Prefabricating and cast-in-place combined bridge deck slab construction method of reinforced concrete superposed beam

Abstract

The invention relates to a construction method of a prefabricated and cast-in-place combined bridge deck of a reinforced concrete superposed beam. The construction method comprises the following steps: prefabricating and transporting a plurality of steel box beams; a plurality of steel box girders are hoisted to the two bridge piers, and a gap exists between every two adjacent steel box girders; prefabricating a bridge deck slab; the bridge deck slab is hoisted to a gap between every two adjacent steel box girders; binding reinforcing steel bars on the bridge deck slab surface and the top plate of the steel box girder; and pouring and curing concrete. The construction method has the beneficial effects that the construction quality controllability is greatly enhanced, the material consumption is greatly reduced, the construction efficiency is remarkably improved, the construction safety is greatly improved, and the construction environment adaptability is high.

Description

Technical Field

[0001] The invention relates to the technical field of bridge construction, and in particular to a construction method for a prefabricated and cast-in-situ composite bridge deck of a steel-concrete composite beam. Background Art

[0002] In the field of steel box girder bridge construction technology, the construction of inter-beam joints is an important link that affects the overall quality of the project and construction safety. In the construction of some existing steel box girder bridges, the design width of the bridge deck of each steel beam main beam is 2.35 meters, and the spacing between the main beams is designed to be 2.1 to 2.2 meters. Compared with the traditional wet joint construction of concrete box girders, the spacing between the steel beam main beams is obviously larger. If the traditional hanging formwork cast-in-place construction method is adopted, many problems will be faced, specifically: the formwork is difficult to support, and the construction requires the erection of scaffolding, resulting in low construction efficiency; at the same time, the erection of scaffolding is very dangerous, which significantly increases the safety risk.

[0003] If the traditional steel hybrid beam construction process is adopted, the bridge deck needs to be cast as a whole, which not only requires the establishment of floor-standing brackets and formwork, but also has problems such as long construction period, large amount of turnover materials, high construction difficulty, and high safety risks. These difficulties are particularly prominent in river-crossing and road-crossing construction scenarios. Specifically, in the construction of floor-standing steel pipe brackets in existing river channels, steel pipe columns need to be driven more than 30 meters deep into the riverbed, which makes construction extremely difficult. In addition, due to the high height of the floor-standing steel pipe bracket, it is easy to deform. Once deformed, the formwork will sink, resulting in the elevation after pouring failing to meet the design requirements. At the same time, the formwork will also affect the linear quality of the pouring due to deformation, which will ultimately have a serious impact on the quality of the project. Summary of the invention

[0004] The object of the present invention is to provide a construction method for a prefabricated and cast-in-situ composite bridge deck of steel-concrete composite beams to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a construction method for a prefabricated and cast-in-place composite bridge deck of a steel-concrete composite beam, the construction method comprising the following steps:

[0006] Step 1: Prefabrication and transportation of several steel box girders;

[0007] Step 2: Several steel box girders are hoisted onto two bridge piers, with a gap between two adjacent steel box girders;

[0008] Step 3: Bridge deck prefabrication;

[0009] Step 4: The bridge deck is hoisted to the gap between two adjacent steel box girders;

[0010] Step 5: Tie steel bars on the bridge deck consisting of the bridge deck plate and the top plate of the steel box girder;

[0011] Step 6: Concrete pouring and curing.

[0012] Preferably, in step 4, both sides of the bridge deck are fixedly connected to the corresponding top plate sides of the steel box girder by shear nails.

[0013] Preferably, the steel box girder described in step 1 includes a steel box girder body and a transverse beam body, and the steel box girder hoisting described in step 2 includes the following sub-steps:

[0014] Sub-step S1: leveling the site and assembling the steel box girder body;

[0015] Sub-step S2: erecting a bridge erecting machine on two bridge piers, and erecting a steel box girder body through the bridge erecting machine; Sub-step S3: welding the transverse beam body to the steel box girder body to complete the installation of the entire steel box girder.

