Large-span steel concrete-steel box composite beam bridge and construction technology

Abstract

The invention discloses a large-span steel concrete-steel box composite beam bridge and a construction technology, and relates to the technical field of bridge engineering, the large-span steel concrete-steel box composite beam bridge comprises a plurality of assembly units, and a bridge deck pavement layer is arranged at the tops of the assembly units; each assembling unit comprises a steel concrete section, a steel box girder section and a transition structure arranged between the steel concrete section and the steel box girder section. Concrete pavement layers are arranged at the tops of the steel box girder sections of the adjacent assembling units, and the top faces of the concrete pavement layers are flush with the top faces of the steel concrete sections. The steel concrete-steel box composite beam is adopted, the self weight of the structure is reduced, and external prestress is eliminated; the steel bridge deck is adopted to bear tensile stress, the cracking problem of the tensile concrete bridge deck can be solved, and the durability of the whole structure is improved; and the pavement layer is a unified pavement system, so that the construction process is simplified, and the construction efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge engineering, and particularly to a long-span steel-concrete - steel box composite beam bridge and a construction technology thereof. Background Art

[0002] At present, long-span steel-concrete composite beam bridges have been widely used in bridge engineering. Such structures can give full play to the tensile performance of steel and the compressive performance of concrete, achieving better economy and mechanical properties. However, for long-span steel-concrete composite beams, the concrete bridge deck at the top of continuous piers is prone to cracking under long-term tensile stress, leading to water seepage, resulting in deterioration of durability and even potential safety hazards. Existing solutions usually adopt measures such as forced displacement at the pier top, internal or external prestress, and strength improvement. Although these can alleviate the above problems to a certain extent, due to the high construction difficulty, poor material synergy, and incomplete control of structural cracking, their actual application effects are restricted to a certain extent.

[0003] To solve problems such as cracking, a steel bridge deck pavement structure provided in the prior art includes a steel bridge deck, a stress transition layer, and a wearing course arranged in sequence from bottom to top. The steel bridge deck consists of a positive moment area and a negative moment area, and a number of assembled concrete precast slabs are arranged at intervals on the steel bridge deck in the positive moment area; although the above solution increases the structural strength through the cooperation of the assembled concrete precast slabs and the steel bridge deck, its bridge deck pavement is not unified, and the construction process is still relatively complex. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a long-span steel-concrete - steel box composite beam bridge and a construction technology thereof. By adopting a steel-concrete - steel box composite beam, the self-weight of the structure is reduced, and external prestress is cancelled; the steel bridge deck is used to bear tensile stress, which can solve the cracking problem of the tensile concrete bridge deck and improve the durability of the overall structure; and the pavement layer is a unified pavement system, simplifying the construction process and improving the construction efficiency.

[0005] To achieve the above purpose, the present invention is realized through the following technical solutions: In a first aspect, an embodiment of the present invention provides a long-span steel-concrete - steel box composite beam bridge, including a plurality of assembling units, and a bridge deck pavement layer is provided on the top of the plurality of assembling units; The assembling unit includes a steel-concrete section, a steel box girder section, and a transition structure arranged between the steel-concrete section and the steel box girder section; a concrete pavement layer is provided on the top of the steel box girder sections of adjacent assembling units, and the top surface of the concrete pavement layer is flush with the top surface of the steel-concrete section.

[0006] As a further implementation manner, the transition structure includes a transition cross beam and a strengthening plate. The transition cross beam connects a plurality of strengthening plates corresponding to the steel-concrete section, and a number of groups of openings are provided on the strengthening plate.

[0007] As a further implementation method, each group of openings includes a first opening and a second opening which are distributed vertically, wherein the diameter of the second opening is larger than that of the first opening. The first opening is used for passing steel bars, and the second opening does not pass steel bars.

[0008] As a further implementation method, the concrete paving layer is made of ultra-high toughness concrete, and the bridge deck paving layer is made of asphalt.

[0009] As a further implementation method, the length of the steel-concrete section is greater than that of the steel box girder section.

[0010] As a further implementation method, it further includes bridge piers. The splicing joints of adjacent assembled units are located on the upper side of the bridge piers and are welded and fixed to the pier tops.

[0011] In a second aspect, an embodiment of the present invention further provides a construction process for a long-span steel-concrete-steel box composite girder bridge, including: Lifting the assembled unit to the upper side of the bridge pier; Welding the steel box girder sections of adjacent assembled units to form a continuous girder bridge; Constructing the concrete paving layer and the bridge deck paving layer on the top surface of the continuous girder bridge in sequence.

[0012] As a further implementation method, the assembled unit is pre-connected by a transition structure from a steel-concrete section and a steel box girder section.

