A method for manufacturing a dense anchoring structure tower bottom steel-concrete joint section

Abstract

The application discloses a kind of dense anchoring structure tower bottom steel concrete joint section manufacturing method, it is related to bridge construction technical field, it includes the following steps: S1: making lower block;S2: making upper block, its specific content includes the following steps: S201: cutting blanking and drilling are carried out to pressure plate;S202: pressure plate is connected wide and welded;S203: positioning assembly lower layer mid-plate unit, lower layer side baffle unit, upper layer baffle unit and inner wall plate unit;Then positioning assembly side box chamber longitudinal baffle unit, wall plate unit, cross baffle unit;Finally, positioning assembly outside wall plate unit, weld seam between wall plate and baffle;S204: installation anchoring frame, complete upper block manufacturing;S3: group splicing upper block and lower block, weld seam of lower block and pressure plate, then install prestressed pipe and reinforcing steel, complete manufacturing.The application solves the technical problem that existing steel concrete joint section cannot meet the demand of bridge structure.

Description

Technical Field

[0001] This invention relates to the field of bridge construction technology, and in particular to a method for manufacturing a steel-concrete composite section at the base of a densely anchored tower structure. Background Technology

[0002] The main tower of a suspension bridge needs to withstand the huge vertical tension and bending moment transmitted by the main cable. As a key transition zone between the steel tower and the concrete foundation, the steel-concrete composite section needs to achieve coordinated stress distribution through shear keys, prestressed anchorage, and other methods due to the significant differences in the elastic modulus and thermal expansion coefficients of steel and concrete.

[0003] Conventional steel-concrete composite sections are either fully bearing or bearing-shear. The fully bearing type has limited shear resistance and is difficult to apply to uniquely shaped steel towers. However, with the increasing demand for aesthetically pleasing bridge structures, there are more and more uniquely shaped steel towers. The steel-concrete composite sections of these towers adopt a structure that combines bearing-shear with dense anchoring to meet the stress requirements. Summary of the Invention

[0004] The purpose of this invention is to provide a method for manufacturing a steel-concrete composite section at the base of a densely anchored tower structure, which solves the technical problem that existing steel-concrete composite sections cannot meet the structural requirements of bridges.

[0005] This application discloses a method for manufacturing a steel-concrete composite section at the base of a densely anchored tower structure, comprising the following steps: S1: Fabrication of the lower block: Assemble the inner concrete wall panel unit, then assemble the outer concrete wall panel unit. After completion, weld the components to complete the fabrication of the lower block. S2: Create the upper block, which includes the following steps: S201: Cutting and drilling the pressure plate; S202: Wiring and welding the bearing plate; S203: Position and assemble the lower middle partition unit, lower side partition unit, upper partition unit and inner wall panel unit; then position and assemble the side compartment longitudinal partition unit, wall panel unit and transverse partition unit; finally position and assemble the outer wall panel unit and weld the welds between the wall panels and partitions. S204: Install the anchor frame, using a piecemeal assembly method. The entire assembly is installed sequentially from the middle of the outer wall panel unit outwards to both sides, completing the fabrication of the upper block. S3: Assemble the upper and lower blocks, weld the lower block to the pressure plate, and then install the prestressed pipes and reinforcing bars to complete the fabrication.

[0006] The steel-concrete composite section in this application adopts a structure that combines "compression + shear transmission" with dense prestressed tendon anchorage, which can meet the stress requirements of the bridge. At the same time, the manufacturing method is also disclosed, which facilitates the manufacturing of the steel-concrete composite section. This control method not only improves the overall quality of the steel-concrete composite section manufacturing and greatly enhances the efficient synergy between steel and concrete, but also provides technical guarantee for the safety and economy of suspension bridges and improves the safe service durability of steel bridges.

[0007] Based on the above technical solution, the embodiments of this application can be further improved as follows: Furthermore, the welding sequence in step S1 is as follows: S101: Assemble the steel wall panels and perform tack welding; S102: After the steel wall panel is assembled, weld the outer secondary top plate, the inner secondary bottom plate and the inner and outer web plates with partial penetration fillet welds. S103: Partial full penetration fillet weld between the inner web plate and the outer top plate and the inner bottom plate; S104: Full penetration fillet weld between the outer web plate and the outer top plate and the inner bottom plate; S105: Weld the outer secondary top plate, inner secondary bottom plate and bearing plate with partial full penetration fillet welds, and perform symmetrical welding; S106: Partial full penetration fillet weld between the inner web plate and the bearing plate, symmetrically welded; S107: The fillet welds between the outer web plate and the bearing plate are partially penetrated and welded symmetrically. The method of using line tack welding followed by partial penetration fillet welds can ensure manufacturing accuracy.

