A factory prefabricated steel shell concrete combined section and construction method

Abstract

This invention discloses a factory-prefabricated steel-shell concrete composite section, comprising an inner wall panel and an outer wall panel, forming a ring structure between them. Transverse and longitudinal stiffening ribs are provided on opposite sides of the ring structure of both the inner and outer wall panels. Concrete is poured inside the ring structure of the inner wall panel to form a ring-shaped concrete section. Two positioning shear keys are provided on the top and bottom surfaces of the ring-shaped concrete section, and two grouting holes are provided on each ring opening. The inner and outer wall panels of each steel-shell concrete section are welded together via a bridge-site ring-shaped steel structure, and the ring-shaped concrete is poured between each steel-shell concrete section. This invention advantageously embodies the optimal combination of steel and concrete structures, solving the problems of complex design and excessively long bridge-site construction periods in existing steel-shell concrete towers, while also facilitating construction.

Description

Technical Field

[0001] This invention relates to the field of bridge construction technology, specifically to a prefabricated steel-concrete composite section and its construction method. Background Technology

[0002] Steel-shell concrete towers utilize a steel outer shell and internal concrete filling working together. The steel shell provides tensile and shear strength, while the concrete bears compressive loads, significantly improving the overall load-bearing capacity and stiffness of the tower, making it particularly suitable for tall, long-span structures. The steel shell can serve as permanent formwork, eliminating the need for traditional formwork erection. After concrete pouring, it forms a unified structure with the steel shell, shortening the construction period. Prefabricated steel shell segments are manufactured in the factory, and on-site assembly is carried out simultaneously with concrete pouring, adapting to complex construction environments. Compared to all-steel structures, steel-shell concrete towers save on steel usage, reducing costs. Furthermore, localized damage can be quickly repaired through steel shell repair or concrete grouting, resulting in lower life-cycle maintenance costs compared to pure concrete structures.

[0003] In conventional steel-shell concrete towers, the steel shell segments are prefabricated in the factory without concrete pouring. Dense stiffening ribs and angle steel are used between the inner and outer wall panels of the steel shell to improve overall rigidity and prevent deformation during hoisting. Numerous steel bars are added as reinforcement to enhance the bond strength with the concrete. Concrete is poured after the steel shell segments are hoisted and welded at the bridge site. This approach results in a long construction period and room for improvement in construction quality. Therefore, a factory-prefabricated steel-shell concrete structure was designed. This not only improves the overall rigidity of the segments by replacing dense angle steel with concrete but also significantly shortens the construction period at the bridge site. Thus, the structural form and manufacturing method became major challenges that urgently needed to be addressed. Summary of the Invention

[0004] This invention proposes a factory-prefabricated steel-concrete composite section and its construction method, which better reflects the optimal combination of steel structure and concrete structure, and can solve the technical problems of complex design and excessively long construction period of existing steel-concrete towers.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: A construction method for a precast steel-shell concrete composite section, characterized by comprising the following steps: S1. Fabrication of the panel: Position the panel on the flat jig, and set transverse stiffening ribs and vertical stiffening ribs on one side surface of the panel; S2. Fabrication of steel shell segments: The panel is positioned around a special jig to form an annular inner wall plate. The panel is positioned circumferentially around the inner wall plate to form an annular outer wall plate. The panels of the inner and outer wall plates are provided with transverse stiffening ribs and vertical stiffening ribs on one side facing each other. The inner and outer wall plates are equally spaced. Welding and flaw detection of the penetration corner welds between each panel in the inner and outer wall plates are completed in sequence. The height of the inner wall plate is no more than 300mm lower than the height of the outer wall plate. A widened groove is formed along the circumferential direction in the inner wall plate as a bridge position wide interlocking segment. S3. Concrete preparation of steel shell segments: Place the steel shell segments prepared in step S2 on a horizontal jig, making the central axis of the steel shell segments horizontal. Lay concrete pouring templates at both ends of the steel shell segments. The concrete pouring templates are evenly provided with multiple round holes and shear key positioning grooves along the circumferential direction. Anchor pipes are installed in the round holes to fix the steel pipes so that after the annular concrete segment is poured between the inner wall panel and the outer wall panel, a concrete reserved hole is formed in the annular concrete segment that penetrates the upper and lower annular openings. Grooves for accommodating shear keys and shear keys are respectively formed on the annular buckle surfaces at both ends of the annular concrete segment. S4. Pre-assembly of steel shell segment concrete segment: Vertical continuous matching pre-assembly is adopted. After the pre-assembly is completed, the matching parts and marking lines are installed. S5. Steel shell segment concrete segment hoisting and positioning: The steel shell segment concrete is hoisted and positioned. First, the steel shell segment concrete is initially and quickly positioned by the shear key position. The positioning accuracy is measured by a total station. After the data is qualified, the matching parts are fixed and the size of the marker line is checked to be consistent with the marking line in S4. S6. Steel shell segment concrete segment bridge site ring steel structure welding: The outer wall panel is opened with a single-sided bevel facing the outside of the steel shell. A ceramic gasket is attached to the back of the outer wall panel near the inner wall panel. The outer wall panel is then welded with full penetration. After the outer wall panel is welded, the inner wall panel is opened with a single-sided bevel facing the center of the steel shell. A steel gasket is placed on the back of the inner wall panel near the outer wall panel. The inner wall panel is then welded with full penetration. S7. Steel shell segment concrete segment bridge site ring concrete pouring: 2-3 steel shell segment concrete segments are poured together through the reserved grouting holes for ring concrete pouring.

