Manufacturing method of inverted v-shaped laminated beam of super-high and heavy load high-strength bolt connection

Abstract

The application is a manufacturing method of super-high, heavy-load high-strength bolt connection inverted V-shaped laminates; comprising steps 1, web plate and flange plate splicing position determination; step 2, web plate arching value determination; step 3, web plate and flange plate blanking and splicing; step 4, upper and lower laminates laminated surface flange plate laminated hole making; step 5, assembling lower laminate BH, that is, laminated plate whole and lower laminate web plate and lower flange plate assembling BH; step 6, lower laminate BH main weld seam welding; step 7, assembling upper laminate BH, that is, upper laminate web plate and upper flange plate and lower laminate BH whole assembling; step 8, upper laminate BH main weld seam welding; step 9, two upper laminate connecting surface flange plate assembling and welding; step 10, upper and lower laminate end plate and stiffener synchronous assembling and welding. The method can avoid three-dimensional pre-assembly, ensure upper and lower laminates synchronous and accurate arching and 100% bolt perforation rate, and solve a series of problems such as low manufacturing precision, long construction period, high cost and large safety risk coefficient of super-high, heavy-load high-strength bolt connection inverted V-shaped laminates.

Description

Technical Field

[0001] This invention relates to the field of steel structure construction, and more particularly to the field of industrial boiler construction technology, specifically a method for manufacturing ultra-high, heavy-duty, high-strength bolt-connected inverted triangular stacked beams. Background Technology

[0002] Large boilers offer advantages in improving energy efficiency and reducing pollutant emissions. Larger capacity and higher-parameter boilers are becoming the current trend in thermal power development. Large power plant boilers typically employ a suspended structure, with thousands of tons of load suspended from large plate beams at the top of the structure. These large plate beams then transfer the load to the tower. The top elevation of these large plate beams is generally over 100m, with a span of approximately 40m and a height of about 8m. They are typically composite beams, with a single beam weighing over 200 tons. Based on structural form, they are generally classified as: upper and lower H-shaped steel composite beams, inverted triangular three-H composite beams, and four-H composite beams with upper and lower H-beams and two end-plate beams of uniform height.

[0003] like Figure 1 , Figure 2 The fabrication process of the inverted triangular H-beam composite stacked beam is complex. Taking a certain project as an example: the upper two welded H-beams are connected by two flange plates with a thickness of 70mm at the ends. The upper flange plate of the lower welded H-beam is connected to the lower flange plate of the two upper welded H-beams by high-strength bolts, forming an inverted triangular shape. The maximum thickness of the web plate is 80mm, the maximum thickness of the cover plate is 120mm, the height of the upper steel section is 5m, the height of the lower steel section is 2m, the total height of the stacked beam is 7m, the total length is 37.28m, the total weight is 344t, the number of bolt holes on the overlapping surface is about 900, and the overall camber value in the installed state is 0.

[0004] The inverted triangular H-shaped composite beams can be hoisted and transported separately, reducing the requirements for hoisting and transportation. Therefore, the use of high-strength bolts to connect ultra-high and heavy-duty inverted triangular beams has become the development direction for large-scale boiler steel frame beams in thermal power generating units. However, key technologies such as the overall dimensions of such beams, precise synchronous cambering, and 100% pass rate control of high-strength bolt perforation on the composite surface are all challenges for existing steel structure companies in China. Therefore, it is necessary to invent a manufacturing method to achieve high-precision, short-term, and low-cost production of such components. Summary of the Invention

[0005] The purpose of this invention is to propose a method for the overall planar fabrication of ultra-high load-bearing, high-strength bolt-connected inverted triangular stacked beams, avoiding three-dimensional pre-assembly, ensuring synchronous and precise arching of the upper and lower stacked beams and a 100% bolt perforation rate, and solving a series of problems such as low fabrication accuracy, long construction period, high cost, and high safety risk factor of ultra-high load-bearing, high-strength bolt-connected inverted triangular stacked beams.

