Construction process of super large offshore anti-collision steel jacket and steel jacket

Abstract

The application relates to the field of ocean engineering, and provides a super-large offshore anti-collision steel jacket construction process and a steel jacket. One of the super-large offshore anti-collision steel jacket construction processes comprises the following steps: intelligent modeling and process optimization; modular segmentation and deformation control; intelligent corrosion prevention and quality control; and total assembly precision control. The application has the effect of utilizing intelligent modeling and segmented manufacturing and providing an efficient corrosion prevention process to meet the anti-collision requirements of a cross-sea.

Description

Technical Field

[0001] The present application relates to the field of marine engineering, and in particular to a construction process and a super-large marine anti-collision steel casing. Background Art

[0002] With the rapid development of my country's infrastructure, the construction of large bridges across rivers and seas has increased significantly. To facilitate the construction of deep-water foundations and reduce bridge construction costs, anti-collision box cofferdams have been widely used.

[0003] Some cross-sea bridges have long-term anti-collision needs. When using traditional steel casings for anti-collision, there are problems such as large spans required and rough anti-corrosion technology required for seawater, resulting in insufficient durability, difficulty in controlling welding deformation, and poor adaptability of parts. Summary of the Invention

[0004] In order to improve the above-mentioned problems, the present application provides a super-large offshore anti-collision steel casing construction process and a steel casing.

[0005] The present application provides a super-large offshore anti-collision steel casing construction process and a steel casing adopting the following technical solutions:

[0006] A process for constructing an ultra-large offshore anti-collision steel casing comprises the following steps:

[0007] Intelligent modeling and process optimization: Using Tekla software to build a BIM model of the steel casing, the segmented design was optimized through virtual pre-assembly. Digital twin technology was used to preview the construction process, optimize the welding sequence and cradle layout, and generate process animations to guide construction briefings.

[0008] Modular segmentation and deformation control: The steel casing is layered according to function and manufactured in sections using a circular arc frame. Pre-arch technology is used to offset welding shrinkage, enabling block-by-block assembly line processing of the steel casing. CO2 gas shielded welding and submerged arc automatic welding are used, along with a real-time monitoring system for welding parameters.

[0009] Intelligent anti-corrosion and quality control: Epoxy glass flake paint + acrylic polysiloxane topcoat are used for double-layer anti-corrosion, combined with automated spraying equipment to control film thickness errors; magnetic thickness gauges and adhesion testers are used to monitor coating quality online, and data is uploaded to the cloud management platform simultaneously;

[0010] Overall assembly precision control: accurately lay out the ground sample line on the tire frame, use the external arc as the base surface to locate the segment, and combine laser calibration technology to control the assembly error; after the segment is completed, a hydraulic flip machine is used to adjust the posture to ensure the interface matching accuracy during vertical overall assembly, and intelligent acceptance is carried out after the overall assembly.

[0011] By adopting the above technical solution and the above manufacturing process, intelligent modeling is used to preset a segmented pre-assembly structure, reduce part collisions, improve the interface accuracy of welding, and cooperate with digital twin technology to optimize the welding sequence and tire frame layout, improve the stable splicing and design accuracy of the overall steel casing, save consumables, and improve material utilization. At the same time, it can reduce labor costs. After intelligent optimization, the steel casing can be processed on a block line through segmented manufacturing to shorten the construction period. The pre-assembled segments after segmented manufacturing are fully welded through an automated welding process to reduce welding deformation. Through intelligent anti-corrosion and quality control, the steel casing can be set in the sea. The erosion of seawater on the steel casing can be stably reduced, and the anti-corrosion life is extended. After anti-corrosion, the pre-assembly segments are fully assembled through the layout positioning method and the block turning and erecting process. Intelligent early warning reduces operational risks, and the overall error value is reduced through intelligent acceptance and model comparison at the intelligent modeling site.

[0012] Optionally, the construction process of the pre-assembly section of the steel casing includes the following procedures: material delivery; steel plate pretreatment; CNC cutting; tooling frame layout; segmented production; auxiliary structure installation; and overall splicing.

[0013] By adopting the above technical solution, after the materials are delivered to the site, they will be sorted and classified, and the processes such as steel plate pretreatment, CNC cutting, and tooling frame layout will be carried out simultaneously. The steel plate pretreatment may include sandblasting, anti-corrosion treatment, etc. CNC cutting is through design drawings, and the design drawings are used for computer modeling and process analysis to determine the distribution, installation, welding points, etc. of the materials. The layout of the tooling frame is site layout to provide a suitable and accurate site for processing or assembly. After the above is completed, segmented production and auxiliary structure installation are carried out to complete the production of the pre-spliced ​​section of the steel casing, and finally the overall splicing is completed to complete the construction.

[0014] Optionally, the steel plate pretreatment is sandblasting to remove rust on the steel plate. The sandblasting construction is carried out in a relatively closed sandblasting room, and sufficient ventilation and lighting are guaranteed.

[0015] By adopting the above technical solution, the steel plate is pre-treated to ensure that the anti-corrosion material applied can fully fit when it is anti-corrosion, ensuring the stable spraying of the anti-corrosion coating.

[0016] Optionally, the following steps are adopted in the CNC blanking process: computer modeling and theoretical determination of dimensions; processability analysis to determine welding, processing compensation amounts, and linear adjustment amounts; part blanking size determination; group analysis; CNC blanking, computer-generated part blanking nesting diagram; CNC programming, material utilization analysis, and final blanking.

[0017] By adopting the above technical solution and through the CNC cutting process, the cutting and blanking of the steel plate is accurately determined by the computer, and the cutting size is determined through process analysis to ensure the accuracy and adaptability of the steel plate size.

[0018] Optionally, during the layout of the tooling tyre frame, the tyre frame is arranged on a hardened concrete ground with good bearing capacity; the main axis of the steel casing is laid out in sections on the ground according to the steel casing, and the axis elevation of each curved surface position is measured along the main axis; the tyre frame material is cut according to the measured results.

[0019] By adopting the above technical solution, the tooling cradle is arranged according to the precise axis to further confirm the accuracy of the cradle erection and ensure that it can stably bear the pre-assembled section of the steel casing.

[0020] Optionally, segment production is divided into segment block division and segment assembly.

[0021] By adopting the above technical solution, the segment blocks are divided according to shape and function and then assembled in sections. The section assembly assembles the segment blocks into various pre-assembled sections. The section assembly can assemble multiple groups of positions at the same time to improve assembly efficiency.

