High-precision hoisting method for platform leg of floating state platform

Abstract

The present application relates to the technical field of shipbuilding, and discloses a high-precision hoisting method for a platform pile leg under a floating state, which comprises the following steps: segmentally prefabricating the pile leg, dividing the segments into a plurality of total segments according to the lifting height of a hoisting device, drawing a center line of a pin hole, a pile leg cross center line with a 45-degree center deflection of the pin hole, and an up-down end closing inspection line of each total segment, and marking a punch point on the outer wall of the pile leg, measuring simulation loading data of the closing of each total segment, and correcting the simulation loading data of the closing of each total segment; and drawing a positioning tool installation line according to the simulation loading data and marking the line. The method simulates the loading data of the closing before hoisting, positions the installation line, closes the pile leg of each segment according to the positioned installation line, so that no deviation occurs during the hoisting and closing, the precision of the closing of the pile leg is greatly improved, and the service life and working efficiency of the pile leg are improved.

Description

Technical Field

[0001] This invention relates to the field of shipbuilding technology, and more specifically, to a high-precision hoisting method for platform legs in a floating state. Background Technology

[0002] With the rise of offshore wind power and the increasing size and depth of wind turbines, the complexity of lifting heights and sea conditions has rendered traditional wind turbine installation platforms inadequate. Therefore, a new platform leg design is required. The new platform leg consists of four cylindrical legs (98mm wall thickness, E690 material), four sets of hydraulic pin-type double-acting ring beam lifting systems and a pile-driving system. The leg length is 105m, the maximum operating draft is 65 meters, the maximum single-pile lifting capacity is 5600 tons, and the maximum lifting capacity is 800 tons at a maximum span of 36 meters. An extra-long crane boom is needed to meet the wind turbine installation requirements. Using a crane alone results in long installation and positioning times, difficulties in positioning, and low positioning accuracy, affecting the working efficiency of the leg support. Summary of the Invention

[0003] The purpose of this invention is to provide a high-precision hoisting method for platform legs in a floating state. This method has high hoisting accuracy, short positioning time, and is simple.

[0004] To achieve the above objectives, the present invention provides a high-precision hoisting method for platform legs in a floating state, comprising the following steps:

[0005] The pile legs are prefabricated in sections, and the sections are divided into multiple main sections and assembled according to the lifting height of the hoisting equipment;

[0006] Draw the center line of the pin hole of each section, the cross center line of the pile leg with the pin hole center offset by 45°, and the inspection line of the upper and lower end closure of each section, and make the punch mark on the outer wall of the pile leg.

[0007] Measure the simulated loading data of each section closure and verify the simulated loading data of each section closure joint;

[0008] Draw the installation lines of the positioning tooling based on the simulated loading data and mark them;

[0009] According to the installation line, install positioning fixtures on the inner side of the upper and lower closure joints of each section of the pile leg;

[0010] Each section was hoisted in turn.

[0011] Preferably, the measurement of the simulated loading data of each segment includes:

[0012] Measure the roundness and spacing of the upper and lower inspection lines of each section, the straightness of the longitudinal line connecting the center points of each pin hole, and the perpendicularity to the plane of the inspection line.

[0013] Preferably, measuring the roundness data of the upper and lower inspection lines of each segment includes:

[0014] Divide the upper and lower inspection lines of the corresponding section into several measurement points, and measure the distance from each measurement point to the tip of the corresponding closure bevel and the spacing between the upper and lower inspection lines.

[0015] Measure the distance between two adjacent measurement points, and the coordinates of each measurement point;

[0016] The coordinates of the measurement points are fitted with roundness.

[0017] Preferably, measuring the coordinates of each measurement point includes:

[0018] Establish two coordinate systems by rotating 180° counterclockwise and clockwise respectively, with the point corresponding to the inspection line at any pin hole position as the origin;

[0019] Measure the coordinates of the points within the corresponding coordinate range.

[0020] Preferably, measuring the straightness data of the longitudinal line connecting the center points of each pin hole and the perpendicularity data with the plane of the inspection line includes:

[0021] On the upper section of the closure detection line, select two measurement points, namely the first and second measurement points, whose lines pass through the center point of the cross center line. On the lower section of the same section, select a third measurement point that is located on the same longitudinal line as the first or second measurement point. Connect the three points to establish a coordinate system. Measure and compare the coordinates of the pin holes at different angles to determine the straightness and perpendicularity.

[0022] Preferably, the sequential hoisting of each section includes:

[0023] Install upright lifting rings on the outside of each section, mark the center line of the pin hole on the outside of the section, and mark the center line of the pin hole on the top plate of the pile fixing frame.

[0024] Steel wires were strung along the inner side of the main section, and scaffolding was erected in the area where the steel wires were strung.

[0025] Join the first section with the pile driver;

[0026] Stack and close the other sections one by one.

[0027] Preferably, the step of joining the first main section with the pile shoe includes:

[0028] After the first section is lifted by a floating crane and left to stand, the working condition of the floating crane is checked, and then the first section is erected.

