Bolt-welding combined steel tower construction site circular seam code-free construction method

Abstract

The invention discloses a bolt-welding combined steel tower construction site circular seam code-free construction method, which relates to the technical field of bridge steel structure construction, and specifically comprises the following steps: S1, processing the bottom of a section to be adjusted to form a penetration groove; s2, a segment to be adjusted is hoisted to the installed segment; s3, assembling a reaction frame assembly, anchoring the reaction frame assembly in the stiffening ribs of the to-be-adjusted section and the installed section, and adjusting the reaction frame assembly to enable the slab staggering quantity of the to-be-adjusted section and the installed section to be qualified; s4, slab staggering fixing is achieved through penetration weld small groove side positioned welding, and penetration grooves are welded and synchronously cleaned for positioned welding; s5, after welding is completed, ultrasonic flaw detection and appearance detection are carried out, and after qualification, the next step is carried out; and S6, the steps S1 to S5 are repeated until the steel tower is machined. The invention further discloses the technical problem of insufficient precision and welding seam quality during circular seam construction of the steel tower construction site.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge steel structure construction, and particularly relates to a method for non-coding construction of on-site circumferential joints of bolt-weld combined steel towers. Background Art

[0002] When fabricating a long-span bridge steel tower, usually each stage is first assembled, and then the segments are assembled, aligned, and welded; because the segments are of large mass, the requirements for circumferential joint construction are relatively high, not only the accuracy needs to be ensured, but also the welding quality during welding needs to be guaranteed.

[0003] Traditional on-site circumferential joint construction of steel towers mainly relies on welding code plates (horseshoe plates) for temporary fixation and leveling, and has the following problems: insufficient accuracy: the welding of code plates is easily affected by heat deformation, resulting in the circumferential joint misalignment being difficult to control within 2 mm, affecting the structural stress and appearance quality; low efficiency: the installation, welding, and subsequent removal processes of code plates are cumbersome, taking a long construction period, and the consumption of temporary components is large; quality hidden dangers: the residual stress of code plate welding is likely to cause surface damage to the steel tower, requiring secondary repair, with a low qualified rate; finished product damage: when the steel tower is under on-site connection construction, the painting construction of the inner and outer surfaces has basically been completed, and the welding and removal of horseshoe plates will seriously damage the finished paint surface, resulting in a large amount of painting rework; resource waste: the temporary tooling cannot be reused, and the material cost is high. In the prior art, there is no systematic process design for non-coding construction of on-site connections of steel towers, and it is difficult to ensure accuracy, efficiency, and quality. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for non-coding construction of on-site circumferential joints of bolt-weld combined steel towers, which solves the technical problems of insufficient accuracy and weld quality during the on-site circumferential joint construction of steel towers in the prior art.

[0005] The embodiments of the present application disclose a method for non-coding construction of on-site circumferential joints of bolt-weld combined steel towers, including the following steps: S1: Process the bottom of the segment to be adjusted to form a full-penetration groove; S2: Hoist the segment to be adjusted onto the installed segment; S3: Assemble the reaction frame assembly, and anchor the reaction frame assembly in the stiffeners of the segment to be adjusted and the installed segment, and adjust the reaction frame assembly to make the misalignment between the segment to be adjusted and the installed segment qualified; S4: Use positioning welding on the small groove side of the full-penetration weld to fix the misalignment, and synchronously clean the positioning weld while welding the full-penetration groove; S5: After welding, perform ultrasonic flaw detection and appearance inspection. After passing, proceed to the next step; S6: Repeat steps S1 - S5 until the steel tower is processed.

[0006] This application applies a jacking force through the hydraulic jack of the reaction frame assembly to achieve millimeter-level displacement compensation. The tooling is locked until the misalignment amount ≤ 1 mm, which can improve the machining accuracy of the circumferential weld.

[0007] Based on the above technical solutions, the embodiments of this application can also be improved as follows: Further, the outer groove angle of the full penetration groove is α, and the inner groove angle is β, where α > β. The beneficial effect of this step is that the asymmetrical groove can ensure the weld penetration and tight fit.

