CN116716788A - Simply supported-rotating continuous combined beam bridge structure for improving crack resistance of bridge deck in hogging moment area - Google Patents

Abstract

The invention relates to a simply-supported continuous composite girder bridge structure that improves the crack resistance of bridge decks in negative bending moment areas. It includes abutments on both sides and a number of piers distributed between the abutments on both sides along the longitudinal bridge direction. There is a composite beam structure between the bridge abutment and the tops of several bridge piers. The composite beam structure includes several steel-concrete composite beams spliced along the transverse bridge direction. The lower part of the composite beam structure is between the bridge abutment and the bridge piers. There are upwardly protruding arch-shaped cable structures between adjacent piers. The raised top of the cable structure is anchored in the mid-span of the composite beam structure, and the bottoms of both ends of the cable structure between the abutment and the pier are They are anchored on the abutment and pier respectively, and the bottoms of both ends of the cable structure located between adjacent piers are anchored on the piers. The invention has simple structure, reasonable design, lower cost, simpler and faster construction, can prevent cracking of negative bending moment concrete slabs, and improves the durability of the structure.

Description

A simply supported to continuous composite girder bridge structure that improves the crack resistance of the bridge deck in the negative bending moment zone

Technical areas:

The invention relates to a simply supported to continuous composite beam bridge structure that improves the crack resistance of the bridge deck in the negative bending moment zone.

Background technique:

The steel-concrete composite continuous box girder bridge uses the tensile properties of steel and the good compressive properties of concrete to work together. It has obvious economic and technical advantages over traditional steel box girder and prestressed concrete bridges. However, for the negative bending moment area on the top of the middle pier of a multi-span steel-concrete composite continuous girder bridge, the concrete bridge deck will be tensile. If the tensile stress exceeds the allowable value of concrete tension, the concrete in the negative bending moment area of the girder bridge will collapse. Cracking occurs, reducing the durability of the structure and affecting the structural service life of the bridge.

The existing methods to solve concrete cracking in the negative bending moment zone of steel-concrete composite continuous box girder bridges are: ① Tension prestressing in the concrete bridge deck in the negative bending moment zone. This method of applying prestressing is complicated in prestressing, tensioning and anchoring, and the prestressing is complicated. The stress loss is large, and the effective prestress is often applied to the steel beams in the long-term effect. The effective prestress of the bridge deck in the negative bending moment area is very small; ② Adjust the relative elevation of the bearing to form precompressed stress. This bearing jacking method, the bearing top The technology is complex and the operation risk is high; ③ Stack a certain temporary load in the positive bending moment area of the composite beam, and then pour concrete in the negative bending moment area when the steel beam is subjected to additional force. This preloading method must add temporary static load to the bridge The workload on the panel is large and the economic effect is poor.

In view of the above-mentioned defects or deficiencies in the existing technology, there is an urgent need for an anti-cracking technology that is cheaper, simpler to construct, and faster to construct, to prevent cracking of negative bending moment concrete slabs and improve the durability of the structure. This case arose from this.

Contents of the invention:

The present invention improves the problems existing in the above-mentioned prior art. That is, the technical problem to be solved by the present invention is to provide a simply supported to continuous composite girder bridge structure that improves the crack resistance of the bridge deck in the negative bending moment zone.

In order to achieve the above purpose, the technical solution adopted by the present invention is: a simply supported to continuous composite girder bridge structure that improves the crack resistance of the bridge deck in the negative bending moment zone, including abutments on both sides, and bridges on both sides distributed along the longitudinal direction of the bridge. There are several piers between the abutments. There is a composite beam structure between the abutments on both sides and the tops of the several piers. The composite beam structure includes several steel-concrete composite beams spliced along the transverse bridge direction. The composite beam structure The lower part is provided with an upwardly protruding arch-shaped cable structure between the abutment and piers and between adjacent piers. The raised top of the cable structure is anchored in the mid-span of the composite beam structure and is located between the abutment and piers. The two end bottoms of the cable structure between them are anchored on the bridge abutment and the bridge pier respectively, and the two end bottoms of the cable structure located between adjacent bridge piers are anchored on the bridge piers.

