Construction process of ultra-large type offshore anti-collision steel jacket box and steel jacket box

Abstract

The invention relates to the field of ocean engineering, and provides an ultra-large type offshore anti-collision steel jacket box construction technology and a steel jacket box, and the ultra-large type offshore anti-collision steel jacket box construction technology comprises the following steps that intelligent modeling and technology optimization are conducted; modular segmentation and deformation control are carried out; intelligent corrosion prevention and quality control are realized; and controlling the total splicing precision. The anti-collision device has the effect that the anti-collision requirement for sea crossing is met by utilizing intelligent modeling and segmented manufacturing and providing an efficient anti-corrosion process.

Description

Technical Field

[0001] The present application relates to the field of ocean engineering, and particularly relates to a construction process and a steel casing for ultra-large offshore anti-collision steel casings. Background Art

[0002] With the rapid development of China's infrastructure construction, the construction of large bridges such as cross-river and cross-sea bridges has increased significantly. To achieve the construction of deep-water foundations and reduce the cost of bridges, anti-collision casing cofferdams have been widely used.

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

[0004] To improve the above problems, the present application provides a construction process and a steel casing for ultra-large offshore anti-collision steel casings.

[0005] The construction process and the steel casing for ultra-large offshore anti-collision steel casings provided by the present application adopt the following technical solutions: A construction process for an ultra-large offshore anti-collision steel casing, comprising the following steps: Intelligent modeling and process optimization: Establish a BIM model of the steel casing based on Tekla software, and optimize the sectional design through virtual pre-assembly; Combine digital twin technology to pre-enact the construction process, optimize the welding sequence and the layout of the jig, and generate process animations to guide construction disclosure; Modular sectioning and deformation control: Layer the steel casing by function, use an arc jig for sectional production, offset welding shrinkage through pre-arching technology, and achieve block assembly line processing of the steel casing; Apply CO2 gas shielded welding and submerged arc automatic welding, and match with a real-time welding parameter monitoring system; Intelligent anti-corrosion and quality control: Adopt a double-layer anti-corrosion of epoxy glass flake paint + acrylic polysiloxane topcoat, and control the film thickness error by combining automated spraying equipment; Online monitor the painting quality through a magnetic thickness gauge and an adhesion tester, and synchronously upload the data to the cloud management platform; Total assembly precision control: Accurately lay out the ground line on the jig, position the section with the outer arc as the base surface, and control the assembly error by combining laser calibration technology; After the section is made, use a hydraulic tilting machine to adjust the attitude to ensure the interface matching precision during vertical total assembly, and conduct intelligent acceptance after total assembly.

[0006] By adopting the above technical solutions, through the above manufacturing process, a segmented pre-assembled structure is preset by intelligent modeling, reducing part collisions, improving the interface accuracy of welding, and cooperating with digital twin technology to optimize the welding sequence and jig layout, improving the stable splicing and design accuracy of the overall steel caisson, saving consumables, increasing the material utilization rate, reducing labor costs at the same time. After intelligent optimization, the steel caisson is processed in a block assembly line through segmented manufacturing, shortening the construction period. The pre-assembled segments after segmented manufacturing are completely welded through an automated welding process, reducing the welding deformation. Through intelligent anti-corrosion and quality control, when the steel caisson is set in the sea, the erosion of seawater on the steel caisson can be stably reduced, and the anti-corrosion life is extended. After anti-corrosion, the pre-assembled segments are completely assembled through the lofting positioning method and the block turning and erection process. Intelligent early warning reduces operation risks, and through the comparison between the intelligent acceptance and the model in the intelligent modeling, the overall error value is reduced.

[0007] Optionally, the construction process of the pre-assembled segments of the steel caisson includes the following processes: material arrival; steel plate pretreatment; numerical control cutting; jig layout; segmented manufacturing; installation of auxiliary structures; overall splicing.

[0008] By adopting the above technical solutions, after the materials arrive, the materials are sorted and classified, and processes such as steel plate pretreatment, numerical control cutting, and jig layout are carried out synchronously. The steel plate pretreatment can include sandblasting treatment, anti-corrosion treatment, etc. Numerical control cutting is carried out by designing drawings and using the design drawings for computer modeling and process analysis, etc., to determine the distribution, installation, welding points, etc. of the materials. The layout of the jig is for site layout, providing a suitable and accurate site for processing or assembly. After the above is completed, segmented manufacturing and installation of auxiliary structures are carried out to complete the production of the pre-assembled segments of the steel caisson, and finally, the construction is completed through overall splicing.

[0009] Optionally, the steel plate pretreatment is sandblasting and rust removal treatment of the steel plate. The sandblasting construction is carried out in a relatively enclosed sandblasting room, and sufficient ventilation and lighting are ensured.

[0010] By adopting the above technical solutions, when the steel plate is pretreated to ensure anti-corrosion, the applied anti-corrosion material can be fully adhered, ensuring the stable spraying of the anti-corrosion coating.

[0011] Optionally, in the numerical control cutting process, the following steps are adopted: computer modeling and theoretically determining the dimensions; process analysis to determine the welding, processing compensation amount, and linear adjustment amount; determination of the part cutting dimensions; group analysis; numerical control cutting, and the computer generates the part cutting nesting drawing; numerical control programming, material utilization rate analysis, and cutting after determination.

[0012] By adopting the above technical solutions, through the numerical control cutting process, the computer accurately determines the cutting and blanking of the steel plate, and determines the blanking dimensions through process analysis, ensuring the accuracy and adaptability of the steel plate dimensions.

[0013] Optionally, during the layout of the tooling jig, the assembly jig is arranged on the hardened concrete ground with good bearing capacity; on the ground, the main axis of the steel casing is lofted according to the sectional division of the steel casing, and the elevation of the axis positions of each curved surface is measured along the main axis; the jig materials are cut according to the measured results.

[0014] By adopting the above technical solution, the tooling jig is arranged according to the precise axis to further confirm the accuracy of the jig erection and ensure that it can stably carry the pre-assembled section of the steel casing.

[0015] Optionally, the sectional fabrication is divided into sectional block division and sectional assembly.

[0016] By adopting the above technical solution, after the sectional blocks are divided according to their shapes and functions, sectional assembly is carried out. The sectional assembly assembles the sectional blocks into each pre-assembled section. Multiple groups of position assemblies can be carried out simultaneously during the sectional assembly to improve the assembly efficiency.

