, with the lifting point positions coinciding with the center of gravity of the steel box girder. Steel strands are used to connect the lifting points to the hydraulic synchronous lifting system of the bridge deck crane. A trial lift is first carried out, lifting the steel box girder 200mm off the barge deck, then pausing the lifting to check the stability of the crane, the levelness of the steel box girder, and the stress on the lifting equipment. After confirming that everything is correct, the steel box girder is lifted vertically at a uniform speed of 3m / h. During the lifting process, the synchronous control system controls the synchronicity of the lifting of the four lifting points, and the levelness deviation of the steel box girder is ≤2mm throughout the entire process.

[0050] Precise alignment and closure: After the steel box girder is lifted to the design elevation, the axis, elevation, and rotation angle of the steel box girder are finely adjusted using the three-dimensional adjustment device of the bridge deck crane. The axis deviation and elevation deviation are controlled to be ≤1mm and ≤1mm during alignment and closure, and the circumferential joint gap meets the design requirements. After the alignment is completed, the circumferential joint is welded and inspected, and then the lifting equipment is unloaded to complete the smooth transfer of the load system, ultimately achieving the precise installation of the entire steel box girder segment.

[0051] Repeat steps 2-6 above to complete the construction of nine complete steel box girder segments, numbered D1-D9, and finally complete the closure of the entire bridge's steel box girder.

[0052] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A method for integrated construction of whole-segment steel box girder sliding onto a ship and hoisting without the intervention of a floating crane, characterized in that, Includes the following steps: S1: Construction preparation and temporary support system construction: Set up a whole segment steel box girder assembly and sliding platform on the land side of the bridge to be built, and lay two sets of sliding tracks in parallel on the assembly and sliding platform; Select a deck barge of suitable tonnage and lay shipborne sliding tracks of the same specifications and spacing as the shore-side sliding tracks on the barge deck; and install a jacking system, a lifting system, a ballast water control system and a monitoring system. S2: Integral assembly of whole steel box girder segments on land: The steel box girder segments are assembled, welded, inspected and inspected on the assembly and sliding platform to form an integral large steel box girder segment; S3: Sliding and positioning of steel box girder and dynamic docking of ship and shore track: The whole large-segment steel box girder that has passed the acceptance is simultaneously lifted by the jacking system. After the sliding bearing device is set up at the bottom of the steel box girder, the girder is lowered so that the sliding bearing device is embedded in the sliding groove of the sliding track. The ballast water system of the barge is adjusted to make the elevation and flatness of the ship-mounted sliding track consistent with the shore sliding track, and the rigid anchoring docking of the ship and shore track is completed. S4: Synchronous jacking and sliding with dynamic balance control of the hull: The synchronous jacking system is used to push the steel box girder along the sliding track to slide towards the barge at a set speed. During the sliding process, the water injection and discharge of the barge's ballast tanks are dynamically adjusted in real time through the ballast water control system to compensate for the changes in the hull's draft caused by the load transfer of the steel box girder. The horizontal docking accuracy of the ship-shore track is maintained throughout the process until the steel box girder slides to the preset position of the barge. S5: Steel box girder hull fixing and water transport: After the steel box girder is slid into place, the ballast water of the barge is adjusted to raise the hull, the anchoring connection of the ship-shore track is released, and the steel box girder is rigidly fixed to the barge deck to form an integral transport unit; the steel box girder is transported to the bridge site water area corresponding to the bridge design axis by tugboat towing the barge. S6: In-situ hoisting and precision installation of bridge deck cranes: Self-propelled bridge deck cranes are deployed on the already erected beam segments of the bridge to be built. The bridge deck cranes vertically lift the entire steel box girder segment from the barge to the design elevation. After the attitude is adjusted, the girder is precisely aligned and connected with the already erected beam segment, realizing the integrated construction of the entire steel box girder segment from land assembly to water transfer and high-altitude installation without floating cranes.

2. The integrated construction method for sliding and hoisting a whole segment of steel box girder onto a ship without the intervention of a floating crane, as described in claim 1, is characterized in that... In step S1, the assembled sliding platform uses Φ630×8mm steel pipe piles as lattice columns, and the columns are reinforced with straight and diagonal braces made of 16# channel steel. Double-segmented 40a I-beam distribution beams are set on the top of the columns. The sliding track and the ship-mounted sliding track are both made of three-segmented HN700×300×13×24mm H-beams. C28 channel steel is fixed on the top of the track as a sliding chute. The parallelism deviation of the two sets of sliding tracks is ≤2mm, and the top surface elevation deviation is ≤1mm.

