Construction method for prefabricating concrete steel shell combined section in factory

Abstract

The invention discloses a construction method for prefabricating a concrete steel shell combined section in a factory, and relates to the technical field of bridge construction, and the construction method comprises the following steps: S1, manufacturing a wallboard unit; s2, the inner wall plate units are positioned, then the outer wall plate units are positioned, and then welding is conducted to manufacture steel shell segments; s3, annular structure concrete between the inner wall plate unit and the outer wall plate unit is poured, and steel shell concrete segments are formed; s4, secondary machining is conducted on the steel shell concrete segments; s5, vertical position continuous matching pre-assembly is carried out, after pre-assembly is completed, matching parts are installed, and marker lines are marked; s6, bridge site hoisting and positioning are conducted on the steel shell concrete sections; s7, outer wall plates of the steel shell concrete sections are subjected to butt-joint penetration welding, and then inner wall plates are welded; and S8, concrete pouring is conducted on bridge site ring openings of the steel shell concrete sections, and machining is completed. The technical problem that the construction period is prolonged due to prefabrication of the steel shell sections of the steel shell concrete tower in the prior art is solved.

Description

Technical Field

[0001] This invention relates to the field of bridge construction technology, and in particular to a construction method for precast concrete-steel shell composite segments in a factory. Background Technology

[0002] As the span of main bridges in my country continues to increase, the technology for setting pylons for cable-stayed or suspension bridges also needs to be constantly updated. Steel-concrete composite towers, through the collaborative work of a steel outer shell and internal concrete filling, with the steel shell providing tensile and shear resistance while the concrete bears compressive loads, significantly improve the overall load-bearing capacity and stiffness of the tower, making it the preferred structure for long-span bridges.

[0003] When the steel shell segments of a conventional steel-concrete tower are prefabricated in the factory, no concrete is poured. Dense stiffening ribs and angle steel are required between the inner and outer wall panels of the steel shell to improve the overall rigidity and avoid deformation during hoisting. The steel shell serves as a permanent formwork, and a large number of steel bars are added to the reinforcement to improve the bonding strength with the concrete. The concrete is poured after the steel shell segments are hoisted and welded at the bridge site. This approach has a long construction period and room for improvement in construction quality. Summary of the Invention

[0004] The purpose of this invention is to provide a construction method for prefabricated concrete-steel shell composite segments in a factory, which solves the technical problem of prolonged construction period caused by the prefabrication of steel shell segments in steel-shell concrete towers in the prior art.

[0005] This application discloses a construction method for precast concrete-steel shell composite segments, including the following steps: S1: Fabrication of wall panel units, wherein the wall panel units include inner wall panel units and outer wall panel units; S2: Position the inner wall panel unit, provide internal support for the inner wall panel unit, then position the outer wall panel unit, provide external support for the outer wall panel, install horizontal connecting ribs between the inner wall panel unit and the outer wall panel unit, and then weld them to form a steel shell segment. S3: Place the steel shell segment on a horizontal frame, arrange the concrete pouring template, and pour the annular structural concrete between the inner and outer wall panel units to form a steel shell concrete segment. S4: Secondary processing of steel-concrete composite segments; S5: Hoist the steel-concrete shell segment onto the pre-assembly jig, perform vertical continuous matching pre-assembly, and after the pre-assembly is completed, install the matching parts and marking lines; S6: Erect and position the steel-concrete composite segment at the bridge site; S7: Use a welding robot to perform butt welding of the outer wall panel of the steel shell concrete segment. After the welding is completed, perform butt welding of the inner wall panel of the steel shell concrete segment. S8: Concrete is poured at the bridge site ring of the steel-concrete composite segment to complete the processing.

[0006] This application involves prefabricating steel shell segments and concrete in the factory, and constructing concrete at the circumferential joints and reserved circumferential openings of the steel shell segments at the bridge site. This allows the concrete to replace dense angle steel, thereby improving the overall rigidity of the segments. At the same time, the construction and curing of the concrete at the bridge site are not considered key processes, which can significantly shorten the construction cycle at the bridge site.

