219 results about "Repair method" patented technology

The invention discloses a composite insulating arm surface repairing material and a repairing method, and the repairing material comprises the following raw material components in parts by weight: 100 parts of matrix resin, 0.8-4 parts of a curing agent, 0.2-1.2 parts of an accelerant, 5-20 parts of color paste, 10-25 parts of inorganic particles, and 10-25 parts of inorganic fibers. The repairing material is simple in preparation method and convenient to use, according to the repairing method, the repairing material is used for replacing gel coat spraying repairing, the operation difficulty is low, the repairing duration is shortened, the repairing efficiency is improved, and all technical indexes of the repaired insulating arm component can meet the use requirements.

The invention discloses a pavement crack rapid repairing method and system, and the method comprises the steps: obtaining multi-source data of a target pavement through a multi-source device, and carrying out the preprocessing of the multi-source data; wherein the multi-source data comprises a target road surface image and target road surface point cloud data; outputting crack features of the target pavement according to the preprocessed target pavement image and the target pavement point cloud data; wherein the crack characteristics comprise the crack length, the crack width, the crack depth, the crack trend, the crack branch number and the crack position; generating a pavement crack repairing scheme based on the crack characteristics; wherein the repairing scheme comprises a repairing material, a repairing mode and repairing process parameters; according to the crack position and the repairing scheme, a repairing track of repairing equipment is determined; and according to the repairing track and the repairing scheme, the repairing equipment is controlled to move to the target position to quickly and accurately repair the pavement crack, so that the repairing efficiency is improved, the cost is reduced, and the repairing quality is ensured.

The invention belongs to the technical field of software test automation, and discloses an automatic test script repair method and related device.The method comprises the steps that feature data in the test script execution process are obtained; detecting a preset error problem of the test script based on the feature data in the execution process of the test script to obtain a problem detection result of the test script; wherein the preset error problem of the test script comprises a grammar error, a logic error, an interface error and an interface error of the test script; based on the problem detection result of the test script, selecting an optimal repair strategy from a pre-constructed repair strategy library, and generating a repair instruction based on the optimal repair strategy; based on the repair instruction, performing automatic repair operation on the test script; according to the method and the device, automatic repair of the test script is realized, a tester does not need to manually check and modify codes related to the interface elements in the script one by one, time and labor cost are greatly saved, and test efficiency is remarkably improved.

The invention discloses a repairing and fitting method for end faces of bending and twisting supporting plates of a diffusion section assembly, which comprises the following steps: reserving machining allowance on an assembling end face of each to-be-assembled bending and twisting supporting plate and an outer ring, then assembling the outer ring on an outer ring assembling clamp, and then acquiring molded surface data of corresponding assembling of each bending and twisting supporting plate on the outer ring; generating an actual molded surface of the bending and twisting supporting plate according to the molded surface data, compiling an assembling end face machining program of the bending and twisting supporting plate according to the molded surface, assembling the bending and twisting supporting plate and the inner ring into a component, and milling the assembling end face after the component is assembled through a milling clamp, and programming, measuring and milling the assembly end face, modeling to obtain an actual molded surface, comparing the actual molded surface with the actual molded surface of the bending and twisting support plate generated before in profile tolerance, assembling the bending and twisting support plate with the outer ring if the actual molded surface meets the requirement, and otherwise, performing supplementary processing until the bending and twisting support plate is qualified. The method solves the technical problems that in an existing repairing method, the assembling clearance cannot be met, the machining efficiency is low, and the engine test run performance requirement cannot be met.

The invention discloses a composite material tenon wrinkle defect identification and repair method and device based on semantic segmentation and generative adversarial network, and belongs to the technical field of composite material fan blade tenon nondestructive testing and computer vision. The method comprises the following steps: acquiring an image containing a wrinkle defect by using an industrial camera, labeling fibers and a background, and constructing a training and verification image set; a semantic segmentation network is established and trained, and wrinkle defects in the image are automatically identified; if the segmentation effect is not good, a generative adversarial network is further introduced to construct a fiber repair model, and fine repair of fiber textures is realized through adversarial training of a generator and a discriminator; and repeating the steps to treat all the composite material tenon test pieces until all the wrinkle defects are identified and repaired. According to the method, the wrinkle defect of the tenon made of the composite material is recognized and repaired, and reliable technical support is provided for intelligent nondestructive testing of the fan blade made of the composite material.