[0016] Preferably, a plurality of pre-embedded steel bar fixings arranged in rows and columns are provided on the bridge deck.

[0017] Preferably, the steel bar fixing piece is in the shape of a barb.

[0018] Preferably, before step 5, the method further includes the step of setting guardrails on the outer sides of the steel box girders on both sides.

[0019] Preferably, the bridge deck prefabrication described in step 3 is prefabricated in batches, and the prefabrication can be arranged on an adjacent completed bridge deck that has been completed, and the bridge deck hoisting described in step 4 is used to lay several bridge decks in the gap between each two adjacent steel box girders.

[0020] Preferably, the curing process adopts a film covering and watering process for curing.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The controllability of construction quality is greatly enhanced: The present invention adopts a combination of prefabricated bridge deck and cast-in-place concrete. The bridge deck is prefabricated in sections, which can accurately control the spacing between steel bars, the thickness of the steel bar protective layer, and the appearance quality of the concrete. The quality control during the prefabrication process is more stringent, reducing the quality problems caused by environmental factors during on-site construction, thereby significantly improving the construction quality of the overall bridge deck. At the same time, the prefabricated bridge deck can also be flexibly prefabricated according to the gap size between the steel box girders to adapt to different bridge deck widths and spacing requirements.

[0023] 2. Material consumption is greatly reduced: Traditional construction methods require a large number of brackets, temporary piers and formwork to support concrete pouring. The present invention uses prefabricated bridge panels as bottom forms. Prefabricated bridge panels can be prefabricated on the completed bridge deck, avoiding the use of these temporary facilities and reducing material waste and construction costs.

[0024] 3. Significantly improved construction efficiency: prefabricated bridge decks can be prefabricated at the same time as the steel box girder is hoisted or in advance, reducing on-site waiting time and construction procedures. In addition, the installation of prefabricated bridge decks is simpler and faster than traditional formwork, without the need for complex support erection and disassembly, greatly shortening the construction period.

[0025] 4. Greatly improved construction safety: In traditional construction, formwork and concrete pouring need to be done at high altitudes near the edge, which poses a high safety risk. The present invention uses prefabricated bridge decks as bottom formwork, which avoids high altitude formwork operations, reduces the edge construction area, and reduces the risk of construction workers falling from high altitudes. At the same time, it reduces the hoisting of large equipment, further improving the construction safety environment.

[0026] 5. Strong adaptability to construction environment: The present invention is particularly suitable for complex construction scenarios such as crossing rivers and roads. In these scenarios, traditional construction methods face many challenges due to the high height of the support and the difficulty of construction. However, the present invention can effectively cope with complex environments and reduce the impact on the surrounding environment through the rapid installation of prefabricated bridge panels and the local construction of cast-in-place concrete. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic cross-sectional view of a steel box girder provided by the present invention;

[0028] Figure 2 A schematic cross-sectional view of the steel-concrete composite beam provided by the present invention during installation;

[0029] Figure 3 A schematic cross-sectional view of the steel-concrete composite beam after the bridge deck pouring construction provided by the present invention is completed;

[0030] Figure 4 A schematic diagram of hoisting the steel box girder provided by the present invention;

[0031] Figure 5 This is a schematic diagram of hoisting a steel box girder in the prior art;

[0032] Figure 6 The bridge deck installation diagram provided by the present invention;

[0033] In the figure: steel box girder 1, steel box girder top plate 11, shear nails 12, bridge deck 2, steel bar fixings 21, reinforced concrete layer 3, bridge erecting machine 4, bridge pier 5, river channel 6, completed bridge deck 7, guardrail 8. DETAILED DESCRIPTION

[0034] The technical solution in one embodiment of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0035] See also Figure 1-6 :