[0029] Align the center line of the top of the pile fixing frame with the center line of the first section pin hole in the front-back and left-right directions.

[0030] Lower the first main section onto the platform and lock it in place;

[0031] The platform is brought into the dock, the relative positions of the pile legs and pile boots are determined, and then the pile legs and pile boots are joined together.

[0032] Preferably, the step of sequentially stacking and closing the other segments includes:

[0033] Scaffolding platforms are erected on the inner and outer sides of the closure opening on the (n-1)th total segment, and the vertical lifting rings on the (n-1)th total segment are removed, where n is a positive integer greater than or equal to 2;

[0034] After the nth section is lifted by a floating crane and left to stand, check the working condition of the floating crane. Then, the nth section is erected and the lower end lifting ring is removed.

[0035] Adjust the positioning direction on the nth segment so that the positioning fixture on it is aligned with the positioning fixture on the (n-1)th segment, and then match the two positioning fixtures on the nth segment below.

[0036] Pull the stretched steel wire to the (n-1)th segment and lock it, then measure the straightness of the outer wall of the pile leg;

[0037] Under the stress condition of the floating crane, measure the distance between the lower closure inspection line of the nth section and the upper closure inspection line of the (n-1)th section, as well as the distance between the two pin holes at the closure.

[0038] After the positioning accuracy of the pile legs meets the requirements, the closure joint is welded.

[0039] Preferably, before welding the closure joint, the method further includes:

[0040] A locking fixture is installed between the lower closing pin hole of the nth segment and the upper closing pin hole of the (n-1)th segment. The locking fixture includes locking plates respectively disposed at the two pin holes and locking bolts for locking the two locking plates.

[0041] Preferably, after welding the closure joint, the process includes:

[0042] Measure the distance between the two mating inspection lines every 8 hours, and measure the straightness of the center line of the pin hole every day. If the measurement data deviation exceeds the standard range, stop construction immediately and report to the project, discuss and determine the plan again before continuing construction.

[0043] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0044] Before hoisting, the mounting data of the closure joint is simulated and the installation line is located. The pile legs of each segment are closed according to the located installation line. This will prevent deviation during hoisting and closure, reduce the difficulty of hoisting and positioning, greatly improve the accuracy of pile leg closure, save hoisting time, and thus improve the service life of the pile legs and work efficiency.

[0045] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0046] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0047] Figure 1 A schematic diagram of the segmented division of the pile leg according to an embodiment of the present invention is shown;

[0048] Figure 2 A schematic diagram of the pile leg segment division according to an embodiment of the present invention is shown;

[0049] Figure 3 A diagram showing the markings for pile leg positioning according to an embodiment of the present invention is shown;

[0050] Figure 4 A schematic diagram of the test line spacing measurement according to an embodiment of the present invention is shown;

[0051] Figure 5 A schematic diagram of the measurement of the distance between the inspection line and the bevel tip according to an embodiment of the present invention is shown;

[0052] Figure 6 A schematic diagram of roundness measurement according to an embodiment of the present invention is shown;

[0053] Figure 7 A schematic diagram of straightness and perpendicularity measurement according to an embodiment of the present invention is shown. Figure 1 ;

[0054] Figure 8 A schematic diagram of straightness and perpendicularity measurement according to an embodiment of the present invention is shown. Figure 2 ;

[0055] Figure 9 A schematic diagram of the positioning fixture installation according to an embodiment of the present invention is shown;

[0056] Figure 10 A schematic diagram of a positioning tooling structure according to an embodiment of the present invention is shown;

[0057] Figure 11 A schematic diagram of a steel wire drawing according to an embodiment of the present invention is shown. Figure 1;

[0058] Figure 12 A schematic diagram of a steel wire drawing according to an embodiment of the present invention is shown. Figure 2 ;

[0059] Figure 13 A schematic diagram of the installation of a wire tooling according to an embodiment of the present invention is shown;

[0060] Figure 14 A schematic diagram of the B05 segment hoisting according to an embodiment of the present invention is shown;

[0061] Figure 15 This diagram illustrates the joining of segment B05 and segment ZT02 according to an embodiment of the present invention.

[0062] Figure 16 This diagram illustrates the B05 segment and ZT02 main segment detection lines and the pin hole spacing measurement according to an embodiment of the present invention.

[0063] Figure 17 A schematic diagram of the installation of a locking fixture according to an embodiment of the present invention is shown;

[0064] Figure 18 A schematic diagram of a locking fixture structure according to an embodiment of the present invention is shown. Detailed Implementation

[0065] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0066] The vessel being modified in this embodiment is a four-legged, hydraulically piling-type, self-elevating, self-propelled emergency salvage and rescue vessel. The original vessel had four legs with piling boots. The legs had a circular cross-section with an outer diameter of 4.8m, and the total length of the legs from the bottom of the piling boots to the top of the legs was 90m. This modification replaces the legs and piling boots. The legs now have a circular cross-section with an outer diameter of 4.8m, and the total length of the legs becomes 105.38m (the top 15.67m utilizes the old legs, and the piling boot height is 4.5m). The maximum wall thickness increases from 86mm to 98mm.