[0017] Optionally, during the sectional assembly, the sectional blocks of the steel casing need to be assembled. The sectional blocks are composed of outer wall plates, inner wall plates, transverse diaphragms, ring plates, diaphragms, and stiffeners; lofting marking lines are made on the tooling jig according to the layout dimensions of the outer wall plates, and the outer wall plates are laid along the marking lines; after the installation of the outer wall plates, the plate units of the ring plates, inner diaphragms, and stiffeners are sequentially positioned and installed according to the lofting axis; the inner wall plates are fabricated into plate unit structures, and the stiffeners are pre-assembled and welded with the inner wall plates. After the inner wall plates are lifted onto the tooling jig, the plate edges of the steel plates are fixed by fixing clamps around the steel plates to make the steel plates fit the jig template, so as to increase the pre-arch of the plate units before welding to control the welding deformation. The fabrication of the inner wall plate units is carried out simultaneously with the welding of the internal structures of the outer wall plates and diaphragms. After the welding of the internal structures of the outer wall plates of the steel casing is completed, the plate units of the inner wall plates are sequentially assembled according to the lofting positioning reference line; the diaphragm units and stiffener plates are welded to the outer wall plates in a segmented and skip-welded manner, and after the welding of the rib plates is completed, the outer wall plates are welded.

[0018] By adopting the above technical solution, according to the above assembly and welding of the sectional blocks, laying and assembling strictly according to the marking lines can reduce the welding amount in the limited space, improve the fabrication efficiency at the same time, reduce the error value, and form a complete pre-assembled section.

[0019] Optionally, after the plate units of the inner wall plates are assembled according to the corresponding dimensions, the ring plates and diaphragms are welded and positioned with the plate units of the inner wall plates, and then the accessory structures are installed.

[0020] By adopting the above technical solution, after all the inner wall plates, ring plates, and diaphragms are welded, the accessory structures are installed and welded, avoiding pre-welding the accessory structures, which may hinder the installation of other structures.

[0021] Optionally, there is an extra-large offshore anti-collision steel caisson. The steel caisson is composed of segment blocks produced by segmented manufacturing, and the segment blocks are assembled in segments to form a pre-assembled segment, and then the pre-assembled segments are assembled into a complete anti-collision steel caisson through overall assembly; it includes a bottom mold, a side mold and a pre-assembled segment; the bottom mold is placed at a preset tool saddle, and the side mold is placed on the bottom mold; on the basis of the bottom mold, the pre-assembled segment is erected; the pre-assembled segment can be divided into a curved surface steel caisson segment and a straight surface steel caisson segment according to its shape; the curved surface steel caisson segment is divided into four groups, namely the first curved surface box, the second curved surface box, the third curved surface box and the fourth curved surface box; the straight surface steel caisson segment is divided into four groups, namely the first straight surface box, the second straight surface box, the third straight surface box and the fourth straight surface box; the erection sequence is: the first straight surface box and the second straight surface box are erected, the third straight surface box and the fourth straight surface box are erected; after the first curved surface box and the second curved surface box are erected, one end of the first curved surface box away from the second curved surface box is erected with the first straight surface box, and one end of the second curved surface box away from the first curved surface box is erected with the third straight surface box; after the third curved surface box and the fourth curved surface box are erected, one end of the third curved surface box away from the fourth curved surface box is erected with the second straight surface box, and one end of the fourth curved surface box away from the third curved surface box is erected with the fourth straight surface box; after the erection is completed, the bottom mold is hoisted and installed and the accessory structure is installed.

[0022] By adopting the above technical solution, after the pre-assembled segment is divided into eight segments, the pre-assembled segment is accurately erected by using the limit of the bottom mold and the side mold. According to a specific erection sequence, the steel caisson is gradually formed and the erection accuracy is high, which is convenient for the subsequent welding process and speeds up the overall assembly efficiency.

[0023] Optionally, the thickness at the connection between the first curved surface box and the second curved surface box is greater than the thickness at the connection between the first curved surface box and the first straight surface box or the connection between the second curved surface box and the third straight surface box; the thickness at the connection between the third curved surface box and the fourth curved surface box is greater than the thickness at the connection between the third curved surface box and the second straight surface box or the connection between the fourth curved surface box and the fourth straight surface box.

[0024] By adopting the above technical solution, the connection points of the first curved surface box and the second curved surface box, and the third curved surface box and the fourth curved surface box face the erosion of the direct sea waves. Using a thicker thickness can improve the compressive resistance to erosion.

[0025] In summary, the present application includes at least one of the following beneficial technical effects: Through the above manufacturing process, a segmented pre-assembled structure is preset using intelligent modeling to reduce part collisions, improve the interface accuracy of welding, and cooperate with digital twin technology to optimize the welding sequence and jig layout, thereby improving the stable splicing and design accuracy of the overall steel caisson, saving consumables, increasing material utilization rate, reducing labor costs at the same time. After intelligent optimization, the steel caisson is processed in a block assembly line through segmented manufacturing, shortening the construction period. The pre-assembled segments after segmented manufacturing are completely welded through an automated welding process, reducing the welding deformation. Through intelligent anti-corrosion and quality control, when the steel caisson is placed in the sea, the erosion of seawater on the steel caisson can be stably reduced, and the anti-corrosion life is extended. After anti-corrosion, the pre-assembled segments are completely assembled through the lofting positioning method and the block turning and erection process. Intelligent early warning reduces operation risks, and through the comparison between the intelligent acceptance and the model in the intelligent modeling, the overall error value is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a three-dimensional structural schematic diagram of an anti-collision steel caisson in an embodiment of the present application; Figure 2 is a top view structural schematic diagram of an anti-collision steel caisson in some embodiments of the present application; Figure 3 is a process schematic diagram of numerical control cutting in some embodiments of the present application; Figure 4 is a cross-sectional structural schematic diagram of an accessory structure in some embodiments of the present application; The reference numerals in the drawings are: 1, pre-assembled segment; 11, curved surface steel caisson segment; 111, first curved surface box; 112, second curved surface box; 113, third curved surface box; 114, fourth curved surface box; 12, straight surface steel caisson segment; 121, first straight surface box; 122, second straight surface box; 123, third straight surface box; 124, fourth straight surface box; 2, accessory structure; 21, embedding groove; 22, pivot port; 3, fastening structure; 31, extension rod; 311, extension protrusion; 32, pivot shaft; 33, fastening bolt. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The following specifically illustrates the embodiments of the present application through specific examples. Those skilled in the art can easily understand other advantages and effects of the present application from the information disclosed in the present application. The present application can also be implemented or applied through other different specific embodiments. Various details in the present application can also be modified or changed according to different viewpoints and applications without departing from the spirit of the present application. It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0028] The following will refer to the accompanying drawings to provide a detailed description of the embodiments of the present application, so that those skilled in the art to which the present application pertains can easily implement it. The present application can be embodied in various different forms and is not limited to the embodiments described herein.

