Fish-bellied box girder structure
By optimizing the box room layout and cantilever bottom plate line shape of the fish belly box girder structure, combined with the application of prestressed steel strands, the problems of unsightly appearance and high construction cost of the traditional fish belly box girder structure are solved, and more efficient and safer bridge construction is achieved.
Patent Information
- Application Number
- CN202421544575.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-02
- Publication Date
- 2025-06-10
- Estimated Expiration
- 2034-07-02
AI Technical Summary
The traditional fish belly box girder structure has problems such as the box girder height, too small cantilever length, and poor linear fluency, resulting in unsightly appearance, high construction costs and high safety risks.
A fish-bellied box girder structure is designed. By reducing the size of the box chamber and increasing the number of box chambers, some box chambers are set inside the cantilever, and a bottom plate piece designed with one positive and one reverse arc shape is adopted to optimize the linear shape of the cantilever bottom plate, and prestressed steel strands are provided on the top plate to improve the load-bearing capacity and stability of the structure.
The overall linear shape of the box girder is achieved smoother and more beautiful, reducing the height and cantilever length of the box girder, improving the load-bearing capacity and construction efficiency of the bridge, and reducing construction costs and safety hazards.
Smart Images
Figure CN222961871U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of box girder construction, in particular to a fish-belly type box girder structure and a supporting assembly thereof. Background Art
[0002] At present, the fish-belly type box girder structure is widely used in urban municipal bridges due to its beautiful appearance, large cantilever length, small floor area and other advantages, and it can well meet the traffic requirements on and under the bridge. However, there are some technical problems in the traditional fish-belly type box girder structure, such as too large box girder height, too small cantilever length, and poor linear smoothness, resulting in an unattractive appearance.
[0003] For the existing construction method of prestressed concrete variable cross-section fish-belly type continuous box girder, the construction technology of bowl-coupled scaffold + steel formwork is adopted. Although the rapid installation of the formwork support frame is realized and the linear control precision of the fish-belly type box girder is improved, there are still some problems. For example, in order to ensure that the bridge deck can bear the load of vehicles on the bridge deck, the linear shape of the bottom slab at the cantilever is basically concave, the stress at the edge of the bridge deck is large, and the thickness of the top and bottom slabs needs to be relatively large (25 cm or more), the height of the box girder is too high (more than 2.5 m), and the cantilever length of the box girder is too small (less than 5 m), making the overall fish-belly type bridge appear relatively bulky, the linear shape is relatively rigid, the self-weight of the bridge is large, and the overall cost of the bridge is high. In addition, in order to ensure the linear shape of the bridge, the construction is carried out with a fixed-type steel formwork, but the linear shape and angle of the bridge are not completely the same, resulting in a low reuse rate of the steel formwork and a relatively high overall construction cost. In addition, the installation of the steel formwork requires a crane for hoisting construction, which has high requirements for the construction site, and the crane needs to be adjusted for a long time, increasing the construction cost and having relatively large potential safety hazards. Summary of the Utility Model
[0004] The purpose of the utility model is to design a fish-belly type box girder structure with high aesthetic degree of the box girder, and capable of improving construction efficiency and reducing construction cost.
[0005] In order to achieve the above purpose, the utility model provides a fish-belly type box girder structure, including:
[0006] A box girder, the box girder includes a beam body and two cantilevers respectively arranged on both sides of the beam body. At least six box chambers are opened inside the box girder and are evenly distributed inside the box girder, and at least part of the box chambers are located inside the cantilevers. The cantilever includes a bottom slab arranged at the bottom of the box chamber. The bottom slab includes a first plate member and a second plate member. One end of the first plate member is connected to the beam body and the other end is connected to the second plate member. The first plate member is in a downward convex arc shape, and the second plate member is in an upward convex arc shape.
[0007] Further, the length of the box girder is L mm, the length of the cantilever is J mm, and the height of the box girder is H mm, satisfying: J:L = 1:3 to 1:4, and L:H = 14.5 to 15.
[0008] Further, the length L of the box girder is 25 m to 26 m, the length J of the cantilever is 7 m to 8 m, and the height H of the box girder is 1.7 m to 2 m.
