Prefabricated assembly first simply supported and then continuous steel-concrete composite bridge and construction method

Abstract

The application discloses a prefabricated and assembled simply-supported and then continuous steel-concrete composite bridge and a construction method, wherein a prefabricated section comprises longitudinal beams arranged side by side, the longitudinal beams comprise a bridge deck and an I-beam arranged at the bottom of the bridge deck, the part of the I-beam extending out of the bridge deck is a to-be-poured beam, the to-be-poured beam is fixed with a baffle on both sides, the end portions of the two prefabricated sections are spliced on a bent cap, the to-be-poured beams of the two prefabricated sections are fixed by welding, an outer sheathing plate is arranged between the two prefabricated sections, the two ends of the outer sheathing plate are connected with the to-be-poured beams respectively, the outer sheathing plate is connected with the baffles, side plates are arranged at the outer sides of the prefabricated sections, the side plates are connected with the baffles on the two prefabricated sections respectively, and the to-be-poured beam, the baffles, the side plates and the outer sheathing plate form cast-in-place grooves with the notches facing upwards. Compared with the prior art, the application only needs to fix two side plates on the to-be-poured beam, the outer sheathing plate can be directly arranged on the bent cap, the whole process is simple, complicated reinforcement is not needed, the construction convenience can be effectively improved, and the construction quality can be better controlled.

Description

Technical Field

[0001] This invention relates to the field of bridge construction technology, and in particular to a prefabricated, simply supported and then continuous steel-concrete composite bridge and its construction method. Background Technology

[0002] Steel-concrete composite bridges, by fully utilizing the compressive strength of concrete and the tensile strength of steel, offer superior span capacity compared to conventional prestressed concrete beam bridges. Furthermore, they are less expensive than steel bridges, demonstrating a clear economic advantage. However, the current design methods for steel-concrete composite bridges are numerous, resulting in diverse structural systems and construction methods, making it difficult to establish a unified and streamlined structural system and construction approach. Therefore, the widespread adoption of steel-concrete composite bridges still faces significant obstacles.

[0003] There are two main approaches to traditional steel-concrete composite continuous beam bridges. One approach is to set up temporary piers, connect the steel beams first, and then install the bridge deck structure. The other approach is to prefabricate steel-concrete beam units and cast the crossbeams on the top of the piers to form a structure that is first simply supported and then continuous.

[0004] The first approach requires numerous temporary structures during construction, occupying space under the bridge and making construction inconvenient. Furthermore, it typically employs a post-construction design, with the bridge deck's dead load entirely borne by the steel structure, resulting in poor span capacity. Overall, this type of steel-concrete composite bridge is unsuitable for large-scale industrial prefabrication.

[0005] The second approach is similar to the traditional precast concrete small box girder. my country has relatively mature construction experience and equipment, making it suitable for large-scale promotion. However, in actual engineering applications, it has been found that the middle crossbeam itself bears the dual functions of continuous longitudinal beam and transverse force of crossbeam, resulting in very complex stress and dense structural reinforcement. Binding and vibration during construction are also difficult, which hinders the construction period and cannot meet the needs of rapid construction. Summary of the Invention

[0006] This invention provides a prefabricated, simply supported, then continuous steel-concrete composite bridge and its construction method, which solves the problem of complex construction and difficulty in rapid construction caused by the dense structural reinforcement of the crossbeams in the prior art.

[0007] This invention provides a precast, simply supported, then continuous steel-concrete composite bridge, comprising precast sections, each precast section including parallel longitudinal beams, each longitudinal beam including a bridge deck and an I-beam located at the bottom of the bridge deck, the portion of the I-beam extending beyond the bridge deck being a cast-in-place beam, with baffles fixed to both sides of the cast-in-place beam, the ends of two precast sections being spliced ​​on a cap beam, the cast-in-place beams of the two precast sections being fixed by welding, an outer cladding plate placed between the two precast sections, the two ends of the outer cladding plate being connected to the cast-in-place beam respectively, the outer cladding plate being connected to the baffles, and side plates provided on the outer side of each precast section, the side plates being connected to the baffles on the two precast sections respectively, the cast-in-place beam, baffles, side plates, and outer cladding plate forming a cast-in-place trough with the opening facing upwards.