Further, the number of spans of the cable structure is the same as the number of spans of the steel-concrete composite beam, and the cable structure is composed of no less than two cables in the transverse direction of the bridge.

Further, the steel-concrete composite beam includes a concrete bridge deck and at least two sections of steel beams spliced along the longitudinal bridge direction. The concrete bridge deck is connected to the upper web of the steel beam through a shear connector.

Furthermore, each cable is connected to the concrete bridge deck of the steel-concrete composite beam through a plurality of tie rods spaced apart along the longitudinal bridge direction.

Further, the upper end of the tie rod is provided with a reserved hole, and the reserved hole is provided with a pull ring, and the pull ring is connected to the embedded anchor point on the bottom surface of the concrete bridge deck; the lower end of the tie rod is fixed with a A cable clamp is used to hold the cable.

Further, when the bridge pier is located at the middle fulcrum of the simply-supported continuous composite beam bridge structure, the pier body of the bridge pier is provided with a first reserved cableway hole, and the cable structure passes through the first reserved cableway hole of the bridge pier. , the first reserved cableway hole is V-shaped, and the lower part of the first reserved cableway hole is a curved transition.

Further, when the bridge pier or abutment is located at the edge fulcrum of the simply-supported continuous composite beam bridge structure, a second reserved cableway hole is provided on the pier body of the bridge pier or the platform body of the bridge abutment, and the second reserved cableway hole is The hole is provided with a groove on the side of the bridge pier or abutment, and an anchor is provided on the bottom surface of the groove. The plane of the anchor is perpendicular to the second reserved cableway hole.

Further, the pre-embedded anchor point is a pre-embedded annular steel bar, the pre-embedded annular steel bar is arranged between two steel-concrete composite beams in the transverse bridge direction, and the pull ring is connected to the pre-embedded annular steel bar.

Further, in the steel-concrete composite beam, adjacent steel beams are connected by welding, and the concrete bridge deck is provided with wet joints.

Another technical solution adopted by the present invention is: a construction method of a simply supported to continuous composite beam bridge structure that improves the crack resistance of the bridge deck in the negative bending moment zone, including the following steps:

Step S1, steel beam processing: Divide the steel beam into several segments. The maximum length of the segmental steel beam is the single span of the composite beam bridge structure; then the steel beam is manufactured in segments in the factory and transported to the prefabricated site;

Step S2, precast concrete bridge deck: Process the precast concrete bridge deck formwork, process the steel bars and tie the steel bars in the formwork, pour concrete in the formwork, and cover and sprinkle with water after the concrete is finally set; when the strength of the concrete bridge deck reaches the specification requirements Finally, the surface of the concrete bridge deck in the wet joints is manually roughened to create a concave and convex rough surface;

Step S3, installation and installation of simply supported steel beams: transport the steel beams to the bridge location, install permanent supports on the bridge piers and abutments, install temporary supports on both sides of the permanent supports, and hoist the steel beams to simply support them. Installed on temporary supports, install the transverse connection system between steel beams;

Step S4, the steel beam is converted from simply supported to continuous: measure the gap between the two simply supported steel beams, process the steel beam connection section, install the steel beam connection section on the permanent support, and weld it to the simply supported steel beams at both ends, and remove the temporary The bearing and composite beam structure are changed from simply supported to continuous;

Step S5, install the bridge deck at the mid-span: install the concrete bridge deck at the mid-span and side span of the composite girder bridge structure, tie the wet joint steel bars between the concrete bridge decks, embed the anchor points of the pre-embedded ring steel bars, and pour the wet joints. joint concrete, concrete curing;