[0029] In the description of the present application, the reference to expressions such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics represented in connection with the embodiment or example are included in at least one embodiment or example of the present application. Moreover, the specific features, structures, materials, or characteristics represented can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples represented in the present application and the features of different embodiments or examples.

[0030] Furthermore, the terms "first" and "second" are only used for indication purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" can explicitly or implicitly include at least one of such features. In the description of the present application, the meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0031] Throughout the specification, when it is said that a device is "connected" to another device, this includes not only the case of "direct connection", but also the case of "indirect connection" with other elements placed therebetween. Additionally, when it is said that a certain device "includes" a certain component, unless there is a particularly contrary record, it does not exclude other components, but means that other components can also be included.

[0032] The following will further describe the present application in conjunction with the attached Figure 1 - attached Figure 4 , to provide a more detailed description of the present application.

[0033] The embodiments of the present application disclose a construction process for an ultra-large offshore anti-collision steel caisson and the steel caisson.

[0034] A construction process for an ultra-large offshore anti-collision steel caisson, which manufactures the anti-collision steel caisson as shown in reference Figure 1 and Figure 2 includes the following steps: Intelligent modeling and process optimization: Based on Tekla software, a BIM model of the steel caisson is established, and the sectional design is optimized through virtual pre-assembly to reduce collisions between a large number of parts, so that the welding interface accuracy can be improved by nearly 30%.

[0035] Combined with digital twin technology, the construction process is rehearsed, the welding sequence and the layout of the jig are optimized, and process animations are generated to guide the construction disclosure. Digital twin technology makes full use of data such as physical models, running histories, etc., integrates multi-disciplinary, multi-physical quantity, multi-scale and multi-probability simulation processes, and completes the mapping in the virtual space. After generating the process animation, it can enable construction personnel to more intuitively and clearly understand the construction disclosure, thereby improving construction efficiency and construction accuracy.

[0036] Modular segmentation and deformation control: The steel caisson is stratified by function, such as the main deck, platform plate, bulkhead, etc., and special circular jigs are used for segmented production. After segmented production, pre-assembled segments are formed, and then assembled. Through the pre-arching technology, the pre-arching amount can reach 5mm, fully offsetting the welding shrinkage. Multiple circular jigs are used for synchronous segmented production and then gradually assembled together, accelerating the production efficiency and assembly process, and realizing the block assembly line processing of the steel caisson.

[0037] During welding, through the automated welding process, CO2 gas shielded welding and submerged arc automatic welding are applied, and a real-time welding parameter monitoring system is equipped, such as using multi-directional sensors to provide real-time data transmission to achieve a complete monitoring system. The weld qualification rate can reach over 99%, ensuring safety and integrity during welding.

[0038] Intelligent anti-corrosion and quality control: During anti-corrosion, after sandblasting and rust removal to reach Sa2.5 level, a robot is used to spray a double-layer anti-corrosion coating of epoxy glass flake paint + acrylic polysiloxane topcoat. The dry film thickness of the epoxy glass flake paint is 300μm, and the dry film thickness of the acrylic polysiloxane topcoat is 130μm. Combined with automated spraying equipment to control the film thickness error, the error range needs to be less than or equal to ±30μm.

[0039] In terms of quality control, an online monitoring of the painting quality is required through magnetic thickness gauges and adhesion testers, so that the film thickness qualification rate reaches over 95%, and the monitored data is synchronously uploaded to the cloud management platform for subsequent reference and supervision.

[0040] Total assembly precision control: Total assembly means the overall splicing. The ground sample line is accurately laid out on a special jig, and the segments are positioned with the external arc as the base surface. Combined with laser calibration technology to control the assembly error, the error range needs to be less than or equal to 30mm. After segmented production, the pre-assembled segments need to be turned over and erected, and a hydraulic tilting machine is used to adjust the attitude after the segment production is completed to ensure the interface matching precision during vertical total assembly, so as to complete the production and splicing of the overall anti-collision steel caisson.

[0041] Intelligent acceptance can compare with the BIM model through laser scanning, and correct the quality error ≤ 3mm, and the overall flatness deviation ≤ 5mm / m.

[0042] Through the above manufacturing process, a segmented pre-assembled structure is preset using intelligent modeling, reducing part collisions, improving the interface accuracy of welding, and optimizing the welding sequence and jig layout in combination with digital twin technology, improving the stable splicing and design accuracy of the overall steel cofferdam, saving consumables, increasing material utilization rate, reducing labor costs at the same time. After intelligent optimization, the steel cofferdam is processed in a block assembly line through segmented manufacturing, shortening the construction period. The pre-assembled segments after segmented manufacturing are completely welded through an automated welding process, reducing the amount of welding deformation. Through intelligent anti-corrosion and quality control, when the steel cofferdam is set in the sea, the erosion of seawater on the steel cofferdam can be stably reduced, and the anti-corrosion life is extended. After anti-corrosion, the pre-assembled segments are completely assembled through the lofting positioning method and the block turning and erection process. Intelligent early warning reduces operation risks, and through the comparison between the intelligent acceptance and the model in the intelligent modeling, the overall error value is reduced.

[0043] Furthermore, the construction process of the pre-assembled segments of the steel cofferdam includes the following processes: material arrival; steel plate pretreatment; numerical control cutting; jig layout; segmented manufacturing; installation of auxiliary structures; overall splicing.

[0044] After the materials arrive, the materials are sorted and classified, and processes such as steel plate pretreatment, numerical control cutting, and jig layout are carried out simultaneously. Steel plate pretreatment can include sandblasting treatment, anti-corrosion treatment, etc. Numerical control cutting is carried out through design drawings, and computer modeling and process analysis are carried out using the design drawings to determine the distribution, installation, welding points, etc. of the materials. The layout of the jig is for site layout, providing a suitable and accurate site for processing or assembly. After the above is completed, segmented manufacturing and installation of auxiliary structures are carried out to complete the production of the pre-assembled segments of the steel cofferdam, and finally, the construction is completed through overall splicing.

[0045] Among them, in the process of material arrival, the materials refer to all the materials included in the steel cofferdam and its auxiliary structures, including steel, welding materials, rubber, and painting materials, etc. The materials used in its manufacturing need to meet the requirements of the design documents and the provisions of the current national standards.

[0046] (1) Steel The main structure of the cofferdam adopts Q235B material, and its technical conditions comply with the provisions of "Carbon Structural Steel" (GB700-2006).

[0047] (2) Stainless steel bolts and screws Stainless steel bolts and screws should meet the technical requirements of A4 in GB / T3098.6-2014.

[0048] (3) High-strength bolts High-strength bolts should meet the requirements of grade 10.9S in GB / T1228-2006 and be hot-dip galvanized (see details in GB / T5267.3-2008).