[0008] Further, the thickness of the side wall steel plate of the segment to be adjusted is t. Then the depth of the outer groove is 0.3(t - 2) mm, the depth of the inner groove is 0.7(t - 2) mm, the root face is 2 mm, and the root gap of the groove is 0 - 0.5 mm. The beneficial effect of this step is to design the groove to ensure the groove quality.

[0009] Further, α = 55° and β = 45°.

[0010] Further, the specific structure of the reaction frame assembly in step S3 includes: Two support plates, which are arranged at intervals; Multiple connecting bolts, which are installed at one end of the support plate; A hydraulic jack, which is installed at the other end of the support plate. The beneficial effect of this step is to provide a thrust force through the reaction frame assembly to complete the misalignment amount adjustment.

[0011] Further, when assembling the reaction frame assembly in step S3, the two support plates are respectively arranged on both sides of the stiffener of the installed segment, and the movable end of the hydraulic jack faces the stiffener of the segment to be adjusted. The beneficial effect of this step is that the thrust force can be adjusted through the hydraulic jack.

[0012] Further, in step S3, the misalignment amount between the segment to be adjusted and the installed segment ≤ 1 mm is considered qualified. The beneficial effect of this step is to improve the structural safety and durability.

[0013] Further, the specific content of step S4 is as follows: S401: Tack welding stage: Intermittent tack welding is carried out on the outer groove side of the full penetration groove to form a tack weld; S402: Inner root pass welding: The inner groove of the full penetration groove is welded using solid wire CO 2 gas shielded welding to form a root pass weld, and the reaction frame assembly is removed; S403: Synchronous gouging for root cleaning: Use carbon arc gouging to remove the positioning weld and root impurities along the outer groove of the penetration groove until the penetration fusion line of the backing weld is exposed; S404: Outer cover pass welding: Multilayer and multi-pass welding is used to fill the outer groove of the penetration groove. After welding is completed, it is polished until it is flush with the base metal. The beneficial effect of this step is that the welding effect can be improved through the coordination of various welding methods.

[0014] Further, the bead length of the positioning weld in step S401 is 150 - 160 mm, and the spacing is 300 - 310 mm. The beneficial effect of this step is that the effect of positioning welding can be ensured through the spaced welds.

[0015] Further, the interlayer temperature of the multilayer and multi-pass welding in step S404 is ≤ 150 °C. The beneficial effect of this step is that while ensuring the welding effect, the performance of the material can be prevented from being affected.

[0016] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages: 1. By providing a reaction frame assembly for providing thrust, the misalignment between two adjacent segments is ≤ 1 mm in the present application, which has higher precision compared with the existing traditional processes and can improve the structural safety and durability.

[0017] 2. The reaction frame assembly of the present application can be reused, and the present application reduces 80% of the temporary components, reducing material waste.

[0018] 3. The present application does not need to use code plates for fixation, that is, no welding residues of code plates will be generated, and the qualified rate of the appearance quality is increased to more than 98%.

[0019] 4. The present application uses a variety of processes in cooperation, taking into account the positioning strength and weld penetration, so as to improve the efficiency.

[0020] 5. The present application can save the construction period, reduce the comprehensive cost, and at the same time, the produced steel tower structure is stable, easy to disassemble, and quick to adjust. Description of the Drawings

[0021] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0022] Figure 1It is a schematic flow chart of a construction method for the on-site circumferential joint of a bolt-welded steel tower without using a code according to Embodiment 1 of the present invention; Figure 2 It is a schematic diagram of the assembly of a reaction frame in a construction method for the on-site circumferential joint of a bolt-welded steel tower without using a code according to Embodiment 1 of the present invention; Figure 3 It is a schematic diagram of a full-penetration groove in a construction method for the on-site circumferential joint of a bolt-welded steel tower without using a code according to Embodiment 1 of the present invention; Figure 4 It is a welding schematic diagram of Step S4 in a construction method for the on-site circumferential joint of a bolt-welded steel tower without using a code according to Embodiment 2 of the present invention; The reference numerals are as follows: 1 - reaction frame assembly; 2 - support plate; 3 - connecting bolt; 4 - hydraulic jack; 5 - installed segment; 6 - segment to be adjusted. Specific embodiments