[0022] Optionally, in the segmented assembly, the segment blocks of the steel casing need to be assembled, and the segment blocks include outer wall panels, inner wall panels, transverse partitions, ring panels, partitions and reinforcing ribs; the tooling frame is marked with a layout line according to the layout size of the outer wall panels, and the outer wall panels are laid along the marking line; after the outer wall panels are installed, the plate units of the ring panels, inner partitions and reinforcing ribs are positioned and installed in sequence according to the layout axis; the inner wall panels are made into a plate unit structure, the reinforcing ribs and the inner wall panels are pre-assembled and welded, and the inner wall panels are adjusted to the tooling frame. After the tire frame is installed, the edges of the steel plates are fixed with fixing clamps around them so that the steel plates fit the tire frame template, thereby increasing the pre-arch of the plate units before welding to control welding deformation. The production of the inner wall plate units is carried out simultaneously with the welding of the outer wall plates and the internal structure of the partitions. After the welding of the internal structure of the outer wall plates of the steel casing is completed, the plate units of the inner wall plates are assembled in sequence according to the layout positioning reference line; the partition plate units and the reinforcing ribs are fixed to the outer wall plates in sections by jump welding. After the rib welding is completed, the outer wall plates are welded.

[0023] By adopting the above technical solution, according to the assembly and welding of the above segment blocks, laying and assembling strictly according to the marking lines, the amount of welding in a limited space can be reduced, while the production efficiency can be improved, the error value can be reduced, and a complete pre-assembled segment can be formed.

[0024] Optionally, after the plate units of the inner wall panel are assembled according to corresponding sizes, the ring plate and the partition plate are welded to the plate units of the inner wall panel and positioned, and then the auxiliary structure is installed.

[0025] By adopting the above technical solution, all inner wall plates, ring plates and partitions are welded before the auxiliary structures are installed and welded, thereby avoiding pre-welding of the auxiliary structures so that the auxiliary structures do not hinder the installation of other structures.

[0026] Optionally, an ultra-large offshore anti-collision steel casing, the steel casing is made of segment blocks generated by segment production, and the segment blocks are assembled into pre-assembled segments, and then the pre-assembled segments are assembled into complete anti-collision steel casing by overall assembly; it includes a bottom mold, a side mold and a pre-assembled segment; the bottom mold is placed on a preset tooling saddle, and the side mold is placed on the bottom mold; on the basis of the bottom mold, the pre-assembled segment is vertically assembled; the pre-assembled segment can be divided into curved steel casing segments and straight steel casing segments according to shape; the curved steel casing segments are divided into four groups, namely the first curved box, the second curved box, the third curved box and the fourth curved box; the straight steel casing segments are divided into four groups, namely the first straight box, the second straight box, the third A straight-surface box and a fourth straight-surface box; the order of vertical assembly is: the first straight-surface box is assembled vertically with the second straight-surface box, and the third straight-surface box is assembled vertically with the fourth straight-surface box; after the first curved-surface box and the second curved-surface box are assembled vertically, the end of the first curved-surface box away from the second curved-surface box is assembled vertically with the first straight-surface box, and the end of the second curved-surface box away from the first curved-surface box is assembled vertically with the third straight-surface box; after the third curved-surface box and the fourth curved-surface box are assembled vertically, the end of the third curved-surface box away from the fourth curved box is assembled vertically with the second straight-surface box, and the end of the fourth curved box away from the third curved box is assembled vertically with the fourth straight-surface box; after the vertical assembly is completed, the bottom mold is hung and installed with the auxiliary structure.

[0027] By adopting the above technical solution, after the pre-assembly segment is divided into eight segments, the pre-assembly segment is accurately assembled using the limit of the bottom mold and the side mold. According to a specific assembly sequence, the steel casing is gradually formed and the assembly accuracy is high, which facilitates the subsequent welding process and speeds up the overall assembly efficiency.

[0028] Optionally, the thickness of the connection between the first curved box and the second curved box is greater than the thickness of the connection between the first curved box and the first straight box or the second curved box and the third straight box; the thickness of the connection between the third curved box and the fourth curved box is greater than the thickness of the connection between the third curved box and the second straight box or the fourth curved box and the fourth straight box.

[0029] By adopting the above technical solution, the connection points between the first curved box and the second curved box, and between the third curved box and the fourth curved box are directly exposed to the scouring of waves, and using a thicker thickness can improve the pressure resistance to scouring.

[0030] In summary, this application includes at least one of the following beneficial technical effects:

[0031] Through the above manufacturing process, intelligent modeling is used to preset a segmented pre-assembly structure, reduce part collisions, improve the interface accuracy of welding, and cooperate with digital twin technology to optimize the welding sequence and tire frame layout, improve the overall stable splicing and design accuracy of the steel casing, save consumables, and improve material utilization. At the same time, it can reduce labor costs. After intelligent optimization, the steel casing is processed on a block line through segmented manufacturing to shorten the construction period. The pre-assembled segments after segmented manufacturing are fully welded through an automated welding process to reduce welding deformation. Through intelligent anti-corrosion and quality control, the steel casing can be set in the sea. The erosion of seawater on the steel casing can be stably reduced, and the anti-corrosion life is extended. After anti-corrosion, the pre-assembly segments are fully assembled through the layout positioning method and the block turning and erecting process. Intelligent early warning reduces operational risks, and the overall error value is reduced through model comparison at the intelligent acceptance and intelligent modeling. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of the three-dimensional structure of the anti-collision steel casing in one embodiment of the present application;

[0033] Figure 2 This is a schematic diagram of the top view of the anti-collision steel casing in some embodiments of the present application;

[0034] Figure 3 is a schematic diagram of the process of CNC blanking in some embodiments of the present application;

[0035] Figure 4 is a schematic cross-sectional view of an accessory structure in some embodiments of the present application;

[0036] The marks in the accompanying drawings are: 1. Pre-assembly section, 11. Curved steel casing section, 111. First curved box, 112. Second curved box, 113. Third curved box, 114. Fourth curved box, 12. Straight steel casing section, 121. First straight box, 122. Second straight box, 123. Third straight box, 124. Fourth straight box, 2. Accessory structure, 21. Embedded groove, 22. Pivot port, 3. Fastening structure, 31. Extension rod, 311. Extension protrusion, 32. Pivot shaft, 33. Fastening bolt. DETAILED DESCRIPTION

[0037] The following describes the embodiments of the present application through specific examples. Those skilled in the art can easily understand the other advantages and effects of the present application from the information disclosed in this application. The present application can also be implemented or applied through different specific embodiments. The details in this application can also be modified or changed according to different viewpoints and application systems without departing from the spirit of this application. It should be noted that the embodiments and features in the embodiments of this application can be combined with each other unless they conflict.

[0038] The following is a detailed description of the embodiments of the present application with reference to the accompanying drawings so that those skilled in the art can easily implement the present application. The present application can be embodied in many different forms and is not limited to the embodiments described herein.

[0039] In the description of this application, reference to the terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of this application. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and integrate different embodiments or examples described in this application, as well as features of different embodiments or examples, unless otherwise contradictory.

[0040] Furthermore, the terms "first" and "second" are used solely to indicate a target and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the context of this application, "plurality" means two or more, unless otherwise specifically defined.

[0041] Throughout this specification, when a device is said to be "connected" to another device, this includes not only "direct connection" but also "indirect connection" with other elements interposed therebetween. Furthermore, when a device is said to "include" a certain component, unless otherwise stated, this does not exclude the inclusion of other components but rather implies that the device may include other components.