[0067] To achieve the above objectives, this embodiment provides a high-precision hoisting method for platform legs in a floating state, including the following steps.

[0068] S1: The pile legs are prefabricated in sections, and the sections are divided into multiple main sections and assembled according to the lifting height of the hoisting equipment.

[0069] (1) Segmentation of New Pile Legs. In this embodiment, the overall weight of each new pile leg is approximately 1150 tons, and each new pile leg is divided into 5 segments for prefabrication, such as... Figure 1As shown in the table below, the weight and length of each pile leg segment are as follows.

[0070] Serial number Component name Length (m) Weight (tons) Remarks 1 B01 (utilizing old pile legs) 15.67 160 Including outfitting parts 2 B02 22 246 Including outfitting parts 3 B03 20 225 Including outfitting parts 4 B04 20 225 Including outfitting parts 5 B05 23.21 275 Including outfitting parts

[0071] (2) New pile leg assembly hoisting and division. After prefabrication in the segment workshop, the sections are transported to the dock and assembled into three sections. The three sections are B01 and B02 (ZT01), B03 and B04 (ZT02), and B05 is a separate section. Figure 2 As shown in the table below, the total lifting weight of the section is as follows.

[0072] Hoisting serial number Component name Length (m) Weight (tons) Remarks 1 B05 23.21 275 Including outfitting parts 2 ZT02 40 450 Including outfitting parts 3 ZT01 37.67 410 Including outfitting parts

[0073] (3) The B01 segment of the pile leg is cut and corrected using the old segment to align the interface. In this embodiment, the required length of the B01 segment is 15670mm, while the length of the old segment is 18540mm. The excess part of the old segment is cut off.

[0074] (4) Unloading the leg sections of the ship. Set up the assembly jig at the assembly site. Use a 600T floating crane to lift sections B03 and B04 onto the jig. Using B04 as the reference section, adjust the position of section B03. Assemble and position the B04 & B03 sections on the jig. Lift the assembled and positioned B04 & B03 sections onto the roller frame to complete the welding of the section joints. For sections that are not welded on the roller frame, continue to complete the welding of the section joints on the jig.

[0075] A 600T floating crane was used to lift section B01 onto the jig. Based on the measurement data for section B02, the interface of section B01 was cut. After the B02 leg sections were fabricated, Yonglian was responsible for loading them onto a ship and transporting them to the Wenchong Repair and Construction Group wharf. Then, the 600T floating crane was used to lift section B02 onto the jig. Using B01 as the reference section, the position of section B02 was adjusted, and the interface between section B01 and section B02 was welded onto the jig.

[0076] S2: Draw the center lines of the pin holes for each section, the cross center lines of the pile legs with the pin hole centers offset by 45°, and the inspection lines for the closure joints at the upper and lower ends of each section. Mark the outer wall of the pile legs with perforated marks for subsequent marking. In this embodiment, the distance from the closure joint inspection line to the tip of the bevel is 100mm. Figure 3 As shown.

[0077] S3: Measure the simulated loading data of each section closure and calibrate the simulated loading data of each section closure joint.

[0078] After the hoisting of the main section is completed, the data of the simulated assembly of the upper and lower sections is measured and must meet the following requirements: the distance between the two pin holes at the closure joint (with a deviation of ±2mm over 2 meters); the straightness of the pile leg (with a deviation of <5mm for any 19.5-meter section); the circumference of the pile leg (with a deviation of +2mm–3mm); and the roundness (with a deviation of <6mm between the longest and shortest diameters).

[0079] The simulated assembly data includes the roundness data and spacing of the upper and lower inspection lines of each section, the straightness data of the longitudinal line connecting the center points of each pin hole, and the perpendicularity data to the plane of the inspection line.

[0080] (1) Measurement of the spacing between the inspection lines of the main section and the distance between the bevel tip and the inspection line. Divide the upper and lower inspection lines of the corresponding main section into several measurement points, and measure the distance from each measurement point to the corresponding bevel tip of the closure joint and the spacing between the upper and lower inspection lines.

[0081] Specifically, taking segment B05 of pile leg #1 as an example, such as Figure 4 As shown in EE and FF, the upper and lower closure inspection lines are divided into 28 equal parts. The distances a and b from the tip of the closure bevel to the inspection line at these 28 points are measured (a is the data for the upper closure and b is the data for the lower closure) as well as the spacing H between the upper and lower closure inspection lines. These measurements are recorded in the "Measurement Table of Spacing Between Inspection Lines and Spacing Between Bevel Tip and Inspection Line".

[0082] When measuring the values ​​of a and b, a set square can be used, positioned at the 28 equal division marks, and then a ruler can be used to measure the corresponding values ​​of a and b. Figure 5 As shown. Note that the measurement points for values ​​a and b when the upper and lower openings are joined must be on the same longitudinal line. The same applies when measuring the value H.