[0023] Hereinafter, embodiments of the technical solution of the present invention will be described in detail with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and thus are only examples and cannot be used to limit the protection scope of the present invention. It should be noted that unless otherwise specified, the technical terms or scientific terms used in this application should have the ordinary meaning understood by those skilled in the art to which the present invention belongs.

[0024] In this application, unless otherwise clearly defined and limited, terms such as "installation", "connection", "fixation" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings of the specification and specific embodiments.

[0026] Embodiment 1: This application discloses a construction method for the on-site circumferential joint of a bolt-welded steel tower without using a code. This construction method is based on the coordinated cooperation of various methods such as "bolt-connected reaction frame without using a code for adjustment and positioning + tight penetration weld + small groove tack welding and synchronous air gouging", so as to achieve millimeter-level control of the circumferential joint misalignment and meet the requirements of high-precision steel tower stress and aesthetics.

[0027] As Figures 1-4 described, the specific steps of the embodiment of this application are as follows: S1: Process the bottom of the segment to be adjusted to form a full penetration groove. The full penetration groove is wider on the outside and narrower on the inside. Specifically, the outside groove angle of the full penetration groove is α, and the inside groove angle is β, where α > β. The preferred values for these angles are α = 55° and β = 45°. If the thickness of the sidewall steel plate of the segment to be adjusted is t, then the depth of the outside groove is 0.3(t - 2) mm, the depth of the inside groove is 0.7(t - 2) mm, the root face is 2 mm, and the root gap of the groove is 0 - 0.5 mm. This step is carried out before the surface coating of this segment. Then, use an orbital flame cutting device to cut the top-tight full penetration groove at the lower port of the steel tower according to the design requirements. The inside groove refers to the side close to the rib plate, and the outside groove refers to the side away from the rib plate. Then, carry out slag cleaning and grinding to make it smooth. S2: Lift the segment to be adjusted and hoist it onto the installed segment. Specifically, this segment to be adjusted is directly hoisted and then connected to the circumferential joint matching part of the installed segment to restore its pre-assembly posture in the factory. Measure the monitoring points around the steel tower, and locally shim and adjust the posture of the steel tower to meet the erection specifications, and then hand it over for welding construction. S3: Assemble the reaction frame assembly and anchor the reaction frame assembly to the stiffeners of the segment to be adjusted and the installed segment. Adjust the reaction frame assembly to make the misalignment between the segment to be adjusted and the installed segment qualified. During assembly, determine the adjustment load and select the specification and model of the jack according to the thickness and material of the panel of the segment to be adjusted. According to the size of the bolt hole group at the connecting port of the members, determine the size, thickness, material, and construction space of the misalignment panel to determine the thickness of the steel plate of the reaction frame body. Fabricate the reaction frame assembly and hand it over to the welding unit for use. Specifically, as Figure 2 shown, the reaction frame assembly 1 includes: two support plates 2, which are arranged at intervals to form a reaction frame; multiple connecting bolts 3, installed at one end of the support plate 2; a hydraulic jack 4, installed at the other end of the support plate 2. When anchoring the reaction frame assembly, the two support plates 2 are respectively arranged on both sides of the stiffener of the installed segment 5, and the movable end of the hydraulic jack 4 faces the stiffener of the segment to be adjusted 6. Use this reaction frame assembly 1 to ensure that the misalignment between the segment to be adjusted and the installed segment ≤ 1 mm (the existing misalignment is difficult to control). This step also includes the following content: Detect the circumferential joint misalignment inside the segment (on the large groove side). At the position where the circumferential joint misalignment does not meet the specification requirements, install steel members according to the distribution of the rib plate hole groups to ensure that the stroke of the jack meets the gap adjustment range. When adjusting the misalignment, it is strictly prohibited to loosen the connection of the matching parts and local shimming to prevent changes in the erection alignment of the steel tower. S4: Use positioning welding on the small groove side of the full penetration weld to fix the misalignment, and clean the positioning weld while welding the full penetration groove. The specific content of this step is as follows: S401: Tack welding stage: Intermittent tack welding is carried out on the outer groove side of the full penetration groove to form a tack weld. Among them, the bead length of the tack weld in step S401 is 150 mm, and the spacing is 300 mm; S402: Inner root pass welding: Use solid wire CO 2 gas shielded welding to complete the welding of the inner groove of the full penetration groove, form a root pass weld, and remove the reaction frame assembly; S403: Synchronous carbon arc gouging for root cleaning: Use carbon arc gouging to remove the tack weld and root impurities along the outer groove of the full penetration groove until the root fusion line of the root pass welding is exposed; S404: Outer cover pass welding: Multilayer and multi-pass welding is used to fill the outer groove of the full penetration groove. After welding is completed, it is polished until it is flush with the base metal; the interlayer temperature of the multilayer and multi-pass welding in step S404 ≤ 150 °C; S5: After welding is completed, ultrasonic flaw detection and appearance inspection are carried out. After passing, proceed to the next step; S6: Repeat steps S1 - S5 until the steel tower processing is completed.