[0006] In step 2, the inner support uses profiles with a cross-section of not less than 60mm. Each panel of the inner wall is supported by multiple pairs of inner supports. The lower ends of each pair of inner supports are anchored together on a special jig, and the upper ends of each pair of inner supports are separately anchored on two support points one above the center of gravity of the inner wall panel, forming a figure-eight brace. Support point one is set on the panel at a distance of not less than 500-800mm from the weld. The outer support uses profiles with a cross-section of not less than 60mm. Each panel of the outer wall is arranged with no less than two outer supports on the side facing away from the inner wall panel. The lower ends of the outer supports are anchored on the jig, and the upper ends of the outer supports are anchored on support point two of the supported panel. Support point two is set on the panel at a distance of not less than 500-800mm from the weld and 1000mm from the top surface of the panel.

[0007] In step S1, the panels on each side of the inner or outer wall panel are connected by a penetration fillet weld. The welding process is a single-sided welding with double-sided forming. The welding deformation of the control panel is controlled by the constraint tooling. First, the vertical penetration fillet welds of the inner wall panel are welded in sequence, and then the vertical penetration fillet welds of the outer wall panel are welded in sequence.

[0008] A precast steel-shell concrete composite section is characterized by comprising multiple axially connected steel-shell concrete segments. Each steel-shell concrete segment includes an inner wall panel and an outer wall panel, forming a ring structure. Transverse stiffening ribs and longitudinal stiffening ribs are provided on opposite sides of the inner and outer wall panels. Wide interlocking sections are provided on the upper and lower sides of the inner wall panel along the circumferential direction. Concrete is poured inside the ring structure to form a ring concrete segment. Multiple grooves for accommodating shear keys, positioning shear keys, and grout passage holes are provided at intervals along the circumferential direction on the top and bottom surfaces of the ring concrete segment. The steel-shell concrete segments are connected by tenon and mortise joints through the grooves and positioning shear keys. The inner wall panels and outer wall panels of the steel-shell concrete segments are welded together through a bridge-position ring steel structure. Ring concrete is poured between the steel-shell concrete segments.

[0009] The height of the inner wall panel is 300mm lower than that of the outer wall panel.

[0010] The thickness of the annular structure is 8 mm.

[0011] The shear key specifications are as follows: length not less than 500mm, width not less than 300mm, and height not less than 500mm.

[0012] The diameter of the slurry passage hole is 200 mm.

[0013] This invention employs a factory-prefabricated steel-concrete composite structure, which better embodies the optimal combination of steel and concrete structures. It not only improves the overall rigidity of segments by replacing dense angle steel with concrete, but also mitigates the impact of uncontrollable shrinkage during concrete pouring at the bridge site on the installation quality of the steel-concrete segments. By utilizing the structural characteristics, the concrete pouring time at the bridge site is not considered a major construction phase, significantly shortening the bridge site construction cycle. Furthermore, it establishes an overall welding and installation scheme for the factory-prefabricated steel-concrete composite segments, effectively ensuring the quality of dense welds within the confined space of the factory-prefabricated steel-concrete composite structure and improving the overall manufacturing precision of the structure. Attached Figure Description