[0083]

[0084]

[0085] (2) Measurement of the roundness of the joint of the whole section. Measure the distance between two adjacent measurement points and the coordinates of each measurement point, and fit the coordinates of the measurement points to the roundness.

[0086] Specifically, the theoretical straight-line distance between two adjacent equally divided points is 537.4 mm (arc length 538.6 mm). (Note: When looking from the top to the bottom, the axial rotation clockwise is 0°, 90°, 180°, and 270° respectively, which are the angular positions of the pin hole. When looking from the bottom to the top, the axial rotation counterclockwise is 0°, 90°, 180°, and 270° respectively, which are the angular positions of the pin hole.)

[0087] When measuring the coordinates of the measurement points, take the point corresponding to the inspection line at any pin hole position as the origin, and establish two coordinate systems by rotating 180° counterclockwise and clockwise respectively, and measure the coordinates of the measurement points within the corresponding coordinate range.

[0088] In this embodiment, as Figure 6 As shown in CC, for ease of inspection, the inspection line at the 0° pin hole position is used as the origin. Two points on the inspection line within the range of "0°-270°-180°" are selected to establish a coordinate system, i.e., coordinate plane "plane 1". The coordinates of the measured points within the range of "0°-270°-180°" are measured counterclockwise and recorded in the "Roundness Measurement Table of Upper and Lower Inspection Lines", recorded as Measurement 1. Again, using the inspection line at the 0° pin hole position as the origin, two points on the inspection line within the range of "0°-90°-180°" are selected to establish a coordinate system, i.e., coordinate plane "plane 2". The marked points within the range of "0°-90°-180°" are measured clockwise and recorded in the "Roundness Measurement Table of Upper and Lower Inspection Lines", recorded as Measurement 2. Inspection lines at other positions are measured in a similar manner and recorded in the "Roundness Measurement Table of Upper and Lower Inspection Lines". Note: For the same inspection line, the origin of the coordinates for two measurements (i.e., measurement 1 and measurement 2) must be the same point. This will make the coordinates more accurate and further improve the hoisting precision.

[0089] Then, the coordinates of the measured points are input into AutoCAD for roundness fitting.

[0090]

[0091] (3) Inspection of the straightness of the longitudinal connection line of the pin hole (i.e., the straightness of the pile leg wall) and its perpendicularity to the plane of the inspection line. On the closure inspection line of the main section, select the first and second measurement points, two lines that pass through the center point of the cross center line. On the closure inspection line of the same main section, select a third measurement point that is located on the same longitudinal connection line as the first or second measurement point. Establish a coordinate system by connecting the three points. Measure the coordinates of the pin holes at different angles and compare them to determine the straightness and perpendicularity.

[0092] Specifically, such as Figure 7 and Figure 8As shown, using a total station, a coordinate system is established with the intersection of the upper closure inspection line and the longitudinal center line of the 0° pin hole as M1, the intersection of the upper closure inspection line and the longitudinal center line of the 180° pin hole as the inner wall point, and the intersection of the lower closure inspection line and the longitudinal center line of the 0° pin hole as point M3, resulting in coordinate plane "Surface 1". Before measurement, several points are selected on the upper closure inspection line to check whether the line connecting M1 and M3 is perpendicular to the upper closure inspection line. After confirming perpendicularity, the straightness of the longitudinal line connecting the pin holes at 0°, 90°, and 270° and their perpendicularity to the inspection line plane are measured. The pin hole data at 180° is measured in the same way (the established coordinate system and the perpendicularity of the pin hole at which axial angle is measured can be adjusted according to the site conditions).

[0093] After the coordinate system is established, the first measurement point for each angular pin hole must be the intersection of the longitudinal line connecting the pin hole centers and the upper closure inspection line. Using this point as the base point, measure and compare the coordinate values ​​of other pin holes on the longitudinal line connecting the pin holes. The measurement data are entered into the "Straightness Measurement Table of the Pin Hole Center Connection Line Relative to the Pile Leg Center" and the "Perpendicularity Measurement Table of the Pin Hole Longitudinal Line and the Inspection Line Plane". Based on the deviation of the x and y values ​​of the measurement point from the x and y values ​​of the base point, the straightness and perpendicularity are judged (the intersection of the longitudinal line connecting the pin hole centers and the lower closure inspection line is the lower inspection line point).

[0094] (4) Verify the simulated mounting data of each section's closure joint. Compare the roundness data, inspection line coordinate data, and verticality data measured for each section to see if the data are consistent or if the error is within the allowable range. If all are within the specified range, proceed to the next step. This method of measuring simulated data before the pile legs are closed facilitates subsequent closure accuracy positioning, resulting in higher hoisting and closure accuracy and avoiding situations where misalignment is discovered after installation, requiring rework.