[0028] Example 2: Based on Example 1, this application further modifies step S401 in Example 1, where the bead length is 160 mm and the spacing is 310 mm.

[0029] Example 3: Based on Example 1, this application further modifies step S401 in Example 1, where the bead length is 155 mm and the spacing is 305 mm.

[0030] For further explanation of this application: This application discloses a construction method for the on-site circumferential joint of a bolt-welded combined steel tower without using a welding code, which has the following advantages: 1. This construction method is based on the bolted non-coding adjustment design. Specifically, it adopts a reaction frame tooling structure: a design bracket + hydraulic jack combined system. The main body of the bracket is composed of high-strength steel plates and bolts. By matching the stiffener bolt holes, a single-directional jacking device (horizontal adjustment accuracy ±0.5 mm) is designed. When installing the tooling, use high-strength bolts (M24, 10.9 grade) to anchor the reaction frame assembly to the adjacent segment stiffener bolt holes to form a "segment - reaction frame - segment" closed-loop force transmission path, and directly transfer the leveling load to the main structure; then take closed-loop leveling operation: apply a jacking force through the hydraulic jack reaction frame screw, and monitor the circumferential joint misalignment in real time to achieve millimeter-level displacement compensation. After the misalignment ≤ 1 mm, lock the tooling.

[0031] 2. Process design of "small groove tack welding + synchronous carbon arc gouging" for tightly pressing the full penetration weld: Structural parameters of the upset penetration weld groove: The asymmetric "small outside and large inside" groove form is adopted. Taking the steel plate thickness as t, the outside groove angle is 55°, the depth is 0.3(t - 2), the inside groove angle is 45°, the depth is 0.7(t - 2), the root face is 2mm, and the root gap of the groove is 0 - 0.5mm to ensure the weld penetration and tight fit.

[0032] Welding process steps: Positioning welding stage: Intermittent positioning welding is carried out on the small groove side of the outside of the tower wall to temporarily fix the circumferential weld. The length of the weld bead is 150 - 160mm, and the spacing is 300 - 310mm to ensure the temporary connection strength of the weld. Internal backing welding: Use solid wire CO 2 Gas shielded welding to complete the backing weld of the large groove on the inside, and the filling amount is ≥100%. Synchronous carbon arc gouging for root cleaning: Use carbon arc gouging to remove the positioning weld and root impurities along the small groove on the outside until the fusion line of the backing weld is exposed. Outside surfacing welding: Multilayer and multi-pass welding is used to fill the outside groove (interpass temperature ≤150°C), and finally it is polished to be flush with the base metal.