[0007] Based on the above technical solution, the present application can be further improved as follows: Furthermore, the specific content of step S2 is as follows: S201: Assemble a special jig, the top surface of which is provided with a horizontal support and the elevation is adjustable; S202: An inner support is provided on the special jig to support the inner wall panel unit; S203: An external support is provided on the special jig, and the outer wall panel unit is supported by the external support plate; S204: Welding is performed using a drag-and-drop collaborative robot. First, the upright penetration fillet welds of the inner wall panel units are welded in sequence, followed by the upright penetration fillet welds of the outer wall panel units, forming steel shell segments. The advantage of this step is that a dedicated jig is used to complete the welding of the inner and outer wall panel units, thereby ensuring the stability of the steel shell segments and facilitating subsequent pouring.

[0008] Furthermore, in step S201, the inner wall support plate of the special jig is 100mm higher than the outer wall support plate; In step S202, the distance between the mating point of the inner support and the inner wall panel unit and the weld edge of the inner wall panel unit is 500-800mm. The contact point between the outer support and the outer wall panel unit is 500-800mm away from the weld edge of the outer wall panel unit. The advantage of this step is that by restricting the support position, sufficient processing space can be ensured in the future.

[0009] Furthermore, the specific content of step S3 is as follows: S301: Concrete casting formwork with shear key formwork on the top and bottom surfaces; S302: Place the steel shell segment on a horizontal jig, and then arrange the concrete pouring template on the steel shell segment; S303: Two vertical steel pipes are installed inside the concrete pouring formwork. The vertical steel pipes are fixed with angle steel to ensure verticality during concrete pouring. S304: Concrete pouring is carried out. After the pouring is completed, a steel shell concrete segment with shear keys is formed. The bottom of the vertical steel pipe is cut to form a half steel pipe. The beneficial effect of this step is that by setting a shear key template, shear keys can be formed after pouring, which facilitates subsequent hoisting and positioning.

[0010] Furthermore, the diameter of the vertical steel pipe in step 303 is 200mm; The dimensions of the shear key in step S304 are not less than 300mm wide, 500mm high and 500mm long, and the length of the shear key is not greater than 1 / 3 of the diameter of the ring opening. The beneficial effect of this step is that a grout passage hole can be formed through the vertical steel pipe, thereby forming the ring opening concrete pouring.

[0011] Furthermore, the specific content of step S5 is as follows: S501: Pre-assembled frame used; S502: Employs continuous pre-assembly in a vertical position, matches the actual bridge condition according to the monitored alignment, verifies the segment manufacturing, and ensures that the segment quality meets the requirements; S503: After the key items have passed inspection, install the matching parts and marking lines. The benefit of this step is that it allows for the installation of the corresponding accessories, which facilitates subsequent assembly.

[0012] Furthermore, in step S503, the L value of the marker line is 400-600mm.

[0013] Furthermore, the specific content of step S6 is as follows: S601: First, the segment is initially and quickly positioned using the shear key; S602: Use a total station to measure the positioning accuracy. After the data is qualified, fix the matching parts. S603: Verify the dimensions of the marker lines.

[0014] Furthermore, the specific content of step S7 is as follows: S701: Complete the welding of the circumferential seam of the outer wall panel, wherein a single-sided bevel is opened on the outer wall panel, the bevel direction is towards the outside of the tower, and a ceramic gasket is attached to the back of the outer wall panel from the direction of the inner wall panel for welding. S702: Complete the welding of the circumferential seam of the inner wall panel. A single-sided bevel is opened on the inner wall panel, with the bevel facing the center of the tower. Since the space behind is not accessible, a steel backing is set on the back for welding.

[0015] Furthermore, in step S7, the inner wall panel of the steel-concrete segment is provided with a 200mm wide patch section.

[0016] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages: 1. This application discloses a construction method that improves the overall rigidity of the segments by replacing dense angle steel with concrete. At the same time, the uncontrollable shrinkage of the concrete pouring at the bridge site will affect the installation quality of the steel shell segments. By utilizing the structural characteristics, the concrete pouring time at the bridge site is not considered a major construction stage, which significantly shortens the construction cycle of the bridge site.

[0017] 2. The construction method disclosed in this application effectively ensures the unstable quality control during the construction process of the factory-precast concrete steel shell composite structure, and improves the overall manufacturing and bridge site construction accuracy of the factory-precast concrete steel shell composite structure. 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 1 This is a process flow diagram of a construction method for a precast concrete-steel shell composite segment according to a specific embodiment of the present invention; Figure 2 for Figure 1 Schematic diagram of the steel shell segment; Figure 3 for Figure 1 Structural schematic diagram of the steel-shell concrete segment; Figure 4 This is a schematic diagram of step S5, continuous matching and pre-assembly in the neutral position, in a construction method for a precast concrete steel shell composite segment according to a specific embodiment of the present invention. Figure 5 The welding sequence in step S7 of the construction method for a precast concrete steel shell composite segment in a specific embodiment of the present invention; Detailed Implementation 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 one of ordinary skill in the art to which this invention pertains.