[0008] Preferably, shear studs are fixed on both sides and the upward-facing side of the beam to be poured.

[0009] Preferably, the baffle is L-shaped, the lower end of the baffle is fixedly connected to the beam to be poured, and a gap is left between the upper end of the baffle and the beam to be poured.

[0010] Preferably, the outer panel includes a U-shaped panel and two wing plates, with the two wing plates respectively fixed to the slots on both sides of the U-shaped panel.

[0011] Preferably, shear studs are fixed inside the U-shaped plate and on the wing plate.

[0012] Preferably, the number of longitudinal beams in the prefabricated section is two.

[0013] Preferably, the number of I-beams at the bottom of the bridge deck is two, and the longitudinal beams have a Π-shaped structure.

[0014] This invention also provides a construction method for a precast, simply supported, then continuous steel-concrete composite bridge, including the precast, simply supported, then continuous steel-concrete composite bridge as described above, and further comprising the following steps:

[0015] Step 1: Fix the baffle plate to the I-beam, fix shear studs to the I-beam, and then transport it to the precast beam yard; construct the substructure of the bridge on site;

[0016] Step 2: Place two I-beams side by side, then set up formwork and tie the reinforcing bars at the bridge deck, and pour the bridge deck to obtain the longitudinal beams;

[0017] Step 3: After the substructure of the bridge is completed, the longitudinal beams are transported to the bridge site and then spliced ​​on the cap beam by hoisting. The two I-beams are welded along the length of the bridge to form a continuous structure.

[0018] Step 4: Fix the side panels to the outer side of the bridge using hoisting. Place the outer cladding between the two bridge decks using hoisting. The baffle, side panels, I-beams, and outer cladding form a cast-in-place trough with the opening facing upwards. Pour concrete into the cast-in-place trough and then pour the bridge deck above the trough.

[0019] Preferably, the specific steps for fixing shear studs on the I-beam are as follows: the I-beam is divided into two parts, and shear studs are fixed at the upper end of the first part of the I-beam; the second part of the I-beam is the beam to be poured, and shear studs are fixed on both sides and the upward-facing side of the beam to be poured.

[0020] Preferably, shear studs are fixed on the outer cladding plate before the steps of pouring concrete in the cast-in-place trench and pouring the bridge deck above the cast-in-place trench.

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

[0022] (1) This invention inherits the advantages of the simple-supported-then-continuous beam bridge system. The construction process does not require the erection of temporary piers. It adopts a pre-combined steel-concrete composite structure, which has higher structural span performance and material utilization efficiency. At the same time, the simple-supported-then-continuous beam bridge system is similar to the traditional precast concrete small box girder, and there is relatively mature construction experience and equipment in the market, which is suitable for large-scale promotion and use.

[0023] (2) Before pouring the joint section, the present invention only needs to fix two side plates on the beam to be poured, and the outer plate can be directly erected on the cap beam. The whole process is simple and does not require complex reinforcement. It can effectively improve the construction convenience and efficiency of steel-concrete composite bridges and better control the construction quality.

[0024] (3) In this invention, after the cast-in-place groove of the joint section is integrated with the bridge deck above, the concrete and the I-beam can be fully combined, and the height of the concrete is also expanded, which effectively improves the lateral and longitudinal stress of the bridge. In the longitudinal direction, the I-beams are connected into a whole by welding, which can further improve the longitudinal stress of the bridge. During the construction of the joint section, it mainly bears the lateral stress and assists the I-beam in resisting compression. The structural stress is clearer, and there is no need for complex reinforcement, which simplifies the construction process.

