A cable-stayed bridge side span cast-in-place section front support formwork cable-stayed cantilever construction method

Abstract

This invention discloses a cable-stayed bridge side span cast-in-place section front support formwork method without cables, comprising the following steps: Step S1, the bridge deck sliding beam travels longitudinally along the main beam to the front end overlapping the supporting column and the rear end anchored to the cast-in-place segment of the main beam; Step S2, the front arc-shaped padlock component and operating platform of the formwork bottom basket are removed using a bridge deck truck crane; Step S3, the formwork bottom basket is pulled to the end of the transition pier cap beam using its own traveling hoisting system and shifter, and after it is in place, the formwork bottom basket is lifted so that its front end overlaps horizontally on the horizontal plane of the transition pier cap beam, and the rear end of the formwork bottom basket is anchored to the cast-in-place segment of the main beam; Step S4, the side span cast-in-place section is finally constructed. After the main beam strength reaches the standard, the cable stays of the side span cast-in-place section are hung to tension the main beam at this point. This method has advantages such as low safety risk, reduced labor costs, significantly shortened construction period, ingenious design, and reasonable structure.

Description

Technical Field

[0001] This invention belongs to the field of construction technology for cast-in-place sections of cable-stayed bridge side spans, specifically relating to a cable-stayed bridge side span cast-in-place section front support hanging basket cableless suspension method. Background Technology

[0002] With the increasing development of expressway construction in my country, the structural forms and span types of extra-large bridges are becoming more and more diverse. The cantilever construction of extra-large bridge beam ends generally adopts the formwork construction method. The structural forms of the formwork are also gradually increasing with the increase of bridge design structural forms, such as diamond formwork, triangular formwork, and front support formwork. However, due to the space limitations of the cast-in-place section of the side span of the cable-stayed bridge, the formwork cannot be moved forward. In most cases, the only option is to rebuild the ground support for load bearing. However, the ground support construction has high safety risks, high costs, and long construction period. Especially for bridges with very high heights, the construction, installation, and dismantling of the ground support is even more complicated. Summary of the Invention

[0003] This invention aims to provide a cable-free cantilever construction method for the front support hanging basket of the cast-in-place section of the side span of a cable-stayed bridge, which reduces costs, facilitates installation and dismantling, and solves the problems of high safety risks, high costs, and long construction periods caused by the limitation of space in the cast-in-place section of the side span of a cable-stayed bridge, which can only be constructed by building ground-mounted supports.

[0004] Therefore, the technical solution adopted in this invention is: a method for cable-stayed bridge side span cast-in-place section front support formwork without cable, comprising the following steps:

[0005] Step S1: After the symmetrical casting of the main beam cable-stayed segment is completed, support columns corresponding to the bridge deck sliding beams are set on the transition pier cap beam. The bridge deck sliding beams travel longitudinally along the main beam to the front end to be connected to the support columns and the rear end to be anchored to the cast segment of the main beam.

[0006] Step S2: Transfer the cable-stayed system that was originally acting on the bottom basket of the main beam to the main beam and perform secondary tensioning of the cable-stayed system. Use the bridge deck crane to remove the arc-shaped padlock component and operating platform at the front end of the bottom basket of the hanging basket.

[0007] Step S3: The bottom basket of the hanging basket is pulled to the end of the transition pier cap beam by its own traveling hoisting system and displacement device. After it is in place, the bottom basket of the hanging basket is lifted so that its front end is horizontally overlapped with the horizontal plane of the transition pier cap beam. The rear end of the bottom basket of the hanging basket is anchored on the cast-in-place segment of the main beam, thus successfully installing the bridge deck sliding beam and the bottom basket of the hanging basket on the upper and lower parts of the side span cast-in-place section.

[0008] Step S4: Finally, construct the cast-in-place section of the side span. After the main beam reaches the required strength, install the stay cables of the cast-in-place section of the side span to tension the main beam at that location.