[0014] Figure 1 This is a three-dimensional schematic diagram of the prefabricated steel-shell concrete composite section in the present invention; Figure 2 This is a three-dimensional view of the factory steel structure of the assembly section in this invention; Figure 3 This is a factory steel structure plan of the assembly section in this invention; Figure 4 This is a three-dimensional view of the precast concrete of the assembly section in this invention. Figure 5 This is a factory precast concrete plan view of the assembly section in this invention; Figure 6 This is a cross-sectional view of the precast concrete of the assembly section in this invention. Figure 7 This is a three-dimensional view of the bridge installation of the steel-concrete composite structure at the bridge site in this invention; Figure 8 This is a schematic diagram of the installation sequence of the steel-concrete composite structure at the bridge site in this invention. The arrows in the attached diagram indicate the welding direction of the welder. Detailed Implementation

[0015] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0016] like Figure 1-8As shown, a precast steel-shell concrete composite segment includes multiple axially connected steel-shell concrete segments. Each steel-shell concrete segment includes a steel shell structure, which comprises an inner wall panel 1 and an outer wall panel 2. An 8cm thick annular structure is formed between the inner wall panel 1 and the outer wall panel 2. Vertical stiffening ribs 8 and transverse stiffening ribs 9 are provided on opposite sides of the inner wall panel 1 and the outer wall panel 2. Wide interlocking sections 5 are provided on the upper and lower sides of the inner wall panel 1 along the circumferential direction. Concrete is poured inside the annular structure to form an annular concrete segment 4. The upper and lower annular openings of the annular concrete segment 4 are respectively provided with grooves for accommodating shear keys 6, shear keys 6, and grout passage holes 7. The grout passage holes 7 penetrate the upper and lower annular openings. The steel-shell concrete segments are connected by tenon and tenon joints through the grooves and positioning shear keys. The inner wall panels and outer wall panels of the steel-shell concrete segments are welded together through the bridge-position annular steel structure. The annular concrete is poured between the steel-shell concrete segments.

[0017] Furthermore, the height of the inner wall plate 1 is set 300mm lower than that of the outer wall plate 2, forming a widened groove along the circumference as a bridge-position wide interlocking section. A bevel is arranged in this groove to facilitate full penetration welding and ensure welding quality.

[0018] A novel construction method for precast steel-concrete composite sections includes the following steps: S1. Panel Creation: First, the panels of each side of the inner wall panel 1 or outer wall panel 2 are positioned and assembled on the flat jig. Vertical stiffening ribs 8 and horizontal stiffening ribs 9 are set. Then, a gantry-type double-arm welding robot is used to complete the welding of the panel of each side of the inner wall panel 1 or outer wall panel 2 with the stiffening ribs.

[0019] S2. Steel shell segment fabrication: First, on a special jig, the panels of each side of the inner wall plate 1 are positioned with the back of the outer wall plate 2 on the side of the inner wall plate 1 to form the inner wall plate 1. Then, the panels of each side of the outer wall plate 2 are positioned on the outer periphery of the inner wall plate 1 to form the outer wall plate 2. The outer wall plate 2 is externally supported and horizontal stiffening ribs are installed to ensure the distance between the inner and outer wall plates. Welding and flaw detection of the penetration corner weld between the inner and outer wall plates are completed. The height of the inner wall plate is no more than 300mm lower than the height of the outer wall plate. A widened groove along the circumference is formed in the inner wall plate as a bridge-position wide interlocking section.

[0020] Furthermore, the special jig is required to have sufficient load-bearing capacity, the top surface of the jig is set as a horizontal support, the elevation is adjustable, and the outer contour dimensions can be adjusted according to the steel shell segments.

[0021] Furthermore, the inner support adopts a profile with a cross-section of not less than 60mm. Each panel of the inner wall panel 1 is supported by multiple pairs of inner supports. The lower end of each pair of inner supports is anchored together on a special jig. The upper end of each pair of inner supports is separately anchored on two support points on the supported panel that are higher than the center of gravity of the inner wall panel, forming a figure-eight brace. The support points are set on the panel at a distance of not less than 500~800mm from the weld.

[0022] The external support uses profiles with a cross-section of not less than 60mm. Each panel of the outer wall 2 has at least two external supports on the side facing away from the inner wall panel. The lower end of the external support is anchored to the jig, and the upper end of the external support is anchored to support point two on the supported panel. Support point two is set on the panel at a distance of not less than 500~800mm from the weld and about 1000mm from the top surface of the panel. The extension length of the external support is adjusted according to the angle of the outer wall panel relative to the ground.

[0023] Furthermore, the panels on each side of the inner wall panel 1 or the outer wall panel 2 are connected by penetration fillet welds, all using a single-sided welding and double-sided forming welding process, and the welding deformation is controlled by restraining the tooling. First, the vertical penetration fillet welds of the inner wall panel are welded in sequence, followed by the vertical penetration fillet welds of the outer wall panel.