[0036] Now, a bridge construction based on steel box girders is used as an example for explanation. Each section of the bridge includes a number of steel box girders 1 arranged side by side. The bridge deck width of each steel box girder 1 is 2.35m, and the interval between the steel box girders 1 is 2.1-2.2m. Among them, a section of the bridge deck is set on the river channel 6, and the bridge deck is constructed by "prefabrication + cast-in-place"

[0037] The specific construction method is:

[0038] Step 1: Prefabricate and transport a number of steel box girders 1;

[0039] Step 2: A number of steel box girders 1 are hoisted onto two bridge piers 5 on the river channel 6, with a gap of 2.1 to 2.2 m between two adjacent steel box girders 1; in this embodiment, the number of steel box girders 1 erected between the two bridge piers 5 is 5;

[0040] The steel box girder 1 includes a steel box girder body and a cross beam body. During prefabrication, the two are prefabricated separately. Therefore, the hoisting of the steel box girder 1 includes the following sub-steps:

[0041] Sub-step S1: leveling the site and assembling the steel box girder body;

[0042] Sub-step S2: erecting a bridge erecting machine 4 on two bridge piers 5 on a river channel 6, and erecting a steel box girder 1 by means of the bridge erecting machine 4;

[0043] Sub-step S3: Weld the cross beam body (not shown) to the steel box beam body 1 to complete the installation of the entire steel box beam 1.

[0044] The above-mentioned steel box girder hoisting construction process includes assembling the beam body into a whole on a flat site, using a bridge erecting machine 4 to erect the steel box girder 1 beam body like a concrete precast beam, and then only welding the cross beam body to form the entire steel beam. This construction process overcomes the shortcomings of the existing steel box girder hoisting, that is, the existing steel box girder hoisting requires the use of temporary piers for on-site hoisting; therefore, the steel box girder hoisting construction process can reduce the process of temporary piers, improve the construction progress, and reduce safety hazards.

[0045] Step 3: prefabrication of the bridge deck 2; since the entire bridge deck is constructed in sections, the bridge deck 2 is prefabricated in batches, and the size of the concrete bridge deck 2 is prefabricated according to the size of the gap between the steel box girders. Each batch of bridge decks 2 includes several bridge decks 2, and each batch of bridge decks 2 can be prefabricated on a completed bridge deck 7 adjacent to the section. In this way, the bridge deck 2 is prefabricated on a completed bridge deck prefabrication site, without the need to rent a prefabrication site, and the transportation of prefabricated bridge deck panels is reduced, reducing safety risks. At the same time, the bridge deck can be prefabricated during the assembly and hoisting of the steel beam body, reducing the construction period.

[0046] Step 4: Hoisting of prefabricated bridge deck 2: Several bridge decks 2 are hoisted to the gap between two adjacent steel box girders 1. In this way, bridge decks 2 are laid one by one on the gap between two adjacent steel box girders 1. Figure 6 As shown, at the same time, in order to firmly connect the prefabricated bridge deck 2 with the steel box girder 1, the connection between the prefabricated bridge deck 2 and the top plate 11 of the steel box girder 1 is connected and fixed by shear nails 12. In this way, after the prefabricated bridge deck 2 is laid between the steel box girders 1, the prefabricated bridge deck 2 can be used as the bottom mold to carry out the steel bar binding and concrete pouring operations of the entire bridge deck. Therefore, when constructing the steel-concrete composite beam bridge deck, there is no need to set up a bracket or support the bottom mold, which avoids the risk of high-altitude operations on the edge of the steel beam in the traditional formwork process, and greatly ensures the safety of workers on the beam; at the same time, the construction steps of installing the bridge deck are simpler than the supporting formwork, the construction efficiency is higher, and there is no need for subsequent demolding, so that better and faster construction is achieved, which can simplify the construction steps, save construction time, improve construction efficiency, and improve the appearance quality of concrete construction.