3. The integrated construction method for sliding and hoisting a whole segment of steel box girder onto a ship without the intervention of a floating crane, as described in claim 1, is characterized in that... In step S1, the lifting system uses four hydraulic jacks with a single lifting force ≥100t and a stroke ≥200mm; the jacking system uses a synchronous hydraulic jacking device with an adjustable jacking speed range of 3-8m / h; the ballast water control system uses two parallel 100CBZ-18 self-priming ballast water pumps with a single pump flow rate ≥100m³ / h and a total displacement ≥200m³ / h; the monitoring system includes a hull tilt monitoring unit, a track displacement monitoring unit, a steel box girder stress monitoring unit, and a water level monitoring unit.

4. The integrated construction method for sliding and hoisting a whole segment of steel box girder onto a ship without the intervention of a floating crane, as described in claim 1, is characterized in that... In step S2, the overall large segment steel box girder is a steel box girder segment with a single section length ≥12m and a weight ≥200t. During the assembly process, circumferential welding, non-destructive testing and anti-corrosion coating are completed between the segments. After the assembly is completed, the axial deviation of the steel box girder is ≤3mm and the elevation deviation of the top surface of the beam segment is ≤2mm.

5. The integrated construction method for sliding and hoisting a whole segment of steel box girder onto a ship without the intervention of a floating crane, as described in claim 1, is characterized in that... In step S3, the sliding bearing device uses four mobile transport tanks with a rated load capacity of ≥100t each. The four transport tanks are symmetrically arranged at the web position at the bottom of the steel box girder. The steel wheels of the transport tanks are embedded in the grooves of the sliding track, and the gap between the steel wheel and the groove on one side is ≤0.5mm. After the ship-shore track is connected, rigid connectors are used to anchor the ship-mounted sliding track to the shore-side sliding track and the steel pipe piles of the assembly platform. After anchoring, the misalignment at the track connection point is ≤1mm.

6. The integrated construction method for sliding and hoisting a whole segment of steel box girder onto a ship without the intervention of a floating crane, as described in claim 1, is characterized in that... In step S4, the uniform speed of the jacking and sliding is set to 6 m / h. The sliding process adopts segmented jacking, and the stroke of each segment is matched with the rated stroke of the hydraulic jack. After each segment of jacking is completed, anti-impact safety wedges are set between the sliding track and the steel box girder. During the sliding process, based on the real-time data of the ship's draft, tilt, and track elevation collected by the monitoring system, the ballast water control system is used to synchronously inject and drain water in real time to maintain the ship's heel ≤0.1°, trim ≤0.05°, and the elevation deviation at the docking point of the ship and shore track is always ≤1 mm.

7. The integrated construction method for sliding and hoisting a whole segment of steel box girder onto a ship without the intervention of a floating crane, as described in claim 1, is characterized in that... In step S4, after the steel box girder is slid to the preset position on the barge, the steel box girder is temporarily locked laterally and longitudinally by the limiting baffle. In step S5, the barge ballast water is discharged to raise the hull by ≥40cm. After the anchoring of the ship-shore track is released, the bottom of the steel box girder is welded and fixed to the support structure of the barge deck using rigid welded parts. The welding and fixing points are symmetrically arranged along the longitudinal direction of the steel box girder and there are no less than 4 sets.

8. The integrated construction method for sliding and hoisting a whole segment of steel box girder onto a ship without the intervention of a floating crane, as described in claim 1, is characterized in that... In step S6, the rated lifting capacity of the self-propelled bridge deck crane is ≥350t. The bridge deck crane is fixed to the front end of the bridge beam segment that has been erected through an anchoring system. The lifting points are symmetrically arranged with the center of gravity of the steel box girder. During the lifting process, a steel strand hydraulic synchronous lifting system is used for vertical lifting. The horizontal deviation of the steel box girder during the lifting process is ≤2mm. After being lifted to the design elevation, the posture of the steel box girder is finely adjusted by a three-dimensional adjustment device. The axial deviation and elevation deviation during the connection are ≤1mm.

9. The integrated construction method for sliding and hoisting a whole segment of steel box girder onto a ship without the intervention of a floating crane, as described in claim 1, is characterized in that... The quality control throughout the construction process complies with the requirements of the "Technical Specification for Construction of Highway Bridges and Culverts" JTG / TF50-2020, the "Code for Acceptance of Construction Quality of Steel Structures" GB50205-2020, and the "Code for Manufacturing and Installation of Highway Steel Structure Bridges" JTG / T3651-2022; the first-time pass rate for welding of steel box girders is ≥92%, the first-time pass rate for unit assembly is ≥93%, and the first-time pass rate for inspection is ≥98%.

10. The integrated construction method for sliding and hoisting a whole segment of steel box girder onto a ship without the intervention of a floating crane, as described in claim 1, is characterized in that... The sliding operation in step S4 and the hoisting operation in step S6 both avoid adverse working conditions such as strong winds, rain, strong sunlight and excessive water level fluctuations. During the sliding operation, the waterway is temporarily controlled, and warning signs and warning vessels are set up in the operation area. Safety nets and fall protection devices are set up throughout the high-altitude assembly and hoisting operation areas, and all special operation personnel are certified to work.

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