A method for rapid assembly of ultra-wide steel box girder

Abstract

The present application relates to a kind of methods for the rapid assembly of ultra-wide steel box girder, the method comprises: S1: steel box girder is longitudinally divided into multiple total assembly segments, each segment is transversely divided into multiple prefabricated module units;S2: rigid total assembly platform with multiple independent work areas is constructed, each work area support surface is preset target linear, and is configured to be synchronously operated;S3: different segment modules are hoisted to different work areas, and the module assembly of each segment is completed synchronously, internal weld welding and detection, form stable unit;S4: the segment of ground shaping is hoisted to bridge location as a whole, and initial positioning is realized using port orientation alignment device, only weld ring seam between segments;S5: repeat operation until closure.The present application realizes the efficient, high-precision, high-quality assembly construction of ultra-wide steel box girder by parallel ground total assembly, integral hoisting and fine closure.

Description

Technical Field

[0001] This invention belongs to the field of bridge engineering technology, specifically relating to a method for rapid assembly of ultra-wide steel box girders. Background Technology

[0002] Ultra-wide steel box girders, as a common load-bearing structure in long-span bridges, especially cable-stayed and suspension bridges, have large cross-sectional widths and high structural weights. Traditionally, their construction employs a "segmented manufacturing and high-altitude segmental assembly" method. This method involves setting up a single assembly station at the bridge site, sequentially completing the high-altitude hoisting, positioning, matching, and welding of each girder segment. Due to limited workspace, the assembly of each segment proceeds linearly, with close process connections but a long overall construction period. Furthermore, a large amount of welding and testing work must be completed at height, significantly affected by environmental wind and temperature, making quality control difficult and posing high construction safety risks. As bridge engineering develops towards wider and longer spans, the traditional single-workspace, high-altitude-based organizational model is no longer sufficient to meet the comprehensive requirements of efficiency, precision, and safety in modern engineering.

[0003] Existing construction methods face the following prominent problems when dealing with ultra-wide steel box girders: First, the workload at height is substantial, and the conditions for circumferential and internal welds are poor, making them susceptible to weather conditions and difficult to guarantee quality stability. Second, the construction process is sequential, with strong inter-segment dependencies, making parallel operations difficult and hindering the improvement of construction speed. Third, adjustments after the wide girder is hoisted into place are difficult, and alignment accuracy control relies on manual experience and repeated measurements, resulting in low efficiency and easy accumulation of errors. Although some technologies have attempted to use partial ground pre-assembly or modular hoisting, the coordination issues between simultaneous construction on multiple work surfaces, overall ground forming, and rapid high-altitude precision assembly have not yet been systematically resolved.

[0004] Therefore, this invention proposes a method for rapid assembly of ultra-wide steel box girders to at least partially solve the above-mentioned problems. Summary of the Invention

[0005] To address the aforementioned problems in the existing technology, this invention provides a method for the rapid assembly of ultra-wide steel box girders, which solves the technical difficulties of low work efficiency, difficulty in controlling forming accuracy, and high welding quality and safety risks in traditional high-altitude segmented assembly methods.

[0006] The objective of this invention can be achieved through the following technical solutions: A method for rapid assembly of ultra-wide steel box girders includes the following steps: Step S1: Modular design and segment division: Based on transportation conditions and hoisting capacity, the ultra-wide steel box girder is divided into N general assembly segments along the longitudinal direction. Each general assembly segment is divided into M prefabricated module units in the transverse direction, where N≥2 and M≥3. Step S2: Parallel assembly platform construction: A rigid assembly platform with multiple independent working areas is set up on the construction side of the bridge site. The support surface of each working area is preset with the target bridge alignment. The multiple independent working areas are configured to allow at least two assembly segments to be assembled simultaneously. Step S3: Ground synchronous forming and inspection: The prefabricated module units corresponding to different assembly segments are hoisted to different independent working areas of the assembly platform to form at least two parallel working surfaces. On each working surface, the module assembly of the corresponding assembly segment, the welding of all internal welds and non-destructive testing are completed simultaneously, so that each assembly segment is independently formed on the ground into a stable unit with overall hoisting rigidity. Step S4: Overall hoisting and high-altitude precision assembly: Using a multi-point synchronous lifting system, any pre-formed segment on the ground is hoisted to the bridge site. The segment is then quickly initially positioned by using a pre-set guide alignment device that matches the pre-installed beam segment. After fine-tuning, only the circumferential weld between the segments is completed. Step S5: Cyclic Operation and Closure: Repeat steps S3 and S4 until the installation and closure of all assembled segments are completed.