Step S6, cable installation and tensioning: Locate the position of the cable clip on the cable, pass the cable through the reserved cableway hole on the abutment or pier, install the cable clamp and tie rod on the cable, and pull the rod through the pull ring. Connect it to the pre-embedded ring steel bars on the concrete bridge deck, install the matching anchors and clips at the end of the cable, and lift the jack with the inverted slide chain on the bracket so that it is aligned with the center of the hole of the cable clamp. , then install the tool anchor, clamp the cable and use a jack to tension both ends of the cable. Try to synchronize the tensioning at both ends of the cable; after confirming that the requirements are met, remove the tensioning equipment and complete the cable tensioning;

Step S7, cast-in-situ construction of the bridge deck in the negative bending moment area: install the bridge deck template in the negative bending moment area, tie the bridge deck steel bars, pour the concrete of the bridge deck in the negative bending moment area, and perform concrete curing;

Step S8, tensioning and dismantling of the cables: After the strength of the concrete bridge deck in the negative bending moment zone reaches the standard value, use a jack to stretch the cables, gradually stretch the cables, and dismantle the cable structure, so that the bridge in the negative bending moment zone The panel generates a certain pre-pressure stress, and then the reserved cableway holes in the piers and abutments are sealed;

Step S9, bridge deck paving and anti-collision wall construction: construct the bridge deck pavement, tie anti-collision wall steel bars, install anti-collision wall formwork, pour anti-collision wall concrete and maintain it.

Compared with the prior art, the present invention has the following effects: the present invention connects the steel-concrete composite beam by setting an arch-shaped cable structure between the bridge piers and between the bridge piers and the abutment, and the tension cable structure makes the steel-concrete The mid-span deflection of the composite beam structure is lowered, and the cable structure is released after the construction of the concrete bridge deck in the negative bending moment zone of the steel-concrete composite beam reaches the specification value, which can generate pressure on the bridge deck in the negative bending moment zone and increase the negative bending moment zone. The crack-resistant performance of the bridge deck is simple in structure, reasonable in design, cheaper in cost, and simpler and faster in construction. It can prevent cracking of negative bending moment concrete slabs and improve the durability of the structure.

Picture description:

Figure 1 is a schematic three-dimensional structural diagram of Embodiment 1 of the present invention;

Figure 2 is a schematic cross-sectional view of the composite beam structure in Embodiment 1 of the present invention;

Figure 3 is a schematic diagram of the anchor point structure of the concrete bridge deck in Embodiment 1 of the present invention;

Figure 4 is a schematic diagram of the cable structure along the bridge in Embodiment 1 of the present invention;

Figure 5 is a partially enlarged schematic diagram of Embodiment 1 of the present invention;

Figure 6 is a schematic diagram of the cable structure along the bridge in Embodiment 2 of the present invention;

Figure 7 is a schematic diagram of the cable structure along the bridge in Embodiment 3 of the present invention.

In the picture:

1-abutment; 2-pier; 3-composite beam structure; 4-steel-concrete composite beam; 5-stay cable structure; 6-stay cable; 7-concrete bridge deck; 8-steel beam; 9-tie rod; 10 - Pull ring; 11 - embedded anchor point; 12 - cable sleeve; 13 - negative bending moment zone; 14 - cable clamp; 15 - transverse connection system; 16 - anchorage.

Detailed ways:

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", The orientations or positional relationships indicated by "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention, rather than indicating or It is implied that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation and is therefore not to be construed as a limitation of the invention.

