Multi-span prestressed concrete continuous rigid frame bridge

Abstract

The utility model discloses a multi-span prestressed concrete continuous rigid frame bridge, which belongs to the technical field of bridge engineering, and comprises a plurality of mid-span main beams, a plurality of middle-span main beams and a plurality of middle-span main beams, every two adjacent mid-span main beams are connected through a mid-span main beam closure section; the bottom of the midspan main beam is fixedly connected with the main pier; the fixing unit is arranged in the mid-span main beam and is connected with the mid-span main beam; one side span cast-in-place section main beam is connected with the mid-span main beam at the head end, and the other side span cast-in-place section main beam is connected with the mid-span main beam at the tail end; and the bottom of the side span cast-in-place section main beam is fixedly connected with the side pier. The multi-span prestressed concrete continuous rigid frame bridge is simple in structure, convenient to install and capable of achieving simultaneous closure of multiple spans, the calculated amount and the site construction workload can be reduced, it is guaranteed that the ages of closure sections are basically the same, the installation construction time of the multi-span prestressed concrete continuous rigid frame bridge can be shortened, the construction period is shortened, and the construction efficiency is improved. And the engineering economic benefits are improved.

Description

Technical Field

[0001] This utility model belongs to the field of bridge engineering technology, specifically relating to a multi-span prestressed concrete continuous rigid frame bridge. Background Technology

[0002] Before closure, a continuous rigid frame bridge is a statically determinate structure, but after closure, it transforms into a statically indeterminate structure, undergoing a system transformation from statically determinate to statically indeterminate. Therefore, the closure construction becomes the link in the system transformation, and the determination of the closure scheme is an important link in the cantilever construction of prestressed continuous rigid frame bridges. Especially in multi-span continuous rigid frame bridges, the choice of closure scheme will not only have a significant impact on the internal stress of the structure and the pre-cast height provided by monitoring during the closure process, but also affect construction safety, cycle and cost.

[0003] There are various construction schemes for the closure of multi-span continuous rigid frame bridges, with different construction sequences. Selecting the optimal closure technology must not only be based on structural safety and stress, but also take into account the construction period and minimize construction costs. Existing continuous rigid frame bridges have complex structures, and the main beams of large-span continuous rigid frame bridges will deflect due to shrinkage and creep. Furthermore, simultaneous closure of multiple spans cannot be achieved, resulting in long construction periods and high costs. Utility Model Content

[0004] To solve the above problems, the present invention adopts the following technical solution:

[0005] A multi-span prestressed concrete continuous rigid frame bridge, comprising:

[0006] Multiple mid-span main beams are arranged sequentially; adjacent mid-span main beams are connected by a mid-span main beam closure section; the bottom of each mid-span main beam is fixedly connected to the main pier.

[0007] A fixing unit is disposed within the main beam of the middle span and connected to the main beam of the middle span.

[0008] Two side span cast-in-place main beams, one of which is connected to the first end of the middle span main beam, and the other of which is connected to the last end of the middle span main beam; the bottom of the side span cast-in-place main beam is fixedly connected to the side pier.

[0009] Further, the fixing unit includes a first steel pipe, a second steel pipe, and multiple transverse diaphragms; the multiple transverse diaphragms are spaced apart within the mid-span main beam and fixedly connected to the mid-span main beam; the first steel pipe and the second steel pipe are symmetrically arranged within the mid-span main beam about the main pier; the first end of the first steel pipe is connected to the mid-span main beam; the second end of the first steel pipe passes through the transverse diaphragm and extends into the closure section of the mid-span main beam, and the first steel pipe is fixedly connected to the transverse diaphragm through a shear-resistant connector; the first end of the second steel pipe is connected to the mid-span main beam; the second end of the second steel pipe passes through the transverse diaphragm and extends into the closure section of the mid-span main beam, and the second steel pipe is fixedly connected to the transverse diaphragm through the shear-resistant connector; in two adjacent mid-span main beams, the second ends of the first steel pipe and the second ends of the second steel pipe are connected by a third steel pipe to form an arch structure.