[0013] As a further implementation method, the construction process of the assembled unit is as follows: Fix the transition cross beam at one end of the steel box girder section, and align the stiffening plate with the steel-concrete section; pass the steel bars through the first openings corresponding to each stiffening plate, and then pour concrete in the steel-concrete section area and the transition area.

[0014] As a further implementation method, the concrete paving layer covers the upper side of the steel box girder sections of adjacent assembled units, making the top surface of the concrete paving layer flush with the top surface of the steel-concrete section.

[0015] The beneficial effects of the present invention are as follows: (1) The present invention replaces the concrete bridge deck prone to tensile stress cracking with a steel bridge deck, uses the steel bridge deck to bear the tensile stress, and retains the compressed concrete bridge deck, which can give full play to the compressive performance of concrete while avoiding the problem of cracking of the tensile concrete bridge deck; a transition structure is provided between the steel bridge deck and the concrete bridge deck to ensure the connectivity of the girder bridge; and the paving layer is a unified paving system, which simplifies the construction process.

[0016] (2) The top of the steel box girder section of adjacent assembled units of the present invention is provided with a concrete paving layer, and the top surface of the concrete paving layer is flush with the top surface of the steel-concrete section; a bridge deck paving layer is provided on the top of the assembled unit to form a unified paving system; while the concrete paving layer can be closely combined with the steel bridge deck, it can achieve the effect of synchronous deformation with the bridge deck paving layer.

[0017] (3) The length of the steel box girder section of the present invention is less than that of the steel-concrete section and meets certain length range requirements. The transition structure between the two has misaligned openings, which can ensure the effective connection of the steel-concrete section and the steel box girder section, forming an assembled unit suitable for the requirements of long-span beam bridges.

[0018] (4) The present invention uses ultra-high toughness concrete as the paving layer on the upper side of the steel bridge deck to further improve the durability of the steel bridge deck; first, a concrete paving layer is set, and then a bridge deck paving layer is set to realize the unified design of the full bridge deck paving layer, simplify the paving construction, and reduce the complexity of subsequent maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The specification drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0020] Figure 1 is a schematic diagram of the composite beam bridge structure according to one or more embodiments of the present invention; Figure 2 is a schematic cross-sectional view of the transition structure according to one or more embodiments of the present invention; Figure 3 is a schematic diagram of the paving layer according to one or more embodiments of the present invention; FIG. 4(a) is a schematic diagram of the hoisted full-span simply supported steel-concrete - steel box composite beam according to one or more embodiments of the present invention; FIG. 4(b) is a schematic diagram of the continuous beam bridge formed by welding the continuous section at the pier top according to one or more embodiments of the present invention; FIG. 4(c) is a schematic diagram of the construction paving layer according to one or more embodiments of the present invention.

[0021] Wherein, 1, steel-concrete section; 2, steel box girder section; 3, transition structure; 4, bridge pier; 5, concrete paving layer; 6, bridge deck paving layer; 7, transition cross beam; 8, stiffening plate; 9, first opening; 10, second opening; 11, diaphragm plate. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0023] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by terms such as "upper", "lower", "one end", "the other end", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0024] Embodiment 1: In order to solve the problem of bridge cracking, although there are some solutions in the prior art that combine a steel bridge deck and a concrete structure, there are still problems with relatively high construction difficulty. Based on this, this embodiment provides a long-span steel-concrete - steel box composite beam bridge. By using a steel-concrete - steel box composite beam, the self-weight is reduced, so external prestress can be cancelled, and the later maintenance work can be reduced. As Figure 1 shown, the steel-concrete - steel box composite beam includes a steel-concrete section 1 and a steel box girder section 2. Taking the connected steel-concrete section 1 and steel box girder section 2 as an assembly unit, multiple assembly units are hoisted onto the pier 4 and then connected to form a continuous beam bridge.

[0025] Since the tensile concrete bridge deck is prone to cracking under long-term tensile stress, in this embodiment, a steel bridge deck is used to bear the tensile stress to solve the cracking problem of the tensile concrete bridge deck, that is, a steel box girder section 2 is provided so that the steel box girder section 2 and the steel-concrete section 1 form a composite structure, improving the durability of the overall structure. As Figure 1 shown, the length of the steel box girder section 2 is less than the length of the steel-concrete section 1. Taking the length of one assembly unit as L, where the length of the steel box girder section 2 is 0.1 - 0.2L, it can ensure the support strength while avoiding cracking.