[0009] Further, the radius R of the circle where the first plate member is located 1 = 3.5 m, and the radius R of the circle where the second plate member is located 2 = 7.5 m.
[0010] Further, six box chambers are provided inside the box girder. The box chambers are symmetrically arranged on both sides of the box girder inside the box girder. Two of the box chambers are respectively located inside two of the cantilevers, two other box chambers are located inside the beam body, and the remaining two box chambers are partially located inside the cantilevers and partially located inside the beam body.
[0011] Further, the cantilever further includes a top plate provided on the top of the box chamber, and prestressed steel strands are provided inside the top plate.
[0012] Further, it further includes two pier columns arranged at intervals. The two pier columns are respectively connected to the bottoms of both sides of the beam body, and the beam body and the pier columns are sequentially connected through bearings and bearing pads.
[0013] Further, it further includes two anti-overturning blocks. The two anti-overturning blocks are respectively connected to the bottoms of both sides of the beam body and are located between the two pier columns.
[0014] Further, the spacing distance K between the anti-overturning block and its corresponding pier column is 5 cm.
[0015] The present application also provides a support assembly for the fish-belly box girder structure, which is used for the above-mentioned fish-belly box girder structure, and includes a sizing formwork, an arc-shaped steel pipe, a plurality of wooden squares and a plurality of disc buckle type support frames. Among them, the disc buckle type support frames are arranged at intervals, the arc-shaped steel pipe is arranged at the top of the disc buckle type support frames, the sizing formwork is arranged above the arc-shaped steel pipe and is arranged at an interval from the arc-shaped steel pipe, and the sizing formwork and the arc-shaped steel pipe are connected by the wooden squares.
[0016] Compared with the prior art, the beneficial effects of a fish-belly box girder structure and its support structure in an embodiment of the present utility model are as follows:
[0017] The fish-belly box girder structure of the embodiment of the present utility model helps to optimize the structure of the cantilever, improve its bearing capacity and stability, thereby increasing the length of the cantilever and making the overall structure lighter by reducing the size of the box chamber, increasing the number of box chambers, and arranging some box chambers inside the cantilever. By cooperating with the first plate member and the second plate member designed with two arc shapes, one positive and one negative, the linear shape of the cantilever bottom plate is optimized, the transmission efficiency of the bridge deck load at the cantilever is improved, the bearing capacity of the bridge is greatly increased while reducing the self-weight of the bridge, and the height of the box girder is greatly reduced and the cantilever length of the bridge is increased, making the linear shape of the bridge smoother and more beautiful, meeting the aesthetic requirements of modern bridge design. Description of the Drawings
[0018] Figure 1 is a schematic structural diagram of the fish-belly box girder structure of the embodiment of the present utility model;
[0019] Figure 2 is Figure 1 an enlarged schematic diagram of part A in
[0020] Figure 3 is a schematic diagram of the anti-overturning block in the fish-belly box girder structure of the embodiment of the present utility model;
[0021] Figure 4 is a schematic structural diagram of the support assembly of the fish-belly box girder structure of the embodiment of the present utility model;
[0022] Figure 5 is Figure 4 an enlarged schematic diagram of part B in
[0023] Figure 6 is a schematic structural diagram of the arc-shaped steel pipe in the support assembly of the fish-belly box girder structure of the embodiment of the present utility model;
[0024] Figure 7 is a schematic structural diagram of the sizing template in the support assembly of the fish-belly box girder structure of the embodiment of the present utility model.
[0025] In the figure, 1, box girder; 10, box chamber; 11, beam body; 12, cantilever; 121, bottom plate; 121a, first plate member; 121b, second plate member; 122, top plate; 2, pier; 3, bearing; 4, bearing pad stone; 5, anti-overturning block; 6, sizing template; 7, arc-shaped steel pipe; 8, wooden square; 9, disc buckle support frame. Detailed Embodiment
[0026] The following will further describe in detail the specific embodiments of the present utility model in conjunction with the drawings and embodiments. The following embodiments are used to illustrate the present utility model, but are not used to limit the scope of the present utility model.
[0027] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. in the present utility model is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model 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 utility model.