[0007] As a preferred technical solution of the present invention, the assembly platform in step S2 is equipped with a computer-controlled hydraulic synchronous adjustment system in each independent working area, which is used to dynamically adjust and maintain the elevation of each support point according to preset alignment data, so as to accurately control the position of the assembly segment on it.

[0008] As a preferred technical solution of the present invention, in step S3, the first reference assembly segment is formed in an independent work area; and the measured geometric parameters of the reference segment are used as the initial reference for subsequent adjustments. Before the assembly operation of the reference segment is completed, the parallel assembly operation of subsequent assembly segments in other independent work areas is started.

[0009] As a preferred technical solution of the present invention, in step S4, the mutually matching guiding and alignment device includes a guide pin disposed at one port and a sleeve with a tapered guide surface disposed at the other port. During the overall hoisting process, the automatic initial alignment of the segment ports in the horizontal and vertical directions is achieved by the meshing of the guide pin and the sleeve.

[0010] As a preferred technical solution of the present invention, in step S1, the division of the prefabricated module units ensures that the longitudinal interface between modules avoids the maximum bending moment area of ​​the lane plate under wheel load and is located near the transverse diaphragm or main stiffening rib.

[0011] As a preferred technical solution of the present invention, in step S3, the same welding process and sequence database are used to control the welding of each assembly segment on each independent working area of ​​the assembly platform, so as to ensure the consistency of mechanical properties of segments produced from different working surfaces.

[0012] As a preferred technical solution of the present invention, the overall hoisting process in step S4 and the ground assembly process in step S3 share the same real-time measurement feedback system based on total station network and 3D modeling software. This system is used to control the forming accuracy in step S3 and to guide the aerial attitude adjustment and fine-tuning in place in step S4.

[0013] As a preferred technical solution of the present invention, the real-time measurement feedback system uses the measured three-dimensional coordinates of the terminal interface of each ground forming assembly segment in step S3 as the preset target value for its corresponding high-altitude alignment fine-tuning in step S4.

[0014] As a preferred technical solution of the present invention, in step S5, the overall assembly and hoisting welding of the closure section are arranged to be completed in a concentrated manner during the stable nighttime temperature period when the day-night temperature difference has the least impact on the structural length.

[0015] The beneficial effects of this invention are as follows: By constructing a modular design and a parallel assembly platform, traditional high-altitude sequential operations are transformed into parallel construction on multiple ground work surfaces, significantly shortening the overall construction period; with the help of a rigid platform with a pre-defined alignment and a hydraulic synchronous adjustment system, combined with real-time measurement feedback from a total station network, high-precision geometric control is achieved throughout the entire process of ground assembly and high-altitude precision joining, effectively ensuring the bridge alignment and structural dimensions; most welding and inspection work is completed in a stable ground environment, which not only significantly reduces the safety risks of high-altitude operations but also ensures the uniformity and reliability of weld quality; the combination of the guiding alignment device and the overall hoisting greatly simplifies the high-altitude alignment process and improves installation efficiency; at the same time, through optimized design of interface positions, application of standardized welding processes, and scientific selection of closure timing, the rationality of structural stress and the final closure accuracy are further ensured, thereby comprehensively improving the efficiency, quality, safety, and cost control of ultra-wide steel box girder construction. Attached Figure Description

[0016] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0017] Figure 1 This is a schematic diagram of the assembly process of the present invention. Detailed Implementation

[0018] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided.

[0019] Please see Figure 1 This embodiment provides a method for the rapid assembly of ultra-wide steel box girders. The core of this method lies in transforming the traditional sequential operations, primarily performed at high altitudes, into parallel operations on the ground through innovative construction organization and high-precision control technology. This enables rapid and precise high-altitude closure, thereby comprehensively improving the assembly efficiency, forming quality, and construction safety of ultra-wide steel box girders. The main steps include: First, step S1 involves modular design and segment division. During the detailed design phase, the size limitations for component transportation, the maximum lifting capacity of on-site hoisting equipment, and the structural stress characteristics are comprehensively considered. The entire ultra-wide steel box girder main structure of the bridge is divided into N (N≥2) independent prefabricated segments along the longitudinal direction of the bridge. Due to their large width, each prefabricated segment is further divided into M (M≥3) prefabricated modular units along the transverse direction of the bridge to facilitate manufacturing, transportation, and ground assembly. This division principle requires meticulous design. For example, it ensures that the longitudinal splicing interfaces between modular units avoid areas of maximum bending moment in the lane slabs under vehicle wheel loads, and that the interface locations are placed near transverse diaphragms or main longitudinal stiffeners as much as possible to facilitate structural force transfer and ensure the integrity and reliability of the structure at the interface.