[0006] To achieve the above objectives, the present invention is implemented as follows: A method for manufacturing ultra-high, heavy-duty, high-strength bolt-connected inverted triangular stacked beams, including... Step 1: Determine the splicing positions of the web and flange plates: BH-shaped steel is an extra-long and extra-wide component. Before processing and manufacturing, it is necessary to determine the splicing position of the web plate and flange plate according to the component drawing dimensions, combined with the steel mill's steel plate production size data and design stress requirements. The splicing diagram is submitted to the design unit for review. After the design unit confirms, steel plates are purchased according to the size of this part. Step 2: Determine the web camber value: Based on the welding shrinkage calculation formula, and combined with the welding method, correction method, and welding sequence, the pre-camber calculation formula for the web of the stacked beam BH is obtained, thereby obtaining the pre-camber value of the web in the width direction of this stacked beam. The calculation formula is: the camber value of the web of the component = the calculated self-weight deflection + the welding shrinkage obtained from the test + the pre-camber value required by the design. During the web blanking process, CNC blanking is carried out according to this camber value. Step 3: Cutting and splicing the web and flange plates: Cut the material with a 10mm allowance on each side along the length direction. No allowance is added in the width direction of the flange plate. Cut the material in the width direction of the web plate according to the camber data obtained in step 2. After cutting, splice the material along the length direction. Weld the thick plates by cleaning the root from the reverse side. Grind the welds at the overlapping surfaces of the flange plates. After splicing, bevel the main welds of the web plate. The main welds on the overlapping surfaces are fillet welds and do not need to bevel. The main welds on the non-overlapping surfaces are partial penetration welds with a 6mm blunt edge. Bevel the material at a 45-degree angle on each side. Step 4: Drill holes for the overlapping flange plates of the upper and lower beams: After the flange plates are spliced, the lower flange plates of the upper stacked beam welded H-beam 1 and upper stacked beam welded H-beam 2 are combined with the upper flange plates of the lower stacked beam welded H-beam. These three flange plates are placed according to the on-site installation position of the components. Fixing steel plates are applied to the outside to ensure that the gap and contact area of ​​the overlapping surfaces meet the design requirements. Holes are drawn according to the dimensions on the drawings. After the dimensions are checked and approved, multiple radial drilling machines are used to drill holes in the composite plates. First, a trial drilling and positioning hole is performed. After there are no problems, the holes are fully drilled. After the holes are drilled, fastening bolts are inserted for fixation. Step 5: Assemble the lower stacked beam BH, that is, assemble the composite slab as a whole with the web and lower flange of the lower stacked beam BH: After drilling, the composite plate is assembled with the lower beam web and lower flange plate to form a BH-shaped steel, and then the main weld seam is tack welded.

[0007] Step 6: Welding of the main weld seam of the lower stacked beam BH: First, weld one main weld seam, then weld the other main weld seam. For each main weld seam, first weld a partial penetration weld seam, then weld a fillet weld seam. Weld symmetrically in sections from the middle of the component to both sides. Use gas shielded welding for the root pass, and use a turning lug and jig to form a boat-shaped weld. Use a submerged arc welding semi-automatic trolley for the filler and cover layers. Step 7: Assemble the upper stacked beam BH, that is, assemble the web and upper flange of the upper stacked beam with the lower stacked beam BH as a whole: After the lower stacked H-beams are welded, they are assembled with the upper BT structure on a jig. After assembly, the main weld on the front of the upper BH-beams is welded firmly. The bolts on the overlapping surface are removed to form three separate BH-beam components. The welded H-beams are then flipped over, and the fastening screws on the overlapping surface are tightened again. Finally, the main weld on the upper H-beams is repaired. Step 8: Welding of the main weld seam of the upper stacked beam BH: Under the premise of ensuring the overall connection state of the composite surface, complete the welding of the main weld of the H-beam of the upper composite beam; Step 9: Assemble and weld the flange plates connecting the two upper stacked beams: The flange plate connection surfaces of the two upper stacked beams are end-milled, and then the flange plates are drilled. The flange plates are then bolted together to form a whole. First, they are welded to the left upper stacked beam. Before welding, a 2mm welding shrinkage allowance is reserved based on experience. After welding, the actual welding shrinkage is measured and the shrinkage value is L1. Before welding the right upper stacked beam, a welding shrinkage allowance of (2*L1-2) is reserved in advance. At the same time, the camber value of the upper stacked beam needs to be considered. If the camber value is less than 6mm, a transition line is used at the flange to complete the welding between the right upper stacked beam and the flange plate. After welding, the fastening bolts between the flange plates are removed. Step 10: Simultaneous assembly and welding of the upper and lower stacked beam end plates and stiffening plates: In the stacked state, the end plates and middle vertical stiffening plates of the stacked beams are assembled and welded in sequence. The upper and lower stacked beams are welded synchronously and symmetrically to ensure consistent welding heat input and avoid welding deformation. After the upper and lower stacked beams are fabricated, a planar verification and pre-assembly are carried out to ensure that the high-strength bolt holes have a 100% pass rate, the gap of the stacked surface meets the design requirements, the overall dimensions of the components meet the specifications, and the overall quality of the components is excellent.