This invention relates to the field of road crack repair, addressing the problem that existing repair devices cannot simultaneously implement grouting repair and crack sealing tape repair methods. It provides a road crack repair device comprising a vehicle body, a storage tank, and a grouting pipe, the storage tank being connected to the grouting pipe. The device further includes: a rotating rod; a compaction roller and a crack sealing tape cylinder, the compaction roller and the crack sealing tape cylinder being disposed on opposite sides of the rotating rod; a release membrane cylinder, the release membrane cylinder passing through the rotating rod and positioned opposite the crack sealing tape cylinder; a driving gear, the driving gear being connected to the side wall of the crack sealing tape cylinder; a driven gear, the driven gear meshing with the driving gear, the driven gear being connected to the side wall of the release membrane cylinder; and a drive mechanism for driving the rotating rod to rotate. This invention, by setting up a rotating rod and distributing the compaction roller and the crack sealing tape cylinder on opposite sides of the rotating rod, simplifies the switching between grouting repair and crack sealing tape repair methods.

The application relates to the technical field of road surface repair, in particular to a dynamic repair method and system for heavy-load road surface rut level evolution. The method comprises the following steps: acquiring a multi-source monitoring data set and a heavy-load traffic load spectrum, analyzing damage evolution characteristics of road surface ruts in depth and layer position based on the multi-source monitoring data set and in combination with the heavy-load traffic load spectrum, and obtaining a road surface level evolution information set; based on the road surface level evolution information set, analyzing interface bonding and performance characteristics of milling intervention behavior and hierarchical repair materials respectively in cooperation with an existing road surface matrix under a heavy-load-movable-load environment during a repair process, and obtaining a dynamic repair information set; and driving a dynamic repair differentiated milling operation according to the dynamic repair information set, and synchronously generating a dynamic repair log. The method effectively prolongs the service life of the repaired road, alleviates the repeated rut disease problem, and improves the overall maintenance level of the heavy-load road surface.

The invention provides an evaluation and repair method and system for a composite bushing umbrella skirt. The method comprises the following steps: detecting and evaluating the current aging state of the composite bushing umbrella skirt to obtain an aging grade; setting a repair decision according to the aging level; and repairing the composite sleeve umbrella skirt according to the result of the repairing decision. Through the processing of the steps, the evaluation and restoration method breaks through the limitation of detection decentralization, evaluation subjectivity and restoration manual operation in the prior art, establishes a standardized grading evaluation and decision-making mechanism, constructs a whole-process automatic restoration system, and improves the accuracy of the whole-process automatic restoration. According to the method, the aging state of the composite sleeve umbrella skirt can be automatically and accurately evaluated, the repairing process is intelligently and adaptively executed, the repairing effect is verified in a closed loop mode, and standardization, automation and precision of aging repairing of the composite sleeve umbrella skirt are achieved, so that the operation and maintenance cost and dependence on manpower are greatly reduced on the premise that the repairing quality is guaranteed, and the repairing efficiency is improved. And the repair efficiency and quality of the composite sleeve umbrella skirt are improved.

To provide a repair method for building rubber products capable of suppressing crack progress and extending the service life of building rubber products, and to provide building rubber products with high repair effectiveness and excellent durability.SOLUTION: A repair method for building rubber products comprises: a cutting step of cutting an area including a crack 17 generated on a surface of a building rubber product 1 to form a recess 20; a filling step of filling the recess 20 with a filling material 21; and a coating step of applying a coating material to cover an opening of the recess 20 to form a protective film 22. A vertical length of the opening of the recess 20 is equal to or greater than a depth of the recess 20. The building rubber product 1 has a repair portion 2. The repair portion 2 comprises: the recess 20 formed by cutting the surface of the building rubber product 1 prior to repair; the filler material 21 filled into the recess 20; and the protective film 22 covering the opening of the recess 20. The vertical length of the opening of the recess 20 is equal to or greater than the depth of the recess 20.SELECTED DRAWING: Figure 2