[0024] S3. Precast concrete of steel shell segments: Place the steel shell segments made in step S2 on a horizontal jig to make the central axis of the steel shell segments horizontal. Lay concrete pouring templates at both ends of the steel shell segments and pour the annular concrete segment 4 between the inner and outer wall panels. After pouring, carry out concrete curing work.

[0025] Furthermore: a shear key positioning groove is provided on the concrete pouring template so as to form a groove for accommodating the shear key 6 on the upper ring opening surface of the annular concrete section 4, and the shear key 6 is formed on the upper ring opening surface of the annular concrete section 4, so that the shear key can be poured simultaneously when pouring concrete.

[0026] Preferably, the shear key 6 and the shear key positioning groove are not less than 300mm (width) × 500mm (height) × 500mm (length), and are paired with each other to form a mortise and tenon structure, which facilitates bridge installation and serves as a guide block.

[0027] Furthermore, the concrete pouring template is provided with multiple φ200mm round holes evenly arranged along the circumference. Anchor pipes are installed in the round holes to fix the steel pipes, so as to form a pre-reserved grout passage hole in the annular concrete section 4 that penetrates the upper and lower annular surfaces. The steel pipe is required to protrude 20mm from the anchor pipe for easy construction.

[0028] S4. Pre-assembly of steel shell segment concrete segment: Vertical continuous matching pre-assembly is adopted. After the pre-assembly is completed, the matching parts and marking lines are installed.

[0029] Preferably, the mating component includes a base, a stiffening plate, and an adjusting plate, with the base having four bolt holes. The mating component is installed after pre-assembly and measurement have been completed and approved.

[0030] S5. Steel Shell Segment Concrete Segment Bridge Site Lifting and Positioning: A tower crane of suitable tonnage for the project is used for the lifting and positioning of the steel shell segment concrete. First, the steel shell segment concrete is initially and quickly positioned using shear key 6. A total station is used to measure the positioning accuracy. After the data is qualified, the matching parts are fixed, and the size of the marker line is checked to ensure consistency with the designed size.

[0031] Furthermore, the matching components are fixed by symmetrical installation using two bolts and two punches to ensure the correct position and safe fixation of the beam segment.

[0032] S6. Steel shell segment concrete segment bridge site ring steel structure welding: The outer wall plate is butt welded with a welding robot. After the outer wall plate is welded, the inner wall plate insert segment 5 is butt welded with full penetration.

[0033] Furthermore, the inner wall panel 1 of the steel shell is provided with a 300mm wide patching section 5 along the circumference. First, the circumferential seam of the outer wall panel 2 is welded, and a single-sided bevel is opened facing the outside of the steel shell. A ceramic gasket is attached to the back of the outer wall panel near the inner wall panel for welding. Then, the circumferential seam of the inner wall panel is welded, and a single-sided bevel is opened facing the center side of the steel shell. Since it is impossible to enter the back, a steel gasket is provided.

[0034] S7. Steel shell segment concrete segment bridge site ring concrete 10 pouring: According to the design requirements, 2-3 steel shell segment concrete segments are poured together through the reserved φ200mm grout passage hole 7 for ring concrete pouring.

[0035] While the specific embodiments of this disclosure have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of this disclosure. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of this disclosure are still within the scope of protection of this disclosure.