[0008] The invention proposes a method for the overall assembly and welding of ultra-high load-bearing, high-strength bolt-connected inverted triangular stacked beams, which involves flipping the beams separately. This method integrates overall assembly and welding with pre-assembly, ensuring synchronous and precise cambering of the upper and lower stacked beams and a 100% bolt perforation rate. It avoids three-dimensional pre-assembly and solves a series of problems such as low construction accuracy, long construction period, high cost, and high safety risk factor in the construction of ultra-high load-bearing, high-strength bolt-connected inverted triangular stacked beams. Attached Figure Description

[0009] Figure 1 A schematic diagram of the disassembly of an inverted triangular stacked beam connected by ultra-high load-bearing, high-strength bolts.

[0010] Figure 2 Schematic diagram of an inverted triangular stacked beam assembly connected by ultra-high load-bearing, high-strength bolts.

[0011] Figure 3 Flowchart of construction process for ultra-high load-bearing, high-strength bolt-connected inverted triangular stacked beams.

[0012] Figure 4 Schematic diagram of the splicing positions of the web and flange plates.

[0013] Figure 5 Schematic diagram of the bevel joint between the web and flange plates.

[0014] Figure 6 Schematic diagram of the bevel of the weld penetration surface in the web section.

[0015] Figure 7 Schematic diagram of drilling in composite slab.

[0016] Figure 8 Schematic diagram of the main weld of the lower beam.

[0017] Figure 9 Schematic diagram of the ship-shaped weld of the main weld seam of the lower stacked beam Figure 1 .

[0018] Figure 10 Schematic diagram of the ship-shaped weld of the main weld seam of the lower stacked beam Figure 2 .

[0019] Figure 11 Schematic diagram of the welding sequence of the main weld seam of the upper stacked beam Figure 1 .

[0020] Figure 12 Schematic diagram of the welding sequence of the main weld seam of the upper stacked beam Figure 2 .

[0021] Figure 13 A schematic diagram of the upper beam before welding to the flange plate.

[0022] Figure 14 A schematic diagram showing the upper beam after welding to the flange plate.

[0023] Figure 15 Schematic diagram of welding the upper beam and flange plate.

[0024] Figure 16 Schematic diagram of the assembly of upper and lower stacked beam stiffening plates. Detailed Implementation

[0025] The present invention will be further illustrated below through specific embodiments.

[0026] A method for manufacturing ultra-high, heavy-duty, high-strength bolt-connected inverted triangular stacked beams includes the following steps: Step 1 - Determining the splicing positions of the web and flange plates BH-section steel is an extra-long and extra-wide component. Before processing and fabrication, it is necessary to determine the splicing positions of the web and flange plates based on the component drawings, combined with the steel mill's steel plate production size data and design stress requirements. Figure 4 The splicing diagram shown is submitted to the design unit for review. After the design unit confirms it, steel plates are purchased according to the dimensions of this part.

[0027] Step 2 - Determining the web arch value Based on the welding shrinkage calculation formula, and combined with the welding method, correction method, welding sequence, etc., a pre-camber calculation formula for the web of the stacked beam BH is designed to obtain the pre-camber value of the web in the width direction of the stacked beam. The camber value of the web of the component = the calculated self-weight deflection + the welding shrinkage obtained by the test + the pre-camber value required by the design. During the web cutting process, CNC cutting is carried out according to this camber value.

[0028] Step 3 - Cutting and splicing of web and flange plates Cut the material along its length with a 10mm allowance on each side. No allowance is added in the width direction of the flange plates. Cut the web plate according to the camber data obtained in step 2. After cutting, splice the plates along their length. For thicker plates, weld using a reverse-side root cleaning method. The splice bevel shape is as follows: Figure 5 As shown, the welds at the flange lamination surfaces are ground smooth. After splicing, the main weld bevels for the web are opened. The main welds on the lamination surfaces are fillet welds and do not require beveling. The main welds on the non-lamination surfaces are partial penetration welds with a 6mm blunt edge, opened at a 45-degree angle on each side. The weld bevel form is as follows. Figure 6 As shown.