[0042] The following is combined with Figure 1 -Attached Figure 4 , further details of this application are given.

[0043] The embodiments of the present application disclose a construction process for an ultra-large offshore anti-collision steel casing and the steel casing.

[0044] A super-large offshore anti-collision steel box construction process, making a reference Figure 1 and Figure 2 The anti-collision steel casing shown includes the following steps:

[0045] Intelligent modeling and process optimization: A BIM model of the steel casing was established based on Tekla software. The segmented design was optimized through virtual pre-assembly to reduce collisions between a large number of parts, thereby improving the accuracy of the welding interface by nearly 30%.

[0046] Combined with digital twin technology, the construction process is rehearsed, the welding sequence and the layout of the cradle are optimized, and process animations are generated to guide construction instructions. Digital twin technology makes full use of physical models, communication emotions, operation history and other data, integrates multi-disciplinary, multi-physical quantities, multi-scale and multi-probability simulation processes, completes mapping in virtual space, and generates process animations. This allows construction personnel to understand the construction instructions more intuitively and clearly, thereby improving construction efficiency and accuracy.

[0047] Modular segmentation and deformation control: The steel casing is layered according to function, such as the main deck, platform plate, bulkhead, etc., and is manufactured in sections using a special arc jig. After the sections are manufactured, pre-assembly sections are formed and then assembled. Through the pre-arch technology, the pre-arch amount can reach 5mm, which fully offsets the welding shrinkage. Multiple arc jigs are synchronously manufactured in sections and then gradually assembled in a unified manner, which speeds up the production efficiency and assembly process, and realizes the block-by-block assembly line processing of the steel casing.

[0048] During welding, through automated welding technology, CO2 gas shielded welding and submerged arc automatic welding are applied, and a real-time monitoring system for welding parameters is used. For example, multi-directional sensors are used to provide real-time data transmission to realize a complete monitoring system. The weld qualification rate can reach more than 99%, ensuring safety and integrity during welding.

[0049] Intelligent anti-corrosion and quality control: During anti-corrosion, after sandblasting to remove rust to Sa2.5 level, a double layer of anti-corrosion is sprayed by robot with epoxy glass flake paint + acrylic polysiloxane topcoat. The dry film of epoxy glass flake paint is 300μm, and the dry film of acrylic polysiloxane topcoat is 130μm. The film thickness error is controlled by automated spraying equipment, and the control error range needs to be less than or equal to ±30μm.

[0050] At the quality control level, it is necessary to monitor the coating quality online through magnetic thickness gauges and adhesion testers to ensure that the film thickness qualification rate reaches more than 95%. The monitored data is also uploaded to the cloud management platform for subsequent review and supervision.

[0051] Overall assembly precision control: Overall assembly means overall splicing. The ground sample line is accurately laid out on a special frame, and the segments are positioned based on the external arc. The laser calibration technology is used to control the assembly error. The control error range needs to be less than or equal to 30mm. After the segment production, the pre-assembled segments need to be turned over and upright. After the segment production is completed, a hydraulic turning machine is used to adjust the posture to ensure the interface matching accuracy during vertical overall assembly, so as to complete the production and splicing of the overall anti-collision steel casing.

[0052] Intelligent acceptance can compare BIM models through laser scanning, correct quality errors ≤ 3mm, and overall flatness deviation ≤ 5mm / m.

[0053] Through the above manufacturing process, intelligent modeling is used to preset a segmented pre-assembly structure, reduce part collisions, improve the interface accuracy of welding, and cooperate with digital twin technology to optimize the welding sequence and tire frame layout, improve the overall stable splicing and design accuracy of the steel casing, save consumables, and improve material utilization. At the same time, it can reduce labor costs. After intelligent optimization, the steel casing is processed on a block line through segmented manufacturing to shorten the construction period. The pre-assembled segments after segmented manufacturing are fully welded through an automated welding process to reduce welding deformation. Through intelligent anti-corrosion and quality control, the steel casing can be set in the sea. The erosion of seawater on the steel casing can be stably reduced, and the anti-corrosion life is extended. After anti-corrosion, the pre-assembly segments are fully assembled through the layout positioning method and the block turning and erecting process. Intelligent early warning reduces operational risks, and the overall error value is reduced through model comparison at the intelligent acceptance and intelligent modeling.

[0054] Furthermore, the construction process of the pre-assembly section of the steel casing includes the following procedures: material delivery; steel plate pretreatment; CNC cutting; tooling frame layout; segmented production; auxiliary structure installation; and overall splicing.

[0055] After the materials are delivered to the site, they will be sorted and classified, and the processes such as steel plate pretreatment, CNC cutting, and tooling frame layout will be carried out simultaneously. Steel plate pretreatment can include sandblasting, anti-corrosion treatment, etc. CNC cutting is through design drawings, and the design drawings are used for computer modeling and process analysis to determine the distribution, installation, welding points, etc. of materials. The layout of the tooling frame is site layout to provide a suitable and accurate site for processing or assembly. After the above is completed, segmented production and auxiliary structure installation are carried out to complete the production of the pre-spliced ​​section of the steel casing, and finally the overall splicing is completed to complete the construction.

[0056] In the material delivery process, materials refer to all materials contained in the steel casing and its auxiliary structures, including steel, welding materials, rubber, and coating materials. The materials used in its manufacturing must comply with the requirements of the design documents and the provisions of current national standards.

[0057] (1) Steel

[0058] The main structure of the casing is made of Q235B material, and its technical requirements comply with the requirements of "Carbon Structural Steel" (GB700-2006).

[0059] (2) Stainless steel bolts and screws

[0060] Stainless steel bolts and screws should comply with the technical requirements of A4 in GB / T3098.6-2014.

[0061] (3) High-strength bolts

[0062] High-strength bolts should comply with the requirements of grade 10.9S in GB / T1228-2006 and be hot-dip galvanized (see GB / T5267.3-2008 for details).

[0063] (4) Welding materials

[0064] Welding materials should be selected through welding procedure qualification tests, and the selected electrodes, flux, and wire should all comply with relevant national standards. The purity of CO2 gas shielded welding should be greater than 99.9%.

[0065] (5) Arch rubber

[0066] The mechanical performance parameters of the arched rubber fender are shown in the table below, which is Table 1:

[0067]

[0068] Table 1 shows the reaction force and energy absorption values ​​per meter of standard rubber fenders. When necessary, the standard values ​​should be multiplied by the actual length to obtain the reaction force and energy absorption values ​​of fenders of various lengths.

[0069] The physical properties of the rubber compound used for fenders are shown in the table below.

[0070] This table is Table 2:

[0071]

[0072] (6) Rubber

[0073] The material technical requirements for rubber parts such as rubber pads and rubber bearings are shown in Table 3 below. The use of recycled rubber or crushed vulcanized rubber is not allowed.