[0025] (4) The longitudinal beams of the present invention are prefabricated and then assembled into prefabricated sections by hoisting. Only the joint sections are cast on the bridge. A large amount of construction is carried out off-site, and the amount of construction work on the bridge is small, which makes the construction of steel-concrete composite bridges more convenient. Compared with traditional processes, the steel-concrete composite bridges of the present invention have no pollution on-site operation, short construction period, and meet the green construction standards of engineering.

[0026] (5) The longitudinal beams of the present invention can be spliced ​​in both the width and length directions of the bridge, which can adapt to the needs of different spans and lengths. Standardized production can be achieved for different spans and different bridge widths, which can greatly improve the level of industrialized construction of steel-concrete composite bridges. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 This is a structural diagram of the present invention when the outer casing and side plates are installed;

[0029] Figure 2 for Figure 1 Enlarged schematic diagram of the structure at point A;

[0030] Figure 3 This is a schematic diagram of the longitudinal beam structure of the present invention;

[0031] Figure 4 This is a schematic diagram of the structure of the I-beam before the installation of the baffle plate according to the present invention;

[0032] Figure 5 This is a schematic diagram of the structure of the I-beam after the baffle is installed according to the present invention;

[0033] Figure 6 This is a schematic diagram of the baffle of the present invention;

[0034] Figure 7 This is a schematic diagram of the structure of the outer packaging plate of the present invention;

[0035] Figure 8 This is a schematic diagram of the structure of the present invention after the outer cover plate and side plates are installed;

[0036] Figure 9 This is a schematic diagram of the structure after the joint section of the present invention has been cast;

[0037] Figure 10 This is a schematic diagram of the joint segment of the present invention.

[0038] Figure label:

[0039] 1. Precast section, 11. Longitudinal beam, 111. Bridge deck, 112. I-beam, 2. Beam to be cast, 3. Baffle, 4. Cap beam, 5. Outer cladding, 6. Side plate, 100. Cast-in-place trough, 7. Shear stud, 51. U-shaped plate, 52. Wing plate, 8. Joint section. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0041] See attached document Figure 1-2 This embodiment provides a prefabricated, simply supported, then continuous steel-concrete composite bridge, including a prefabricated section 1. The prefabricated section 1 includes parallel longitudinal beams 11, which are prefabricated in a factory or at a prefabrication yard outside the bridge. These longitudinal beams 11 are then assembled onto a cap beam 1 to form the prefabricated section 1. The longitudinal beams 11 include a bridge deck 111 and an I-beam 112 located at the bottom of the bridge deck 111. The I-beam 112 includes a top plate, a bottom plate, and a web. The upper and lower ends of the web are fixed to the top plate and the bottom plate, respectively. The width of the top plate is smaller than the width of the bottom plate. The I-beam 112 extends beyond the bridge deck 111. The bridge is divided into several precast sections 1, each consisting of a cast-in-place beam 2. Multiple cast-in-place beams 2 are distributed along the width of the precast section 1. Each cast-in-place beam 2 has a baffle 3 fixed to both sides, the length of which is less than the length of the cast-in-place beam 2. The baffle 3 is connected to the bridge deck 111, meaning that the sides of the cast-in-place beam 2 furthest from the bridge deck 111 are not covered by the baffle 3. The ends of two precast sections 1 are spliced ​​onto a cap beam 4. The cast-in-place beams 2 of the two precast sections 1 are fixed by welding, thus forming a continuous structure along the length of the bridge. No baffle 3 is provided at the connection point between the cast-in-place beams 2 of the two precast sections 1 to facilitate welding. (See attached diagram.) Figure 8An outer cladding plate 5 is placed between two precast sections 1. The two ends of the outer cladding plate 5 are connected to the beams 2 to be poured. Specifically, in the width direction of the bridge, the outer cladding plate 5 is placed between the two beams 2 to be poured, and the two ends of the outer cladding plate 5 are in contact with the two beams 2 to be poured. The two ends of the outer cladding plate 5 are connected to the baffle plate 3. In the length direction of the bridge, the two sides of the outer cladding plate 5 are connected to the bottom of the two bridge deck panels 111. The outer side of the precast section 1 is provided with a side plate 6, which is connected to the baffles 3 on the two precast sections 1 respectively. The beam to be poured 2, the baffles 3, the side plate 6 and the outer plate 5 form a cast-in-place trough 100 with the groove facing upward. The groove is set in multiple places. Specifically, the groove is set on the outer plate 5, between the outer plate 5 and the beam to be poured 2, between the baffles 3 and the beam to be poured 2, and between the side plate 6 and the beam to be poured 2. This groove design facilitates the pouring of the cast-in-place trough 100. After the cast-in-place trough 100 is poured, the bridge deck 111 will be poured on it to obtain the joint section 8. Secondly, the multiple grooves can strengthen the connection strength between the cast-in-place trough 100 and the bridge deck 111 above it. Compared to simply casting the bridge deck 111 between two precast sections 1, the bridge deck 111 of this invention is integrated with the cast-in-place trough 100, significantly improving both lateral and longitudinal stress resistance. Secondly, the structure between the two precast sections 1 is simple, with clear stress distribution and no complex reinforcement, greatly improving construction convenience. Thirdly, this structure inherits the simple-supported-then-continuous system, eliminating the need for temporary piers, and is compatible with mature construction equipment such as bridge erecting machines, facilitating large-scale market adoption.