[0095]

[0096]

[0097] S4: Draw the installation line of positioning fixture 10 according to the simulated loading data and mark it. Install positioning fixture 10 on the inner side of the upper and lower closure of each section of the pile leg according to the installation line.

[0098] The pile legs are hoisted at the dock to facilitate precise positioning. Installation lines are drawn based on relevant simulation data. Positioning fixture 10 is installed at the junction of the upper and lower sections of the pile leg. Fixture 10 is installed on the inside of the pile leg. Welding can only proceed after the fixture has passed precision inspection and QC approval, ensuring the upper and lower fixtures of positioning fixture 10 are aligned (the single-sided deviation of positioning fixture 10 is 3mm). Figure 9As shown, the positioning fixture 10 has four installation positions, corresponding to the four intersection points of the cross center lines of the pile leg. The positioning fixture 10 includes an upper fixture and a lower fixture, which are respectively installed at the lower closure opening of the upper section and the upper closure opening of the lower section. When closing, the upper fixture is inserted into the lower fixture to perform positioning.

[0099] Specifically, such as Figure 10 As shown, the upper fixture includes two parallel upper positioning plates 101 with right-angled trapezoidal cross-sections, an upper reinforcing plate 102, an upper fixing plate 103, and an insert plate 104. The inclined surfaces of both upper positioning plates 101 face downwards. The upper reinforcing plate 102 fixes the two upper positioning plates 101 together. The upper fixing plate 103 is fixed to the bottom of the two upper positioning plates 101 and has two threaded holes. The insert plate 104 is positioned between the two upper positioning plates 101, with its plug extending downwards. The distance between the two upper positioning plates 101 matches the width of the insert plate 104. The lower fixture includes two parallel L-plates 105, a lower reinforcing plate 106, a lower fixing plate 107, and a pad 108. Two L-plates 105 correspond one-to-one with two upper positioning plates 101, and their inner sidewalls are provided with inclined surfaces that fit with the inclined surfaces of the upper positioning plates 101. The lower reinforcing plate 106 fixes the two L-plates 105 together. The lower fixing plate 107 is fixed to the top of the two L-plates 105. The lower fixing plate 107 corresponds to the upper fixing plate 103 and also has two threaded holes. The lower fixing plate 107 and the upper fixing plate 103 are fixed by bolts passing through the threaded holes and engaging with nuts. The insert plate 104 is inserted into the gap between the two L-plates 105. The gap between the two L-plates 105 is the same as the gap between the two upper positioning plates 101. The pad plate 108 can be inserted between the inclined surfaces of the upper positioning plate 101 and the L-plates 105. In this way, the insert plate 104 can position the front and back of the main section, with a 3mm gap reserved on each side for adjustment. The two fixing plates are fixed with bolts and nuts to position the upper and lower parts of the main section. The upper positioning plate 101 and the L plate 105 cooperate to position the left and right parts of the main section, with a 3mm gap reserved on each side for adjustment.

[0100] S5: Each section is hoisted in sequence.

[0101] Before hoisting, mark the locations on the outside of the main pile leg with paint at 45°, 135°, 225°, and 315° to check the hoisting positioning fixture 10 and its dimensions. Mark the joint opening with a 100mm inspection line on the outer wall of the pile leg.

[0102] (1) Install vertical lifting rings on the outside of each section, mark the center line of the pin hole on the outside of the section and mark the center line of the pin hole on the top plate of the pile fixing frame.

[0103] Based on the structural characteristics of the new pile leg and the requirements of floating crane hoisting, upright lifting rings are installed on the upper and lower sections of the outer side of the pile leg. Before hoisting the B05 section, the positioning points are marked. According to the center lines of the four pin holes on the pile leg (marked at 45°, 135°, 225°, and 315°), the center lines of the pin holes are marked on the top plate of the pile fixing frame. By using the positioning points on the top plate of the pile fixing frame, the direction of the pile leg is ensured, so that the pins of the pin device of the guide ring beam can be inserted into the pin holes of the pile leg.

[0104] (2) Tie steel wires on the inside of the main section and erect scaffolding in the area where the steel wires are tied. For example... Figure 11 and Figure 12 As shown, the center lines of four sets of pin holes are marked on the inner wall of the upper and lower pile legs for hoisting the main section. A steel wire tool 20 is set at the pin hole more than 10 meters away from the lower closing opening. The steel wire is 20mm away from the inner wall of the pin hole (Note: the steel wire should not touch the outfitting platform or pipelines). A 13-meter steel wire length is reserved. After closing, the steel wire is pulled to the lower end more than 10 meters. Scaffolding is erected inside the pile leg in the area where the steel wire is pulled.

[0105] Specifically, such as Figure 13 As shown, the wire tooling 20 includes a channel plate 201, a fixing rod 202, and a fixing bolt 203. The channel plate 201 is clamped on the pile leg wall at the pin hole, and the fixing bolt 203 is used to fix the channel plate 201. The fixing rod 202 is set on the top of the channel plate 201, and its length exceeds the pile leg wall thickness by at least 20mm. The wire is tied to the end of the fixing rod 202 away from the channel plate 201.