[0074] Table 3:

[0075]

[0076] (7) Heavy-duty anti-corrosion coating materials

[0077] Epoxy glass flake paint is a fast-curing, high-build, wear-resistant epoxy paint reinforced with glass flakes, offering excellent corrosion protection. The addition of glass flakes, which alternate within the paint film, prevents penetration by corrosive chemicals such as water, salt, and oxygen. Furthermore, this high-solids epoxy paint boasts a typical dry film thickness of 200-300 μm after a single application, without cracking. This paint offers outstanding resistance to seawater corrosion and high wear resistance, making it suitable for use in tidal splash zones on steel structures. Its surface treatment also allows for excellent repairability. Its key technical parameters are listed in Table 4.

[0078] Technical requirements for epoxy glass flake paint, Table 4:

[0079]

[0080] Acrylic Polysiloxane Topcoat is a two-component, acrylic-modified polysiloxane high-performance topcoat with excellent gloss and color retention, mechanical properties, and chemical resistance. It is recommended for use in harsh, corrosive environments where gloss and color retention are critical, and can meet high durability and weathering requirements.

[0081] This acrylic polysiloxane topcoat is isocyanate-free, lead-free, and environmentally friendly. With a volume solids content of 65%, it can achieve a film thickness as high as 130μm or as low as 50μm in one application. It can be applied in all seasons at temperatures ranging from 0°C to 40°C. It is lead-free and environmentally friendly. This durable, high-performance topcoat not only resists harsh atmospheric corrosion but also offers a rich palette of colors. Its key technical parameters are listed in Table 5.

[0082] Technical requirements for acrylic polysiloxane topcoat, Table 5:

[0083]

[0084] (8) Composite materials

[0085] Glass fiber multiaxial warp knit fabric (alkali-free): has excellent toughness, tensile strength, and corrosion resistance. The physical and mechanical properties of the steel-clad composite material are shown in Table 6 below.

[0086] Table 6:

[0087]

[0088] (9) Energy-consuming core material

[0089] The energy-absorbing core material should be made of polyurethane closed-cell foam and other materials. The physical and mechanical properties are shown in Table 7.

[0090] Table 7:

[0091]

[0092] (10) Watertight manhole cover

[0093] Watertight manhole covers should comply with the provisions of marine manhole covers (GB11628-89).

[0094] Furthermore, the steel plate pretreatment is to perform sandblasting to remove rust on the steel plate. After the sandblasting is completed, the surface roughness of the steel plate is measured using a roughness profiler. The measurement results need to meet the standard requirements: when the first coating is an anti-corrosion coating, the surface rust removal level needs to reach Sa2.5 level, and the average roughness needs to reach 50-100μm roughness, which meets the requirements of "Surface Rust Level and Anti-Rust Level of Steel Plates Before Painting" (GB8923-88).

[0095] Sandblasting should be performed in a relatively enclosed sandblasting room with adequate ventilation and lighting. Coating application should be performed within the factory building whenever possible. The spraying area should be open and equipped with a dedicated operation area. The room should have good ventilation and bright lighting. Steel grit and steel shot should be used. The mix ratio of steel grit (specifications: G18, G25, G40) to steel shot (specifications: S330, S390, S460) should be 3:7 to 5:5.

[0096] The surface treatment of the steel plate must undergo self-inspection and be approved by the supervising engineer. If qualified, it must be sprayed within 4 hours. The shorter the interval, the better. If the steel plate substrate surface is damp due to rain or other conditions, wait until the environment meets the construction conditions, blow dry the surface moisture and remove dust with dry compressed air, and then re-sandblast to the design level.

[0097] When the steel plate is pretreated to ensure corrosion protection, the applied anti-corrosion material can fully fit in and ensure the stable spraying of the anti-corrosion coating.

[0098] In some embodiments, reference Figure 3 The flowchart of CNC blanking process adopts the following steps: computer modeling and theoretical determination of dimensions; processability analysis to determine welding, processing compensation and linear adjustment; part blanking size determination; group analysis; CNC blanking, computer generated part blanking nesting diagram; CNC programming, material utilization analysis, and final blanking.

[0099] Steel plates are cut and nested according to the material plan layout. Each steel plate corresponds to a separate cutting list. After cutting the steel plates, the remaining materials must be marked with the project and material.

[0100] Computer three-dimensional lofting technology is used to accurately lay out the components of the steel casing, and detailed drawings of each component are drawn as the basis for drawing the cutting and nesting drawings and CNC programming; when laying out, the production and installation welding shrinkage compensation, processing allowance and linear adjustment amount are reserved according to the process requirements.

[0101] The process analysis is divided into unit component division and welding groove design; the compensation amount is determined based on welding processability tests, actual measured data of other bridges undertaken, and parts processing requirements.

[0102] The contents of component analysis include: parts cutting method; parts processing method; unit component's demand for parts; segment's demand for unit machine.

[0103] The contents of material utilization analysis include: CNC blanking parts are automatically analyzed by CNC programming software; non-CNC blanking parts are judged based on the proportion of the store's layout area; nesting that does not meet the adjustment requirements must be approved by the project leader before implementation.

[0104] Through the CNC cutting process, the computer accurately determines the cutting and blanking of the steel plate, and the cutting size is determined through process analysis to ensure the accuracy and adaptability of the steel plate size.

[0105] In some embodiments, during the layout of the tooling tire frame, the assembled tire frame is arranged on a concrete hardened ground with good bearing capacity; the main axis of the steel casing is laid out in sections on the ground according to the steel casing, and the axis elevation of each curved surface position is measured along the main axis; and the tire frame material is cut according to the measured results.

[0106] The outer wall plate of the steel casing is laid out in a 1:1 ratio to set up a special cradle, and the vertical and horizontal reference lines are set. The cradle is made of steel materials with good support properties, and can be made of 40# and 10# channel steel. Each supporting rod is fixed by welding. The cradle foundation is fixed to the ground with embedded steel bars. The cantilever height of the supporting steel shall not exceed 500mm, otherwise a reverse support shall be set to prevent the support from horizontal displacement.

[0107] After the cradle is erected, the elevation of each point along each axis is re-measured. It can only be put into use after passing the acceptance inspection. The cradle is strictly prohibited from being used directly without acceptance or if it fails the acceptance inspection. This can further confirm the accuracy of the cradle erection, so that when the cradle is used to assemble the pre-assembled section, the assembly accuracy is more accurate. During the use of the cradle, the verticality of the supporting steel should be regularly checked. At the same time, it is necessary to check whether the bottom of each supporting steel is hanging in the air and whether the welds are cracked to ensure that it can stably support the pre-assembled section of the steel casing.

[0108] In some embodiments, segmented production is divided into segment block division and segment assembly. Segment block division means that when a single segment is manufactured in the factory, the outer wall panels are spliced ​​according to the steel plant's steel plate rolling capacity and the factory's lifting capacity. After the single block is assembled, vertical assembly and pre-assembly are performed to form a pre-assembled segment. According to the design drawings, each steel casing is segmented, such as into 1-8 segments, and then segmented assembly is performed to assemble the materials one by one into 1-8 pre-assembled segments.