[0028] In the description of the present utility model, it should be understood that the terms "connected", "connected to", "fixed", etc. used in the present utility model should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or a welded connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.
[0029] The terms "first", "second", etc. are used in the present utility model to describe various information, but this information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present utility model, the "first" information may also be referred to as the "second" information, and similarly, the "second" information may also be referred to as the "first" information.
[0030] Referring to Figure 1 , a fish-belly box girder 1 structure of an embodiment of the present utility model includes: a box girder 1, the box girder 1 includes a beam body 11 and two cantilevers 2 respectively arranged on both sides of the beam body 11. At least six box chambers 10 are opened inside the box girder 1 and are evenly distributed inside the box girder 1, and at least part of the box chambers 10 are located inside the cantilever 2. The cantilever 2 includes a bottom plate 121 arranged at the bottom of the box chamber 10. The bottom plate 121 includes a first plate member 121a and a second plate member 121b. One end of the first plate member 121a is connected to the beam body 11 and the other end is connected to the second plate member 121b. The first plate member 121a is in an arc shape protruding downward, and the second plate member 121b is in an arc shape protruding upward.
[0031] By reducing the size of the chamber 10, increasing the number of chambers 10, and arranging some chambers 10 inside the cantilever 2, it helps to optimize the structure of the cantilever 2, improve its load-bearing capacity and stability, thereby increasing the length of the cantilever 2 and making the overall structure lighter; combined with the first plate 121a and the second plate 121b designed with one positive and one negative circular arc shapes, the linear shape of the bottom plate 121 of the cantilever 2 is optimized, and the transfer efficiency of the bridge deck load at the cantilever 2 is improved. While reducing the self-weight of the bridge, the load-bearing capacity of the bridge is greatly improved, and the height of the box girder 1 is greatly reduced and the length of the cantilever 2 of the bridge is increased, making the linear shape of the bridge more smooth and beautiful, meeting the aesthetic requirements of modern bridge design. Specifically, the shape of the chamber 10 is set as close as possible to the shape of the bridge.
[0032] In some improved solutions of the present application, the length of the box girder 1 is L mm, the length of the cantilever 2 is J mm, and the height of the box girder 1 is H mm, satisfying: J:L = 1:3 to 1:4, L:H = 14.5 to 15, to ensure the length of the cantilever 2 and avoid the overall box girder 1 from being too bulky.
[0033] In some improved solutions of the present application, the length L of the box girder 1 is 25 m to 26 m, the length J of the cantilever 2 is 7 m to 8 m, and the height H of the box girder 1 is 1.7 m to 2 m. In a specific embodiment of the present application, the length L of the box girder 1 is 25.6 m, the length J of the cantilever 2 is 7.35 m, the height of the box girder 1 is reduced to 1.938 m, the single span is 35 m, the self-weight of the box girder 1 is controlled, the overall linear shape of the bridge is more elegant and beautiful, and the floor area under the bridge is effectively reduced.
[0034] In some improved solutions of the present application, the radius R of the circle where the first plate 121a is located 1 = 3.5 m, the radius R of the circle where the second plate 121b is located 2 = 7.5 m. This arc design helps to optimize the stress distribution of the structure of the bottom plate 121, reduce local stress concentration, and extend the service life of the box girder 1.
[0035] In some improved solutions of the present application, six chambers 10 are provided inside the box girder 1. The chambers 10 are symmetrically arranged on both sides of the box girder 1 along the box girder 1. Among them, two chambers 10 are located in the two cantilevers 2 in one-to-one correspondence, and the other two chambers 10 are located in the beam body 11. The remaining two chambers 10 are both partially located in the cantilever 2 and partially located in the beam body 11. The symmetric chambers 10 can effectively improve the overall stability of the structure, enabling the box girder 1 to better resist external loads and dynamic effects; at the same time, evenly distributing some chambers 10 at the cantilever 2 can optimize the overall linear shape of the box girder 1 and increase the length of the cantilever 2.