[0010] Furthermore, the cross-sections of the first steel pipe, the second steel pipe, and the third steel pipe are all circular.

[0011] Furthermore, closure counterweights are provided at both ends of the closure section of the mid-span main beam to apply vertical downward counterweights to the mid-span main beam at both ends of the closure section of the mid-span main beam.

[0012] Furthermore, a closure section of the side span main beam connects the side span main beam and the middle span main beam.

[0013] Furthermore, the two ends of the side span main beam closure section are provided with side span main beam closure counterweights to apply vertical downward counterweights to the middle span main beam and the side span cast-in-place main beam at both ends of the side span main beam closure section.

[0014] Furthermore, a stiffening frame is provided on the closure section of the side span main beam; one end of the stiffening frame is fixedly connected to the middle span main beam, and the other end is fixedly connected to the side span cast-in-place main beam.

[0015] Beneficial effects:

[0016] This utility model provides a multi-span prestressed concrete continuous rigid frame bridge. An arched circular steel pipe is installed inside the mid-span box girder to assist in the load-bearing capacity of the box girder, helping to solve the problem of main girder deflection due to shrinkage and creep in large-span continuous rigid frame bridges. Simultaneously, this multi-span prestressed concrete continuous rigid frame bridge can achieve simultaneous closure of multiple spans, reducing the amount of calculation and on-site construction work, ensuring that the age of each closure segment is basically the same, accelerating the installation and construction time of the multi-span prestressed concrete continuous rigid frame bridge, shortening the construction cycle, and improving the economic benefits of the project. Attached Figure Description

[0017] Figure 1This is a front elevation layout diagram of the multi-span prestressed concrete continuous rigid frame bridge of this utility model before closure.

[0018] Figure 2 This is an elevation view of the multi-span prestressed concrete continuous rigid frame bridge of this utility model after applying closure counterweights before closure.

[0019] Figure 3 This is an elevation view showing the arrangement of applying the jacking force before the closure of the multi-span prestressed concrete continuous rigid frame bridge of this utility model.

[0020] Figure 4 This is an elevation view showing the installation of the first steel pipe, the second steel pipe, the third steel pipe, and the stiffening frame before the closure of the multi-span prestressed concrete continuous rigid frame bridge of this utility model.

[0021] Figure 5 This is an elevation layout diagram of the side and middle spans of the multi-span prestressed concrete continuous rigid frame bridge of this utility model after the first closure.

[0022] Among them, 1. Main beam; 2. Side span cast-in-place main beam; 3. Mid-span main beam closure section; 4. Side span main beam closure section; 5. Mid-span main beam closure counterweight; 6. Side span main beam closure counterweight; 7. Mid-span main beam closure front thrust; 8. Stiffening frame; 9. Main pier; 10. Side pier; 11. First steel pipe; 12. Second steel pipe; 13. Third steel pipe. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model 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 utility model. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this utility model provided in the accompanying drawings is not intended to limit the scope of the claimed utility model, but merely to illustrate selected embodiments of the utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

[0024] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0025] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0026] Example 1

[0027] like Figures 1 to 5 As shown, a multi-span prestressed concrete continuous rigid frame bridge includes:

[0028] Multiple mid-span main beams 1 are arranged sequentially; adjacent mid-span main beams 1 are connected by a mid-span main beam closure section 3; the bottom of the mid-span main beam 1 is fixedly connected to the main pier 9.

[0029] A fixing unit is installed inside the main beam 1 of the middle span and connected to the main beam 1 of the middle span.

[0030] Two side span cast-in-place main beams 2, one side span cast-in-place main beam 2 is connected to the first end of the middle span main beam 1, and the other side span cast-in-place main beam 2 is connected to the last end of the middle span main beam 1; the bottom of the side span cast-in-place main beam 2 is fixedly connected to the side pier 10.

[0031] In this embodiment, the fixing unit includes a first steel pipe 11, a second steel pipe 12, a third steel pipe 13, and multiple transverse diaphragms; the multiple transverse diaphragms are spaced apart within the main beam 1 and are fixedly connected to the main beam 1.