[0042] As another embodiment of the present invention: refer to the appendix Figure 4-5 Shear studs 7 are fixed on both sides and the upward-facing side of the beam to be poured 2 to improve the bond strength between the concrete and the beam to be poured 2.

[0043] As another embodiment of the present invention: refer to the appendix Figure 6 The baffle 3 is L-shaped. The lower end of the baffle 3 is fixedly connected to the beam 2 to be poured, and a gap is left between the upper end of the baffle 3 and the beam 2 to be poured. Concrete is poured between the baffle 3 and the beam 2 through this gap. Specifically, the top of the baffle 3 is stepped. A part of the baffle 3 is inserted between the top plate and the bottom plate and connected to the web plate, while the other part is flush with the top plate.

[0044] As another embodiment of the present invention: refer to the appendix Figure 7 The outer cladding plate 5 includes a U-shaped plate 51 and two wing plates 52. The two wing plates 52 are fixed to the slots on both sides of the U-shaped plate 51. This arrangement allows the outer cladding plate 5, the bridge deck 111, the I-beam 112, and the baffle 3 to form an upward-facing groove, which facilitates subsequent concrete pouring and also allows the outer cladding plate 5 to be placed directly on the cap beam 4.

[0045] As another embodiment of the present invention: shear nails 7 are fixed inside the U-shaped plate 51 and on the wing plate 52 to improve the bonding force between the concrete and the outer plate 5.

[0046] Specifically, the outer panel 5, the baffle 3, and the side panel 6 are all made of stainless steel.

[0047] Specifically, there are two longitudinal beams 11 in the precast section 1, and two I-beams 112 at the bottom of the bridge deck 111. The longitudinal beams 11 have a Π-shaped structure.

[0048] This invention also provides a construction method for a precast, simply supported, then continuous steel-concrete composite bridge, including the precast, simply supported, then continuous steel-concrete composite bridge as described above, and further including the following steps:

[0049] Step 1: Refer to the appendix Figure 5 Fix baffle 3 to I-beam 112, fix shear studs 7 to I-beam 112, and then transport it to the precast beam yard; construct the substructure of the bridge on site; refer to the appendix. Figure 4 The specific steps for fixing shear studs 7 on the I-beam 112 are as follows: The I-beam 112 is divided into two parts. The upper end of the first part of the I-beam 112 is fixed with shear studs 7, which can effectively strengthen the connection between the bridge deck 111 and the I-beam 112 when the bridge deck 111 is poured on it later. The second part of the I-beam 112 is the beam to be poured 2. Shear studs 7 are fixed on both sides and the upward side of the beam to be poured 2.