The application discloses a power supply board batch repair device and a repair method thereof, and relates to the technical field of power supply board repair, which comprises a circuit board repair box, an inlet is fixedly installed at one end of the outer part of the circuit board repair box, an outlet is fixedly installed at the other end of the outer part of the circuit board repair box, two groups of first identification cameras are symmetrically installed at one side of the outer part of the circuit board repair box, and two groups of second identification cameras are symmetrically installed at the other side of the outer part of the circuit board repair box. Through the cooperation of the repair control system and the first identification cameras, the types of pollutants on the board surface and the back surface of the circuit board can be automatically identified, the identification results are used to control the automatic adjustment of the cleaning agent in the built-in adjustment liquid storage cavity of the cleaning water tank through the repair control sub-module, the opening and closing degrees of the valves are automatically adjusted according to the differences between the board surface and the back surface to change the cleaning intensity, the board surface is gently cleaned, the precise components are prevented from being damaged, the back surface is strongly flushed, and the residual welding slag is prevented.

The invention discloses a repairing production line for a cathode copper plate and a repairing method. The repairing production line comprises a special repairing machine and further comprises a first conveying section and a second conveying section which are arranged side by side; the two ends of the first conveying section are provided with an abnormal copper wire feeding opening and an RGV goods taking position respectively, the middle area of the first conveying section is provided with an abnormal copper goods taking position and an unrepairable copper plate placing position, and the abnormal copper goods taking position is provided with a hemming detection position. The device is simple in structure, the mobile module and the camera work cooperatively, the surface of the cathode copper plate can be scanned in an omnibearing and high-precision mode, defect or abnormal data of the copper plate are collected in real time, and the data information is fed back to the control unit in time; and the control unit performs rapid analysis and calculation based on the received data, generates a corresponding repair instruction, and drives the repair mechanism to complete repair operation on the cathode copper plate, so that the repair efficiency and quality are remarkably improved, and the manual intervention cost is reduced.

A repair search system proposing a repair method corresponding to a trouble code, the repair search system includes a microprocessor and a memory coupled to the microprocessor. The memory has a database storing the trouble code and the repair method performed in a past in association with each other. The microprocessor is configured to perform: by using a plurality of different search conditions created with the trouble code of a troubled vehicle as a reference, searching the database for a plurality of repair methods corresponding to the trouble code by every search condition; scoring each of repair method groups included in a search result acquired by every search condition; and outputting information indicating a repair method group with a highest score among the repair method groups.

The application discloses a kind of laminated composite intercalation repair methods, belong to laminated composite maintenance technical field.The application uses the way of multilayer intercalation reinforcement patch, significantly increase the bonding area of patch and original laminated laminated composite material, can effectively improve the bonding strength of repair area, so that repair area will not become laminated laminated composite material / member dangerous area;The bonding surface is composed of multiple planes, and adjacent bonding surfaces bear tensile or shear load respectively, and after debonding or damage of a certain bonding surface, the crack will not spread to other bonding surfaces, significantly enhance the damage tolerance of repair bonding area, and further improve the mechanical properties of repair material / member.

The application discloses an underwater dam defect self-adaptive repair method, which solves the problems of existing repair methods, such as solidification of a repair method process, dependence on experience for parameter setting, and lack of intelligent closed-loop feedback. The method comprises the following steps: acquiring multi-source detection data of a target defect area of an underwater dam, and extracting defect characteristic parameters; generating a customized repair scheme containing a repair process sequence and process parameters based on the defect characteristic parameters; performing a repair operation according to the customized repair scheme, and synchronously collecting process monitoring data; assessing the repair quality in real time based on the process monitoring data, and obtaining a repair quality conclusion; when the repair quality conclusion is unqualified, updating the defect characteristic parameters and the process parameters according to the unqualified degree and dimension, and re-performing the repair operation and quality assessment based on the updated parameters. The application improves the intelligent level and resource efficiency of underwater repair operation by constructing an adaptive closed loop of perception-planning-execution-evaluation-feedback.

This application provides a vehicle body repair sticker and a vehicle body repair method. The method includes: affixing the repair sticker to the entrance of a hole to be repaired on the vehicle body to form a closed space containing the hole; injecting a liquid repair material for repairing the hole into the closed space; inputting an electric current into the liquid repair material to solidify it into a solid repair material; and determining that the vehicle body repair is successful when the solid repair material reaches a preset state. This application utilizes a material that can gradually harden from a liquid to a solid state when energized as the vehicle body repair material. This material is injected into the hole to be repaired, and the state of the repair material is continuously observed after energizing. If the state of the repair material reaches the expected state, the hole repair can be determined to be complete, i.e., the vehicle body repair is successful. This method has many advantages, including simple repair method, high repair efficiency, low repair cost, and strong applicability.