[0020] In the description of this application, it should be understood that the terms "upper", "lower", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0021] 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.

[0022] Example: This application discloses a construction method for prefabricated concrete-steel shell composite segments in a factory, which enables the prefabrication of concrete-steel shell composite segments in the factory and on-site construction, significantly shortening the bridge site construction cycle.

[0023] The specific structure of the precast concrete steel shell composite segment in this application includes inner and outer wall panel units, wherein the inner and outer wall panel units form a ring structure with a gap of not less than 8cm, which is used to install concrete pouring formwork to facilitate subsequent concrete pouring.

[0024] Among them, such as Figure 2 As shown, the inner and outer wall panels of this application are provided with transverse and longitudinal stiffening ribs on the annular structure side. Specifically, the thickness of the inner wall panel is at least 10 mm, and dense stiffening ribs are installed on the inner wall panel with a spacing of 200 mm. The welding is carried out using automated welding technology to prevent the thin-walled dense rib unit from deforming during welding.

[0025] The inner and outer wall panel units are connected only by horizontal ribs, eliminating the need for steel reinforcement. Therefore, a special jig is required for subsequent support and positioning to ensure the manufacturing accuracy of the segments.

[0026] The top and bottom of the concrete pouring formwork include shear key formwork, which forms a tenon-and-mortise shear key after the concrete is poured.

[0027] like Figure 1-5 As shown, the construction method in this application includes the following steps: S1: Positioning and assembling the wall panel unit, which includes an inner wall panel unit and an outer wall panel unit. Specifically, the wall panel, vertical stiffening ribs and horizontal stiffening ribs are positioned and assembled on a flat jig. Then, a gantry-type double-arm welding robot is used to complete the welding of the wall panel and the stiffening ribs with fillet welds, thereby completing the welding of the inner wall panel unit and the outer wall panel unit. S2: Locate the inner wall panel unit and provide internal support; then locate the outer wall panel unit, provide external support, and weld them together to form a steel shell segment; the specific details of step S2 are as follows: S201: Assemble a special jig. The top surface of the special jig is provided with a horizontal support and the elevation is adjustable. At the same time, the outer contour dimension of the special jig is fixed and the support can be adjusted according to the outer contour of the steel shell segment. The inner wall support plate of the special jig is 100mm higher than the outer wall support plate. S202: An inner support is installed on the dedicated jig to support the inner wall panel unit. Specifically, the inner support uses a profile with a cross-section of not less than 60mm, and the height of the support is higher than the center of gravity of the inner wall panel unit. At the same time, each inner wall panel unit has no less than two inner supports. When supporting, the distance between the mating part of the inner support and the inner wall panel unit and the weld edge of the inner wall panel unit is 500-800mm. The angle of the support is adjusted according to the angle of the inner wall panel, and a figure-eight brace is installed.

[0028] S203: An external support is provided on the special jig, which supports the outer wall panel unit. The external support is made of profile with a cross-section of not less than 60mm. The support height is about 1000mm from the top surface of the outer wall panel unit. Each panel unit is provided with no less than 2 external supports. The distance between the contact point between the external support and the outer wall panel unit and the weld edge of the outer wall panel unit is 500-800mm. The extension length of the external support is adjusted according to the angle of the outer wall panel. S204: Install horizontal stiffening ribs to ensure the distance between the inner and outer wall panels. Use a drag-and-teach collaborative robot for welding. First, weld the vertical penetration corner welds of the inner wall panel units in sequence, and then weld the vertical penetration corner welds of the outer wall panel units in sequence to form steel shell segments. The steel shell panels are connected by penetration corner welds, and a single-sided welding double-sided forming welding process is used. The welding deformation is controlled by constraint tooling. Then, use a drag-and-teach collaborative robot to weld the vertical penetration corner welds of the inner wall panel units in sequence, and then weld the vertical penetration corner welds of the outer wall panel units in sequence to form steel shell segments.