[0109] Furthermore, in the segmented assembly, the segment blocks need to be assembled into pre-assembly sections. The segment blocks are composed of structures such as outer wall panels, inner wall panels, cross partitions, ring plates, partitions and reinforcing ribs. Key marking lines are laid out on the tooling frame according to the layout size of the outer wall panels, and the outer wall panels are laid through the marking lines. The steel plates are cut in sections before assembly, and the steel plates are fixed to the tooling frame with code plates to prevent the steel plates from loosening.

[0110] The laying of the outer wall panels starts from the reference segment of each round. The central bottom formwork unit is placed on the frame, and the horizontal and vertical baselines are accurately aligned with the ground sample marking lines. Then, other outer wall panel units are positioned on both sides in turn, and the bottom formwork blocks on both sides are welded symmetrically in turn. During assembly, the width is accurately reserved for welding shrinkage. Special fixtures are used to check the outside of the outer wall panels to ensure the curvature of the inner wall panels.

[0111] After the installation of the outer wall panel is completed, the plate units of the ring plate, the inner partition and the reinforcing ribs are positioned and installed in sequence according to the layout axis. Before the inner partition and the ring plate are positioned and assembled, a working scaffolding platform is set up inside the box. After the installation of the inner partition is completed, it must be inspected before welding. The quality inspector shall inspect the internal dimensions of the structure, the partition spacing and other external dimensions. Welding can only be carried out after passing the inspection to ensure that the welding points of the inner partition are accurate. The internal plates of the segment block should be welded in accordance with the pre-established welding sequence. In order to prevent the deformation of the outer wall panel after welding, the partition unit and the reinforcing rib are first fixed to the outer wall panel by segmented jump welding. After the rib welding is completed, the outer wall panel can be welded.

[0112] The inner wall panel is made into a plate unit structure, and the reinforcing ribs and the inner wall panel are pre-assembled and welded. Special tooling frames should be used in the production of plate units to ensure assembly accuracy and welding quality, and control and correct welding deformation.

[0113] After the inner wall panel is placed on the tooling frame, the edges of the steel plate are fixed with fixing clamps around the steel plate to make the steel plate fit the frame template, thereby adding a certain pre-arch to the plate unit before welding to control welding deformation. The production of the inner wall panel unit is carried out simultaneously with the welding of the outer wall panel and the internal structure of the partition. After the welding of the internal structure of the outer wall panel of the steel casing is basically completed, the plate units of the inner wall panel are assembled in sequence according to the layout positioning reference line, thereby improving production efficiency.

[0114] According to the assembly and welding of the above-mentioned segment blocks, laying and assembling strictly according to the marking lines can reduce the amount of welding in a limited space, while improving production efficiency, reducing error values, and forming a complete pre-assembled segment.

[0115] Furthermore, after the plate units of the inner wall panel are assembled according to the corresponding sizes, the ring plate and the partition plate are welded to the plate units of the inner wall panel and positioned, and then the auxiliary structure is installed. The auxiliary structure is installed along the wall surface of the inner wall panel or the wall surface of the ring plate. After the installation of the auxiliary components is completed, the box beam stage is turned over to complete the welding of all structural welds, thereby ensuring the integrity of the overall pre-assembled section.

[0116] Among them, after the installation of the auxiliary structure, the pre-assembly section is assembled as a whole, and the steel casing is assembled as a whole in the final assembly area. The assembly is carried out by a 2,000-ton crawler crane. After the vertical assembly is completed, the overall matching drilling is carried out.

[0117] The overall assembly process description needs to be explained based on the overall structure, with reference to the following anti-collision steel box structure.

[0118] This application also provides an ultra-large marine anti-collision steel box, reference Figure 1 and Figure 2 As shown, the steel casing is made of segment blocks produced in sections, and the segment blocks are assembled in sections to form pre-assembled sections 1, and then the pre-assembled sections 1 are assembled into a complete anti-collision steel casing through overall assembly.

[0119] It includes a bottom mold, a side mold and a pre-assembly segment 1; the bottom mold is placed on a preset tooling saddle, and the side mold is placed on the bottom mold, so as to limit the installation position of the bottom and side of the pre-assembly segment 1, thereby ensuring the accuracy of the assembly position. After the side mold is installed, the pre-assembly segment 1 is assembled vertically on the basis of the bottom mold.

[0120] The pre-assembled section 1 can be divided into a curved steel casing section 11 and a straight steel casing section 12 according to its shape. The curved steel casing section 11 is divided into four groups, namely the first curved box 111, the second curved box 112, the third curved box 113 and the fourth curved box 114; the straight steel casing section 12 is divided into four groups, namely the first straight box 121, the second straight box 122, the third straight box 123 and the fourth straight box 124. Therefore, the pre-assembled section 1 is divided into 8 groups in total, and the 8 groups are assembled vertically to form a complete steel casing.

[0121] The order of standing together is: the first straight box 121 is stood together with the second straight box 122, and the third straight box 123 is stood together with the fourth straight box 124; after the first curved box 111 and the second curved box 112 are stood together, the end of the first curved box 111 away from the second curved box 112 is stood together with the first straight box 121, and the end of the second curved box 112 away from the first curved box 111 is stood together with the third straight box 123; after the third curved box 113 and the fourth curved box 114 are stood together, the end of the third curved box 113 away from the fourth curved box 114 is stood together with the second straight box 122, and the end of the fourth curved box 114 away from the third curved box 113 is stood together with the fourth straight box 124.

[0122] After the vertical assembly is completed, the bottom formwork is hung and installed on the auxiliary structure 2. The auxiliary structure 2 may include a connecting structure that bridges between any adjacent pre-assembled segments 1 to reinforce the connection between adjacent pre-assembled segments 1.

[0123] After the pre-assembly segment 1 is divided into eight segments, the pre-assembly segment 1 is accurately assembled vertically by utilizing the limit of the bottom mold and the side mold. According to a specific assembly sequence, the steel casing is gradually formed and the assembly accuracy is high, which facilitates the subsequent welding process and speeds up the overall assembly efficiency.

[0124] According to the above-mentioned steel casing vertical assembly sequence, the vertical assembly process is provided:

[0125] When assembling the steel casing, first place the bottom mold of the steel casing on the tooling saddle, place the side mold segments of the steel casing on the bottom mold, and then assemble the steel casing on the basis of the bottom mold.

[0126] The assembly order is: steel casing bottom mold → first straight box 121 and second straight box 122 → third straight box 123 and fourth straight box 124 → first curved box 111 and second curved box 112 → third curved box 113 and fourth curved box 114 → hanging installation of steel casing bottom mold → installation of auxiliary structure 2.

[0127] Furthermore, the thickness of the connection between the first curved box 111 and the second curved box 112 is greater than the thickness of the connection between the first curved box 111 and the first straight box 121 or the second curved box 112 and the third straight box 123; the thickness of the connection between the third curved box 113 and the fourth curved box 114 is greater than the thickness of the connection between the third curved box 113 and the second straight box 122 or the fourth curved box 114 and the fourth straight box 124, that is, the thickness at the connection point of the first curved box 111 and the second curved box 112, the third curved box 113 and the fourth curved box 114 is thicker, and the thickness of the first straight box 121-the fourth straight box 124 is low. This is because the connection points of the first curved box 111 and the second curved box 112, the third curved box 113 and the fourth curved box 114 are directly exposed to the scouring of waves, and using a thicker thickness can improve the pressure resistance to scouring.