[0049] (4) Welding materials Welding materials shall be selected through welding procedure qualification tests. The selected electrodes, fluxes, and welding wires shall all comply with the corresponding national standards. The purity of the gas for CO2 gas shielded welding shall be greater than 99.9%.

[0050] (5) Arch-shaped rubber The mechanical property parameters of the arch-shaped rubber fender are shown in the following table, which is Table 1:

[0051] Table 1 gives the reaction force and energy absorption value per meter length of the standard rubber fender. When needed, the reaction force and energy absorption value of fenders of various lengths shall be obtained by multiplying the standard value by the actual length.

[0052] The physical properties of the rubber compound for the fender are shown in the following table.

[0053] This table is Table 2:

[0054] (6) Rubber The material technical requirements for rubber parts such as rubber pads and rubber bearings are as shown in Table 3 below. The use of recycled rubber or crushed vulcanized rubber is not allowed.

[0055] Table 3:

[0056] (7) Heavy-duty anti-corrosion coating materials Epoxy glass flake paint is a fast-curing, thick-film wear-resistant epoxy paint strengthened with glass flakes, with excellent anti-corrosion characteristics. Due to the addition of glass flakes, which alternate and cover each other in the paint film, it makes corrosive chemical substances such as water, salt, and oxygen not easily penetrate and invade. Moreover, this type of paint belongs to high-solid epoxy paint, with a typical dry film thickness of 200 - 300μm for one-time construction, and the surface does not crack. Therefore, it has outstanding seawater corrosion resistance and high wear resistance, and is suitable for the tidal splash zone of steel structures. Due to its surface treatment characteristics, it has excellent maintenance performance. Its main technical parameters are as shown in Table 4.

[0057] Technical requirements for epoxy glass flake paint, Table 4:

[0058] Acrylic polysiloxane topcoat is a two-component, acrylic-modified polysiloxane high-performance topcoat, with excellent light and color retention, mechanical properties, and chemical resistance. It is recommended to be used in a harsh corrosive atmospheric environment with high requirements for light and color retention, and can meet high durability and weather resistance requirements.

[0059] The acrylic polysiloxane topcoat contains no isocyanate and no lead or chromium, being green and environmentally friendly. The volume solid content is 65%, and the single coat film thickness can be as high as 130μm or as low as 50μm, suitable for construction in various seasonal environments from 0°C to 40°C. It contains no lead or chromium, being green and environmentally friendly. Besides being able to resist severe atmospheric corrosion, this solid and durable high-performance topcoat can also provide a rich variety of colors. Its main technical parameters are shown in Table 5 below.

[0060] Technical requirements for acrylic polysiloxane topcoat, Table 5:

[0061] (8) Composite materials E-glass fiber multi-axial warp knitted fabric (alkali-free): It 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.

[0062] Table 6:

[0063] (9) Energy-dissipating core materials Energy-dissipating core materials should preferably use materials such as polyurethane closed-cell foam, and their physical and mechanical properties are as follows: Table 7.

[0064] Table 7:

[0065] (10) Watertight manhole covers Watertight manhole covers should comply with the provisions of ship manhole covers (GB11628 - 89).

[0066] Furthermore, the pretreatment of the steel plate is to carry out sandblasting and rust removal on the steel plate. After sandblasting, use a roughness profiler to measure the surface roughness of the steel plate. The measurement results need to meet the standard requirements: when the first coat is an anti-corrosion coating, the surface rust removal grade needs to reach Sa2.5, and the average roughness needs to reach 50 - 100μm roughness, meeting the requirements of "Rust grades and anti-rust grades of steel plate surfaces before painting" (GB8923 - 88).

[0067] Sandblasting construction should be carried out in a relatively enclosed sandblasting room, and sufficient ventilation and lighting should be ensured. The coating application process should be carried out in the factory as much as possible. The spraying site is open and has a dedicated operation area. The indoor air circulates and the light is bright. It is required to use steel sand and steel shot, and the mixing ratio of steel sand (specifications: G18, G25, G40) and steel shot (specifications: S330, S390, S460) is 3:7 - 5:5.

[0068] The surface treatment of the steel plate has passed the quality self-inspection and obtained the approval of the supervising engineer. Spraying must be carried out within 4 hours after passing the inspection, and the shorter the interval time, the better. In case of rain or other situations that cause the surface of the steel plate substrate to be wet, after the environment reaches the construction conditions, the surface moisture and dust should be blown dry with dry compressed air, and re-blasting should be carried out to the grade required by the design.

[0069] When ensuring anti-corrosion through the pretreatment of the steel plate, the applied anti-corrosion materials can be fully adhered to ensure the stable spraying of the anti-corrosion coating.

[0070] In some embodiments, referring to Figure 3 the flowchart of, in the numerical control blanking process, the following steps are adopted: computer modeling and theoretically determining the dimensions; technological analysis to determine the welding, machining compensation amount, and linear adjustment amount; determining the blanking dimensions of parts; group analysis; numerical control blanking, and the computer generates the part blanking nesting drawing; numerical control programming, material utilization rate analysis, and then blanking.

[0071] The steel plate blanking is nested according to the material plan layout. Each steel plate corresponds to a single blanking list, and the remaining materials after the steel plate blanking need to be marked with the project and material.

[0072] Adopt computer three-dimensional lofting technology to accurately loft each component of the steel cofferdam, draw the detailed drawings of each component part, which serve as the basis for drawing the blanking nesting drawing and numerical control programming; when lofting, reserve the welding shrinkage compensation amount, machining allowance, and linear adjustment amount according to the technological requirements.

[0073] The technological analysis is divided into unit part division and welding groove design; the determination basis of the compensation amount includes welding process tests, measured data of other bridges manufactured, and part processing requirements.

[0074] The content of the component analysis includes: the blanking method of parts; the processing method of parts; the requirements of unit parts for parts; the requirements of segments for unit machines.

[0075] The content of the material utilization rate analysis includes: the numerical control blanking parts are analyzed by the numerical control programming software itself; the non-numerical control blanking parts are judged based on the lofting area ratio in the store; for the nesting that does not meet the adjustment, it needs to be approved by the person in charge of the project before implementation.

[0076] Through the numerical control blanking process, the computer accurately determines the cutting and blanking of the steel plate, and determines the blanking dimensions through technological analysis to ensure the accuracy and adaptability of the steel plate dimensions.