[0029] S3: Place the steel shell segment on a horizontal support frame, arrange the concrete pouring template, and pour the annular structural concrete between the inner and outer wall panel units to form the steel shell concrete segment; wherein, the specific content of step S3 is as follows: S301: Select a concrete casting formwork with shear key templates on the top and bottom surfaces. This shear key template facilitates the formation of shear keys in the mother-daughter structure after the steel shell segment is cast. S302: Place the steel shell segment on a horizontal jig, and then arrange the concrete pouring template on the steel shell segment; S303: At least two vertical steel pipes are installed inside the concrete pouring formwork. The vertical steel pipes are fixed with angle steel to ensure verticality during concrete pouring. The diameter of the vertical steel pipe is 200mm and it is fixed with L50 angle steel. S304: Pour the annular structural concrete between the inner and outer wall panel units. After pouring, a steel shell concrete segment with shear keys is formed, and concrete curing is carried out. The bottom of the vertical steel pipe is cut to form a semi-steel pipe to facilitate bridge site construction. At the same time, the length of the vertical steel pipe is consistent with the height of the beam segment. S4: Secondary processing of steel-concrete composite segments to eliminate deviations caused by manufacturing and concrete pouring deformation, ensuring the outer contour dimensions. Specifically, this can be accomplished through machining. S5: Hoist the steel-concrete composite segment onto the pre-assembly jig for continuous vertical matching and pre-assembly. After pre-assembly, install the matching parts and marking lines. The specific content of step S5 is as follows: S501: A pre-assembled jig is selected; the foundation and jig bearing capacity of the pre-assembly site must meet the pre-assembly requirements. The weight of the two sections is approximately 600t, so the jig must be able to withstand at least 600t of weight; at the same time, the pre-assembled jig has the functions of setting up a baseline, providing access to upper and lower passages, and a circular walkway, which facilitates construction; similarly, the weight of the hoisting equipment must meet the pre-assembly requirements, and the crane tonnage must be no less than 300t; S502: The "1+1" continuous pre-assembly method is adopted for vertical positioning. The actual bridge condition is matched according to the monitored alignment, and the segment manufacturing is verified to ensure that the segment quality meets the requirements. S503: After the key items pass the inspection, install the matching parts and marking lines. The key items include axis deviation, misalignment, etc. S6: The steel-concrete composite segment is hoisted and positioned at the bridge site; the specific details of step S6 are as follows: S601: First, the segment is initially and quickly positioned using the shear key; S602: Use a total station to measure the positioning accuracy. After the data is qualified, fix the matching parts. S603: Verify the dimensions of the marker lines; S7: A welding robot is used to perform butt welding of the outer wall panels of the steel-concrete segment. After welding, the inner wall panel of the steel-concrete segment is butt welded to achieve full penetration. The specific content of step S7 is as follows: S701: Complete the welding of the circumferential seam of the outer wall panel, wherein a single-sided bevel is opened on the outer wall panel, the bevel direction is towards the outside of the tower, and a ceramic gasket is attached to the back of the outer wall panel from the direction of the inner wall panel for welding. S702: Complete the welding of the circumferential seam of the inner wall panel. A single-sided bevel is opened on the inner wall panel, with the bevel direction facing the center of the tower. Since the space behind is not accessible, a steel liner is set on the back for welding. S8: Concrete is poured at the bridge site ring of the steel-concrete composite segment to complete the processing.

[0030] In step S304, each steel-shell concrete segment has at least two shear keys on its annular surface. These shear keys are poured simultaneously with the internal concrete. The shear key is no less than 300mm (width) x 500mm (height) x 500mm (length), and its length is no more than 1 / 3 of the annular diameter. It is designed with a mortise and tenon structure to facilitate bridge installation and to serve as a positioning guide block.

[0031] In step S503, the marker line design is a fixed size L value. The value of the bridge position ring is fixed, and the L value is set to 400-600mm. The marker line is marked after the pre-assembly is completed and the measurement is qualified. The marker point position is restored after the painting is completed.

[0032] In step S7, the inner wall plate of the steel-concrete segment is provided with a 200mm wide patch section.

[0033] In step S8, every 2-3 steel-shell concrete segments are filled with annular concrete through a pre-reserved φ200mm grout passage.