Claims

1. A construction method for a precast steel-shell concrete composite section, characterized in that, Includes the following steps: S1. Panel fabrication: Position the panel on the flat jig, and set transverse stiffening ribs and vertical stiffening ribs on one side surface of the panel; S2. Fabrication of steel shell segments: The panels are positioned around a special jig by internal supports to form an annular inner wall plate. The panels are positioned circumferentially around the inner wall plate to form an annular outer wall plate. Each panel of the outer wall plate has at least two external supports on the side facing away from the inner wall plate. The panels of the inner and outer wall plates are arranged facing each other with transverse stiffening ribs and vertical stiffening ribs on the same side. The inner and outer wall plates are spaced equally. Welding and flaw detection of the penetration corner welds between each panel of the inner and outer wall plates are completed in sequence. The height of the inner wall plate is no more than 300mm lower than the height of the outer wall plate. A widened groove is formed along the circumferential direction in the inner wall plate as a bridge-position wide interlocking segment. S3. Concrete preparation of steel shell segments: Place the steel shell segments prepared in step S2 on a horizontal jig, making the central axis of the steel shell segments horizontal. Lay concrete pouring templates at both ends of the steel shell segments. The concrete pouring templates are evenly provided with multiple round holes and shear key positioning grooves along the circumferential direction. Anchor pipes are installed in the round holes to fix the steel pipes so that after the annular concrete segment is poured between the inner wall panel and the outer wall panel, a concrete reserved hole is formed in the annular concrete segment that penetrates the upper and lower annular openings. Grooves for accommodating shear keys and shear keys are respectively formed on the annular buckle surfaces at both ends of the annular concrete segment. S4. Pre-assembly of steel shell segment concrete segment: Vertical continuous matching pre-assembly is adopted. After the pre-assembly is completed, the matching parts and marking lines are installed. S5. Steel shell segment concrete segment hoisting and positioning: The steel shell segment concrete is hoisted and positioned. First, the steel shell segment concrete is initially and quickly positioned by the shear key position. The positioning accuracy is measured by a total station. After the data is qualified, the matching parts are fixed and the size of the marker line is checked to be consistent with the marking line in S4. S6. Steel shell segment concrete segment bridge site ring steel structure welding: The outer wall panel is opened with a single-sided bevel facing the outside of the steel shell. A ceramic gasket is attached to the back of the outer wall panel near the inner wall panel. The outer wall panel is then welded with full penetration. After the outer wall panel is welded, the inner wall panel is opened with a single-sided bevel facing the center of the steel shell. A steel gasket is placed on the back of the inner wall panel near the outer wall panel. The inner wall panel is then welded with full penetration. S7. Steel shell segment concrete segment bridge site ring concrete pouring: 2-3 steel shell segment concrete segments are poured together through the reserved grouting holes for ring concrete pouring.

2. The construction method according to claim 1, characterized in that, In step 2, the inner support uses profiles with a cross-section of not less than 60mm. Each panel of the inner wall is supported by multiple pairs of inner supports. The lower ends of each pair of inner supports are anchored together on a special jig, and the upper ends of each pair of inner supports are separately anchored on two support points one above the center of gravity of the inner wall panel, forming a figure-eight brace. Support point one is set on the panel at a distance of not less than 500-800mm from the weld. The outer support uses profiles with a cross-section of not less than 60mm. The lower end of the outer support is anchored on the jig, and the upper end of the outer support is anchored on support point two of the panel. Support point two is set on the panel at a distance of not less than 500-800mm from the weld and 1000mm from the top surface of the panel.

3. The construction method according to claim 1, characterized in that, In step S1, the panels on each side of the inner or outer wall panel are connected by a penetration fillet weld. The welding process is a single-sided welding with double-sided forming. The welding deformation of the control panel is controlled by the constraint tooling. First, the vertical penetration fillet welds of the inner wall panel are welded in sequence, and then the vertical penetration fillet welds of the outer wall panel are welded in sequence.

4. The precast steel-shell concrete composite section manufactured using the construction method described in claim 1, characterized in that, The structure comprises multiple axially connected steel shell concrete segments. Each steel shell concrete segment includes an inner wall panel and an outer wall panel, forming a ring structure. Transverse stiffening ribs and longitudinal stiffening ribs are provided on opposite sides of the inner and outer wall panels. Wide interlocking sections are provided on the upper and lower sides of the inner wall panel along the circumferential direction. Concrete is poured inside the ring structure to form a ring concrete segment. Multiple grooves for accommodating shear keys, positioning shear keys, and grout passage holes are provided at intervals along the circumferential direction on the top and bottom surfaces of the ring concrete segment. The steel shell concrete segments are connected by tenon and mortise joints through the grooves and positioning shear keys. The inner wall panels and outer wall panels of the steel shell concrete segments are welded together through a bridge-position ring steel structure. Ring concrete is poured between the steel shell concrete segments.

5. The factory-prefabricated steel-shell concrete composite section according to claim 4, characterized in that, The height of the inner wall panel is 300mm lower than that of the outer wall panel.

6. The factory-prefabricated steel-shell concrete composite section according to claim 4, characterized in that, The thickness of the ring structure is 8cm.

7. The factory-prefabricated steel-shell concrete composite section according to claim 4, characterized in that, The shear key specifications are as follows: length not less than 500mm, width not less than 300mm, and height not less than 500mm.

8. The factory-prefabricated steel-shell concrete composite section according to claim 4, characterized in that, The diameter of the slurry passage hole is 200 mm.

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