[0077] In some embodiments, in the layout of the tooling jig, the assembly jig is arranged on the well-bearing concrete hardened ground; the main axis of the steel cofferdam is lofted on the ground according to the steel cofferdam segmentation, and the elevation of the axis of each curved surface is measured along the main axis; the jig materials are cut according to the measured results.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] After the installation of the outer wall plates is completed, the plate units of the ring plates, inner partitions and stiffeners are successively positioned and installed according to the lofting axes. Before the positioning and assembly of the inner partitions and ring plates, a working scaffolding platform is erected inside the box body. After the installation of the inner partitions is completed, inspection shall be carried out before welding. The quality inspector shall check the internal dimensions of the structure, the spacing between partitions and other external dimensions. Welding can only be carried out after passing the inspection to ensure the accuracy of the welding points of the inner partitions. When welding the internal plates of the segment blocks, the pre-determined welding sequence shall be followed. To prevent deformation after welding at the butt welding position of the outer wall plates, the partition units and stiffener plates are first fixed to the outer wall plates by skip welding in sections, and then the outer wall plates are welded after the welding of the stiffener plates is completed.

[0084] The inner wall plates are made into plate unit structures. The stiffeners and inner wall plates are pre-assembled and welded. Special tooling jigs shall be used for the production of the plate units to ensure the assembly accuracy and welding quality and control and correct the welding deformation.

[0085] After the inner wall plates are lifted onto the tooling jigs, the edges of the steel plates are fixed by fixing clamps around the steel plates to make the steel plates fit the template of the jigs, so that a certain pre-arch is added to the plate units before welding to control the welding deformation. The production of the inner wall plate units is carried out simultaneously with the welding of the internal structures of the outer wall plates and partitions. After the welding of the internal structures of the outer wall plates of the steel caisson is basically completed, the plate units of the inner wall plates are successively assembled according to the lofting positioning reference line, thus improving the production efficiency.

[0086] According to the above-mentioned assembly and welding of the segment blocks, laying and assembling are carried out strictly in accordance with the marking lines, which can reduce the welding amount in the limited space, improve the production efficiency at the same time, reduce the error value, and form a complete pre-assembly section.

[0087] Furthermore, after the plate units of the inner wall plates are assembled according to the corresponding dimensions, the ring plates and partitions are welded and positioned with the plate units of the inner wall plates, and then the accessory structures are installed. The accessory structures are installed along the wall surface of the inner wall plates or the ring plates. After the installation of the accessory components is completed, the box girder stage is turned over to complete the welding of all structural welds, thus ensuring the integrity of the overall pre-assembly section.

[0088] Among them, after the installation of the accessory structures, the pre-assembly section is integrally assembled. The overall assembly of the steel caisson is carried out in the general assembly area. The assembly is hoisted by a 2000-ton crawler crane. After the vertical assembly is completed, overall matching drilling is carried out.

[0089] The process description of the overall assembly needs to be described according to the overall structure. Refer to the following anti-collision steel caisson structure.

[0090] This application also provides an ultra-large offshore anti-collision steel caisson. Refer to Figure 1 and Figure 2 As shown, the steel caisson is composed of segment blocks produced by segmented manufacturing, and the segment blocks are segmented and assembled to form a pre-assembly section 1, and then the pre-assembly section 1 is integrally assembled into a complete anti-collision steel caisson.

[0091] It includes a bottom formwork, side formworks and pre-assembled section 1; the bottom formwork is placed at a preset tooling saddle, and the side formworks are placed on the bottom formwork, so as to limit the installation positions of the bottom and side parts of the pre-assembled section 1, thereby ensuring the accuracy of the assembly position. After the side formworks are installed, on the basis of the bottom formwork, the pre-assembled section 1 is erected for assembly.

[0092] The pre-assembled section 1 can be divided into a curved surface steel casing section 11 and a straight surface steel casing section 12 according to the shape. The curved surface steel casing section 11 is divided into four groups, namely the first curved surface box 111, the second curved surface box 112, the third curved surface box 113 and the fourth curved surface box 114; the straight surface steel casing section 12 is divided into four groups, namely the first straight surface box 121, the second straight surface box 122, the third straight surface box 123 and the fourth straight surface box 124. Therefore, the pre-assembled section 1 is divided into 8 groups in total, and the 8 groups are erected for assembly to form a complete steel casing.

[0093] The erection sequence is as follows: the first straight surface box 121 and the second straight surface box 122 are erected for assembly, and the third straight surface box 123 and the fourth straight surface box 124 are erected for assembly; after the first curved surface box 111 and the second curved surface box 112 are erected for assembly, one end of the first curved surface box 111 away from the second curved surface box 112 is erected for assembly with the first straight surface box 121, and one end of the second curved surface box 112 away from the first curved surface box 111 is erected for assembly with the third straight surface box 123; after the third curved surface box 113 and the fourth curved surface box 114 are erected for assembly, one end of the third curved surface box 113 away from the fourth curved surface box 114 is erected for assembly with the second straight surface box 122, and one end of the fourth curved surface box 114 away from the third curved surface box 113 is erected for assembly with the fourth straight surface box 124.

[0094] After the erection for assembly is completed, the bottom formwork is hoisted and installed and the accessory structure 2 is installed. The accessory structure 2 may include a connection structure bridging between any adjacent pre-assembled sections 1 for strengthening the connection of the adjacent pre-assembled sections 1.

[0095] By dividing the pre-assembled section 1 into eight sections, the pre-assembled section 1 is accurately erected for assembly by using the limit of the bottom formwork and the side formworks. According to a specific erection sequence, the steel casing is gradually formed and the accuracy of the erection for assembly is high, which is convenient for the subsequent welding process and speeds up the overall assembly efficiency.

[0096] According to the above-mentioned steel casing erection sequence, a vertical assembly process flow is provided: During erection for assembly, first place the bottom formwork of the steel casing on the tooling saddle, place the side formwork sections of the steel casing on the bottom formwork, and then carry out the erection for assembly of the steel casing on the basis of the bottom formwork.

[0097] The vertical assembly sequence is: bottom die of steel casing→the first straight box 121 and the second straight box 122→the third straight box 123 and the fourth straight box 124→the first curved box 111 and the second curved box 112→the third curved box 113 and the fourth curved box 114→hanging and installing the bottom die of steel casing→installing the accessory structure 2.

[0098] Furthermore, the thickness at the connection between the first curved box 111 and the second curved box 112 is greater than the thickness at the vertical assembly connection between the first curved box 111 and the first straight box 121 or between the second curved box 112 and the third straight box 123; the thickness at the connection between the third curved box 113 and the fourth curved box 114 is greater than the thickness at the vertical assembly connection between the third curved box 113 and the second straight box 122 or between the fourth curved box 114 and the fourth straight box 124, that is, the thickness at 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 is thicker, and the thickness of the first straight box 121 - the fourth straight box 124 is lower. This method 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 face the scouring of ocean waves head-on, and using a thicker thickness can improve the compressive resistance to scouring.