[0034] 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. In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as 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, 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 will 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 construction method for precast concrete-steel shell composite segments, characterized in that, Includes the following steps: S1: Fabrication of wall panel units, wherein the wall panel units include inner wall panel units and outer wall panel units; S2: Position the inner wall panel unit, provide internal support for the inner wall panel unit, then position the outer wall panel unit, provide external support for the outer wall panel, install horizontal connecting ribs between the inner wall panel unit and the outer wall panel unit, and then weld them to form a steel shell segment. S3: Place the steel shell segment on a horizontal frame, arrange the concrete pouring template, and pour the annular structural concrete between the inner and outer wall panel units to form a steel shell concrete segment. S4: Secondary processing of steel-concrete composite segments; S5: Hoist the steel-concrete shell segment onto the pre-assembly jig, perform vertical continuous matching pre-assembly, and after the pre-assembly is completed, install the matching parts and marking lines; S6: Erect and position the steel-concrete composite segment at the bridge site; S7: Use a welding robot to perform butt welding of the outer wall panel of the steel shell concrete segment. After the welding is completed, perform butt welding of the inner wall panel of the steel shell concrete segment. S8: Concrete is poured at the bridge site ring of the steel-concrete composite segment to complete the processing.

2. The construction method according to claim 1, characterized in that, The specific content of step S2 is as follows: S201: Assemble a special jig, the top surface of which is provided with a horizontal support and the elevation is adjustable; S202: An inner support is provided on the special jig to support the inner wall panel unit; S203: An external support is provided on the special jig, and the outer wall panel unit is supported by the external support plate; S204: Welding is performed using a drag-and-drop collaborative robot. First, the upright penetration corner welds of the inner wall panel units are welded in sequence, and then the upright penetration corner welds of the outer wall panel units are welded in sequence to form steel shell segments.

3. The construction method according to claim 2, characterized in that, In step S201, the inner wall support plate of the special jig is 100mm higher than the outer wall support plate. In step S202, the distance between the mating point of the inner support and the inner wall panel unit and the weld edge of the inner wall panel unit is 500-800mm. The distance between the contact point between the external support and the outer wall panel unit and the weld edge of the outer wall panel unit is 500-800mm.

4. The construction method according to claim 1, characterized in that, The specific content of step S3 is as follows: S301: Concrete casting formwork with shear key formwork on the top and bottom surfaces; S302: Place the steel shell segment on a horizontal jig, and then arrange the concrete pouring template on the steel shell segment; S303: Two vertical steel pipes are installed inside the concrete pouring formwork. The vertical steel pipes are fixed with angle steel to ensure verticality during concrete pouring. S304: Concrete is poured. After pouring, a steel-shell concrete segment with shear keys is formed, and the bottom of the vertical steel pipe is cut to form a semi-steel pipe.

5. The construction method according to claim 4, characterized in that, The diameter of the vertical steel pipe in step 303 is 200mm; The dimensions of the shear key in step S304 are not less than 300mm wide, 500mm high and 500mm long, and the length of the shear key is not greater than 1 / 3 of the diameter of the ring opening.

6. The construction method according to claim 1, characterized in that, The specific content of step S5 is as follows: S501: Pre-assembled frame used; S502: Employs continuous pre-assembly in a vertical position, matches the actual bridge condition according to the monitored alignment, verifies the segment manufacturing, and ensures that the segment quality meets the requirements; S503: Install matching parts and marking lines after the key items have passed inspection.

7. The construction method according to claim 6, characterized in that, In step S503, the L value of the marker line is 400-600mm.

8. The construction method according to claim 7, characterized in that, The specific content of step S6 is as follows: S601: First, use shear keys to perform preliminary and rapid segment positioning; S602: Use a total station to measure the positioning accuracy. After the data is qualified, fix the matching parts. S603: Verify the dimensions of the marker lines.

9. The construction method according to claim 8, characterized in that, The specific content of step S7 is as follows: S701: Complete the welding of the circumferential seam of the outer wall panel, wherein a single-sided bevel is opened on the outer wall panel, the bevel direction is towards the outside of the tower, and a ceramic gasket is attached to the back of the outer wall panel from the direction of the inner wall panel for welding. S702: Complete the welding of the circumferential seam of the inner wall panel. A single-sided bevel is opened on the inner wall panel, with the bevel facing the center of the tower. Since the space behind is not accessible, a steel backing is set on the back for welding.

10. The construction method according to claim 9, characterized in that, In step S7, a 200mm wide patch section is provided on the inner wall panel of the steel-concrete segment.

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