[0128] Furthermore, the auxiliary structure 2 at the connection point of the adjacent pre-assembled segments 1 is further provided with a fastening structure 3, referring to Figure 4 As shown, in the figure, taking the connection between the first straight box and the second straight box as an example, the fastening structure 3 enables the adjacent pre-assembled sections 1 to provide a fastening effect when they are assembled, and provides stable connection stability when welding or drilling.

[0129] The fastening structure 3 includes an extension rod 31, a pivot shaft 32 and a fastening bolt 33; a T-shaped embedding groove 21 is opened on the surface of the auxiliary structure 2, and a pivot opening 22 is opened in the embedding groove 21, the pivot shaft 32 is pivotally connected to the pivot opening 22, the extension rod 31 is connected to the pivot shaft 32, and the extension rod 31 can be rotated to the embedding groove 21 of another auxiliary structure 2 through the pivot shaft 32.

[0130] An extension protrusion 311 is provided on the extension rod 31, so that the extension rod 31 is T-shaped and adapted to the embedding groove 21. A threaded hole is also provided on the side of the embedding groove 21 close to the other auxiliary structure 2, and a fastening bolt 33 is screwed into the threaded hole. The fastening bolt 33 rotates with the threaded hole, so that the fastening bolt 33 can be extended into the embedding groove 21.

[0131] When the extension rod 31 is rotated to another embedded groove 21 through the pivot shaft 32, the two auxiliary structures 2 are bridged. At this time, no tension is applied to tighten the two pre-assembled sections 1. By rotating the fastening bolt 33, the fastening bolt 33 extends into the embedded groove 21 through the threaded hole and presses against the extension protrusion 311. As the fastening bolt 33 is tightened, one end of the extension rod 31 is limited by the pivot opening 22, and the other end is tightened by the fastening bolt 33, thereby cooperating with the auxiliary structure 2 to tighten the two adjacent pre-assembled sections 1, so that the position of the pre-assembled section 1 is stable during welding or drilling, reducing errors.

[0132] When welding or drilling to the extension rod 31, in order to prevent the extension rod 31 from obstructing the welding or drilling process, the fastening bolt 33 is loosened, and the extension rod 31 can be rotated out of the embedding groove 21 on one side through the pivot shaft 32, and the point can be welded or drilled.

[0133] After the segment blocks are assembled in sections, the auxiliary structure 2 is installed, and then the pre-assembled segments 1 are assembled vertically. The rotatable extension rod 31 ensures that no obstruction will occur during the assembly.

[0134] This application also provides the anti-corrosion coating process of steel casing:

[0135] 1. Pre-coating shop primer

[0136] Before unloading, the plates and steel sections are shot blasted and sprayed with shop primer on the pretreatment line.

[0137] 2. Segmental painting

[0138] Surface preparation and painting are performed in a dedicated paint shop, where the temperature and humidity meet regulatory requirements. The painting process follows the sequence of "grinding edges and corners → degreasing and staining → sandblasting → cleaning → painting."

[0139] 3. Repainting

[0140] The reserved parts and damaged parts of the segment assembly welds are polished to ensure that the rust removal level and surface roughness meet the specifications, and then the paint is applied layer by layer by brushing according to the coating system.

[0141] Process requirements:

[0142] (1) The anti-corrosion coating requirements shall comply with the provisions of the "Code for Anti-corrosion Construction of Water Transport Engineering Structures" (JTS / T 209-2020).

[0143] (2) Painting environment requirements

[0144] ① Ambient temperature ≥ 5 degrees;

[0145] ② The relative humidity is lower than 85 degrees Celsius, and construction is strictly prohibited on rainy days;

[0146] ③ The surface temperature of the steel is more than 3 degrees Celsius higher than the dew point;

[0147] ④ Construction should not be carried out under direct sunlight in summer.

[0148] (3) Surface pretreatment

[0149] Before shot blasting the painted surface of steel components, all grease and oil should be removed using a suitable detergent (water-soluble alkaline emulsifier) ​​according to SSPCSP1. When cleaning with a rag and solvent, avoid forming a dry film on the surface and avoid using flammable materials. When using solvents, provide workers with necessary protective gear to effectively protect their respiratory system, eyes, and skin.

[0150] Visible burrs, cutting chips, steel cracks, delamination, welding spatter, welding slag, etc. on the painted surface should be effectively removed before shot blasting. All free edges should be ground and removed (P2).

[0151] During surface treatment, the surface temperature should be at least 3 degrees Celsius above the dew point. Appropriate indirect heating methods can be used to meet the above conditions. Direct heating of the treated surface is not permitted.

[0152] (4) Sandblasting

[0153] All sandblasted surfaces must meet the following standards:

[0154] Cleanliness – Sa 2.5 (ISO 8501);

[0155] Roughness - N9a to N10a (Ra = 6-12.5 micron) - Rugotest No. 3; Medium (G) - ISO 8503 - or Keane-Tator Surface Compactor, 2-3 mils roughness measurement value is 40-75 micron;

[0156] The shot blasting medium should be clean, dry, and free of oil and foreign matter. Mechanical shot blasting media should be a mixture of angular sand to ensure a surface roughness of 50-100 μm, as required by ISO 8503-2. Recycled metal sand should meet the requirements of ISO 11124.

[0157] (5) Power tool cleaning

[0158] Power tool cleaning should refer to SSPC-SP3 or ISO-8501. Hand tool cleaning should refer to SSPC-SP2. Abrasive blasting, whether performed by hand or power tools, must be approved by the owner. During the fabrication process, sharp edges and spatter from thermal cutting and welding must be removed using power tools before painting.

[0159] (6) Surface cleaning before paint spraying

[0160] Before spraying, remove any debris from the surface with clean, dry compressed air. Install a filter box in the spray equipment's air line to clean the air. If compressed air is not sufficient, vacuum the surface.

[0161] (7) Receiving and storing paint

[0162] The paint should be delivered in the following conditions: unopened, clearly labeled with the product, batch number and production date. Paint cans that are damaged should not be used.

[0163] Paint should be stored according to the product instructions and protected from damage, moisture, and direct sunlight. The storage temperature should be maintained between 5°C and 25°C, and away from flammable materials. Paint should be used within its expiration date and should be used immediately after opening.

[0164] The acceptance conditions, relevant product names, validity periods, etc. of the above-mentioned coatings should be confirmed one by one when the coatings arrive, and it should be ensured that the coatings are used within the validity period.

[0165] (8) Mixing and dilution

[0166] Mixing should be done strictly according to the manufacturer's recommendations for complete components, allowing for partial mixing when necessary (e.g., for touch-ups). Each individual component should be thoroughly stirred before mixing with the others. Curing agents and additives should be added slowly and gently at low mixer speed. Stir at medium speed to obtain a uniformly mixed coating.