[0099] Still further, a fastening structure 3 is also provided at the connection point of adjacent pre-assembled segments 1 of the accessory structure 2. Refer to Figure 4 As shown, taking the connection between the first straight box and the second straight box as an example in the figure, the fastening structure 3 can provide a fastening effect when adjacent pre-assembled segments 1 are vertically assembled, facilitating stable connection during welding or drilling connection.

[0100] 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 formed on the surface of the accessory structure 2, and a pivot port 22 is formed in the embedding groove 21. The pivot shaft 32 is pivotally connected to the pivot port 22. The extension rod 31 is connected to the pivot shaft 32, and the extension rod 31 can be rotated through the pivot shaft 32 into the embedding groove 21 of another accessory structure 2.

[0101] An extension protrusion 311 is provided on the extension rod 31, making the extension rod 31 in a T-shaped shape adapted to the embedding groove 21. A threaded hole is also provided on the side of the embedding groove 21 close to another accessory structure 2. A fastening bolt 33 is screwed into the threaded hole, and the fastening bolt 33 can be rotated with the threaded hole to extend the fastening bolt 33 into the embedding groove 21.

[0102] When the extension rod 31 rotates through the pivot shaft 32 and turns into another embedding groove 21, the two auxiliary structures 2 are bridged. At this time, no tensile force for fastening the two pre-assembled segments 1 is applied. By rotating the fastening bolt 33, the fastening bolt 33 extends into the embedding groove 21 through the threaded hole and abuts against the extension protrusion 311. Along with the tightening degree of the fastening bolt 33, one end of the extension rod 31 is limited through the pivot port 22, and the other end is fastened through the fastening bolt 33, so as to cooperate with the auxiliary structure 2 to fasten the two adjacent pre-assembled segments 1, making the positions of the pre-assembled segments 1 stable during welding or drilling connection and reducing errors.

[0103] When welding or drilling and connecting to the extension rod 31, in order to avoid the extension rod 31 from hindering the welding or drilling process, loosen the fastening bolt 33, and then the extension rod 31 can be rotated through the pivot shaft 32 to disengage from the embedding groove 21 on one side, and this point can be welded or drilled and connected.

[0104] Among them, after the sectional blocks are assembled in segments, the auxiliary structure 2 will be installed, and then the vertical assembly of the pre-assembled segment 1 will be carried out. Through the rotatable extension rod 31, no hindrance phenomenon will occur during the vertical assembly.

[0105] This application also provides an anti-corrosion coating process for the steel cofferdam: 1. Pre-coat shop primer Before blanking, the plates and sections are both subjected to shot blasting and spraying of shop primer through the pretreatment production line.

[0106] 2. Section coating The surface treatment and spraying operations are both carried out in a dedicated coating workshop, and the temperature and humidity in the coating room should meet the requirements of the corresponding specifications. The coating operation procedure follows the operation sequence of "corner grinding → degreasing and defouling → sandblasting → cleaning → spraying".

[0107] 3. Supplementary coating Grind the reserved parts of the segment assembly welds and the damaged parts to make their rust removal grade and surface roughness meet the specification requirements, and carry out supplementary coating layer by layer in a brushing manner according to the coating system.

[0108] Process requirements: (1) The anti-corrosion coating requirements should comply with the provisions of the "Code for Anti-corrosion Construction of Marine Engineering Structures" (JTS / T 209 - 2020).

[0109] (2) Coating environment requirements ① The environmental temperature ≥ 5 °C; ② The relative humidity is lower than 85%, and construction is strictly prohibited in rainy days; ③ The surface temperature of the steel is more than 3 °C higher than the dew point; ④ It is not suitable to construct under direct sunlight in summer.

[0110] (3)Surface pretreatment Before the shot blasting and derusting treatment on the painted surface of steel structural parts, all grease on this surface shall be solvent-cleaned with a suitable cleaner (water-soluble alkaline emulsifier) in accordance with the requirements of SSPC-SP1. When cleaning with a rag and solvent, dry film formation on this surface after cleaning shall be avoided, and the use of flammable materials shall be minimized. Necessary labor protection articles shall be provided when using this solvent to effectively protect the respiratory system, eyes, skin, etc. of operators.

[0111] Visible burrs, cutting fragments, steel cracking, delamination, welding spatter, welding slag, etc. on the painted surface shall be effectively removed before shot blasting. All free edges and sharp edges shall be ground and removed (P2).

[0112] During surface treatment, the temperature of this surface shall be more than 3 degrees Celsius higher than the dew point. Appropriate indirect heating methods can be used to meet the above conditions. Direct heating of the treated surface is not allowed.

[0113] (4)Sandblasting All sandblasted surfaces shall meet the following standards: Cleanliness - Sa 2.5 (ISO 8501); Roughness - N9a to N10a (Ra = 6 - 12.5 micron) – Rugotest No.3; Medium (G) - ISO8503 - or Keane-Tator Surface Compactor, with the measured roughness value of 40 - 75 micron for 2 - 3 mils; The shot blasting medium shall be clean, dry, free of oil and foreign matters. The mechanical shot blasting medium shall be a mixture of angular sand to ensure that the surface roughness meets the requirements of ISO 8503-2, reaching 50~100μm. The recycled metal sand shall meet the requirements of ISO11124.

[0114] (5)Power tool cleaning Power tool cleaning shall refer to SSPC-SP3 or ISO-8501. Manual tool cleaning shall refer to SSPC-SP2. When sandblasting is followed by manual tool cleaning or power tool cleaning, it must be approved by the owner. During the structural fabrication process, sharp edges, spatter, etc. generated due to thermal cutting, welding, etc. shall be removed with power tools before painting.

[0115] (6)Surface cleaning before paint spraying Before paint spraying, sundries on the surface shall be cleaned with clean and dry compressed air. A filter steel sleeve box shall be installed in the air pipeline of the spraying equipment to clean the air. If the surface cannot be cleaned with compressed air, a vacuum cleaner shall be used to clean the surface.

[0116] (7) Receiving and Storage of Coating The coating should meet the following conditions upon arrival: unopened, with clear product identification, batch number and production date. Paint buckets containing damaged coatings shall not be used.

[0117] The storage of the coating shall be carried out according to the product instructions of the coating, and damage, moisture absorption and direct sunlight shall be prevented. Meanwhile, the temperature at the storage location shall be maintained between 5°C and 25°C, and away from flammable materials. The coating should be ensured to be used within the validity period. After the coating is opened, it should be used immediately.

[0118] The above acceptance conditions of the coating, related product names, validity periods, etc. shall be confirmed one by one upon the arrival of the coating, and it shall be ensured that the coating is used within the validity period.