[0047] In addition, after the bridge deck 2 is hoisted, a guardrail 8 can be set along the entire bridge edge. In this way, there are no gaps in other positions, the safety environment for construction workers is greatly improved, and at the same time, the construction of materials such as formwork is reduced, reducing the construction difficulty and construction costs.

[0048] Step 5: Reinforcement is tied on the bridge deck formed by the bridge deck surface and the top plate of the steel box girder. In order to make the bridge deck 2 and the top plate of the steel box girder 1 more firmly connected, a number of rebar fixings 21 for fixing rebars are embedded in rows and columns on the bridge deck 2 surface when prefabricating the bridge deck 2. The rebar fixings 21 are in the shape of barbed hooks. During the rebar tying, the transverse rebars are tied to the rebar fixings 21, and the rebars are tied to the rebars arranged on the top plate of the steel box girder 1, so that the bridge deck 2 and the steel box girder 1 form an integral structure.

[0049] Step 6: Concrete pouring and curing. After the steel bars are tied, concrete pouring and curing are carried out. The curing process adopts the film covering and water sprinkling process. After the curing is completed, the bridge deck includes not only the reinforced concrete layer 3, but also the bridge deck 2 below the reinforced concrete layer 3.

[0050] The above are only embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A construction method for a prefabricated and cast-in-place composite bridge deck of a steel-concrete composite beam, the construction method comprising the following steps: Step 1: Prefabrication and transportation of several steel box girders; Step 2: Several steel box girders are hoisted onto two bridge piers, with a gap between two adjacent steel box girders; Step 3: Bridge deck prefabrication; Step 4: The bridge deck is hoisted to the gap between two adjacent steel box girders; Step 5: Tie steel bars on the bridge deck consisting of the bridge deck plate and the top plate of the steel box girder; Step 6: Concrete pouring and curing.

2. The method for constructing a prefabricated and cast-in-situ composite bridge deck of a steel-concrete composite beam according to claim 1, characterized in that: In step 4, both sides of the bridge deck are fixedly connected to the corresponding top plate sides of the steel box girder by shear nails.

3. The method for constructing a prefabricated and cast-in-situ composite bridge deck of a steel-concrete composite beam according to claim 1, characterized in that: The steel box girder described in step 1 includes a steel box girder body and a transverse beam body, and the steel box girder hoisting described in step 2 includes the following sub-steps: Sub-step S1: leveling the site and assembling the steel box girder body; Sub-step S2: erecting a bridge erecting machine on two bridge piers, and erecting a steel box girder body by means of the bridge erecting machine; Sub-step S3: Weld the cross beam body to the steel box beam body to complete the installation of the entire steel box beam.

4. The method for constructing a prefabricated and cast-in-situ composite bridge deck of a steel-concrete composite beam according to claim 1, characterized in that: A plurality of pre-buried steel bar fixings arranged in rows and columns are arranged on the bridge deck.

5. The method for constructing a prefabricated and cast-in-situ composite bridge deck of a steel-concrete composite beam according to claim 4, characterized in that: The steel bar fixing piece is in the shape of a barb.

6. The method for constructing a prefabricated and cast-in-situ composite bridge deck of a steel-concrete composite beam according to claim 1, characterized in that: Before step 5, the method also includes the step of setting guardrails on the outer sides of the steel box girders on both sides.

7. The method for constructing a prefabricated and cast-in-situ composite bridge deck of a steel-concrete composite beam according to claim 1, characterized in that: The bridge deck prefabrication described in step 3 is prefabricated in batches, and the prefabrication can be set up on the adjacent completed bridge deck that has been completed. The bridge deck hoisting described in step 4 is used to lay several bridge decks on the gap between each two adjacent steel box girders.

8. The method for constructing a prefabricated and cast-in-situ composite bridge deck of a steel-concrete composite beam according to claim 1, characterized in that: The curing process adopts a film covering and watering process for curing.

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