[0008] Furthermore, the specific content of step S201 is as follows: The thickness of the bearing plate is at least 150mm. During processing, holes larger than φ30mm are cut out on the bearing plate, and holes smaller than φ30mm are drilled using a CNC drilling machine. Before cutting, a small hole of φ26mm is drilled in the center of the holes larger than φ30mm to serve as both a cutting start-up and a hole-enlarging positioning tool. Then, the bearing plate is cut out using the small hole for positioning, and holes larger than φ30mm are cut out. Next, after the bearing plate is cut out, holes smaller than φ30mm are drilled using the cut-out holes for positioning. The advantage of this step is that by drilling some holes first and then drilling the remaining holes later, the processing accuracy can be guaranteed.

[0009] Furthermore, at least six pressure plates are obtained using step S201. All the pressure plates are butt-welded together, and the butt welds on both sides are full penetration welds, while the remaining butt welds are partial penetration welds. Welding is performed using low current, multi-layer, and multi-pass welding to control welding deformation. Multiple flipping and simultaneous welding on both sides are also performed. The benefit of this step is to ensure welding accuracy.

[0010] Furthermore, in step S202, the pressure plate has a reserved welding shrinkage allowance on both sides. The reserved welding shrinkage allowance for the side with partial penetration welding is 1mm, and the reserved welding shrinkage allowance for the side with full penetration welding is 2mm. The beneficial effect of this step is to ensure the welding accuracy by reserving the welding shrinkage allowance.

[0011] Furthermore, when assembling the inner wall panel unit and the outer wall panel unit in step S203, they are tilted outwards. The advantage of this step is that it avoids the occurrence of concavity during subsequent welding, thereby ensuring processing accuracy.

[0012] Furthermore, the specific content of step S203 is as follows: Step 1: Position the lower middle partition, assemble the adjacent secondary inner wall panels and perform tack welding; position the lower side partition, assemble the adjacent outer secondary top panel and inner secondary bottom panel and perform tack welding. Step II: Assemble the inner web plate and perform tack welding; assemble the remaining secondary inner wall plates, outer secondary top plates, and inner secondary bottom plates and perform tack welding. Step 3: Assemble the outer top plate, inner bottom plate, and outer web plate, and perform tack welding; Step IV: After all the steel tower wall panels are positioned, first weld the bevel fillet weld between the secondary intermediate inner wall panel and the inner web panel, and then weld the bevel fillet weld between the outer secondary inner wall panel and the inner and outer web panels. Step V: First, weld the full penetration fillet welds of the outer secondary top plate, the inner secondary bottom plate and the inner and outer web plates. Then, weld the full penetration fillet welds of the inner web plate with the outer top plate and the inner bottom plate. Finally, weld the full penetration fillet welds of the outer web plate with the outer top plate and the inner bottom plate. Step VI: Weld the bevel fillet welds between the inner wall plate and the bearing plate, symmetrically; weld the partial penetration fillet welds between the outer secondary top plate, inner secondary bottom plate and the bearing plate, symmetrically; weld the partial penetration fillet welds between the inner web plate and the bearing plate, symmetrically; weld the partial penetration fillet welds between the outer web plate and the bearing plate, symmetrically; weld the partial penetration fillet welds between the outer top plate, inner bottom plate and the bearing plate, symmetrically; weld the bevel fillet welds between the pre-installed plate rib and the bearing plate.

[0013] Furthermore, the specific content of step S204 is as follows: The anchoring frame is divided into a long anchoring frame and a short anchoring frame. The long anchoring frame includes a long stiffener, and the short anchoring frame includes a short stiffener. The welding sequence of the long anchor frame is as follows: First, install the anchor frame web and weld the full penetration fillet weld between the anchor frame web and the outer wall panel unit. Secondly, weld the full penetration fillet weld between the long stiffener and the web of the anchor frame, and weld the fillet weld between the web of the anchor frame and the bearing plate, and between the stiffener of the anchor frame and the bearing plate. Secondly, fillet welds between the welding end plate and the anchoring structure components; Finally, weld the fillet weld between the anchor plate and the anchoring structure component; The welding sequence of the short anchorage frame is as follows: First, install the web of the anchor frame and weld the full penetration fillet weld between the web of the anchor frame and the wall panel. Secondly, weld the short stiffeners and the full penetration fillet welds of the anchor frame web; Secondly, fillet welds between the welding end plate and the anchoring structure components; Next, weld the fillet weld between the anchor plate and the anchoring structure component; Finally, the bevel fillet weld between the prestressed outer plate and the web of the anchor frame is welded.