This application discloses a directional repair device and method for hollow areas in the foundation of existing buildings, relating to the field of building technology. It not only enables effective grouting to repair hollow areas without damaging the existing foundation, but also allows the drill bit to extend and retract during the grouting process, eliminating the need to pull out the directional drill before grouting. The device includes a drill bit power unit, a grouting pipe section, and multiple connecting pipe sections. The drill bit power unit includes a first outer casing assembly, a drill bit, a drill bit drive mechanism, a drill bit retraction mechanism, a drill bit deflection mechanism, and a first support forward mechanism. The drill bit drive mechanism drives the drill bit to rotate; the drill bit retraction mechanism retracts the drill bit into the first outer casing assembly; the drill bit deflection mechanism adjusts the drilling direction of the drill bit; and the first support forward mechanism drives the drill bit drive mechanism, drill bit retraction mechanism, and drill bit deflection mechanism forward. This application also discloses a repair method.

The invention discloses a stand column repairing method which comprises the steps that S1, a defective stand column is detected, and a defective section of the defective stand column is found out; s2, temporary supporting pieces are arranged on earthworks on the two sides, in the length direction of the supporting beam, of the faulty stand column correspondingly, each temporary supporting piece is provided with a supporting end capable of moving in the vertical direction, the supporting ends are connected to the supporting beam, and the temporary supporting pieces are started to lift the supporting beam; s3, earthwork between the faulty stand column and the temporary supporting piece is excavated till the faulty section of the faulty stand column is completely exposed; s4, the problem segments are cleaned; s5, concrete is poured on the outer side of the problem segment to form a repaired concrete segment; and S6, the supporting beams are reinforced. Compared with the prior art, the problem stand column can be repaired in situ, two stand column piles and cross beams do not need to be newly constructed for underpinning according to a conventional scheme, and the construction period and the manufacturing cost can be better saved.

The invention discloses a Vue component dynamic layout offset repairing method and device, equipment and a storage medium, and is used for solving the technical problem that the existing Vue component dynamic layout offset repairing effect is poor. The method comprises the following steps: monitoring a layout offset event; removing a non-user operation associated event from the layout offset event to obtain a target event; extracting a displacement amount, an influence area and a trigger timestamp from the target event; positioning a source Vue component instance generating layout offset according to the coordinates of the influence area, and acquiring component information of the source Vue component instance; and repairing the source Vue component instance according to the displacement and the component information.

The present disclosure provides an aviation composite material repair digital twin and intelligent repair method, system and device, wherein the method comprises: transmitting the repair elements of the aviation composite material repair entity collected in real time to the aviation composite material repair digital twin; the digital twin establishes an initial visual digital model of the repair entity according to the structure parameters and damage parameters of the repair entity; the digital twin searches the design space according to the repair process parameters, predicts the key performance of different repair process parameter combinations, and obtains the target repair process parameters required for the repaired repair entity to achieve the key performance; the digital twin predicts the full-field distribution information of the key performance of the repair entity according to the repair process parameters and the initial visual digital model, and displays and analyzes; and transmitting the received target repair process parameters to the repair tool; setting the repair process according to the target repair process parameters through the repair tool, and implementing intelligent repair of the repair entity.

The invention provides a boiler tube plate crack defect repairing method. The boiler tube plate crack defect repairing method comprises the steps that S10, the two-dimensional morphology in a to-be-repaired area with a crack as the center on a first tube plate is collected; s20, a first cutting boundary L1 is determined according to the two-dimensional morphology in the to-be-repaired area; s30, the first tube plate is cut according to the first cutting boundary L1, when no tube hole exists in the to-be-repaired area, the second tube plate is not treated, and when the tube hole exists in the to-be-repaired area, the second tube plate is cut at the same position of the second tube plate; s40, according to the first cutting boundary L1, a required number of supplementary plates with the same shape are cut on the blank; and S50, when no pipe hole exists in the to-be-repaired area, the repairing plates are installed on the first pipe plate, and when pipe holes exist in the to-be-repaired area, the two repairing plates are installed on the first pipe plate and the second pipe plate correspondingly. By means of the technical scheme, the problem that in the prior art, cracks of the boiler tube plate cannot be repaired, and only scrapping treatment can be conducted can be effectively solved.