[0106] (3) Join the first section with the pile shoe. After lifting the first section with a floating crane and letting it stand still, check the working condition of the floating crane, and then stand the first section upright.

[0107] Before hoisting B05, the platform was leveled using its own ballast. The B05 sections were hoisted in sections using a design that incorporated lifting rings and adjustments to the length of the steel cables to ensure a balanced center of gravity and vertical legs. The B05 sections were placed vertically on the dock. A 600T floating crane was used to lift them 200mm, then allowed to stand for 5 minutes to check for any abnormalities in the crane's hook, signals, and control devices. The lifting lugs and structure of each section were also inspected for any significant deformation. Once the inspection was deemed satisfactory, the sections were uprighted using the combined large and small hooks of the floating crane. Figure 14 As shown.

[0108] Align the top centerline of the pile fixing frame with the centerline of the first section's pin hole in the front-back, left-right directions. Then, lower the first section onto the platform and lock it in place. Position the platform in the dock, determine the relative positions of the pile legs and pile shoes, and then assemble and connect the pile legs and pile shoes. Specifically, use a 600T floating crane to vertically lift section B05. Align the centerline of the pin hole on the top plate of the pile fixing frame with the centerline of the pin hole on section B05 in the front-back, left-right directions, and determine the orientation. Then, slowly lower the pile leg section. When the top of section B05 is 5250mm from the top plate of the pile fixing frame, stop lowering. readjust the alignment of the pile leg pin hole with the mark on the top of the pile fixing frame. Finally, lock section B05 onto the platform by adjusting the platform's pile leg pin cylinder locking device.

[0109] The platform enters the dry dock, and the B05 leg and pile shoe are joined together. After the platform is dry-docked on the pier, the pile shoe is adjusted to position itself, using the B05 leg segment as a reference. The positioning trolley is moved to align with the leg at 45°, 135°, 225°, and 315°, with an accuracy deviation of 0.5mm, in all directions. The spacing between the inspection lines at the joining joint is measured to be 200mm. Any deviations are adjusted by moving the positioning trolley, with an accuracy deviation of ±2mm. After meeting the above accuracy requirements, the joining joint is spot-welded, the mounting plates are installed, and the joining joint is welded, strictly following relevant WPS requirements. The welds undergo flaw detection, and the leg is checked for tightness. Finally, the platform is undocking and docked at the pier.

[0110] (4) Stack the other sections together in sequence. That is, hoist the second section onto the first section, the third section onto the second section, and so on.

[0111] Scaffolding platforms are erected on the inner and outer sides of the closure opening on the (n-1)th total segment, and the vertical lifting rings on the (n-1)th total segment are removed, where n is a positive integer greater than or equal to 2;

[0112] After the nth section is lifted by a floating crane and left to stand, check the working condition of the floating crane. Then, the nth section is erected and the lower end lifting ring is removed.

[0113] Adjust the positioning direction on the nth segment so that the positioning fixture 10 on it is aligned with the positioning fixture 10 on the (n-1)th segment, and then match the two positioning fixtures 10 on the nth segment below.

[0114] Pull the stretched steel wire to the (n-1)th segment and lock it, then measure the straightness of the outer wall of the pile leg;

[0115] Under the stress condition of the floating crane, measure the distance between the lower closure inspection line of the nth section and the upper closure inspection line of the (n-1)th section, as well as the distance between the two pin holes at the closure.

[0116] After the positioning accuracy of the pile legs meets the requirements, the closure joint is welded.

[0117] In this embodiment, the hoisting of the second section to the first section is used as an example for illustration.

[0118] a) Erect scaffolding platforms inside and outside the pile legs at the upper end of section B05, remove the vertical lifting rings of section B05 and grind them, check the section closure positioning fixture 10, inspection line and other preparatory work before closure.

[0119] b) Place the ZT02 section vertically at the dock. Use a 1500T floating crane to lift it 200mm high, then let it stand still for 5 minutes. Check the floating crane's hook, signal, and control devices for any abnormalities. Check the lifting lugs and structure of the section for any obvious deformation. Once the inspection is satisfactory, use the floating crane's large and small hooks to stand the section upright.

[0120] c) After the ZT02 main section is erected, approximately 200mm from the ground, remove the lower end lifting ring (the lifting ring is on the outside of the pile leg and collides with the Kling crane platform; therefore, it must be removed after erection). After removing the lifting ring, lift the main section. The floating crane will lift the main section and move it to the platform lifting position. When it reaches the upper end of section B05, adjust the front-back, left-right directions of the pile leg and the direction of the section positioning fixture 10. Then, slowly lower the pile leg section into the B05 positioning fixture 10. Figure 15 As shown.