[0014] Furthermore, step S204 also includes the following: First, install the rear plate ribs and weld them to the wall panel and the pressure plate with bevel fillet welds. Secondly, weld the bevel fillet weld between the lower partition plate and the inner wall plate of the segment; Next, assemble the upper partition and weld its fillet weld to the wall panel; Finally, the bevel fillet weld between the outer prestressed shroud and the web of the anchoring structure is completed.

[0015] Furthermore, step S3 also includes the following: welding the outer top plate, inner bottom plate and bearing plate of the lower block with partial penetration fillet welds, and performing symmetrical welding.

[0016] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages: 1. The steel-concrete composite section of this application adopts a structure that combines "compression + shear transmission" with dense prestressed tendon anchorage, which can meet the stress requirements of the bridge.

[0017] 2. This application also discloses a method for fabricating the steel-concrete composite section at the base of a densely anchored tower structure, and determines the overall assembly scheme for fabricating the steel-concrete composite section at the base of the densely anchored tower structure. This facilitates the fabrication of such steel-concrete composite sections, while further improving the fabrication precision of such steel-concrete composite sections, achieving efficient synergy between steel and concrete, providing technical support for the safety and economy of suspension bridges, and enhancing the safe service durability of steel bridges. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1This is an overall schematic diagram of the steel tower section at the bottom of the tower, which is part of the dense anchoring structure of this invention. Figure 2 This is a block diagram of the steel-concrete composite section at the bottom of the tower in the dense anchoring structure of the present invention; Figure 3 This is a structural schematic diagram of the steel-concrete composite section at the bottom of the tower, part of the densely anchored structure of this invention; Figure 4 This is a schematic diagram of the welding sequence of the lower block of the steel-concrete composite section at the bottom of the tower in the dense anchoring structure of the present invention. In the figure, the numbers ①-④ indicate the welding sequence, and the arrows point to the welding direction. Figure 5 This is a schematic diagram of the remaining welding sequence of the lower block of the steel-concrete composite section at the bottom of the tower base in the densely anchored structure of the present invention. In the figure, numbers ⑤-⑦ indicate the welding sequence, and the arrows point to the welding direction. Figure 6 This is a schematic diagram of the pressure plate segment of the steel-concrete composite section at the bottom of the tower in the densely anchored structure of the present invention; Figures 7-12 This is a schematic diagram of the welding sequence of the upper block of the steel-concrete composite section at the bottom of the tower in the dense anchoring structure of the present invention. In the figure, the numbers ①-⑮ indicate the welding sequence, and the arrows point to the welding direction. Figures 13-16 This is a schematic diagram of the welding sequence of the long anchoring frame of the steel-concrete composite section at the bottom of the tower in the dense anchoring structure of the present invention. In the figure, the numbers ①-⑦ indicate the welding sequence, and the arrows point to the welding direction. Figures 17-21 This is a schematic diagram of the welding sequence of the short anchoring frame of the steel-concrete composite section at the bottom of the tower in the dense anchoring structure of the present invention. In the figure, the numbers ①-⑥ indicate the welding sequence, and the arrows point to the welding direction.

[0020] Figure label: 1- Densely anchored structure tower base steel-concrete composite section; 2- Upper block; 3- Lower block; 4- Steel wall panel; 5- Shear plate; 6- Bearing plate; 7- Anchoring frame; 8- Lower middle partition unit; 9- Upper partition unit; 10- Outer wall panel unit. Detailed Implementation

[0021] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention. It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning as understood by those skilled in the art to which this invention pertains.

[0022] To better understand the above technical solutions, the following will provide a detailed description of the technical solutions in conjunction with the accompanying drawings and specific embodiments.

[0023] Example: like Figure 1-21 As shown in the embodiment of this application, a method for manufacturing a steel-concrete composite section at the base of a densely anchored tower structure is disclosed. Specifically, the steel-concrete composite section at the base of the densely anchored tower structure adopts a "pressure-bearing + shear-transfer" type structure with dense prestressed tendons anchored together. Specifically, the total height of the steel-concrete composite section can be 8m, the thickness of the pressure plate can be 150mm, the part below the pressure plate is a concrete composite section with a height of 4m, and the part above the pressure plate (including the pressure plate) is a steel tower segment with a height of 4m.