[0020] Secondly, step S2 involves constructing a parallel assembly platform. A large, sufficiently rigid assembly platform is pre-constructed on one side of the bridge construction site. This platform is not a single working surface but is divided into multiple independent working areas. The support surfaces of each independent working area can be pre-set according to the final target alignment data of the bridge design, for example, by arranging adjustable support seats. Crucially, the platform is configured to allow at least two assembly segments to be assembled simultaneously and independently in different working areas, thus achieving parallel construction across multiple working surfaces. To achieve high-precision control, a computer-controlled hydraulic synchronous adjustment system can be installed beneath each independent working area. This system can dynamically and synchronously adjust the height of each support point within the working area based on the input preset alignment data, thereby precisely controlling the three-dimensional pose of the assembly segments located on it during the assembly process. This three-dimensional pose includes elevation and slope, laying the foundation for subsequent precise high-altitude alignment.

[0021] Next, step S3 involves simultaneous ground forming and testing. The prefabricated modular units are transported to their respective independent work areas on the assembly platform, according to the assigned assembly segments. This creates at least two parallel construction work surfaces. On each work surface, the modular assembly, adjustment, and fixing of their respective assembly segments are carried out simultaneously. Subsequently, concentrated efforts are made to complete the welding of all welds within that segment (inter-module welds, stiffening rib welds, etc.), followed by non-destructive testing such as ultrasonic testing and radiographic testing. It is recommended that all welding processes be controlled using a unified and validated welding process and sequence database in each work area to ensure a high degree of consistency in the mechanical properties of products from different work surfaces and segments, such as weld strength and toughness. Through this series of processes, each assembly segment is fully formed on the ground and passes inspection, becoming an independent unit with sufficient overall rigidity and dimensional stability, fully meeting the requirements for overall hoisting. In practice, the first "base assembly segment" can be formed and accurately measured in a work area. Its final measured geometric parameters (such as the three-dimensional coordinates of the port) can be used as the initial reference for the alignment adjustment of parallel assembly segments in other work areas. This allows subsequent segments to begin parallel assembly even before the base segment is lifted, greatly reducing the waiting time for the process.

[0022] Then, step S4 involves overall hoisting and high-altitude precision assembly. Once a complete assembly segment has completed all procedures and passed acceptance on the ground, it can proceed to the hoisting stage. Using large gantry cranes or floating cranes, and equipped with a multi-point synchronous lifting system, the entire formed segment is smoothly and horizontally hoisted to the designed position on the bridge site. To significantly reduce the difficulty and time of high-altitude alignment adjustments, matching guide alignment devices are pre-installed at the docking ports of the segment to be installed and the installed beam segment. For example, a guide pin is set at one end port, and a sleeve with a tapered guide surface is set at the corresponding position at the other end. During the hoisting and descent process, the automatic engagement of the guide pin and the tapered sleeve allows for rapid initial positioning of the two segment ports in both the horizontal and vertical directions. Subsequently, a real-time measurement feedback system connecting ground and high-altitude operations, typically built based on a total station network and 3D modeling software, is used to fine-tune the segment's attitude. During the ground assembly stage, this system monitors and controls the forming accuracy, recording the precise three-dimensional coordinates of the terminal interfaces of each formed segment. During the aerial hoisting stage, it monitors the aerial attitude of the hoisted segments in real time and guides operators to adjust them to the target position, which is based on the interface coordinates measured during ground forming. After fine-tuning and positioning, temporary connections are immediately made, followed by only the circumferential welding of the interface between the two segments, significantly reducing the amount of welding work at high altitude.

[0023] Finally, step S5 involves cyclical operations and closure. The "ground forming – overall hoisting" cycle of steps S3 and S4 is repeated, with all assembly segments installed sequentially or in alternation. Special arrangements are required for the construction of the last closure segment. Typically, its ground assembly and hoisting welding operations are scheduled to be completed quickly and efficiently during a specific nighttime period when the impact of diurnal temperature variations on the steel structure's length is minimal and the temperature field is most stable. This effectively controls structural expansion and contraction caused by temperature changes, ensuring the precision and quality of the final closure.