The invention discloses a surfacing repair method for a continuous casting roller, and relates to the technical field of metallurgical manufacturing, and the surfacing repair method comprises the following steps: S1, turning the surface of a low alloy steel matrix continuous casting roller, removing a fatigue layer until the depth is greater than or equal to 1.5 mm, and then adopting sand blasting treatment to enable the surface roughness Ra to be less than or equal to 6.3 microns; s2, a pulse arc welding process is adopted, a nickel-based alloy transition layer is overlaid on the surface of the base body, the Ni content is larger than or equal to 65 wt%, the thickness of the transition layer is 0.8-1.2 mm, and the interlayer temperature is controlled to range from 150 DEG C to 200 DEG C; s3, the transition layer is clad with a high-chromium cast iron composite coating through a submerged arc welding technology, the high-chromium cast iron composite coating comprises 25%-30% of Cr, 2.5%-3.2% of C, 1.5%-2.5% of Mo and the balance Fe and microelements, the thickness of a single layer is smaller than or equal to 0.5 mm, and the thickness of a total surfacing layer is 3-6 mm; and S4, stepped cooling heat treatment is conducted after surfacing is completed, cooling is conducted to 300 DEG C at the speed smaller than or equal to 30 DEG C / h in the first stage, air cooling is conducted to the room temperature in the second stage, and ultrasonic impact strengthening treatment is conducted on the surface of a surfacing layer.

The invention provides a quality rating and repairing method for a buried steel skeleton reinforced polyethylene composite pipe. The quality rating and repairing method comprises rating standard formulation, a measuring method, a rating process, repairing and replacing suggestions and the like. Through visual observation and accurate measurement, quality standards of different grades are clearly divided, and corresponding repair or replacement suggestions are given. According to the method, multiple detection means are combined, the accuracy and reliability of the rating result are ensured, and a scientific basis and technical support are provided for safe operation and effective management of the pipeline. The method is suitable for evaluating the quality condition of the buried pipeline after excavation and guiding subsequent maintenance and repair work.

A water leakage repair fitting is provided with: a first unit (1) having a fastening mechanism (4) and a plurality of metal strips (3) provided at intervals in the pipe circumferential direction of a fluid pipe (K), the fastening mechanism (4) fastening the pipe circumferential direction ends of the plurality of metal strips (3) to each other; a second unit (2) which is disposed adjacent to the first unit, and which is provided with a fastening mechanism (4) and a plurality of metal straps (3), the plurality of metal straps (3) being provided at intervals in the pipe circumferential direction of the fluid pipe (K), the fastening mechanism (4) fastening the ends of the plurality of metal straps (3) in the pipe circumferential direction to each other; and a first water stop piece (6) which is formed of an elastic body and extends from a first metal band (3 ') included in the first unit to a second metal band (3' ') included in the second unit in the axial direction (AD) of the tube. The length (L2) of the first water stop piece (6) in the pipe circumferential direction is smaller than the lengths of the first metal band (3 ') and the second metal band (3' ') in the pipe circumferential direction, and the first water stop piece (6) is pressed against the outer circumferential surface of the fluid pipe (K) by the first metal band (3') and the second metal band (3 '').

The application relates to the field of repair and remanufacture, and discloses a friction stir repair method based on high-combination joint design, which is used for realizing high-combination design of a material filled in a repair area and improving the overall mechanical properties of a repair joint. The method is as follows: I. preparing high-combination filling powder according to the material of a workpiece; II. opening a straight blind hole according to the size of a defect; III. determining the size of a stir head; IV. inserting the stir head into the blind hole to compact the filling powder; V. rotating and pressing the stir head to solidify the filling powder; and VI. repeating steps IV and V to complete the filling and welding process of the defect. The application has the beneficial effect that, based on the design of the high-combination joint, the weakening effect of a heat affected zone in a repair interface area can be reduced through the strengthening effect of the filled composite material, so that the purpose of strengthening the mechanical properties of the repair joint is achieved.