Embodiment 1: As shown in Figure 1, a simply supported to continuous composite girder bridge structure of the present invention that improves the crack resistance of the bridge deck in the negative bending moment zone includes abutments 1 on both sides, and bridges on both sides distributed along the longitudinal direction of the bridge. There are several piers 2 between the platforms 1. There is a composite beam structure 3 between the bridge abutments 1 on both sides and the tops of the several piers 2. The composite beam structure 3 includes several steel-concrete combinations spliced along the transverse bridge direction. Beam 4, the lower part of the composite beam structure 3 is provided with an upwardly convex arch-shaped cable structure 5 between the abutment 1 and the pier 2 and between the adjacent piers 2. The raised top of the cable structure 5 is anchored In the mid-span of the composite beam structure 3, the bottoms of both ends of the cable structure 5 located between the abutment 1 and the pier 2 are respectively anchored on the abutment 1 and the pier 2. The cable structure 5 located between the adjacent piers 2 The bottoms of both ends are anchored on pier 2. During construction, the tension cable structure causes the mid-span deflection of the steel-concrete composite beam, and then the concrete bridge deck in the negative bending moment zone of the steel-concrete composite beam is constructed. After the strength of the concrete deck in the negative bending moment zone reaches the specification value, the tension is released. The cable structure generates pressure on the bridge deck in the negative bending moment area and improves the crack resistance of the bridge deck in the negative bending moment area.

In this embodiment, the number of spans of the cable structure 5 is the same as the number of spans of the steel-concrete composite beam 4, and the cable structure 5 is composed of no less than two cables 6 in the transverse direction.

In this embodiment, the steel-concrete composite beam 4 includes a concrete bridge deck 7 and at least two sections of steel beams 8 spliced along the longitudinal bridge direction. The concrete bridge deck 7 is connected to the upper belly of the steel beam 8 through shear connectors. boards are connected. Further, adjacent steel beams 8 are connected by welding, and the concrete bridge deck 7 is provided with wet joints.

In this embodiment, each cable 6 is connected to the concrete bridge deck 7 of the steel-concrete composite beam through a plurality of tie rods 9 spaced apart along the longitudinal bridge direction. Further, the upper end of the tie rod 9 is provided with a reserved hole, and a pull ring 10 is provided in the reserved hole. The pull ring 10 is connected to the pre-embedded anchor point 11 on the bottom surface of the concrete bridge deck 7; A cable clamp 14 is fixed at the lower end of the pull rod 8, and the cable clamp holds the cable.

In this embodiment, when the pier 2 is located at the middle fulcrum of the simply-supported continuous composite beam bridge structure, the pier body of the pier 2 is provided with a first reserved cableway hole, and the cable structure 5 is connected from the first hole of the pier 2 The reserved cableway hole passes through, the first reserved cableway hole is V-shaped, and the lower part of the first reserved cableway hole is a curved transition.

In this embodiment, after the strength of the concrete bridge deck in the negative bending moment area reaches the standard value, the cable force of the cable structure is released, causing the bridge deck in the negative bending moment area to generate pressure, thereby improving the crack resistance of the bridge deck in the negative bending moment area.

In this embodiment, the pre-embedded anchor point 11 is a pre-embedded annular steel bar. The pre-embedded annular steel bar is arranged between two steel-concrete composite beams in the transverse bridge direction. The pull ring is in contact with the pre-embedded annular steel bar. connect.

In this embodiment, along the cross bridge upward, the steel beams 8 of adjacent steel-concrete composite beams are connected through a transverse connection system.

The construction method of a simply supported to continuous composite girder bridge structure that improves the crack resistance of the bridge deck in the negative bending moment zone includes the following steps:

Step S1, steel beam processing: The steel beam is a steel plate beam or a steel box beam. First, the steel beam is divided into several segments. The maximum length of the segmental steel beam is the single span of the composite beam bridge structure; then the steel beam is processed Through a series of processes such as pretreatment, blanking, welding, cutting, assembly, and painting, the steel beams are produced in sections in the factory and transported to the prefabrication site; the shear connectors use shear nails and the shear nails are welded When welding is carried out using drawn arc welding, the shear nails should be positioned accurately and vertically;

Step S2, precast concrete bridge deck: Process the precast concrete bridge deck formwork, process the steel bars and tie the steel bars in the formwork, pour concrete in the formwork, and cover and sprinkle with water after the concrete is finally set; when the strength of the concrete bridge deck reaches the specification requirements Finally, the surface of the concrete bridge deck in the wet joints is manually roughened to create a concave and convex rough surface;