[0024] The section above the bearing plate includes wall panel units, partition units, and a dense anchorage structure. Below the bearing plate, the concrete bonding section is connected to the concrete tower base via shear studs, steel bars welded to the steel plate, PBL shear keys, and prestressed steel strands. The shear studs are φ22mm, 150mm long weld studs. The PBL shear key's through-bar is located at the center of a φ60mm diameter circular hole, with φ25mm steel bars running the entire length. The bonding section's steel mesh uses φ25mm steel bars, which are cut off at the steel plate where they intersect and welded to it. The bonding section uses 37-φ15.2 bonded prestressed steel strands. The prestressed steel strands pass through the bearing plate, with the upper end anchored to the anchorage structure and the lower end anchored inside the concrete tower base. Single-end tensioning is used, and 101 prestressed steel strands are installed inside the tower. To ensure the integrity of the concrete between the steel grating chambers, oblong holes with a width of 100-300mm and a height of 1000mm are made in the steel wall panels and shear plates of the concrete bonding section to facilitate concrete flow.

[0025] In this application, the steel-concrete composite section above the bearing plate includes steel tower wall panel units, anchor frame structures, and partition units. Below the bearing plate is a frame structure composed of concrete and steel wall panel units. The overall segment is top-heavy and bottom-light. Based on the structural characteristics, the segment is divided into a lower block and an upper block. The lower block includes concrete and steel wall panel units, and the upper block includes a 150mm thick bearing plate, wall panel units, and anchor frame structures. The specific manufacturing method disclosed in this application for the above structure is as follows: S1: Fabrication of the lower block: Assemble the inner concrete wall panel unit, then assemble the outer concrete wall panel unit. After completion, weld the assembly to complete the fabrication of the lower block. Step S1 is as follows: Set up longitudinal and transverse survey lines. Assemble the inspected and qualified concrete inner wall panel units symmetrically along these survey lines, adjusting the panel spacing to ensure the upper ends of the panels are flush. Use inner tubes for temporary support, ensuring the verticality deviation of the panels is ≤1mm. Using the survey lines as a reference, assemble the concrete outer wall panel units, ensuring the upper ends of the panels are flush with the inner wall panels. Adjust the panel spacing deviation to ≤2mm and the verticality deviation to ≤1mm. After passing inspection, weld the inner and outer wall panel seams to complete the lower block fabrication. Welding should be performed according to the following steps: S101: Assemble the steel wall panels and position them; that is, only position them and do not perform formal welding. S102: After the steel wall panel is assembled, weld the outer secondary top plate, the inner secondary bottom plate and the inner and outer web plates with partial penetration fillet welds, i.e. welds ① / ②. S103: Partial full penetration fillet weld between the inner web plate and the outer top plate and the inner bottom plate, i.e. weld ③; S104: Full penetration fillet weld between the outer web plate and the outer top plate and the inner bottom plate, i.e. weld ④; S105: Weld the outer secondary top plate, inner secondary bottom plate and bearing plate with partial penetration fillet welds, and weld symmetrically, i.e. weld ⑤; S106: Weld the fillet weld between the inner web plate and the bearing plate, and weld symmetrically, i.e. weld ⑥; S107: Weld the fillet weld between the outer web plate and the bearing plate, and weld symmetrically, i.e. weld ⑦; S2: Create the upper block, which includes the following steps: S201: Cutting and drilling the pressure plate, specifically including: the thickness of the pressure plate is at least 150mm; during processing, holes larger than φ30mm are cut out of the pressure plate, while holes smaller than φ30mm are drilled using a CNC drilling machine. Before cutting, a small φ26mm hole is drilled in the center of the holes larger than φ30mm to serve as both a cutting ignition point and a positioning point for enlargement. Then, the pressure plate is cut out using the small hole for positioning, and holes larger than φ30mm are cut out. Next, after cutting the pressure plate, holes smaller than φ30mm are drilled using the cut-out holes for positioning. For holes with low precision requirements, the cutting can be carried out; for smaller diameter holes, drilling is still used to ensure hole wall quality. Drilling a ignition hole in the center of the hole before cutting can be used for auxiliary positioning of the raw material on the cutting platform and can also prevent the ignition hole from running out of the cutting hole