[0167] (9) Painting construction

[0168] High pressure airless spray is recommended. Brush and roller can be used for pre-coating, especially brush.

[0169] For areas that are difficult to spray, such as edges and dead corners, you can pre-coat with a paint brush before spraying to achieve the film thickness requirements.

[0170] For paints whose performance is not familiar, the wet film control method provided by the manufacturer should be used for spraying. During the construction process, the required wet film thickness should be maintained as much as possible to ensure the required dry film thickness.

[0171] (10) Paint repair

[0172] Unless otherwise specified, repairs to damaged areas should be made with the same paint as the original. Application defects such as runs, skips, bubbles, heavy marks, and paint peeling may occur. These defects in the dry film should be removed with a power tool, and the surrounding area should be properly sanded before repainting.

[0173] After the anti-corrosion coating process, testing is required. The testing standards and methods include:

[0174] (1) Inspection frequency: random inspection shall be carried out according to the steel anti-collision box block number, with a random inspection ratio of 100% and ten random inspection points on the inner and outer surfaces.

[0175] (2) Surface treatment: Visual inspection shows that the surface treatment reaches Sa2.5 (ISO8501-1:1988) or SSPC-SP10 standard.

[0176] (3) Inspection of coating appearance quality: According to Article 14.2.3 of GB50205-2001, the surface must be smooth, bright and uniform.

[0177] (4) Film thickness quality: Use a dry film magnetic thickness gauge to check according to GB50205-2001 standard. The dry film thickness at the inspection point is 600±30μm on the inner surface and 670±30μm on the outer surface.

[0178] (5) Color: Safety color - orange.

[0179] (6) Coating bonding strength: The bonding strength at the test points is ≥5MPa (GB / T 5210).

[0180] (7) Acceptance: After anti-corrosion treatment, the steel anti-collision box meets the above inspection standards and is signed and confirmed by all responsible persons.

[0181] This application also provides welding processes, including:

[0182] 1) Cleaning before welding. All oxide scale, rust, oil stains and other debris within 50-100mm on both sides of the intended weld surface and the groove should be cleaned. Each weld should also be cleaned promptly after welding and inspected before welding.

[0183] 2) Welding method

[0184] The following welding methods can be used (gas shielded welding can only be performed in a workshop approved by the owner):

[0185] . Manual arc welding

[0186] . Submerged arc welding

[0187] . Flux-cored arc welding (self-shielded)

[0188] . Flux-cored arc welding (gas shielded)

[0189] . Gas / metal arc welding (spray arc)

[0190] . Tungsten inert gas welding

[0191] The heat energy input for all welding processes should be between 1.0 kJ / mm and 4.5 kJ / mm.

[0192] 3) Tack Welding. Structural connections must be positioned and assembled using tack welding or other methods approved by the owner and supervisor. This work should be performed as efficiently as possible, minimizing the number of temporary components and ensuring adequate structural stability. Tack welding should conform to the root pass parameters specified in the approved welding procedure specification. Otherwise, the tack weld should not be considered a production weld and should be removed during root gouging.

[0193] 4) Preheating and interpass temperature

[0194] The preheat treatment for tack welding, production welding, arc gouging and thermal cutting should be the same. Welding should not be carried out when the ambient temperature is below -20℃ unless special precautions are taken to maintain the preheat level specified by the owner.

[0195] 5) Welding construction

[0196] All necessary steps should be taken to ensure that all structural connections are adequately supported and welded according to qualified welding procedures approved by the owner. The welding sequence should be arranged to minimize the effects of residual stress, deformation and warping on structural components.

[0197] All full penetration welds shall be made in accordance with a welding procedure approved by the Owner. Single-sided full penetration welds may be made only if the reverse side is impractical. All double-sided full penetration butt welds shall be back-grooved to a sound finish or grooved using a procedure approved by the Owner before welding on the second side. The welds shall be thoroughly cleaned after each weld pass. After completion of structural connection welds, the weld and adjacent areas shall be cleaned of all spatter and deposits. All welds shall be cleaned between passes and at the final stage using a wire brush or grinder.

[0198] 6) Weld surface grinding

[0199] After the various subassemblies are fabricated, the contractor must remove all burrs, tack welds, and other marks caused by scaffolding or temporary supports. Random arc strikes and any harmful defects must be removed. Welds must be inspected and repaired, if necessary. All weld repairs must be performed before any post-weld treatment. After temporary supports are removed, the parent metal must undergo MT testing to confirm the absence of harmful defects such as cracks. Carbon arc gouging must not be used to remove temporary supports.

[0200] After welding, weld inspection is also required, including the following inspection methods:

[0201] 1) Set up a full-time quality control team with sufficient qualifications and experience to control and ensure that all tests and inspections of this project meet the requirements of the specifications.

[0202] 2) The quality control group is responsible for and ensures that all document quality, welding procedures, welder qualifications, welding production, manufacturing, inspection and testing are carried out in an appropriate manner and form, and explains this to the owner / supervisor.

[0203] 3) Before fabrication begins, component and weld numbers should be established. The reporting basis for all weld inspections should be clearly marked within the work area so that the precise location of weld defects can be determined.

[0204] 4) The qualifications and capabilities of all non-destructive testing personnel shall at least meet the qualification and certification requirements of Level II or above of the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China and be approved by the owner.

[0205] 5) Magnetic particle testing (MT) can be used for all types of connected welding surfaces, radiographic testing (RT) is only applicable to butt welds, and ultrasonic testing (UT) is applicable to all types of connecting welds.

[0206] The examples of this specific embodiment are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, any equivalent changes made based on the structure, shape, and principle of this application should be included in the scope of protection of this application.