Step S3, installation and installation of simply supported steel beams: transport the steel beams to the bridge location, install permanent supports on the bridge piers and abutments, install temporary supports on both sides of the permanent supports, and hoist the steel beams to simply support them. Installed on temporary supports, install the transverse connection system between steel beams;

Step S4, the steel beam is converted from simply supported to continuous: measure the gap between the two simply supported steel beams, process the steel beam connection section, install the steel beam connection section on the permanent support, and weld it to the simply supported steel beams at both ends, and remove the temporary The bearing and composite beam structure are changed from simply supported to continuous;

Step S5, install the bridge deck at the mid-span: install the concrete bridge deck at the mid-span and side span of the composite girder bridge structure, tie the wet joint steel bars between the concrete bridge decks, embed the anchor points of the pre-embedded ring steel bars, and pour the wet joints. joint concrete, concrete curing;

Step S6, cable installation and tensioning: Locate the position of the cable clip on the cable, pass the cable through the reserved cableway hole on the abutment or pier, install the cable clamp and tie rod on the cable, and pull the rod through the pull ring. Connect it to the pre-embedded ring steel bars on the concrete bridge deck, install the matching anchors and clips at the end of the cable, and lift the jack with the inverted slide chain on the bracket so that it is aligned with the center of the hole of the cable clamp. , then install the tool anchor, clamp the cable and use a jack to tension both ends of the cable. Try to synchronize the tensioning at both ends of the cable; after confirming that the requirements are met, remove the tensioning equipment and complete the cable tensioning;

Step S7, cast-in-situ construction of the bridge deck in the negative bending moment area: install the bridge deck template in the negative bending moment area, tie the bridge deck steel bars, pour the concrete of the bridge deck in the negative bending moment area, and perform concrete curing;

Step S8, tensioning and dismantling of the cables: After the strength of the concrete bridge deck in the negative bending moment zone reaches the standard value, use a jack to stretch the cables, gradually stretch the cables, and dismantle the cable structure, so that the bridge in the negative bending moment zone The panel generates a certain pre-pressure stress, and then the reserved cableway holes in the piers and abutments are sealed;

Step S9, bridge deck paving and anti-collision wall construction: construct the bridge deck pavement, tie anti-collision wall steel bars, install anti-collision wall formwork, pour anti-collision wall concrete and maintain it.

In this embodiment, the steel-concrete composite beam is prefabricated in sections in the factory, and each section is transported from the factory to the temporary section installation platform and spliced section by section.

Embodiment 2: The only difference between this embodiment and Embodiment 1 is that the anchoring position of the cable is different. Specifically: as shown in Figure 6, the pier or abutment is located at the edge fulcrum of the simply supported to continuous composite beam bridge structure. At the same time, the pier body of the bridge pier or the abutment body of the bridge abutment is provided with a second reserved cableway hole. The second reserved cableway hole is provided with a groove on the side of the bridge pier or abutment, and an anchor is provided on the bottom surface of the groove. 16. The plane of the anchor is perpendicular to the second reserved cableway hole. It should be noted that the groove will be sealed after the cable structure is removed.

The remaining specific implementations not described here are the same as those in Embodiment 1 and will not be described again here. The construction steps are the same as those in Specific Embodiment 1 and will not be repeated here.

Embodiment 3: The difference between this embodiment and Embodiment 1 is that, as shown in Figure 7, cable sleeves are pre-embedded at the bottom of the bridge deck, and the cable heads are anchored at the cap beams of the bridge piers.

The remaining specific implementations not described here are the same as those in Embodiment 1 and will not be described again here. The construction steps are the same as those in Specific Embodiment 1 and will not be repeated here.

If the present invention discloses or relates to components or structural parts that are fixedly connected to each other, then unless otherwise stated, fixed connection can be understood as: removably fixed connection (for example, using bolts or screws), or it can also be understood as: unavailable. Disassembled fixed connections (such as riveting, welding), of course, mutual fixed connections can also be replaced by an integrated structure (such as one-piece manufacturing using a casting process) (except for obvious cases where the one-piece forming process cannot be used).