due to large positioning deviation of the raw material. Drilling the small hole after cutting completely avoids the situation where the original drilling hole is misaligned due to raw material misalignment during cutting. Because the 150mm bearing plate is too thick to be penetrated by flame cutting, an ignition hole is needed to assist in the cutting. Simultaneously, the prestressed steel strands in the steel-concrete composite section of the densely anchored tower base need to pass upwards through the bearing plate and anchor to the anchoring frame structure. Concrete is poured below the bearing plate, resulting in a dense network of steel strand holes, grouting holes, venting holes, and pressure grouting holes on the 150mm bearing plate. Hole position deviations can interfere with the anchoring frame structure. To ensure the accuracy of the hole group, a step-by-step drilling process is adopted. The first step involves drilling smaller positioning holes (which also serve as ignition holes) at corresponding positions on the original material for holes with larger diameters that cannot be drilled directly. These holes are then cut out during the material cutting process. The positioning holes are used as a reference to determine the position of the original material during cutting to avoid the positioning holes deviating from the drilled holes. The second step involves using the cut-out holes as a reference for positioning and drilling smaller diameter holes using a CNC drilling machine. The position of the ignition holes that are close to the butt weld needs to be adjusted to prevent them from affecting the weld inspection; some holes that are close to the butt weld will be cut out using a profile cutting machine after the pressure plate butt welding is completed. S202: The bearing plates are widened and welded. The specific contents of this step are as follows: at least six bearing plates are obtained using step S201. All the bearing plates are butted together and then welded. The butt welds on both sides are full penetration welds, and the remaining butt welds are partial penetration welds. During welding, low current multi-layer and multi-pass welding is used to control welding deformation. The plates are turned over multiple times and welded simultaneously on both sides. After the bearing plates are widened and welded, they are inspected. The qualified bearing plate units are then placed on the assembly jig. According to the anchor frame structure and the wall panel unit assembly position, the flatness is checked with a level and straightedge. For local deviations, a combination of welding and grinding is used to ensure the flatness of the anchor frame structure and the wall panel unit installation position. S203: Position and assemble the lower middle partition unit, lower side partition unit, upper partition unit, and inner wall panel unit; then position and assemble the side compartment longitudinal partition unit, wall panel unit, and transverse partition unit; finally position and assemble the outer wall panel unit, and weld the welds between the wall panels and partitions; during positioning and assembly, the following operation method should be followed: First, using the longitudinal and transverse baselines of the pressure plate as a reference, position and assemble the lower middle partition unit, use temporary tooling to assist in positioning, control the height and level of the partition, assemble the inner wall panel unit with the partition as the inner core, ensure that the longitudinal baselines of the inner wall panels on both sides are aligned, and ensure that the verticality is ≤1mm. First, assemble the lower side partition unit, upper partition unit, and inner wall panel unit sequentially, using the longitudinal and transverse baselines of the pressure plate as references, ensuring the wall panel spacing and verticality. Second, using the longitudinal and transverse baselines of the pressure plate as references, symmetrically assemble the side compartment longitudinal partition unit, wall panel unit, and transverse partition unit, ensuring the wall panel spacing, transverse partition positioning height, and horizontality. Finally, using the longitudinal and transverse baselines of the pressure plate as references and the partition unit as the inner core, assemble the outer wall panel unit, check the angle between the wall panel and the pressure plate and the dimensions of each compartment opening, and make adjustments. After passing the inspection, weld the inner wall panel and the weld between the partitions. S204: Install the anchor frame, using a piecemeal assembly method. The entire assembly is installed sequentially from the middle of the outer wall panel unit outwards to both sides, completing the fabrication of the upper block. S3: Assemble the upper and lower blocks, weld the lower block to the pressure plate, and then install the prestressed pipes and reinforcing bars to complete the fabrication.