Claims

1. A process for constructing an ultra-large offshore anti-collision steel casing, characterized in that: The steps include: Intelligent modeling and process optimization: Using Tekla software to build a BIM model of the steel casing, the segmented design was optimized through virtual pre-assembly. Digital twin technology was used to preview the construction process, optimize the welding sequence and cradle layout, and generate process animations to guide construction briefings. Modular segmentation and deformation control: The steel casing is layered according to function and manufactured in sections using arc jigs. Pre-arching technology is used to offset welding shrinkage, enabling block assembly line processing of the steel casing. CO2 gas shielded welding and submerged arc automatic welding are used, with a real-time welding parameter monitoring system. The process of pre-assembly of the steel casing includes the following steps: material delivery; steel plate pretreatment; CNC blanking; jig layout; segmented production; auxiliary structure installation; overall splicing; segment production is divided into segment block division and segment assembly. During the segmented assembly, the segment blocks of the steel casing need to be assembled. The segment blocks include outer wall panels, inner wall panels, transverse partitions, ring panels, partitions and reinforcing ribs. According to the layout size of the outer wall panels, the layout marking lines are made on the tooling frame, and the outer wall panels are laid through the marking lines. After the outer wall panels are installed, the plate units of the ring panels, inner partitions and reinforcing ribs are positioned and installed in sequence according to the layout axis. The inner wall panels are made into a plate unit structure, and the reinforcing ribs are pre-assembled and welded to the inner wall panels. After the inner wall panels are adjusted to the tooling frame, the plate edges of the steel plates are fixed with fixing clamps around them to ensure that the steel plates are The plate is fitted to the frame template, so that the plate unit has a pre-arch before welding to control welding deformation. The production of the inner wall plate unit is carried out simultaneously with the welding of the outer wall plate and the internal structure of the partition plate. After the welding of the internal structure of the outer wall plate of the steel casing is completed, the plate units of the inner wall plate are assembled in sequence according to the layout positioning reference line; the partition plate unit and the reinforcing rib plate are fixed to the outer wall plate in sections by jump welding. After the rib plate welding is completed, the outer wall plate is welded. After the plate units of the inner wall plate are assembled according to the corresponding size, the ring plate and the partition plate are welded to the plate units of the inner wall plate and the auxiliary structure is installed; The auxiliary structure is installed along the inner wall or ring plate wall. After the auxiliary structure is installed, the box girder stage is turned over to complete the welding of all structural welds. After the auxiliary structure is installed, the pre-assembled section is assembled as a whole. The auxiliary structure at the connection point of adjacent pre-assembled sections is also provided with a fastening structure. The fastening structure enables the adjacent pre-assembled sections to provide a fastening effect when they are assembled, and provides a stable connection stability when welding or drilling. Intelligent anti-corrosion and quality control: Epoxy glass flake paint + acrylic polysiloxane topcoat are used for double-layer anti-corrosion, combined with automated spraying equipment to control film thickness errors; magnetic thickness gauges and adhesion testers are used to monitor coating quality online, and data is uploaded to the cloud management platform simultaneously; Overall assembly precision control: accurately lay out the ground sample line on the tire frame, use the external arc as the base surface to locate the segment, and combine laser calibration technology to control the assembly error; after the segment is completed, a hydraulic flip machine is used to adjust the posture to ensure the interface matching accuracy during vertical overall assembly, and intelligent acceptance is carried out after the overall assembly.

2. The process for constructing an ultra-large offshore anti-collision steel casing according to claim 1, characterized in that: The steel plate pretreatment is sandblasting to remove rust. The sandblasting construction is carried out in a relatively closed sandblasting room, and sufficient ventilation and lighting are guaranteed.

3. The process for constructing an ultra-large offshore anti-collision steel casing according to claim 1, characterized in that: The following steps are used in the CNC blanking process: computer modeling and theoretical determination of dimensions; processability analysis to determine welding, processing compensation amounts, and linear adjustment amounts; part blanking size determination; group analysis; CNC blanking, computer-generated part blanking nesting diagrams; CNC programming, material utilization analysis, and final blanking.

4. The process for constructing a super-large offshore anti-collision steel casing according to claim 1, characterized in that: During the layout of the tooling tyre frame, the assembled tyre frame is arranged on a hardened concrete ground with good bearing capacity; the main axis of the steel casing is laid out in sections on the ground according to the steel casing, and the axis elevation of each curved surface position is measured along the main axis; the tyre frame material is cut according to the measured results.

5. An ultra-large marine anti-collision steel casing, characterized in that: The invention relates to a super-large offshore anti-collision steel casing manufactured by the construction process of any one of claims 1 to 4, wherein the steel casing is made of segment blocks generated by segment production, and the segment blocks are assembled into pre-assembled segments (1) by segment production, and then the pre-assembled segments (1) are assembled into a complete anti-collision steel casing by overall assembly; it includes a bottom mold, a side mold and a pre-assembled segment (1); the bottom mold is placed on a preset tooling saddle, and the side mold is placed on the bottom mold; on the basis of the bottom mold, the pre-assembled segment (1) is vertically assembled; the auxiliary structure (2) at the connection point of adjacent pre-assembled segments (1) is also provided with a fastening structure (3), and the fastening structure (3) includes an extension rod (31), a pivot shaft (32) and a fastening rod (31). A fixing bolt (33); a T-shaped embedding groove (21) is provided on the surface of the auxiliary structure (2), and a pivot opening (22) is provided in the embedding groove (21), the pivot shaft (32) is pivotally connected to the pivot opening (22), the extension rod (31) is connected to the pivot shaft (32), and the extension rod (31) can be rotated to the embedding groove (21) of another auxiliary structure (2) through the pivot shaft (32), the extension rod (31) is provided with an extension protrusion (311), so that the extension rod (31) is in a T-shape adapted to the embedding groove (21), and a threaded hole is further provided on the side of the embedding groove (21) close to the other auxiliary structure (2), and a fixing bolt (33) is screwed in the threaded hole, and the fixing bolt (33) As the threaded hole rotates, the fastening bolt (33) extends into the embedded groove (21). When the extension rod (31) rotates to the other embedded groove (21) through the pivot shaft (32), the fastening bolt (33) is rotated, and the fastening bolt (33) extends into the embedded groove (21) through the threaded hole and is tightly pressed against the extension protrusion (311). As the fastening bolt (33) is tightened, one end of the extension rod (31) is limited by the pivot opening (22), and the other end is fastened by the fastening bolt (33), thereby cooperating with the auxiliary structure (2) to fasten the two adjacent pre-assembled sections (1), so that the position of the pre-assembled section (1) is stable when welding or drilling. The assembly section (1) can be divided into a curved steel casing section (11) and a straight steel casing section (12) according to the shape; the curved steel casing section (11) is divided into four groups, namely a first curved box (111), a second curved box (112), a third curved box (113) and a fourth curved box (114); the straight steel casing section (12) is divided into four groups, namely a first straight box (121), a second straight box (122), a third straight box (123) and a fourth straight box (124); the vertical assembly sequence is: the first straight box (121) is vertically assembled with the second straight box (122), and the third straight box (123) is vertically assembled with the fourth straight box (124);After the first curved box (111) and the second curved box (112) are assembled vertically, the end of the first curved box (111) away from the second curved box (112) is assembled vertically with the first straight box (121), and the end of the second curved box (112) away from the first curved box (111) is assembled vertically with the third straight box (123); after the third curved box (113) and the fourth curved box (114) are assembled vertically, the end of the third curved box (113) away from the fourth curved box (114) is assembled vertically with the second straight box (122), and the end of the fourth curved box (114) away from the third curved box (113) is assembled vertically with the fourth straight box (124); after the assembly is completed, the bottom mold is hung and installed with the auxiliary structure (2).

6. The super-large marine anti-collision steel casing according to claim 5, characterized in that: The thickness of the connection between the first curved box (111) and the second curved box (112) is greater than the thickness of the connection between the first curved box (111) and the first straight box (121) when the first curved box (111) and the second straight box (123) are assembled vertically; the thickness of the connection between the third curved box (113) and the fourth curved box (114) is greater than the thickness of the connection between the third curved box (113) and the second straight box (122) when the third curved box (114) and the fourth straight box (124) are assembled vertically.

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