[0026] The stiffness of the steel bridge deck is different from that of the concrete wall surface of the steel-concrete section 1. By providing a transition structure 3 to connect the concrete bridge deck and the steel bridge deck, the stiffness transition is achieved. As Figure 2 shown, both the steel-concrete section 1 and the steel box girder section 2 are supported by diaphragms 11; the transition structure 3 includes a transition cross beam 7 and a plurality of stiffening plates 8. The transition cross beam 7 is connected to one end of the steel box girder section 2 and is fixedly welded to the steel box girder section 2; the stiffening plates 8 are fixed to one side of the transition cross beam 7 (the side opposite to the steel box girder section 2), and a plurality of them are evenly distributed at intervals along the length of the transition cross beam 7, increasing the connection strength with the steel-concrete section 1 through the stiffening plates 8.

[0027] The stiffening plate 8 has a certain length, and several groups of openings are arranged along the height direction of the stiffening plate 8, and multiple openings are arranged along the length direction of the stiffening plate 8 in each group. Each group of openings includes two rows arranged up and down. The upper layer is multiple uniformly distributed first openings 9, and the lower layer is multiple uniformly distributed second openings 10. The diameter of the second opening 10 is larger than that of the first opening 9, and the second opening 10 and the first opening 9 are arranged in a staggered manner in the length direction. The first opening 9 is used for passing steel bars, and the second opening 10 does not pass steel bars. The staggered arrangement and the enlarged hole diameter are to increase the continuity of the concrete in the transition section, and the arrangement of opening holes and passing steel bars is to ensure the effective connection between the steel-concrete section 1 and the steel box girder section 2.

[0028] The number of groups of openings is determined according to the actual installation requirements. In this embodiment, one group of openings is set, that is, one row of first openings 9 and one row of second openings 10 are set.

[0029] The steel-concrete section 1 and the steel box girder section 2 of this embodiment are connected by a transition structure 3 to form an assembled unit, and the transition structure 3 realizes seamless connection in terms of material connection performance, interface shear resistance and deformation coordination.

[0030] The assembled unit is hoisted to the top of the pier 4, and the ends of the steel box girder sections 2 of two adjacent assembled units are both located on the upper side of the pier 4. The steel box girder section 2 is welded and fixed to the pier top of the pier 4, so that multiple assembled units form a continuous girder bridge. After the continuous girder bridge is formed, for the same construction paving layer, as Figure 3 shown, a concrete paving layer 5 is laid on the top of the steel box girder section 2 (steel bridge deck), and the concrete paving layer 5 adopts ultra-high toughness concrete. Ultra-high toughness concrete is a new type of cement-based composite material with ultra-high strength, high toughness and excellent durability, which can enhance the impact resistance of the steel bridge deck and improve the durability of the steel bridge deck.

[0031] The ultra-high toughness concrete is paved until its top surface is flush with the top surface of the concrete bridge deck, and then the bridge deck paving layer 6 of the entire continuous girder bridge is paved; the bridge deck paving layer 6 can adopt ordinary asphalt. Since the bonding force between ordinary asphalt and the steel bridge deck is relatively weak, under the action of vehicle load and temperature load, diseases such as rutting and bulging are likely to occur. Therefore, in this embodiment, ultra-high performance concrete is laid on the steel box girder section 2. Relying on its ultra-high toughness, while being closely combined with the steel bridge deck, it achieves the effect of synchronous deformation with the asphalt paving; realizing the unified design of the entire bridge deck paving layer, simplifying the paving construction and reducing the complexity of subsequent maintenance.

[0032] The composite girder bridge of this embodiment is composed of a steel-concrete section 1 and a steel box girder section 2 connected by a transition structure 3. The length of the steel-concrete section 1 is greater than that of the steel box girder section 2. By retaining the compressed concrete bridge deck and arranging the steel box girder section 2 in the area prone to tension, the compressive performance of the concrete can be fully exerted, and at the same time, the cracking problem of the concrete bridge deck caused by tensile stress can be solved, meeting the stiffness and durability requirements of long-span girder bridges. By setting the length range of the steel box girder section 2, the cost and construction difficulty will not be increased additionally on the basis of ensuring the structural durability.

[0033] In this embodiment, at the splicing joint of adjacent splicing units, the steel box girder section 2 is uniformly paved, and then the entire bridge deck pavement layer 6 is set. This not only realizes the integrated design of the bridge deck pavement, but also effectively eliminates the construction and maintenance complexity at the connection between the steel bridge deck and the concrete bridge deck.

[0034] Embodiment 2: This embodiment provides a construction technology for a long-span steel-concrete-steel box composite girder bridge. Based on the steel-concrete-steel box composite girder bridge of Embodiment 1, it includes the following steps: Step 1: Complete the integral hoisting and placement of the bridge based on the "simply supported first and then continuous" technology.