This invention discloses a rapid assessment and precise repair method for the degree of pulverization in ballastless track bed concrete. By preparing concrete reference specimens of different strength grades, a correlation curve between pull-out strength and overall strength is established. Combined with probe diameter selection, surface grinding, and adhesive bonding techniques, a non-destructive and rapid detection of the pulverized layer is achieved. Specifically, the method includes: a preliminary preparation stage where specimens are prepared and a pull-out strength-strength model is established; an evaluation stage where layer-by-layer pull-out testing combined with precise hollow drilling quantitatively determines the depth and extent of pulverization; and a repair stage where the pulverized layer is replaced with a high-toughness material and a drainage slope is installed. This invention solves the problems of low efficiency, significant damage, and inaccurate repair associated with existing methods. Through parametric design and a modular system, it significantly improves detection accuracy and repair effectiveness. It is applicable to the maintenance of concrete structures such as high-speed railway track base plates, meets industry standards, and has the advantages of simple operation, low cost, and strong adaptability.

The application provides a kind of tool for thin-walled component defect solid-phase repair and repair method, it is related to material processing and manufacturing technical field.The repair tool includes: disc base, it is equipped with center mounting hole, can be installed with transmission key groove, disc base outer periphery is equipped with repair area, repair area surface is provided with interval arrangement groove, repair area is used to rotate pre-press and cooperate repair material to repair;The two sides of repair area are equipped with finishing area, and the outer periphery of finishing area is provided with positive rotation finishing blade and reverse rotation finishing blade arranged uniformly in sequence.The repair method includes: milling to thin-walled component defect, clamping with repair material, solid-phase repair by reciprocating friction roller, finishing to repair area, finally finishing to remove trace material balance, obtain high-quality thin-walled component.The repair cost of the application is low, and the material waste is less, the performance and service life of thin-walled component are improved by simultaneous repair and finishing operation of repair tool.

The application discloses a kind of carbon fiber composite material defect repair equipment and repair method, it is related to gas cylinder repair equipment field, technical scheme is, including chassis, the middle part of chassis is set through passage, the lower portion of passage is set for supporting the support mechanism of carbon fiber gas cylinder, the upper surface of chassis one side parallelly arranged two slide rails, each slide rail is slidably connected with a slider, the clamping mechanism for clamping carbon fiber gas cylinder is fixedly arranged on slider, the middle part of clamping mechanism is set inflation passage, the inflation passage is coaxial with the axis of carbon fiber gas cylinder with gas inlet;The side of chassis is fixedly set main push rod;It further includes the guide rail fixedly set in the side of chassis, the repair mechanism for carbon fiber composite material repair is slidably arranged on guide rail.The beneficial effects of the application are: simple structure, convenient to use, fast repair speed, effectively shorten the repair time of carbon fiber gas cylinder, improve repair efficiency, reduce manpower and material cost.

The application discloses a repairing method, which first provides a receiving component and a repair site component; the receiving component comprises a receiving substrate, and a first surface of the receiving substrate is provided with at least one repair site area; the repair site component comprises a repair site substrate and at least one repair site piece arranged on a second surface of the repair site substrate, and at least part of the repair site piece is provided with a repair site chip on a side away from the repair site substrate. Then, the second surface is arranged opposite to the first surface, and the repair site chip is attached to the corresponding repair site area; the attachment force between the repair site chip and the repair site piece is smaller than the attachment force between the repair site chip and the repair site area. Then, the repair site piece is separated from the repair site chip, so that the repair site chip is left in the repair site area, and the repairing is completed. According to the application, the number and position of the repair site chip can be accurately arranged according to the distribution of the repair site area on the receiving substrate, the repairing efficiency is improved, and the attachment of the repair site chip and the repair site area is realized through the repair site piece as an intermediate body, so that the damage to the receiving substrate in the repairing process is reduced.

This invention provides a method for repairing underwater concrete structures that allows for easy and reliable repair of areas requiring repair, while minimizing the risk of the repair filler material falling off after repair. [Solution] A method for repairing a part requiring repair formed on the bottom surface 1a of a concrete structure 1 underwater, comprising: a filling space formation step of chipping away the part requiring repair to form a filling space A for a repair filling material 4 having an opening 3a on the bottom surface 1a of the concrete structure 1; a filling space shaping step of forming an inclined surface 3b that expands upward on the entire circumference or part of the inner surface of the opening 3a; a repair filling material filling step of filling the filling space A with the repair filling material 4; and a filling space closing step of closing the opening 3a from below with a bottom plate 5 and placing a buoyancy body 7 filled with air below the bottom plate 5, thereby pressing the bottom plate 5 against the opening 3a with the buoyancy of the buoyancy body 7.