In addition, unless otherwise stated, terms used to express positional relationships or shapes used in any of the technical solutions disclosed in the present invention include their meanings include states or shapes that are similar, similar or close to them.

Any component provided by the present invention can be assembled from multiple individual components, or it can be an individual component manufactured by an integrated forming process.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention but not to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the present invention can still be modified. Modifications to the specific embodiments of the invention or equivalent substitutions of some of the technical features without departing from the spirit of the technical solution of the present invention shall be covered by the scope of the technical solution claimed by the present invention.

Claims (10)

1. The utility model provides a promote simple branch of hogging moment district bridge deck crack resistance changes continuous composite beam bridge structure, includes both sides abutment, along a plurality of pier of longitudinal bridge direction distribution between both sides abutment, is equipped with composite beam structure, its characterized in that between the top of both sides abutment and a plurality of pier: the combined beam structure comprises a plurality of steel-concrete combined beams spliced along the transverse bridge direction, wherein the lower part of the combined beam structure is provided with an arch-shaped inhaul cable structure protruding upwards between an abutment and a pier and between adjacent piers, the protruding top of the inhaul cable structure is anchored in the span of the combined beam structure, the bottoms of the two ends of the inhaul cable structure between the abutment and the pier are respectively anchored on the abutment and the pier, and the bottoms of the two ends of the inhaul cable structure between the adjacent piers are anchored on the pier.

2. The simply supported-to-continuously combined beam bridge structure for improving crack resistance of bridge deck in hogging moment area according to claim 1, wherein: the number of spans of the inhaul cable structure is the same as that of the bridge spans of the steel-concrete composite beam, and the inhaul cable structure is composed of at least 2 inhaul cables in the transverse bridge direction.

3. The simply supported-to-continuously combined beam bridge structure for improving crack resistance of bridge deck in hogging moment area according to claim 2, wherein: the steel-concrete composite beam comprises a concrete bridge deck and at least two sections of steel beams spliced along the longitudinal bridge direction, wherein the concrete bridge deck is connected with an upper web plate of the steel beams through a shear connector.

4. The simply supported-to-continuously combined beam bridge structure for improving crack resistance of deck slab in hogging moment area according to claim 3, wherein: each inhaul cable is connected with a concrete bridge deck of the steel-concrete composite beam through a plurality of pull rods which are distributed at intervals along the longitudinal bridge direction.

5. The simply supported-to-continuously combined beam bridge structure for improving crack resistance of deck slab in hogging moment region according to claim 4, wherein: the upper end of the pull rod is provided with a reserved hole, a pull ring is penetrated in the reserved hole, and the pull ring is connected with an embedded anchor point on the bottom surface of the concrete bridge deck; the lower extreme of pull rod is fixed with the cable clamp, the cable clamp presss from both sides the cable.

6. The simply supported-to-continuously combined beam bridge structure for improving crack resistance of bridge deck in hogging moment area according to claim 1, wherein: when the bridge pier is positioned at the middle pivot of the simply supported continuous combined beam bridge structure, a first reserved cableway hole is formed in the pier body of the bridge pier, the inhaul cable structure penetrates through the first reserved cableway hole of the bridge pier, the first reserved cableway hole is in a V shape, and the lower part of the first reserved cableway hole is in curve transition.

7. The simply supported-to-continuously combined beam bridge structure for improving crack resistance of bridge deck in hogging moment area according to claim 1, wherein: when the bridge pier or the abutment is positioned at the side pivot of the simply supported-rotated continuous combined beam bridge structure, a second reserved cableway hole is formed in the pier body of the bridge pier or the abutment body of the abutment, a groove is formed in the side of the bridge pier or the abutment in the second reserved cableway hole, an anchor is arranged on the bottom surface of the groove, and the plane of the anchor is perpendicular to the second reserved cableway hole.