[0035] As shown in Figure 4(a), first use a floating crane to transport the simply supported steel-concrete-steel box composite girder (splicing unit) as a whole, and then hoist the simply supported steel-concrete-steel box composite girder as a whole to the top of the pier 4. Then, as shown in Figure 4(b), weld and fix the steel box girder section 2 of the splicing unit to the top of the pier.

[0036] Step 2: As shown in Figure 4(c), lay ultra-high toughness concrete on the top of the two steel box girder sections 2 corresponding to each pier top to form a concrete pavement layer 5. The top surface of the concrete pavement layer 5 is flush with the top surface of the steel-concrete section 1. Then lay asphalt on the top of each splicing unit as the bridge deck pavement layer 6.

[0037] In this embodiment, the splicing unit is pre-connected by a steel-concrete section 1 and a steel box girder section 2 through a transition structure 3. The construction process of the splicing unit is as follows: Fix the transition cross beam 7 at one end of the steel box girder section 2, and correspond the stiffening plate 8 to the steel-concrete section 1; weld the assembled segment to the steel beam of the steel-concrete section 1; set up a wooden formwork between the diaphragm 11 and the transition cross beam 7, pass the steel bars through the first openings 9 corresponding to each stiffening plate 8, and then pour concrete in the steel-concrete section 1 area and the transition area.

[0038] In this embodiment, the concrete pavement layer 5 is set first, and then the bridge deck pavement layer 6 is set, realizing the unified design of the whole bridge deck pavement layer, simplifying the pavement construction, and reducing the subsequent maintenance complexity. The construction technology of this embodiment can reduce the moment in the negative moment area of the pier top, making the structural force more reasonable and shortening the construction period.

[0039] The foregoing are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various modifications and variations can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A long-span steel-concrete - steel box composite girder bridge, characterized in that, It includes multiple assembled units, and a bridge deck pavement layer is provided on the top of the multiple assembled units; The assembled unit includes a steel-concrete section, a steel box girder section, and a transition structure arranged between the steel-concrete section and the steel box girder section; a concrete pavement layer is provided on the top of the steel box girder section of adjacent assembled units, and the top surface of the concrete pavement layer is flush with the top surface of the steel-concrete section.

2. A long-span steel-concrete - steel box composite girder bridge according to claim 1, characterized in that, The transition structure includes a transition cross beam and stiffening plates. The transition cross beam connects multiple stiffening plates corresponding to the steel-concrete section, and several groups of openings are provided on the stiffening plates.

3. A long-span steel-concrete - steel box composite girder bridge according to claim 2, characterized in that, Each group of openings includes a first opening and a second opening distributed vertically. The diameter of the second opening is larger than that of the first opening. The first opening is used for passing through steel bars, and the second opening does not pass through steel bars.

4. A long-span steel-concrete - steel box composite girder bridge according to claim 1, characterized in that, The concrete pavement layer adopts ultra-high toughness concrete, and the bridge deck pavement layer adopts asphalt.

5. A long-span steel-concrete - steel box composite beam bridge according to claim 1, characterized in that, The length of the steel-concrete section is greater than that of the steel box girder section.

6. A long-span steel-concrete - steel box composite beam bridge according to claim 1, characterized in that, It also includes bridge piers. The splicing joints of adjacent assembled units are located above the bridge piers and are welded and fixed to the pier tops.

7. The construction process of a long-span steel-concrete - steel box composite girder bridge according to any one of claims 1 - 6, characterized in that, It includes: Lifting the assembled unit to the upper side of the bridge pier; Welding the steel box girder sections of adjacent assembled units to form a continuous girder bridge; Constructing the concrete pavement layer and the bridge deck pavement layer on the top surface of the continuous girder bridge in sequence.

8. The construction process of a long-span steel-concrete - steel box composite girder bridge according to claim 7, characterized in that, The assembled unit is pre-connected by a steel-concrete section and a steel box girder section through a transition structure.

9. The construction process of a long-span steel-concrete - steel box composite girder bridge according to claim 8, characterized in that, The construction process of the assembled unit is as follows: Fix the transition cross beam at one end of the steel box girder section, and align the stiffening plates with the steel-concrete section; pass the steel bars through the first openings corresponding to each stiffening plate, and then pour concrete in the steel-concrete section area and the transition area.

10. The construction process of a long-span steel-concrete - steel box composite girder bridge according to claim 7, characterized in that, The concrete pavement layer covers the upper side of the steel box girder section of adjacent assembled units, so that the top surface of the concrete pavement layer is flush with the top surface of the steel-concrete section.

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