[0050] Step Two: Refer to Appendix Figure 3 Two I-beams 112 are placed side by side, then formwork is erected and steel bars are tied at the bridge deck 111, the bridge deck 111 is poured to obtain the longitudinal beam 11 and then cured.

[0051] Step 3: After the substructure of the bridge is completed, transport longitudinal beam 11 to the bridge site, referring to the attached document. Figure 1 Then, the longitudinal beams 11 are spliced ​​onto the cap beam 4 by hoisting, and two I-beams 112 are welded along the length of the bridge to form a continuous structure, improving the longitudinal load-bearing capacity of the bridge. Specifically, when welding the two I-beams 112, the top plate, bottom plate, and web of one I-beam 112 are welded to the top plate, bottom plate, and web of the other I-beam 112, respectively. When splicing the longitudinal beams 11 onto the cap beam 4, the longitudinal beams 11 are spliced ​​along the length of the bridge and also along the width of the bridge.

[0052] Step Four: Refer to Appendix Figure 8 The side plate 6 is fixed to the outer baffle 3 of the bridge by hoisting, and the outer cladding plate 5 is placed between the two bridge deck panels 111 by hoisting. The baffle 3, side plate 6, I-beam 112 and outer cladding plate 5 form a cast-in-place trough 100 with the groove facing upwards. (Refer to the attached diagram.) Figure 9-10 Concrete is poured into the cast-in-place trench 100, and the bridge deck 111 is poured on top of the cast-in-place trench 100 to obtain the joint section 8. During the pouring of the joint section 8, a wet joint is poured between the longitudinal beams 11 in the width direction of the bridge. Before pouring the joint section 8, shear studs 7 are fixed to the outer cladding plate 5.

[0053] Step 5: Carry out the construction of paving layers, guardrails, etc.

[0054] This invention inherits the advantages of the simple-supported-then-continuous beam bridge system. The construction process does not require the erection of temporary piers, and it employs a pre-assembled steel-concrete composite structure, resulting in higher structural span performance and material utilization efficiency. Furthermore, the simple-supported-then-continuous beam bridge system is quite similar to traditional precast concrete box girder bridges, and there is mature construction experience and equipment available in the market, making it suitable for large-scale promotion and use.

[0055] Before pouring the joint section 8, this invention only requires fixing two side plates 6 on the beam 2 to be poured, and the outer plate 5 can be directly erected on the cap beam 4. The whole process is simple and does not require complex reinforcement. It can effectively improve the construction convenience and efficiency of steel-concrete composite bridges and better control the construction quality.

[0056] In this invention, after the cast-in-place groove 100 of the joint section 8 and the bridge deck 111 above it are integrated, the concrete and the I-beam 112 can be fully combined, and the height of the concrete is also expanded, which effectively improves the lateral and longitudinal stress of the bridge. In the longitudinal direction, the I-beam 112 is connected into a whole by welding, which can further improve the longitudinal stress of the bridge. When constructing the joint section 8, it mainly bears the lateral stress and assists the I-beam 112 in resisting compression. The structural stress is clearer, and there is no need for complex reinforcement, which simplifies the construction process.

[0057] The longitudinal beams 11 of this invention are prefabricated and then assembled into prefabricated sections 1 by hoisting. Only the joint sections 8 are cast-in-place on the bridge. A large amount of construction is carried out off-site, and the amount of on-site construction work is small, making the construction of steel-concrete composite bridges more convenient. Compared with traditional processes, the steel-concrete composite bridges of this invention have no pollution during on-site operation, a short construction period, and meet the green construction standards for engineering projects.