[0121] d) The lower fixture of the ZT02 main section is inserted into the upper fixture of the B05 section, and then fixed with bolts. Under the load of the floating crane, the positioning steel wires of the four pin holes of the main section are pulled to the B05 section, and the steel wires are tightened with turnbuckles (204). Measure the straightness of the outer wall of the pile leg at 1-meter intervals (mark each measurement point for easy comparison and verification of multiple measurements later). Measure the distance between the lower closure detection line of the ZT02 main section and the upper closure detection line of the B05 section (200mm), and the distance between the two sets of pin holes opposite the upper and lower closures (2000mm, with a deviation of ±2mm over 2m). Figure 16 As shown.

[0122] The positioning accuracy requirements for the pile legs are as follows: the distance between the two pin holes at the joint (with a deviation of ±2mm over 2 meters), the straightness of the pile legs (with a deflection of <5mm over any 19.5-meter section), the center line of the pin holes (±0.5mm), and the circumference of the pile legs (with a deviation of +2mm–3mm).

[0123] e) After the positioning accuracy of the pile legs is adjusted to meet the requirements, report to QC, ship owner, and ship inspection. After passing the inspection, install the mounting plates. Divide the perimeter into 20 equal parts, and install one mounting plate every 754mm. When the gap between the joints is greater than 2mm, add flat iron to fill the gap between the bevels. Place one pad every 500mm in the perimeter direction to prevent large welding shrinkage from affecting the accuracy requirements of the pile legs.

[0124] f) After the overall segment is precisely positioned, to ensure the rigidity of the pile leg closure joint during welding, and to prevent cracks from forming during the weld joint due to the platform's swinging of the pile legs at the dock, a locking fixture 30 is installed between the upper and lower overall segment pin holes of the pile leg. Specifically, a locking fixture 30 is installed between the two pin holes at the closure joint of segment B05 and overall segment ZT02. Since there are four pin holes at each height of the pile leg, four locking fixtures 30 are required. Figure 17 As shown.

[0125] The operating parameters of the floating crane used in this embodiment are shown in Tables 1 and 2 below.

[0126] Main hook safe working load

[0127] Boom elevation (°) 70 65 60 55 50 45 Work load (t) 2X300 2X275 2X225 2×150 2×100 2X50 Amplitude (m) 28.8 34.9 40.8 46.3 51.5 56.3 Lifting height (m) 70.0 67.2 63.9 60.1 55.8 51.1

[0128] Safe working load of auxiliary hook

[0129] Boom elevation (°) 70 65 60 55 50 45 Work load (t) 300 280 260 190 120 70 Amplitude (m) 42.1 50.7 58.9 66.7 74.0 80.7 Lifting height (m) 100.0 95.9 91.2 85.7 79.5 72.8

[0130] Table 1. Lifting Capacity Parameters of 600T Floating Crane

[0131]

[0132] Table 2 Lifting Capacity Parameters of 1500T Floating Crane

[0133] Specifically, such as Figure 18 As shown, the locking fixture 30 includes locking plates 301 respectively disposed at two pin holes and locking bolts 302 (with nuts) for locking the two locking plates 301. During installation, the locking plates 301 are placed in the two pin holes respectively, so that the two threaded holes on the two locking plates 301 are located on both sides of the pile leg wall. Then, the two locking bolts 302 pass through the threaded holes on both sides of the locking plates 301 respectively, and finally the two locking plates 301 are locked by nuts 303.

[0134] g) After the pile leg positioning accuracy is inspected and approved, the mounting plate, flat iron shims, and locking fixture 30 are installed. After all the work is completed, the QC inspection is completed and welding is carried out.

[0135] h) Welding process precision monitoring: measure the inspection line (200mm) of the two joined joints every 8 hours, and measure the straightness of the center line of the pin hole once a day. If the measurement data deviation exceeds the standard range, construction should be stopped immediately and the project should be reported. Construction can only proceed after the solution has been discussed and determined again.

[0136] i) When the welding reaches 1 / 3 of the inner bevel (21mm), the floating crane's lifting force is 1 / 2 of its weight. When the welding reaches 3 / 5 of the inner bevel (32mm), the floating crane's lifting force is 1 / 4 of its weight. When the welding reaches 2 / 3 of the inner bevel (42mm), the floating crane can only be released after QC confirms that the requirements are met.

[0137] After all the joints of ZT02 section were welded, piles were driven into the mud on the port side of the platform, with a depth of 6 meters and a draft of 9 meters, meaning the pile legs were 15 meters below the waterline. The floating crane then lifted the ZT01 section on the starboard side and installed it onto ZT02 in the same manner.

[0138] The above examples are wind power platform retrofit projects undertaken by our company for offshore wind power installation. These projects have provided us with extensive experience in the construction level, precision control, and construction techniques of wind power installation platforms. In particular, the floating hoisting and positioning of the pile legs at the wharf achieved precision control that met construction requirements. This significantly reduced dock hoisting time, greatly improved economic efficiency, and shortened installation and positioning time, solving the problem of difficult positioning. This reduced construction difficulty and cost while ensuring accuracy requirements, thus enhancing our company's competitiveness in future wind power installation platform projects.

