Post-cast strip-free large-span low-influence swivel T-shaped beam

Abstract

The utility model relates to the technical field of bridge design and construction, in particular to a post-cast strip-free large-span low-influence swivel T-shaped beam, which is characterized in that two outer side beam end parts of a T-shaped beam body are respectively provided with a local part of a double-layer structure, and the local part of the double-layer structure consists of an outer layer structure, an inner layer structure and a temporary support structure, wherein the outer-layer structure is constructed before the inner-layer structure, the outer-layer structure and the T-shaped structure beam body are connected to form an integral structure, the temporary supporting structure is arranged in the outer-layer structure, and the inner-layer structure is cast in situ in the outer-layer structure after the temporary supporting structure is dismantled. The utility model has the advantages that: a cast-in-place section bracket and a template after rotation are canceled, so that zero influence of construction on surrounding sensitive objects after rotation is realized; t-shaped beam side fulcrum stress is achieved through subsection construction, the middle fulcrum bending moment of a rear main beam without a cast-in-place section is reduced, the side support reaction force is increased, and side support disengaging is prevented.

Description

Technical Field

[0001] The utility model relates to the technical field of bridge design and construction, in particular to a large-span low-impact swivel T-beam without a post-casting strip. Background Art

[0002] At present, in order to ensure the reasonable force of the rotating T structure, Figure 1 As shown in the figure, it is necessary to set up a part of cast-in-place section at the position of the side support through the formwork and corresponding brackets to solve the problem of negative reaction force at the support point and tensile stress of the beam body. However, the T-beam rotation construction is adopted in some work sites mainly to reduce the impact on sensitive objects. However, the formwork and brackets built in the cast-in-place construction increase the impact on sensitive objects, which violates the construction purpose of rotating the T-beam to reduce interference. Especially for sensitive objects such as high-speed railways and rail transit, it is strictly forbidden to set up brackets above their lines.

[0003] For T-beams with relatively small spans, this problem can be solved by installing jacks at the side supports. However, when the span is larger, the jack solution cannot be implemented, and when the jack force is too large, secondary internal forces will be generated, which will cause structural risks. Summary of the invention

[0004] The purpose of the utility model is to provide a large-span, low-impact swivel T-beam without a post-cast strip based on the deficiencies of the above-mentioned prior art. By arranging a double-layer structure at the beam end of the T-beam, the construction of the outer layer structure is completed before the rotation, and the internal structure is cast after the rotation is completed, the stress is improved, so as to achieve the purpose of not affecting sensitive objects under the bridge and achieving reasonable stress.

[0005] The purpose of this utility model is achieved by the following technical solutions:

[0006] A large-span, low-impact swivel T-beam without a post-cast strip comprises a T-beam body, and is characterized in that two outer beam ends of the T-beam body are respectively provided with partial double-layer structures, the partial double-layer structures consisting of an outer layer structure, an inner layer structure and a temporary support structure, wherein the outer layer structure is constructed before the inner layer structure, and is connected with the T-beam body to form an integral structure, the temporary support structure is arranged inside the outer layer structure, and the inner layer structure is cast in situ inside the outer layer structure after the temporary support structure is removed.

[0007] A first batch of prestressed structures is arranged between the outer layer structure and the T-beam body.

[0008] A second batch of prestressed structures is arranged between the inner layer structure and the T-beam body.

[0009] The outer layer structure includes a top plate, a web plate and a bottom plate, wherein the top plate and its cantilever portion match the top plate and cantilever portion of the T-beam body, and the web plate and bottom plate of the outer layer structure are thinner than the web plate and bottom plate of the T-beam body; the inner layer structure is arranged on the web plate, the inner side of the bottom and the outer side ends of the outer layer structure.

[0010] The cavity of the outer structure is provided with steel bars for casting the inner structure in situ.

[0011] The temporary support structure adopts cross steel supports or steel plate beams.

[0012] The advantages of the utility model are:

[0013] 1) The cast-in-place bracket and formwork after the rotation are eliminated, so that the construction after the rotation has zero impact on the surrounding sensitive objects. It is particularly suitable for crossing railways, highways, subways and other environments with high requirements for the upper environment;

[0014] 2) The position of the cast-in-place side support after the conversion is located inside the outer structure, which reduces the bending moment of the support point in the main beam after the non-cast-in-place section, can reduce the amount of concrete and prestressed steel bars, and save project investment;

[0015] 3) The reaction force of the side support is increased to prevent the side support from falling off, which increases safety and saves the engineering work of pressing the side support points;

[0016] 4) Except for the internal cast-in-place part, all T-beams can be constructed by prefabricated cantilever assembly. The external structure reserves a part of equal width section at the web and bottom plate positions, which has better fit with the previous stage. The prefabricated cantilever assembly construction has little impact on the surrounding environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the prior art;

[0018] Figure 2 It is a cross-sectional schematic diagram of the double-layer structure at the end of the middle beam of the utility model;

[0019] Figure 3 It is a cross-sectional schematic diagram of the double-layer structure with steel bars at the end of the middle beam of the utility model;

[0020] Figure 4 This is a comparison diagram of the bending moments of the utility model and the prior art. DETAILED DESCRIPTION

[0021] The following is a further detailed description of the features of the present invention and other related features through embodiments in conjunction with the accompanying drawings to facilitate understanding by technicians in the same industry:

[0022] like Figure 1-4As shown, the marks 1-6 in the figure respectively represent: outer structure 1, inner structure 2, temporary support structure 3, the first batch of prestressed structure 4, the second batch of prestressed structure 5, and steel bar 6.