[0036] In some improved solutions of the present application, the cantilever 2 further includes a top plate 122 provided at the top of the box chamber 10, and prestressed steel strands are provided inside the top plate 122. The top plate 122 of the cantilever 2 uses prestressed steel strands and adopts the reverse tension prestressing technique. The prestressed steel strand is a steel cable twisted by multiple high-strength steel wires. By tensioning the steel strand and anchoring it in the concrete, when the steel strand retracts, a compressive force will be generated in the concrete. This compressive force can effectively offset the tensile stress generated by the external load acting on the concrete, thereby improving the tensile capacity of the concrete. Therefore, the top plate 122 of the box girder 1 can bear a greater load at a smaller thickness because the prestress can effectively compensate the internal stress of the concrete under the load. This not only improves the bearing capacity of the structure but also reduces the self-weight of the structure.
[0037] While adopting the reverse tension prestressing technique for the prestressed steel strands of the top plate 122, increasing the diameters of the longitudinal and transverse steel bars of the top and bottom plates of the beam body 11 can greatly improve the vertical compressive and tensile capacities of the top and bottom plates of the box girder 1, and achieve the reduction of the thickness of the top and bottom plates of the box girder 1, reduce the self-weight of the box girder 1, and improve the bearing capacity of the box girder 1.
[0038] Refer to Figure 2 , in some improved solutions of the present application, it further includes two pier columns 2 arranged at intervals. The two pier columns 2 are respectively connected to the bottom sides of the two sides of the beam body 11, and the beam body 11 and the pier columns 2 are sequentially connected through a bearing 3 and a bearing pad stone 4.
[0039] Refer to Figure 3 In some improved solutions of the present application, it further includes two anti-overturning blocks 5. The two anti-overturning blocks 5 are respectively connected to the bottom sides of the two sides of the beam body 11 and are located between the two pier columns 2 to improve the anti-overturning ability of the bridge and reduce the probability of bridge overturning accidents.
[0040] In some improved solutions of the present application, the spacing distance K between the anti-overturning block 5 and its corresponding pier column 2 is 5 cm. In a specific embodiment, an anti-overturning block 5 with a length of 1 m and a width of 0.3 m is provided at the bottom of the box girder 1 inside the pier column 2, and the spacing from the inside of the pier column 2 is only 0.5 m. When the box girder 1 tilts to one side, the anti-overturning block 5 contacts the pier column 2, which can provide a thrust in the direction opposite to the tilting direction, improve the anti-overturning ability of the box girder 1, and reduce the probability of bridge overturning accidents.
[0041] Refer to Figure 4 and Figure 5, aiming at the problems of high construction cost of using steel formwork + support frame for the existing fish-belly box girder 1 bridge and poor linear control accuracy of traditional wooden formwork + straight main rib support frame, the preferred embodiment of the present application also provides a support assembly for the fish-belly box girder 1 structure, which is used for the above-mentioned fish-belly box girder 1 structure, including a shaped formwork 6, an arc-shaped steel pipe 7, a plurality of wooden squares 8 and a plurality of disc buckle support frames 9. Among them, the disc buckle support frames 9 are arranged at intervals, the arc-shaped steel pipe 7 is arranged at the top of the disc buckle support frames 9, the shaped formwork 6 is arranged above the arc-shaped steel pipe 7 and is spaced from the arc-shaped steel pipe 7, and the shaped formwork 6 and the arc-shaped steel pipe 7 are connected by the wooden squares 8.
[0042] Referring to Figure 6 and Figure 7 , according to the characteristics of the large cantilever 2 ultra-thin fish-belly box girder 1 structure of the present application, the shaped formwork 6 is numerically controlled and bent at the two positive and negative arcs of the first plate member 121a and the second plate member 121b of the cantilever 2 according to the arc radius to ensure the control accuracy of the linearity of the bottom plate 121 of the box girder 1; at the same time, in order to ensure the linear accuracy of the bottom shaped formwork 6 and ensure that the shaped formwork 6 will not deform during preloading and concrete pouring, a transverse high-precision numerically controlled bent shaped steel pipe is added above the longitudinal main rib at the cantilever 2. The arc-shaped steel pipe 7 is provided with two positive and negative arcs according to the structural characteristics of the bottom shaped formwork 6 of the bridge, closely fitting the high-precision shaped formwork 6, bearing and transmitting the load transmitted by the shaped formwork 6, ensuring the linear control of the shaped formwork 6, improving the construction quality and efficiency, reducing the hoisting time of the crane at the same time, and improving the construction safety.