[0033] Acceptance criteria: The circumferential weld misalignment ≤1mm (measured with a feeler gauge), the qualified rate of ultrasonic flaw detection of the weld ≥99%, and the appearance flatness ≤0.5mm / m.

[0034] In the description of the specification of the present invention, a large number of specific details are described. However, it can be understood that the embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures, and technologies are not shown in detail so as not to obscure the understanding of this specification. In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements 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 by the scope of the claims and the description of the present invention.

Claims

1. A bolt-welded steel tower construction site annular seam codeless construction method, characterized in that: The following steps are involved: S1: Process the bottom of the segment to be adjusted to form a melt-through groove; S2: hoist the segment to be adjusted onto the installed segment; S3: Assembling a reaction frame assembly, and anchoring the reaction frame assembly in the stiffening ribs of the segment to be adjusted and the installed segment, and adjusting the reaction frame assembly so that the misalignment between the segment to be adjusted and the installed segment is acceptable; S4: Use the small groove side positioning welding of the penetration weld to achieve the misalignment fixation, and the penetration groove is cleaned and positioned at the same time; S5: After welding is completed, ultrasonic flaw detection and appearance inspection are carried out. If qualified, proceed to the next step; S6: Repeat steps S1-S5 until the steel tower is processed.

2. The bolt-welded steel tower construction site circumferential seam codeless construction method according to claim 1 is characterized in that: The outer groove angle of the penetration groove is α, and the inner groove angle is β, and α>β.

3. The bolt-welded steel tower construction site circumferential seam codeless construction method according to claim 2 is characterized in that: The thickness of the side wall steel plate of the segment to be adjusted is t, the outer groove depth is 0.3 (t-2) mm, the inner groove depth is 0.7 (t-2) mm, the blunt edge is 2 mm, and the groove root gap is 0~0.5 mm.

4. The bolt-welded steel tower construction site circumferential seam codeless construction method according to claim 2 is characterized in that: The α=55°, β=45°.

5. The bolt-welded steel tower construction site circumferential seam codeless construction method according to claim 1 is characterized in that: The specific structure of the reaction frame assembly in step S3 includes: Two support plates, the support plates are arranged at intervals; A plurality of connecting bolts are installed at one end of the support plate; A hydraulic jack is installed at the other end of the support plate.

6. The bolt-welded steel tower construction site circumferential seam codeless construction method according to claim 5 is characterized in that: When the reaction frame assembly is assembled in step S3, the two support plates are respectively arranged on both sides of the stiffening ribs of the installed segment, and the movable end of the hydraulic jack faces the stiffening ribs of the segment to be adjusted.

7. The bolt-welded steel tower construction site circumferential seam codeless construction method according to claim 1 is characterized in that: In step S3, the adjustment is qualified when the misalignment between the segment to be adjusted and the installed segment is ≤1 mm.

8. The bolt-welding combined steel tower construction site circumferential seam codeless construction method according to claim 1 is characterized in that: The specific content of step S4 is as follows: S401: Positioning welding stage: intermittent positioning welding is performed on the outer groove side of the penetration groove to form a positioning weld; S402: Internal backing welding: Use solid wire CO2 gas shielded welding to complete the inner groove welding of the penetration groove to form a backing weld, and remove the reaction frame assembly; S403: Synchronous air gouging and root cleaning: Use a carbon arc air gouging to gouge out the positioning weld and root impurities along the outer groove of the penetration groove to a depth to expose the base weld fusion line; S404: Outer cover welding: multi-layer multi-pass welding fills the outer groove of the penetration groove, and after welding, it is polished until it is flush with the parent material.

9. The bolt-welded steel tower construction site circumferential seam codeless construction method according to claim 8 is characterized in that: The weld bead length of the tack weld in step S401 is 150-160 mm, and the spacing is 300-310 mm.

10. The bolt-welded steel tower construction site circumferential seam codeless construction method according to claim 9, characterized in that: The interlayer temperature of the multi-layer multi-pass welding in step S404 is ≤150°C.

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