[0139] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, and these simple modifications all fall within the protection scope of the present invention. Furthermore, it should be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0140] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for high-precision hoisting of platform legs in a floating state, characterized in that, include: The pile legs are prefabricated in sections, and the sections are divided into multiple main sections and assembled according to the lifting height of the hoisting equipment; Draw the center line of the pin hole of each section, the cross center line of the pile leg with the pin hole center offset by 45°, and the inspection line of the upper and lower end closure of each section, and make the punch mark on the outer wall of the pile leg. Measure the roundness data and spacing of the upper and lower inspection lines of each section, the straightness data of the longitudinal line connecting the center points of each pin hole, and the perpendicularity data of the line to the plane of the inspection line. The simulated mounting data of the closure joint of each section is then calibrated; the measurement of the roundness data of the upper and lower inspection lines of each section includes: dividing the upper and lower inspection lines of the corresponding section into several measurement points, measuring the distance from each measurement point to the tip of the corresponding closure joint bevel and the spacing between the upper and lower inspection lines; measuring the distance between two adjacent measurement points and the coordinates of each measurement point; and performing roundness fitting on the coordinates of the measurement points. Draw the installation lines of the positioning tooling based on the simulated loading data and mark them; According to the installation line, install positioning fixtures on the inner side of the upper and lower closure joints of each section of the pile leg; Each section was hoisted in turn.

2. The high-precision hoisting method for platform legs in a floating state according to claim 1, characterized in that, Measuring the coordinates of each measurement point includes: Establish two coordinate systems by rotating 180° counterclockwise and clockwise respectively, with the point corresponding to the inspection line at any pin hole position as the origin; Measure the coordinates of the points within the corresponding coordinate range.

3. The high-precision hoisting method for platform legs in a floating state according to claim 1, characterized in that, Measuring the straightness data of the longitudinal line connecting the center points of each pin hole and the perpendicularity data to the plane of the inspection line includes: On the upper section of the closure detection line, select two measurement points, namely the first and second measurement points, whose lines pass through the center point of the cross center line. On the lower section of the same section, select a third measurement point that is located on the same longitudinal line as the first or second measurement point. Connect the three points to establish a coordinate system. Measure and compare the coordinates of the pin holes at different angles to determine the straightness and perpendicularity.

4. The high-precision hoisting method for platform legs in a floating state according to claim 1, characterized in that, The sequential hoisting of each section includes: Install upright lifting rings on the outside of each section, mark the center line of the pin hole on the outside of the section, and mark the center line of the pin hole on the top plate of the pile fixing frame. Steel wires were strung along the inner side of the main section, and scaffolding was erected in the area where the steel wires were strung. Join the first section with the pile driver; Stack and close the other sections one by one.

5. The high-precision hoisting method for platform legs in a floating state according to claim 4, characterized in that, The process of joining the first main section with the pile shoe includes: After the first section is lifted by a floating crane and left to stand, the working condition of the floating crane is checked, and then the first section is erected. Align the center line of the top of the pile fixing frame with the center line of the first section pin hole in the front-back and left-right directions. Lower the first main section onto the platform and lock it in place; The platform is brought into the dock, the relative positions of the pile legs and pile boots are determined, and then the pile legs and pile boots are joined together.

6. The high-precision hoisting method for platform legs in a floating state according to claim 5, characterized in that, The process of sequentially stacking and closing the other segments includes: Scaffolding platforms are erected on the inner and outer sides of the closure opening on the (n-1)th total segment, and the vertical lifting rings on the (n-1)th total segment are removed, where n is a positive integer greater than or equal to 2; After the nth section is lifted by a floating crane and left to stand, check the working condition of the floating crane. Then, the nth section is erected and the lower end lifting ring is removed. Adjust the positioning direction on the nth segment so that the positioning fixture on it is aligned with the positioning fixture on the (n-1)th segment, and then match the two positioning fixtures on the nth segment below. Pull the stretched steel wire to the (n-1)th segment and lock it, then measure the straightness of the outer wall of the pile leg; Under the stress condition of the floating crane, measure the distance between the lower closure inspection line of the nth section and the upper closure inspection line of the (n-1)th section, as well as the distance between the two pin holes at the closure. After the positioning accuracy of the pile legs meets the requirements, the closure joint is welded.

7. The high-precision hoisting method for platform legs in a floating state according to claim 6, characterized in that, Before welding the closure joint, the process also includes: A locking fixture is installed between the lower closing pin hole of the nth segment and the upper closing pin hole of the (n-1)th segment. The locking fixture includes locking plates respectively disposed at the two pin holes and locking bolts for locking the two locking plates.

8. The high-precision hoisting method for platform legs in a floating state according to claim 7, characterized in that, After welding the closure joint, the process includes: Measure the distance between the two mating inspection lines every 8 hours, and measure the straightness of the center line of the pin hole every day. If the measurement data deviation exceeds the standard range, stop construction immediately and report to the project, discuss and determine the plan again before continuing construction.

Images