[0043] In summary, the embodiment of the present utility model provides a fish-belly box girder 1 structure and its support assembly, which have the following advantages:
[0044] 1. The fish-belly box girder 1 structure is optimized by increasing the number of box chambers 10, reducing the size of the box chambers 10, changing the shape of the box chambers 10, optimizing the linearity of the bottom plate 121 of the cantilever 2, increasing the diameter of the top and bottom plate steel bars of the box girder 1, and reverse tensioning the prestressed steel strands of the top plate 122 of the cantilever 2, etc., to form a large cantilever 2 ultra-thin fish-belly box girder 1, increasing the length of the cantilever 2 of the box girder 1 structure and reducing the height of the box girder 1, making the overall linearity of the box girder 1 more elegant and beautiful.
[0045] 2. By setting an anti-overturning block 5 at the bottom of the box girder 1 inside the pier column 2, when the box girder 1 tilts to one side, the anti-overturning block 5 contacts the pier column 2 to provide a thrust in the opposite direction to the tilting direction, improving the anti-overturning ability of the box girder 1 and reducing the probability of the box girder 1 overturning accident.
[0046] 3. The linear accuracy control of the bottom of the box girder 1 is improved by the prefabricated high-precision shaped formwork 6 and the high-precision numerically controlled arc-shaped steel pipe 7, improving the construction quality and construction efficiency, and reducing the hoisting safety hazards.
[0047] The above are only the preferred embodiments of the present utility model. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present utility model, several improvements and substitutions can be made, and these improvements and substitutions should also be regarded as the protection scope of the present utility model.
Claims
1. A fish-belly box beam structure, characterized in that: include: A box beam, comprising a beam body and two cantilevers respectively arranged on both sides of the beam body, at least six box chambers are opened inside the box beam and are evenly distributed inside the box beam, wherein at least part of the box chambers are located in the cantilevers, the cantilever comprises a bottom plate arranged at the bottom of the box chamber, the bottom plate comprises a first plate member and a second plate member, one end of the first plate member is connected to the beam body, and the other end is connected to the second plate member, the first plate member is in the shape of a downwardly protruding arc, and the second plate member is in the shape of an upwardly protruding arc.
2. The fish-belly box beam structure according to claim 1, characterized in that: The length of the box beam is Lmm, the length of the cantilever is Jmm, and the height of the box beam is Hmm, satisfying: J:L=1:3~1:4, L:H=14.5~15.
3. The fish-belly box beam structure according to claim 2, characterized in that: The length of the box beam is L=25m~26m, the length of the cantilever is J=7m~8m, and the height of the box beam is H=1.7m~2m.
4. The fish-belly box beam structure according to claim 1, characterized in that: The radius of the circle where the first plate is located is R1=3.5m, and the radius of the circle where the second plate is located is R2=7.5m.
5. The fish-belly box beam structure according to claim 1, characterized in that: Six box chambers are arranged in the box beam, and the box chambers are symmetrically arranged along both sides of the box beam. Two of the box chambers are located in the two cantilevers one by one, and the other two box chambers are located in the beam body. The remaining two box chambers are partially located in the cantilever and partially located in the beam body.
6. The fish-belly box beam structure according to claim 1, characterized in that: The cantilever also includes a top plate arranged on the top of the box chamber, and a prestressed steel strand is arranged inside the top plate.
7. The fish-belly box beam structure according to claim 1, characterized in that: It also includes two piers arranged at intervals, the two piers are respectively connected to the bottoms of both sides of the beam body, and the beam body and the piers are connected in sequence through bearings and bearing pad stones.
8. The fish-belly box beam structure according to claim 7, characterized in that: It also includes two anti-overturning blocks, which are respectively connected to the bottom of both sides of the beam body and are located between the two piers.
9. The fish-belly box beam structure according to claim 8, characterized in that: The spacing distance K between the anti-overturning stopper and the corresponding pier is 5 cm.