[0009] As a preferred embodiment of the above scheme, in step S1, three bridge deck sliding beams are used, thus providing three supporting columns on the transition pier cap beam. The bridge deck sliding beams are connected by crossbeams, thereby forming an integral load-bearing structure with a reasonable structural design.

[0010] A further preferred embodiment is that the supporting columns are made of φ609×16mm steel pipes with a horizontal spacing of 7m to 8m to ensure the load-bearing capacity of the supporting columns, and the crossbeams are made of 2H700 steel, which is a reasonable material selection.

[0011] A further preferred embodiment is that, in step S3, the bottom of the cantilevered section of the side span is supported by a hanging basket, but a disc-locked bracket is erected for support in the transition pier cap beam section, thereby filling the support gap in the transition pier cap beam section, which is a reasonable design.

[0012] The beneficial effects of this invention are:

[0013] (1) Compared with building a ground support frame as a support frame for the construction of the cast-in-place section of the side span of the cable-stayed bridge, the bridge deck sliding beam supported by the support column and the bottom basket of the front support hanging basket after the front arc-shaped padlock component and the operating platform are removed, form a support structure for the construction of the cast-in-place section of the side span of the cable-stayed bridge. This makes the construction steps of the cast-in-place section of the side span consistent with those of the main beam cable-stayed section, with low safety risk, reduced labor costs, and significantly shortened construction period. Compared with the traditional ground support frame, it can save nearly 45 days of construction period, bring significant benefits, and has high practicality.

[0014] (2) The front end of the bridge deck sliding beam is connected to the supporting column and the rear end is anchored to the cast-in-place segment of the main beam. The structure is stable and firm. The front end of the hanging basket bottom basket is horizontally connected to the horizontal plane of the transition pier cap beam and the rear end is anchored to the cast-in-place segment of the main beam. The hanging basket bottom basket load-bearing system used during the construction of the standard segment of the main beam is fully utilized. The cable-stayed force system of the front support hanging basket is changed to a simple support force system built by relying on the cap beam at the top of the transition pier. The design is ingenious and the structure is reasonable.

[0015] In summary, it has advantages such as low safety risk, reduced labor costs, significantly shortened construction period, ingenious design, and reasonable structure. Attached Figure Description

[0016] Figure 1 A schematic diagram showing the completion of the symmetrical casting construction of the main beam cable-stayed segments.

[0017] Figure 2 This is a schematic diagram of step S1.

[0018] Figure 3 This is a schematic diagram of step S2.

[0019] Figure 4 This is a schematic diagram of step S3.

[0020] Figure 5 This is a schematic diagram of step S4.

[0021] Figure 6 for Figure 5 Sectional view along the AA direction. Detailed Implementation

[0022] The present invention will be further described below with reference to the embodiments and accompanying drawings:

[0023] Combination Figure 1 — Figure 6 As shown, a method for cable-stayed bridge side span cast-in-place section front support formwork without cables is described, and the specific operation steps are as follows:

[0024] Step S1: After the symmetrical casting of the cable-stayed sections of the main beam 4 is completed, support columns 2 corresponding to the bridge deck sliding beams 3 are set on the transition pier cap beam 1. The bridge deck sliding beams 3 travel longitudinally along the main beam 4 until the front end overlaps with the support columns 2 and the rear end is anchored to the cast sections of the main beam 4.

[0025] In step S1, three bridge deck sliding beams 3 are used, so that three supporting columns 2 are provided on the transition pier cap beam 1, and the bridge deck sliding beams 3 are connected by crossbeams 31.

[0026] The support column 2 is preferably made of φ609×16mm steel pipe, and the lateral spacing is preferably 7m~8m. The crossbeam 31 is preferably made of 2H700 steel.

[0027] Step S2: Transfer the cable-stayed system that was originally acting on the bottom basket 5 of the cast-in-place segment of the main beam 4 to the main beam 4 and perform secondary tensioning of the cable-stayed system. Use the bridge deck crane to remove the arc-shaped padlock component and operating platform at the front end of the bottom basket 5.