[0026] Further explanation of step S202: Considering the welding shrinkage in the direction perpendicular to the weld after butt welding of the ultra-thick pressure plate, which affects the outline size of the pressure plate and the opening spacing, the width of the perpendicular weld edge needs to be increased when cutting the pressure plate. Specifically, the width of the two sides of the partially penetrated weld is increased by 1mm as welding shrinkage allowance, leaving a total of 2mm welding shrinkage allowance; the width of the two sides of the fully penetrated weld is increased by 2mm as welding shrinkage allowance, leaving a total of 4mm welding shrinkage allowance.

[0027] Step S203 in this application requires assembling the various partition units. Since the anchoring structures in the upper and middle sections are densely distributed along the perimeter of the outer wall panels, post-weld shrinkage will cause the pressure plate to deform into a "pot-shaped" concave form, and the wall panels will also tilt inwards. Therefore, when assembling the inner and outer wall panels, an outward tilt is added (the bottom of the wall panels is assembled according to the design spacing, and the spacing at the upper ends of the wall panels is increased by 2mm), and the perimeter of the upper partition is enlarged by 1mm. The wall panels are pre-assembled with openings to accommodate the overall welding deformation of the block; specifically, when assembling the inner and outer wall panel units in step S203, they are tilted outwards.

[0028] Step 203 of this application discloses the assembly and welding of the respective units, the specific details of which are as follows: Step 1: Position the lower middle partition, assemble the adjacent secondary inner wall panels and perform tack welding; position the lower side partition, assemble the adjacent outer secondary top panel and inner secondary bottom panel and perform tack welding. Step II: Assemble the inner web plate and perform tack welding; assemble the remaining secondary inner wall plates, outer secondary top plates, and inner secondary bottom plates and perform tack welding. Step 3: Assemble the outer top plate, inner bottom plate, and outer web plate, and perform tack welding; Step IV: After all the steel tower wall panels are positioned, first weld the bevel fillet weld ① between the secondary intermediate inner wall panel and the inner web panel, and then weld the bevel fillet weld ② between the outer secondary inner wall panel and the inner web panel and the outer web panel. Step V: First, weld the full penetration fillet welds ③ between the outer secondary top plate, the inner secondary bottom plate and the inner and outer web plates; then weld the full penetration fillet welds ④ between the inner web plate and the outer top plate and the inner bottom plate; finally, weld the full penetration fillet welds ⑤ between the outer web plate and the outer top plate and the inner bottom plate. Step VI: Weld the bevel fillet welds ⑥ between the inner wall plate and the bearing plate, symmetrically; weld the partial penetration fillet welds ⑦ between the outer secondary top plate, inner secondary bottom plate and the bearing plate, symmetrically; weld the partial penetration fillet welds ⑧ between the inner web plate and the bearing plate, symmetrically; weld the partial penetration fillet welds ⑨ between the outer web plate and the bearing plate, symmetrically; weld the partial penetration fillet welds ⑩ between the outer top plate, inner bottom plate and the bearing plate, symmetrically; weld the bevel fillet welds ⑪ between the pre-installed plate rib and the bearing plate (not all are shown in the figure).

[0029] Before assembling the anchoring frame, this application requires hole alignment. Specifically, the upper block steel strands need to pass upward through the bearing plate and be anchored on the anchoring frame structure anchor plate. To ensure concentricity of the holes, the anchor plate and the bearing plate steel strand holes are adjusted and positioned using hole-aligning tools.

[0030] Further explanation is given regarding step S204 in this application. The anchor frame in this application is installed in a piecemeal manner. The entire frame is installed sequentially from the middle of the wall panel to both sides. For a single anchor frame, the two side webs are installed first, and the welds between the anchor frame web and the wall panel and between the anchor frame web and the bearing plate are welded. Then, the long or short stiffeners between the webs are installed, and the welds between the long or short stiffeners and the anchor frame web are welded. If it is a long anchor frame, the welds between its internal long stiffeners and the bearing plate are welded. Finally, the anchor frame sealing plate and anchor pad plate are installed and welded.

[0031] Specifically, the anchoring frame is divided into a long anchoring frame and a short anchoring frame. The long anchoring frame includes a long stiffener, and the short anchoring frame includes a short stiffener. The welding sequence of the long anchor frame is as follows: First, install the anchor frame web and weld the full penetration fillet weld between the anchor frame web and the outer wall panel unit ①; Secondly, weld the full penetration fillet welds ②-⑤ between the long stiffener and the web of the anchor frame, and weld the fillet welds between the web of the anchor frame and the bearing plate, and between the stiffener of the anchor frame and the bearing plate; Secondly, the fillet welds between the welding end plate and the anchoring structure components ⑥ (not fully shown in the figure); Finally, fillet welds are made between the anchor plate and the anchorage components (not all of which are shown in the figure). The welding sequence of the short anchorage frame is as follows: First, install the web plate of the anchor frame and weld the full penetration fillet weld between the web plate of the anchor frame and the wall plate ①; Secondly, weld the short stiffeners and the full penetration fillet welds of the anchorage web plate ② and ③; Secondly, the fillet welds ④ between the welding end plate and the anchorage structure (not fully shown in the figure); Next, the fillet weld between the anchor plate and the anchorage component ⑤ (not all of which are shown in the figure); Finally, the bevel fillet weld between the prestressed outer plate and the web of the anchor frame is completed.