8. The simply supported-to-continuously combined beam bridge structure for improving crack resistance of deck slab in hogging moment region according to claim 6, wherein: the embedded anchor point is embedded annular steel bars, the embedded annular steel bars are arranged between two steel-concrete composite beams in the transverse bridge direction, and the pull ring is connected with the embedded annular steel bars.

9. The simply supported-to-continuously combined beam bridge structure for improving crack resistance of bridge deck in hogging moment area according to claim 1, wherein: in steel-concrete composite beams, adjacent steel beams are connected by welding, and the concrete bridge deck is provided with wet joints.

10. A construction method for a simply supported-to-continuously combined girder bridge structure for improving the crack resistance of a bridge deck in a hogging moment region according to any one of claims 1 to 9, which is characterized by comprising the following steps: the method comprises the following steps:

step S1, processing a steel beam: dividing the steel girder into a plurality of sections, wherein the length of the section steel girder is the maximum single span of the combined girder bridge structure; then, the steel beam is manufactured in sections in a factory and transported to a prefabricated site;

step S2, prefabricating a concrete bridge deck slab: processing a prefabricated concrete bridge deck template, processing steel bars, binding the steel bars in the template, pouring concrete in the template, and performing covering, sprinkling and curing after the concrete is finally solidified; when the strength of the concrete bridge deck meets the standard requirement, manually roughening the surface of the concrete bridge deck in the wet joint so as to form a concave-convex rough surface;

step S3, installing a steel beam simple support frame: transporting the steel beam to a bridge site, installing permanent supports on bridge piers and bridge decks, installing temporary supports on two sides of the permanent supports, hoisting the steel beam, installing a simple support on the temporary supports, and installing a transverse connection system among the steel beams;

step S4, simply supporting and continuously rotating the steel beam: measuring the gap between two simply supported steel beams, processing a steel beam connecting section, installing the steel beam connecting section on a permanent support, welding the steel beam connecting section with the simply supported steel beams at two ends, dismantling a temporary support, and converting the combined beam structure from a simply supported structure to a continuous structure;

step S5, installing bridge decks at the midspan: installing a concrete bridge deck plate at the middle part of a middle span and a side span of the combined beam bridge structure, binding wet joint steel bars among the concrete bridge deck plates, embedding embedded annular steel bars of anchor points, pouring wet joint concrete, and performing concrete maintenance;

s6, cable installation and tensioning: the method comprises the steps of positioning a cable clamp on a inhaul cable, enabling the inhaul cable to pass through a reserved cableway hole of a bridge abutment or a bridge pier, installing the cable clamp and a pull rod on the inhaul cable, connecting the pull rod with an embedded annular steel bar on a concrete bridge deck through a pull ring, installing an anchor and a clamping piece matched with the pull rod at the end part of the inhaul cable, hoisting a jack by using a chain block on a pulling support to center the jack with the center of the hole of the cable clamp, installing a tool anchor, clamping the inhaul cable, tensioning the two ends of the inhaul cable by using the jack, and synchronizing the tensioning of the two ends of the inhaul cable as much as possible; after confirming the requirement, removing the tensioning equipment, and ending tensioning the inhaul cable;

s7, cast-in-situ construction of bridge deck in hogging moment area: installing a bridge deck slab template in the hogging moment area, binding bridge deck slab steel bars, pouring bridge deck slab concrete in the hogging moment area, and carrying out concrete curing;

step S8, the inhaul cable is put and removed: after the strength of the concrete bridge deck in the hogging moment area reaches a standard value, the jack is utilized to carry out tension on the inhaul cable, the inhaul cable is gradually tensioned, the inhaul cable structure is dismantled, so that the bridge deck in the hogging moment area generates certain pre-compression stress, and then the reserved cableway holes of the bridge pier and the bridge abutment are blocked;

step S9, bridge deck pavement and anti-collision wall construction: and paving a construction bridge deck, binding anti-collision wall steel bars, installing an anti-collision wall template, pouring anti-collision wall concrete and maintaining.