[0029] Step 4 - Drilling holes for the overlapping flange plates of the upper and lower beams After the flange plates are assembled, combine the lower flange plates of the upper stacked beam welded H-beam one and upper stacked beam welded H-beam two with the upper flange plate of the lower stacked beam welded H-beam. Place these three flange plates according to their on-site installation positions. Apply external fixing steel plates to ensure that the overlap gap and contact area of ​​the mating surfaces meet design requirements. Draw holes according to the dimensions on the drawings. Figure 7 As shown, after the dimensions are inspected and approved, multiple radial drilling machines are used to drill holes in the composite plate. First, a trial drilling is performed to make positioning holes. After there are no problems, the holes are fully drilled. After the holes are completed, fastening bolts are inserted for fixation.

[0030] Step 5 - Assemble the lower stacked beam BH (assembly of the composite slab with the lower stacked beam web and lower flange plate BH) After drilling, the composite slab is assembled with the web and lower flange of the lower beam to form a BH-shaped steel section, such as... Figure 8 As shown, then perform tack welding on the main weld seam.

[0031] Step 6 - Welding of the main weld seam of the lower stacked beam BH First weld one side of the main weld, then weld the other side. For each side of the main weld, first weld the partial penetration weld, then weld the fillet weld, following the order of welds 1 to 4. Figure 8 As shown, welding is performed symmetrically in sections from the middle of the component outwards. Gas-shielded welding is used for the root pass. Figure 9 and Figure 10 The turning lugs and jig shown form a boat-shaped weld, and the submerged arc welding semi-automatic trolley performs the filling layer and cover layer welding.

[0032] Step 7 - Assemble the upper stacked beam BH (the web and upper flange of the upper stacked beam are assembled as a whole with the lower stacked beam BH). After the lower stacked H-beams are welded, they are assembled with the upper BT structure horizontally on a jig, as follows: Figure 11 As shown, after assembly, the main welds 5 and 6 on the front of the upper BH-section steel are welded firmly. Since the overall weight of the stacked beams is close to 200 tons, the factory's lifting equipment cannot meet the requirements. Therefore, the bolts on the overlapping surface need to be removed, forming three separate BH-section steel components. Then, the welded H-section steel is flipped over, and the fastening screws on the overlapping surface are tightened again. Finally, the main welds 7 and 8 on the upper H-section steel are welded. Figure 12 As shown.

[0033] Step 8 - Welding of the main weld seam of the upper stacked beam BH While ensuring the overall connection of the composite surfaces, complete the main weld of the H-beams of the upper composite beam.

[0034] Step 9 - Assemble and weld the flange plates connecting the two upper stacked beams. The flange connection surfaces of the two upper stacked beams are end-milled, followed by drilling holes in the flange plates. The flange plates are then bolted together to form a single unit, and first welded to the left upper stacked beam. Before welding, a 2mm welding shrinkage allowance is made based on experience. The actual welding shrinkage is measured after welding and is valued as L1. Before welding the right upper stacked beam, a welding shrinkage allowance of (2*L1-2) is made in advance. Simultaneously, the camber value of the upper stacked beam must be considered; if the camber value is less than 6mm, a transition line is used at the flange. Figures 13-15 As shown, complete the welding between the upper right beam and the flange plate, and remove the fastening bolts between the flange plates after welding.

[0035] Step 10 - Synchronous assembly and welding of the upper and lower stacked beam end plates and stiffening plates In the stacked state, the end plates and middle vertical stiffening plates of the stacked beams are assembled and welded in sequence. The upper and lower stacked beams are welded synchronously and symmetrically to ensure consistent welding heat input and avoid welding deformation. After the upper and lower stacked beams are fabricated, a planar verification and pre-assembly are carried out to ensure that the high-strength bolt holes have a 100% pass rate, the gap of the stacked surface meets the design requirements, the overall dimensions of the components meet the specifications, and the overall quality of the components is excellent.