[0024] Through the above specific implementation methods, the method of the present invention organically combines modularization, parallel operation, ground integral forming, intelligent precision control and rapid high-altitude alignment technologies, systematically solving a series of problems in traditional methods such as low efficiency, difficulty in precision control and high risk of high-altitude operation, and realizing safe, high-quality and efficient assembly and construction of ultra-wide steel box girders.

[0025] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for rapid assembly of ultra-wide steel box girders, characterized in that, Includes the following steps: Step S1: Modular design and segment division: Based on transportation conditions and hoisting capacity, the ultra-wide steel box girder is divided into N general assembly segments along the longitudinal direction. Each general assembly segment is divided into M prefabricated module units in the transverse direction, where N≥2 and M≥3. Step S2: Parallel assembly platform construction: A rigid assembly platform with multiple independent working areas is set up on the construction side of the bridge site. The support surface of each working area is preset with the target bridge alignment. The multiple independent working areas are configured to allow at least two assembly segments to be assembled simultaneously. Step S3: Ground synchronous forming and inspection: The prefabricated module units corresponding to different assembly segments are hoisted to different independent working areas of the assembly platform to form at least two parallel working surfaces. On each working surface, the module assembly of the corresponding assembly segment, the welding of all internal welds and non-destructive testing are completed simultaneously, so that each assembly segment is independently formed on the ground into a stable unit with overall hoisting rigidity. Step S4: Overall hoisting and high-altitude precision assembly: Using a multi-point synchronous lifting system, any pre-formed segment on the ground is hoisted to the bridge site. The segment is then quickly initially positioned by using a pre-set guide alignment device that matches the pre-installed beam segment. After fine-tuning, only the circumferential weld between the segments is completed. Step S5: Cyclic Operation and Closure: Repeat steps S3 and S4 until the installation and closure of all assembled segments are completed.

2. The method for rapid assembly of ultra-wide steel box girders according to claim 1, characterized in that, The assembly platform in step S2 is equipped with a computer-controlled hydraulic synchronous adjustment system in each independent working area. This system dynamically adjusts and maintains the elevation of each support point according to preset alignment data, so as to precisely control the position and posture of the assembly segments on it.

3. The method for rapid assembly of ultra-wide steel box girders according to claim 1, characterized in that, In step S3, the first reference assembly segment is formed in an independent work area; and the measured geometric parameters of the reference segment are used as the initial reference for subsequent adjustments. Before the assembly operation of the reference segment is completed, the parallel assembly operation of subsequent assembly segments in other independent work areas is started.

4. A method for rapid assembly of ultra-wide steel box girders according to claim 1, characterized in that, In step S4, the mutually matching guiding and alignment device includes a guide pin disposed at one port and a sleeve with a tapered guide surface disposed at the other port. During the overall hoisting process, the segment ports are automatically initially aligned horizontally and vertically through the engagement of the guide pin and the sleeve.

5. A method for rapid assembly of ultra-wide steel box girders according to claim 1, characterized in that, In step S1, the division of the prefabricated module units ensures that the longitudinal interfaces between modules avoid the maximum bending moment area of ​​the lane plate under wheel load and are located near the diaphragm or main stiffening rib.

6. A method for rapid assembly of ultra-wide steel box girders according to claim 1, characterized in that, In step S3, the same welding process and sequence database are used to control the welding of each assembly segment in each independent work area of ​​the assembly platform, so as to ensure the consistency of mechanical properties of segments produced from different work surfaces.

7. A method for rapid assembly of ultra-wide steel box girders according to claim 1, characterized in that, The overall hoisting process in step S4 and the ground assembly process in step S3 share the same real-time measurement feedback system based on total station network and 3D modeling software. This system is used to control the forming accuracy in step S3 and to guide the aerial attitude adjustment and fine-tuning in place in step S4.

8. A method for rapid assembly of ultra-wide steel box girders according to claim 7, characterized in that, The real-time measurement feedback system uses the measured three-dimensional coordinates of the terminal interface of each ground forming assembly segment in step S3 as the preset target value for its corresponding high-altitude alignment fine-tuning in step S4.

9. A method for rapid assembly of ultra-wide steel box girders according to claim 1, characterized in that, In step S5, the assembly and hoisting welding of the closure section are scheduled to be completed intensively during the stable nighttime temperature period when the day-night temperature difference has the least impact on the structural length.

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