[0028] Step S3: The hanging basket bottom basket 5 is pulled to the end of the transition pier cap beam 1 by its own traveling hoisting system and displacement device. After it is in place, the hanging basket bottom basket 5 is lifted so that its front end is horizontally overlapped with the horizontal plane of the transition pier cap beam 1. The rear end of the hanging basket bottom basket 5 is anchored on the cast-in-place segment of the main beam 4, thus successfully installing the bridge deck sliding beam 3 and the hanging basket bottom basket 5 on the upper and lower parts of the side span cast-in-place section.

[0029] In step S3, the bottom of the cantilevered section of the side span is supported by a hanging basket 5, but a disc-lock bracket 6 is erected for support on the transition pier cap beam 1.

[0030] Step S4: Finally, construct the cast-in-place section of the side span. After the main beam reaches the required strength, install the stay cables of the cast-in-place section of the side span to tension the main beam 4 at that location.

[0031] First, the bridge deck sliding beam, which supports the end of the column, is used to form a support structure for the construction of the cast-in-place section of the side span of the cable-stayed bridge, together with the front support hanging basket bottom basket after the front arc-shaped padlock component and the operating platform have been removed. This makes the construction steps of the cast-in-place section of the side span consistent with those of the main beam cable-stayed section.

[0032] By utilizing the hanging basket bottom basket load-bearing system used in the construction of the standard segment of the main beam, the cable-stayed force system of the front support hanging basket is changed to a simply supported force-bearing system that relies on the cap beam at the top of the transition pier.

Claims

1. A method for cable-stayed bridge side span cast-in-place section front support hanging basket without cable, characterized in that, Includes the following steps: Step S1: After the symmetrical casting of the cable-stayed sections of the main beam (4) is completed, support columns (2) corresponding to the bridge deck sliding beam (3) are set on the transition pier cap beam (1). The bridge deck sliding beam (3) travels longitudinally along the main beam (4) until the front end is connected to the support column (2) and the rear end is anchored to the cast section of the main beam (4). Step S2: Transfer the cable-stayed system of the cast-in-place segment of the main beam (4) that was originally acting on the bottom basket (5) to the main beam (4) and perform secondary tensioning of the cable-stayed system. Use the bridge deck truck crane to remove the arc-shaped padlock component and operating platform at the front end of the bottom basket (5). Step S3: The hanging basket (5) is pulled to the end of the transition pier cap beam (1) by its own traveling hoisting system and shifter. After it is in place, the hanging basket (5) is lifted so that its front end is horizontally connected to the horizontal plane of the transition pier cap beam (1). The rear end of the hanging basket (5) is anchored on the cast-in-place segment of the main beam (4), so that the bridge deck sliding beam (3) and the hanging basket (5) are successfully installed on the upper and lower sections of the side span cast-in-place section. Step S4: Finally, construct the cast-in-place section of the side span. After the main beam reaches the required strength, hang the stay cables of the cast-in-place section of the side span to tension the main beam (4) at this location. In step S3, the bottom of the cantilevered section of the side span is supported by a hanging basket (5), but a disc buckle bracket (6) is built on the transition pier cap beam (1) as a support.

2. The method for cable-stayed bridge side span cast-in-place section front support formwork without cables, as described in claim 1, is characterized in that: In step S1, three bridge deck sliding beams (3) are used, so that three supporting columns (2) are provided on the transition pier cap beam (1), and the bridge deck sliding beams (3) are connected by crossbeams (31).

3. The method for cable-stayed bridge side span cast-in-place section front support formwork without cables, as described in claim 2, is characterized in that: The supporting column (2) is made of φ609×16mm steel pipe with a horizontal spacing of 7m~8m, and the crossbeam (31) is made of 2H700 steel.

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