Claims

1. A method for manufacturing ultra-high, heavy-duty, high-strength bolt-connected inverted triangular stacked beams, characterized by: include Step 1: Determine the splicing positions of the web and flange plates: BH-shaped steel is an extra-long and extra-wide component. Before processing and manufacturing, it is necessary to determine the splicing position of the web plate and flange plate according to the component drawing dimensions, combined with the steel mill's steel plate production size data and design stress requirements. The splicing diagram is submitted to the design unit for review. After the design unit confirms, steel plates are purchased according to the size of this part. Step 2: Determine the web camber value: Based on the welding shrinkage calculation formula, and combined with the welding method, correction method, and welding sequence, the pre-camber calculation formula for the web of the stacked beam BH is obtained, thereby obtaining the pre-camber value of the web in the width direction of this stacked beam. The calculation formula is: the camber value of the web of the component = the calculated self-weight deflection + the welding shrinkage obtained from the test + the pre-camber value required by the design. During the web blanking process, CNC blanking is carried out according to this camber value. Step 3: Cutting and splicing the web and flange plates: Cut the material with a 10mm allowance on each side along the length direction. No allowance is added in the width direction of the flange plate. Cut the material in the width direction of the web plate according to the camber data obtained in step 2. After cutting, splice the material along the length direction. Weld the thick plates by cleaning the root from the reverse side. Grind the welds at the overlapping surfaces of the flange plates. After splicing, bevel the main welds of the web plate. The main welds on the overlapping surfaces are fillet welds and do not need to bevel. The main welds on the non-overlapping surfaces are partial penetration welds with a 6mm blunt edge. Bevel the material at a 45-degree angle on each side. Step 4: Drill holes for the overlapping flange plates of the upper and lower beams: After the flange plates are spliced, the lower flange plates of the upper stacked beam welded H-beam 1 and upper stacked beam welded H-beam 2 are combined with the upper flange plates of the lower stacked beam welded H-beam. These three flange plates are placed according to the on-site installation position of the components. Fixing steel plates are applied to the outside to ensure that the gap and contact area of ​​the overlapping surfaces meet the design requirements. Holes are drawn according to the dimensions on the drawings. After the dimensions are checked and approved, multiple radial drilling machines are used to drill holes in the composite plates. First, test drilling is performed to make positioning holes. After there are no problems, the holes are fully drilled. After the holes are made, bolts are inserted for fixation. Step 5: Assemble the lower stacked beam BH, that is, assemble the composite slab as a whole with the web and lower flange of the lower stacked beam to form BH: After drilling, the composite plate is assembled with the web plate and lower flange plate of the lower beam to form a BH-shaped steel, and then the main weld seam is tack welded. Step 6: Welding of the main weld seam of the lower stacked beam BH: First, weld one main weld seam, then weld the other main weld seam. For each main weld seam, first weld a partial penetration weld seam, then weld a fillet weld seam. Weld symmetrically in sections from the middle of the component to both sides. Use gas shielded welding for the root pass, and use a turning lug and jig to form a boat-shaped weld. Use a submerged arc welding semi-automatic trolley for the filler and cover layers. Step 7: Assemble the upper stacked beam BH, that is, assemble the web and upper flange of the upper stacked beam with the lower stacked beam BH as a whole: After the lower stacked H-beams are welded, they are assembled with the upper BT structure on a jig. After assembly, the main welds on the front of the upper BH-beams are welded firmly. The bolts on the overlapping surface are removed to form three separate BH-beam components. The welded H-beams are then flipped over, and the bolts on the overlapping surface are tightened again. Finally, the remaining main welds of the upper H-beams are welded. Step 8: Welding of the main weld seam of the upper stacked beam BH: Under the premise of ensuring the overall connection state of the composite surface, complete the welding of the main weld of the H-beam of the upper composite beam; Step 9: Assemble and weld the flange plates connecting the two upper stacked beams: The flange plate connection surfaces of the two upper stacked beams are end-milled, and then holes are drilled in the flange plates. The flange plates are then bolted together to form a whole. First, they are welded to the left upper stacked beam. Before welding, a 2mm welding shrinkage allowance is reserved based on experience. After welding, the actual welding shrinkage is measured and the shrinkage value is L1. Before welding the right upper stacked beam, a welding shrinkage allowance of 2*L1-2 is reserved in advance. At the same time, the camber value of the upper stacked beam needs to be considered. If the camber value is less than 6mm, a transition line is used at the flange to complete the welding between the right upper stacked beam and the flange plate. After welding, the bolts between the flange plates are removed. Step 10: Simultaneous assembly and welding of the upper and lower stacked beam end plates and stiffening plates: In the stacked state, the end plates and middle vertical stiffening plates of the stacked beams are assembled and welded in sequence. The upper and lower stacked beams are welded synchronously and symmetrically to ensure consistent welding heat input and avoid welding deformation. After the upper and lower stacked beams are fabricated, a planar verification and pre-assembly are carried out to ensure that the high-strength bolt holes have a 100% pass rate, the gap of the stacked surface meets the design requirements, the overall dimensions of the components meet the specifications, and the overall quality of the components is excellent.

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