[0032] When welding the anchor frame, step S204 also includes the following: First, install the rear plate rib and weld it to the inner wall plate of the segment and the bevel fillet weld ⑫, so as not to interfere with the position of the anchor frame web plate welding; Secondly, weld the bevel fillet weld between the lower partition plate and the wall plate (13); Next, assemble the upper partition and weld its fillet weld to the wall panel. Finally, fillet welds are made between the outer prestressed shroud and the web of the anchoring structure. Specifically, the upper and lower diaphragms here refer to the upper and lower diaphragm units within the segment. The welding here refers to the welding of all diaphragm units of the nine chambers to the surrounding wall panels. The diaphragm and wall panels are fillet welds. The dense anchoring structure welding causes large segment deformation. The fillet welds of the diaphragms are left to be welded last to avoid deformation and cracking of the welds. The assembly of the diaphragms here can be changed to welding. The diaphragms have been assembled before the anchoring frame is welded. Before assembling the upper and lower blocks in step S3, a level, steel ruler, and straightedge are used to measure the deformation of the upper block's bearing plate after welding, the overall size of the block, and the size of the box opening, and to correct the deformation. A theodolite is used to mark the machining line at the top of the block, and a portable machining equipment is used to machine and mill the edge of the wall panel according to the line to complete the production of the upper block.

[0033] The specific content of step S3 is as follows: First, lay out the longitudinal and transverse survey lines, locate the lower blocks according to the lines, adjust the verticality of the blocks and the horizontality of the upper ends, locate the upper blocks using the longitudinal and transverse survey lines as a reference, and weld the lower blocks to the bearing plate, that is, weld the outer top plate and inner bottom plate of the lower blocks to the bearing plate with partial penetration fillet welds, and perform symmetrical welding; second, adjust the steel-concrete composite section to ensure the bearing plate is horizontal, and install the prestressed ducts by positioning them with the steel strand holes, ensuring the ducts are vertical; finally, install the reinforcing bars layer by layer from top to bottom, and install the lower reinforcing bars after the upper layer of reinforcing mesh is welded and tied.

[0034] Further explanation of this application: The bearing plate structure of the pressure-bearing shear-transfer composite steel-concrete section with dense anchorage is complex. Above the pressure plate, anchorage structures are densely distributed, forming multiple narrow spaces. Below the pressure plate, it is a lattice structure with shear studs and perforated steel plate shear keys, requiring the installation of dense steel mesh before concrete pouring. This structure presents challenges such as limited working space, poor construction environment, difficulty in controlling welding deformation, difficulty in ensuring fabrication precision, and difficulty in installing prestressing tendons at the bridge site. This application solves these problems while further improving fabrication precision, achieving efficient synergy between steel and concrete, and providing technical assurance for the safety and economy of suspension bridges.

[0035] Numerous specific details are set forth in this specification. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification. Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A method for fabricating a steel-concrete composite section at the base of a tower with a densely anchored structure, characterized in that, Includes the following steps: S1: Fabrication of the lower block: Assemble the inner concrete wall panel unit, then assemble the outer concrete wall panel unit. After completion, weld the components to complete the fabrication of the lower block. S2: Create the upper block, which includes the following steps: S201: Cut and drill holes in the pressure plate; the thickness of the pressure plate is at least 150mm; during processing, holes with a diameter of φ30mm or larger are cut out on the pressure plate, and holes with a diameter of φ30mm or smaller are drilled using a CNC drilling machine. Before cutting, a small hole with a diameter of φ26mm is drilled in the center of the holes with a diameter of φ30mm or larger, which serves as both a cutting start-up and a hole enlargement positioning function. Then, the pressure plate is cut out and holes with a diameter of φ30mm or larger are cut out using the small hole for positioning. Next, after the pressure plate is cut out, holes with a diameter of φ30mm or smaller are drilled using the cut-out holes for positioning. S202: Wiring and welding the bearing plates; the specific details of this step are as follows: at least six bearing plates are obtained using step S201. All the bearing plates are butted together and then welded. The butt welds on both sides are full penetration welds, and the remaining butt welds are partial penetration welds. During welding, low current multi-layer multi-pass welding is used to control welding deformation, and the plates are flipped multiple times for simultaneous welding on both sides. Welding shrinkage allowance is reserved on both sides of the bearing plates. The welding shrinkage allowance reserved on the side with partial penetration welding is 1mm, and the welding shrinkage allowance reserved on the side with full penetration welding is 2mm. S203: Position and assemble the lower middle partition unit, the lower side partition unit, the upper partition unit, and the inner wall panel unit; then position and assemble the side compartment longitudinal partition unit, the wall panel unit, and the transverse partition unit; finally position and assemble the outer wall panel unit, and weld the welds between the wall panels and partitions; the inner wall panel unit and the outer wall panel unit are tilted outwards during assembly. S204: Install the anchor frame, using a piecemeal assembly method. The entire assembly is installed sequentially from the middle of the outer wall panel unit outwards to both sides, completing the fabrication of the upper block. S3: Assemble the upper and lower blocks, weld the lower block to the pressure plate, and then install the prestressed pipes and reinforcing bars to complete the fabrication.