[0119] (8) Mixing and Dilution Mixing shall be carried out strictly according to the complete components recommended by the manufacturer. Partial mixing is allowed when needed (e.g., for patching). Each independent component shall be fully stirred before being mixed with other components. Curing agents and additives shall be added gently and slowly at low speed of the mixer. Stir at medium speed to obtain a uniformly mixed coating.

[0120] (9) Painting Construction High-pressure airless spraying is recommended. Brushing and rolling can be used for pre-coating, especially brushing.

[0121] For difficult-to-spray areas such as edges and dead corners, pre-coating with a paintbrush can be carried out before spraying to meet the film thickness requirements.

[0122] For paints with unfamiliar properties, the wet film control method provided by the manufacturer shall be used for spraying. During the construction process, the required wet film thickness shall be maintained as much as possible to ensure the required dry film thickness.

[0123] (10) Paint Repair Unless otherwise specified, the same paint as the original shall be used for paint repair of damaged areas. Defects such as sagging, missed coating, bubbles, and heavy marks may occur during construction, and it is also possible that the product coating peels off. These defects existing in the dry film coating shall be removed with power tools, and the surrounding areas shall also be appropriately sanded and then re-coated.

[0124] After the anti-corrosion painting process, inspections are also required. The inspection standards and methods include: (1) Inspection Frequency: Sampling inspection shall be carried out in units of the steel anti-collision caisson block numbers, with a sampling ratio of 100%. Ten points shall be randomly selected from the inner and outer surfaces of the sampling points.

[0125] (2) Surface Treatment: Visually inspect the surface to meet the surface standards of Sa2.5 (ISO8501-1:1988) or SSPC-SP10.

[0126] (3)Coating appearance quality inspection: In accordance with Article 14.2.3 of the standard GB50205-2001, the surface is smooth, clean, and uniform.

[0127] (4)Film thickness quality: Inspected with a dry film magnetic thickness gauge in accordance with the standard GB50205-2001. The dry film thickness at the inspection points is 600±30μm for the inner surface and 670±30μm for the outer surface.

[0128] (5)Color: Safety color - orange red.

[0129] (6)Coating adhesion strength: The adhesion strength at the inspection points is ≥5MPa (GB / T 5210).

[0130] (7)Acceptance: After the steel anti-collision caisson is anti-corrosion treated, it meets the above inspection standards, and each person in charge signs and confirms.

[0131] This application also provides a welding process, including: 1) Cleaning before welding. All oxide scales, rust, oil stains, and other sundries within a range of 50~100mm on both sides of all surfaces to be welded and the weld grooves should be cleaned thoroughly. After each weld pass is completed, it should also be cleaned in a timely manner. After inspection and passing, welding can be carried out.

[0132] 2) Welding methods The following methods can be used for welding (gas shielded welding can only be carried out in the workshop approved by the owner): . Manual arc welding . Submerged arc welding . Flux cored arc welding (self-shielded) . Flux cored arc welding (gas shielded) . Gas / metal arc welding (spray arc) . Tungsten inert gas welding The heat energy input during all welding processes should be between 1.0 kJ / mm and 4.5 kJ / mm.

[0133] 3) Tack welding. Structural connections need to be positioned and assembled through tack welding or other methods approved by the owner and the supervision party. This part of the work should be carried out as efficiently as possible, minimizing the total amount of temporary components and ensuring that the structure has sufficient stability. The tack welding should be consistent with the root pass parameters set in the approved welding process specification. Otherwise, the tack weld shall not be used as the product weld and should be removed during root cleaning.

[0134] 4) Preheating and interpass temperature The preheating treatment for tack welding, production welding, arc air gouging, and thermal cutting should be the same. When the ambient temperature is lower than -20°C, welding cannot be carried out unless specific preventive measures can maintain the preheating level specified by the owner.

[0135] 5) Welding construction All necessary steps shall be taken to ensure that all structural connection parts are sufficiently supported and welded according to the qualified welding process approved by the Employer. The Contractor shall be responsible for arranging a reasonable welding sequence to minimize the impact of residual stress, deformation and warping on structural members.

[0136] All full penetration welds shall be carried out according to the welding process recognized by the Employer. Single-sided full penetration welding is only allowed when the reverse side is inaccessible. Before welding on the second side, all double-sided full penetration butt welds shall be back gouged to a sound condition or gouged according to the process approved by the Employer. After each weld pass is completed, the weld shall be thoroughly cleaned. After the structural connection welds are completed, all spatter and deposits in the weld and adjacent areas shall be cleaned. Use a wire brush or grinder to clean the welds between passes and finally.

[0137] 6) Weld surface grinding After different sub-assemblies are manufactured, the Contractor shall remove all burrs, tack welds and other marks such as mud marks and horse hoof marks caused by scaffolding or temporary supports. Random arc strikes and all harmful defects shall be removed. If necessary, the welds shall be inspected and repaired. All weld repairs shall be carried out before any post-weld treatment. After the temporary supports are removed, the base metal shall be inspected by MT to confirm that there are no harmful defects such as cracks on the base metal. The removal of temporary supports shall not be carried out by carbon arc gouging.

[0138] Weld inspection is also required after welding, including the following inspection methods: 1) Set up a full-time quality control group, which has sufficient qualifications and experience to control and ensure that all tests and inspections of this project comply with the specification requirements.

[0139] 2) The quality control group is responsible for and ensures that all document quality, welding process, welder qualifications, welding production, manufacturing, inspection and testing are carried out in an appropriate manner and form, and report to the Employer / Supervision Party.

[0140] 3) Before manufacturing starts, establish part and weld numbers. The reporting reference for all weld inspections shall be clearly marked in the working area so that the exact location of weld defects can be obtained.

[0141] 4) The qualifications and capabilities of all non-destructive testing personnel shall meet at least the requirements of Grade II or above qualification and certification of the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China and be approved by the Employer.

[0142] 5) Magnetic particle testing (MT) can be used for the welded surfaces of various connections. Radiographic testing (RT) is only applicable to butt welds. Ultrasonic testing (UT) is applicable to various connection welds.

[0143] The embodiments of this specific implementation manner are all preferred embodiments of this application, and do not limit the protection scope of this application accordingly. The same components are denoted by the same reference numerals. Therefore, all equivalent changes made according to the structure, shape, and principle of this application shall be covered within the protection scope of this application.