[0023] Example: Figures 2 to 4 As shown, in this embodiment, the large-span, low-impact rotating T-beam without a post-cast strip is constructed by arranging a double-layer structure at the two outer beam ends to replace the original cast-in-place section. The construction of the outer layer structure 1 is completed in advance before the T-beam rotates, and the inner layer structure 2 is cast-in-place after the rotation is completed, thereby improving the stress and achieving the purpose of not affecting sensitive objects under the bridge and achieving reasonable stress.

[0024] Specifically, combined Figure 2 and Figure 3 As shown, the double-layer structure arranged at both ends of the T-beam includes three parts: an outer layer structure 1, an inner layer structure 2 and a temporary supporting structure 3.

[0025] The outer structure 1 is located outside the last beam stage of the T-beam and is constructed with the same concrete as the T-beam body. The outer structure 1 is provided with steel bars and a temporary support structure 3 required for the cast-in-place inner structure 2. In this embodiment, the top plate and cantilever part of the outer structure 1 match the structure of the T-beam, while the web and bottom plate of the outer structure 1 are set as a pre-constructed concrete layer with a thickness of 10-30 cm, which is less than the design thickness of the web and bottom plate of the T-beam; at this time, the structure formed by the outer structure 1 can not only ensure the strength and rigidity of the structure during the rotation of the T-beam, but also serve as a template for the inner structure 2 after the rotation is completed.

[0026] After the T-beam is rotated, the inner structure 2 is cast in place inside the outer structure 1, and is mainly arranged on the web, the inner side of the bottom plate and the end beam; in this embodiment, the inner structure 2 is the cast-in-place part inside the outer structure 1, and in essence, it cooperates with the outer structure 1 and forms the design structure of the T-beam together. At the same time, the inner structure 2 can also be used to adjust the internal force of the completed bridge and complete the load bearing of the completed bridge.

[0027] The temporary support structure 3 is arranged inside the outer structure 1. On the one hand, it provides additional rigidity and support for the outer structure 1 during the rotation of the T-beam. At the same time, it can also serve as a connecting structure between the outer structure 1 and the inner structure 2, connecting the outer structure 1 and the inner structure 2 cast in sections before and after, greatly improving the integrity between the two, and thereby ensuring the strength and rigidity of the double-layer structure after the bridge is completed.

[0028] like Figure 2As shown, the first batch of prestressed structures 4 are arranged at the outer structure 1, and the first batch of prestressed structures 4 are tensioned after the outer structure 1 is constructed to form the outer structure 1 and the previous segment structure of the T-beam adjacent thereto as a whole, so as to further improve the structural strength and rigidity during the rotation construction. The second batch of prestressed structures 5 are arranged at the inner structure 2, and the second batch of prestressed structures 5 are tensioned after the inner structure 2 is constructed to completely form the completed double-layer structure with the previous segment through prestressed tensioning to improve the overall structural strength and rigidity after the bridge is completed.

[0029] like Figure 3 As shown, the steel bars 6 of the inner layer structure 2 have been tied during the construction of the outer layer structure 1. At this time, the steel bars 6 of the inner layer structure 2 and the structural steel bars of the outer layer structure 1 can be further connected into an integral structure by tying or welding, thereby improving the integrity between the outer layer structure 1 and the inner layer structure 2.

[0030] In the specific implementation of this embodiment: the temporary support structure 3 can adopt, for example, Figure 2 or Figure 3 The cross steel supports shown may also be steel plate beams or other common temporary support structures.

[0031] like Figure 4 As shown, compared with the stress of the conventional T-beam without cast-in-place section during rotation, this embodiment changes the final stress of the T-beam during rotation through the double-layer beam end structure, significantly reduces the bending moment of the middle support, and can further save investment.

[0032] Although the above embodiments have described the concepts and embodiments of the purpose of the utility model in detail with reference to the accompanying drawings, ordinary technicians in this field can recognize that various improvements and modifications can still be made to the utility model without departing from the scope of the claims, so they are not described one by one here.

Claims

1. A large-span low-impact swivel T-beam without post-casting strip, comprising a T-beam body, characterized in that: The two outer beam ends of the T-beam body are respectively provided with partial double-layer structures, and the partial double-layer structure consists of an outer layer structure, an inner layer structure and a temporary supporting structure, wherein the outer layer structure is constructed before the inner layer structure, and is connected with the T-beam body to form an integral structure, the temporary supporting structure is arranged inside the outer layer structure, and the inner layer structure is cast in place inside the outer layer structure after the temporary supporting structure is removed.

2. The large-span low-impact swivel T-beam without post-casting strip according to claim 1 is characterized in that: A first batch of prestressed structures is arranged between the outer layer structure and the T-beam body.

3. The large-span low-impact swivel T-beam without post-casting strip according to claim 1 is characterized in that: A second batch of prestressed structures is arranged between the inner layer structure and the T-beam body.

4. The large-span low-impact swivel T-beam without post-casting strip according to claim 1 is characterized in that: The outer layer structure includes a top plate, a web plate and a bottom plate, wherein the top plate and its cantilever portion match the top plate and cantilever portion of the T-beam body, and the web plate and bottom plate of the outer layer structure are thinner than the web plate and bottom plate of the T-beam body; the inner layer structure is arranged on the web plate, the inner side of the bottom and the outer side ends of the outer layer structure.

5. The large-span low-impact swivel T-beam without post-casting strip according to claim 4 is characterized in that: The cavity of the outer structure is provided with steel bars for casting the inner structure in situ.

6. The large-span low-impact swivel T-beam without post-casting strip according to claim 1, characterized in that: The temporary support structure adopts cross steel supports or steel plate beams.

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