2. The manufacturing method according to claim 1, characterized in that, The welding sequence in step S1 is as follows: S101: Assemble the steel wall panels and perform tack welding; S102: After the steel wall panel is assembled, weld the outer secondary top plate, the inner secondary bottom plate and the inner and outer web plates with partial penetration fillet welds. S103: Partial full penetration fillet weld between the inner web plate and the outer top plate and the inner bottom plate; S104: Full penetration fillet weld between the outer web plate and the outer top plate and the inner bottom plate; S105: Weld the outer secondary top plate, inner secondary bottom plate and bearing plate with partial full penetration fillet welds, and perform symmetrical welding; S106: Partial full penetration fillet weld between the inner web plate and the bearing plate, symmetrically welded; S107: Weld the fillet welds between the outer web plate and the bearing plate, and perform symmetrical welding.

3. The manufacturing method according to claim 2, characterized in that, The specific content of step S203 is as follows: Step 1: Position the lower middle partition, assemble the adjacent secondary inner wall panels, and perform tack welding; position the lower side partition, assemble the adjacent outer secondary top panel and inner secondary bottom panel, and perform tack welding. Step II: Assemble the inner web plate and perform tack welding; assemble the remaining secondary inner wall plates, outer secondary top plates, and inner secondary bottom plates and perform tack welding. Step 3: Assemble the outer top plate, inner bottom plate, and outer web plate, and perform tack welding; Step IV: After all the steel tower wall panels are positioned, first weld the bevel fillet weld between the secondary intermediate inner wall panel and the inner web panel, and then weld the bevel fillet weld between the outer secondary inner wall panel and the inner and outer web panels. Step V: First, weld the full penetration fillet welds of the outer secondary top plate, the inner secondary bottom plate and the inner and outer web plates. Then, weld the full penetration fillet welds of the inner web plate with the outer top plate and the inner bottom plate. Finally, weld the full penetration fillet welds of the outer web plate with the outer top plate and the inner bottom plate. Step VI: Weld the bevel fillet welds between the inner wall plate and the bearing plate, symmetrically; weld the partial penetration fillet welds between the outer secondary top plate, inner secondary bottom plate and the bearing plate, symmetrically; weld the partial penetration fillet welds between the inner web plate and the bearing plate, symmetrically; weld the partial penetration fillet welds between the outer web plate and the bearing plate, symmetrically; weld the partial penetration fillet welds between the outer top plate, inner bottom plate and the bearing plate, symmetrically; weld the bevel fillet welds between the pre-installed plate rib and the bearing plate.

4. The manufacturing method according to claim 1, characterized in that, The specific content of step S204 is as follows: The anchoring frame is divided into a long anchoring frame and a short anchoring frame. The long anchoring frame includes a long stiffener, and the short anchoring frame includes a short stiffener. The welding sequence of the long anchorage frame is as follows: First, install the anchor frame web and weld the full penetration fillet weld between the anchor frame web and the outer wall panel unit. Secondly, weld the full penetration fillet weld between the long stiffener and the web of the anchor frame, and weld the fillet weld between the web of the anchor frame and the bearing plate, and between the stiffener of the anchor frame and the bearing plate. Secondly, fillet welds between the welding end plate and the anchoring structure components; Finally, weld the fillet weld between the anchor plate and the anchoring structure component; The welding sequence of the short anchorage frame is as follows: First, install the web of the anchor frame and weld the full penetration fillet weld between the web of the anchor frame and the wall panel. Secondly, weld the short stiffeners and the full penetration fillet welds of the anchor frame web; Secondly, fillet welds between the welding end plate and the anchoring structure components; Next, weld the fillet weld between the anchor plate and the anchoring structure component.

5. The manufacturing method according to claim 4, characterized in that, Step S204 also includes the following: First, install the rear plate ribs and weld them to the inner wall plate and the pressure plate of the segment with bevel fillet welds. Secondly, weld the bevel fillet weld between the lower partition plate and the wall plate; Next, assemble the upper partition and weld its fillet weld to the wall panel; Finally, the bevel fillet weld between the outer prestressed shroud and the web of the anchoring structure is completed.

6. The manufacturing method according to claim 5, characterized in that, Step S3 also includes the following: welding the outer top plate, inner bottom plate and bearing plate of the lower block with partial penetration fillet welds, and performing symmetrical welding.

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