[0058] The longitudinal beam 11 of the present invention can be spliced ​​in both the width and length directions of the bridge, which can adapt to the needs of different spans and lengths. It can achieve standardized production for different spans and different bridge widths, which can greatly improve the level of industrialized construction of steel-concrete composite bridges.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A prefabricated, simply supported, then continuous steel-concrete composite bridge, characterized in that, The system includes precast sections, each comprising parallel longitudinal beams. Each longitudinal beam includes a bridge deck and an I-beam located at the bottom of the bridge deck. The portion of the I-beam extending beyond the bridge deck is the to-beam to be cast. Baffles are fixed to both sides of the to-beam. The ends of two precast sections are spliced ​​onto a cap beam. The to-beams of the two precast sections are fixed by welding. An outer cladding plate is placed between the two precast sections. Both ends of the outer cladding plate are connected to the to-beam and to the baffles. Side plates are provided on the outer side of each precast section, and these side plates are connected to the baffles on both precast sections. The to-beam, baffles, side plates, and outer cladding plate form an upward-facing cast-in-place trough. The outer cladding plate includes a U-shaped plate and two wing plates, with the two wing plates fixed to the slots on both sides of the U-shaped plate.

2. The prefabricated, simply supported, then continuous steel-concrete composite bridge according to claim 1, characterized in that, Shear studs are fixed to both sides and the upward-facing side of the beam to be poured.

3. The prefabricated, simply supported, then continuous steel-concrete composite bridge according to claim 1, characterized in that, The baffle is L-shaped, with its lower end fixedly connected to the beam to be poured, and a gap left between the upper end of the baffle and the beam to be poured.

4. The prefabricated, simply supported, then continuous steel-concrete composite bridge according to claim 3, characterized in that, Shear studs are fixed inside the U-shaped plate and on the wing plate.

5. The prefabricated, simply supported, then continuous steel-concrete composite bridge according to claim 1, characterized in that, The number of longitudinal beams in the prefabricated section is two.

6. The prefabricated, simply supported, then continuous steel-concrete composite bridge according to claim 1, characterized in that, The bridge deck has two I-beams at its bottom, and the longitudinal beams have a Π-shaped structure.

7. A construction method for a precast, simply supported, then continuous steel-concrete composite bridge, characterized in that, Including the precast, simply supported, then continuous steel-concrete composite bridge as described in any one of claims 1-6, the bridge further includes the following steps: Step 1: Fix the baffle plate to the I-beam, fix shear studs to the I-beam, and then transport it to the precast beam yard; construct the substructure of the bridge on site; Step 2: Place two I-beams side by side, then set up formwork and tie the reinforcing bars at the bridge deck, and pour the bridge deck to obtain the longitudinal beams; Step 3: After the substructure of the bridge is completed, the longitudinal beams are transported to the bridge site and then spliced ​​on the cap beam by hoisting. The two I-beams are welded along the length of the bridge to form a continuous structure. Step 4: Fix the side panels to the outer side of the bridge using hoisting. Place the outer cladding between the two bridge decks using hoisting. The baffle, side panels, I-beams, and outer cladding form a cast-in-place trough with the opening facing upwards. Pour concrete into the cast-in-place trough and then pour the bridge deck above the trough.

8. The construction method for a precast, simply supported, then continuous steel-concrete composite bridge according to claim 7, characterized in that, The specific steps for fixing shear studs on the I-beam are as follows: The I-beam is divided into two parts. Shear studs are fixed at the upper end of the first part of the I-beam; the second part of the I-beam is the beam to be poured, and shear studs are fixed on both sides and the upward-facing side of the beam to be poured.

9. The construction method for a precast, simply supported, then continuous steel-concrete composite bridge according to claim 8, characterized in that, Before pouring concrete into the cast-in-place trench and then pouring the bridge deck above the trench, shear studs are fixed on the outer cladding.

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