Claims

1. A construction process for an ultra-large offshore anti-collision steel casing, characterized in that, It includes the following steps: Intelligent modeling and process optimization: Establish a BIM model of the steel caisson based on Tekla software, and optimize the sectional design through virtual pre-assembly; Combine digital twin technology to pre-enact the construction process, optimize the welding sequence and the layout of the jigs, and generate process animations to guide the construction disclosure; Modular sectioning and deformation control: Layer the steel caisson by function, fabricate sections using arc jigs, and offset welding shrinkage through pre-arching technology to achieve block assembly line processing of the steel caisson; Apply CO2 gas shielded welding and submerged arc automatic welding, and equip with a real-time welding parameter monitoring system; Intelligent anti-corrosion and quality control: Adopt a double-layer anti-corrosion of epoxy glass flake paint + acrylic polysiloxane topcoat, and combine automated spraying equipment to control the film thickness error; Online monitor the painting quality through magnetic thickness gauges and adhesion testers, and synchronously upload the data to the cloud management platform; Total assembly precision control: Accurately lay out the ground line on the jig, position the segments based on the external arc as the base surface, and combine laser calibration technology to control the assembly error; After the segments are fabricated, use a hydraulic tilting machine to adjust the attitude to ensure the interface matching precision during vertical total assembly, and conduct intelligent acceptance after total assembly.

2. The construction process of an ultra-large offshore anti-collision steel casing according to claim 1, characterized in that The construction process of the pre-assembly section of the steel caisson includes the following processes: Material arrival; Steel plate pretreatment; CNC cutting; Jig layout; Section fabrication; Installation of auxiliary structures; Overall splicing.

3. A construction process for an ultra-large offshore anti-collision steel caisson according to claim 2, characterized in that, The steel plate pretreatment is to perform sandblasting and rust removal on the steel plate. The sandblasting construction is carried out in a relatively enclosed sandblasting room, and sufficient ventilation and lighting are ensured.

4. The construction process of an ultra-large offshore anti-collision steel caisson according to claim 2, characterized in that, In the CNC cutting process, the following steps are adopted: Computer modeling and theoretically determining the dimensions; Process analysis to determine the welding, machining compensation amounts, and linear adjustment amounts; Determining the part cutting dimensions; Group analysis; CNC cutting, and the computer generates the part cutting nesting drawing; CNC programming, material utilization rate analysis, and cutting after determination.

5. A construction process for an ultra-large offshore anti-collision steel caisson according to claim 2, characterized in that In the jig layout, install the assembly jig on the concrete hardened ground with good bearing capacity; Lay out the main axis of the steel caisson on the ground according to the steel caisson sections, and measure and set the axis elevation of each curved surface position based on the main axis; Cut the jig materials according to the measured results.

6. The construction process of an ultra-large offshore anti-collision steel caisson according to claim 2, characterized in that, Section fabrication is divided into section block division and sectional assembly.

7. A construction process for an ultra-large offshore anti-collision steel casing according to claim 6, characterized in that, In the sectional assembly, it is necessary to assemble the section blocks of the steel caisson. The section blocks are composed of outer wall plates, inner wall plates, transverse diaphragms, ring plates, diaphragms, and stiffeners; Make layout marking lines on the jig according to the layout dimensions of the outer wall plates, and lay the outer wall plates through the marking lines; After the installation of the outer wall plates is completed, sequentially position and install the plate units of the ring plates, inner diaphragms, and stiffeners according to the layout axis; The inner wall plates are fabricated into plate unit structures, and the stiffeners are pre-assembled and welded with the inner wall plates. After the inner wall plates are lifted onto the jig, the plate edges of the steel plates are fixed with fixed clamps around the steel plates to make the steel plates fit the jig template, so as to increase the pre-arch of the plate units before welding to control the welding deformation. The fabrication of the inner wall plate units is carried out simultaneously with the welding of the internal structures of the outer wall plates and diaphragms. After the welding of the internal structures of the outer wall plates of the steel caisson is completed, sequentially assemble the plate units of the inner wall plates according to the layout positioning reference lines; The diaphragm units and stiffener plates are welded to the outer wall plates in a segmented skip welding manner, and after the welding of the rib plates is completed, the outer wall plates are welded.

8. The construction process of an ultra-large offshore anti-collision steel caisson according to claim 7, characterized in that, After the plate units of the inner wall panel are assembled according to the corresponding dimensions, the ring plate and the partition plate are welded and positioned with the plate units of the inner wall panel, and then the accessory structure is installed.

9. A super-large offshore anti-collision steel casing, characterized in that, Manufactured by the construction process of the super-large offshore anti-collision steel caisson described in Claim 8, the steel caisson is composed of segment blocks produced by segmented manufacturing, and the segment blocks are assembled into a pre-assembled section (1) by segmented assembly, and then the pre-assembled section (1) is assembled into a complete anti-collision steel caisson through overall assembly; it includes a bottom mold, a side mold and a pre-assembled section (1); the bottom mold is placed at a preset tooling saddle, and the side mold is placed on the bottom mold; on the basis of the bottom mold, the pre-assembled section (1) is erected and assembled; the pre-assembled section (1) can be divided into a curved surface steel caisson section (11) and a straight surface steel caisson section (12) according to its shape; the curved surface steel caisson section (11) is divided into four groups, namely the first curved surface box (111), the second curved surface box (112), the third curved surface box (113) and the fourth curved surface box (114); the straight surface steel caisson section (12) is divided into four groups, namely the first straight surface box (121), the second straight surface box (122), the third straight surface box (123) and the fourth straight surface box (124); the erection and assembly sequence is: the first straight surface box (121) is erected and assembled with the second straight surface box (122), and the third straight surface box (123) is erected and assembled with the fourth straight surface box (124); after the first curved surface box (111) and the second curved surface box (112) are erected and assembled, one end of the first curved surface box (111) away from the second curved surface box (112) is erected and assembled with the first straight surface box (121), and one end of the second curved surface box (112) away from the first curved surface box (111) is erected and assembled with the third straight surface box (123); after the third curved surface box (113) and the fourth curved surface box (114) are erected and assembled, one end of the third curved surface box (113) away from the fourth curved surface box (114) is erected and assembled with the second straight surface box (122), and one end of the fourth curved surface box (114) away from the third curved surface box (113) is erected and assembled with the fourth straight surface box (124); after the erection and assembly are completed, the bottom mold is hoisted and installed and the accessory structure (2) is installed.

10. A super-large offshore anti-collision steel casing according to claim 9, characterized in that, The thickness at the joint between the first curved surface box (111) and the second curved surface box (112) is greater than the thickness at the joint where the first curved surface box (111) is erected and assembled with the first straight surface box (121) or the second curved surface box (112) is erected and assembled with the third straight surface box (123); the thickness at the joint between the third curved surface box (113) and the fourth curved surface box (114) is greater than the thickness at the joint where the third curved surface box (113) is erected and assembled with the second straight surface box (122) or the fourth curved surface box (114) is erected and assembled with the fourth straight surface box (124).

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