[0032] A first steel pipe 11 is installed at one end of the main beam 1 at the beginning of the middle span, away from the end of the cast-in-place main beam 2 at the end of the side span; a second steel pipe 12 is installed at one end of the main beam 1 at the end of the middle span, away from the end of the cast-in-place main beam 2 at the end of the middle span; the first steel pipe 11 and the second steel pipe 12 are symmetrically arranged in the main beam 1 between the main beam 1 at the beginning of the middle span and the main beam 1 at the end of the middle span, about the main pier 9.

[0033] The first end of the first steel pipe 11 is connected to the main beam 1 in the middle span; the second end of the first steel pipe 11 passes through the diaphragm and extends into the closure section 3 of the main beam in the middle span, and the first steel pipe 11 is fixedly connected to the diaphragm through a shear connector; the first end of the second steel pipe 12 is connected to the main beam 1 in the middle span; the second end of the second steel pipe 12 passes through the diaphragm and extends into the closure section 3 of the main beam in the middle span, and the second steel pipe 12 is fixedly connected to the diaphragm through a shear connector; in two adjacent main beams in the middle span, the second ends of the first steel pipe 11 and the second ends of the second steel pipe 12 are connected by a third steel pipe 13 to form an arch structure.

[0034] In this embodiment, the cross-sections of the first steel pipe 11, the second steel pipe 12, and the third steel pipe 13 are all circular.

[0035] In this embodiment, the two ends of the mid-span main beam closure section 3 are provided with mid-span main beam closure counterweights 5 to apply vertical downward counterweights to the mid-span main beams 1 at both ends of the mid-span main beam closure section 3.

[0036] In this embodiment, the main beam 2 of the side span cast-in-place section and the main beam 1 of the middle span are connected by the closure section 4 of the side span main beam.

[0037] In this embodiment, the two ends of the side span main beam closure section 4 are provided with side span main beam closure counterweights 6 to apply vertical downward counterweights to the middle span main beam 1 and the side span cast-in-place main beam 2 at both ends of the side span main beam closure section 4.

[0038] In this embodiment, a stiffening frame 8 is provided on the closure section 4 of the side span main beam; one end of the stiffening frame 8 is fixedly connected to the middle span main beam 1, and the other end is fixedly connected to the side span cast-in-place main beam 2.

[0039] This utility model provides a multi-span prestressed concrete continuous rigid frame bridge, and the rapid closure construction method for this multi-span prestressed concrete continuous rigid frame bridge is as follows:

[0040] S1. Construct the mid-span main beam 1 above the main pier 9 of the multi-span prestressed concrete continuous rigid frame bridge to the maximum cantilever state. Use a support frame to cast the mid-span main beam 1 above the side pier 10. Only two side-span main beam closure segments 4 and multiple mid-span main beam closure segments 3 remain on the entire bridge.

[0041] S2. Apply vertically downward side span main beam closure weight 6 to both ends of the side span main beam closure segment 4, and apply vertically downward middle span main beam closure weight 5 to the cantilever ends of the middle span main beam 1 on both sides of the multiple middle span main beam closure segments 3. The size of the side span main beam closure weight 6 is half the weight of the side span main beam closure segment 4 at the location, and the size of the middle span main beam closure weight 5 is half the weight of the middle span main beam closure segment 3 at the location.

[0042] S3. Install large-tonnage jacks on the cantilever ends of the main beams 1 on both sides of the closure section 3 of the main beams in the middle span. Apply a horizontal jacking load to the cantilever ends of the main beams 1 in the closure section 3 of the main beams in the middle span, that is, apply a jacking force 7 before the closure of the main beams in the middle span to achieve the purpose of pre-deflection of the pier top, so as to partially offset the displacement of the pier top towards the middle span caused by the prestressing tension of the bottom plate, the shrinkage and creep of the concrete in the later stage, and the cooling, and improve the stress and alignment of the main beams 1 and the piers. Specifically, take the horizontal displacement of the pier top as the control target, the jacking load as the control variable, and the stress of the control section of the pier bottom as the constraint condition, and use the influence matrix method and other methods to determine the maximum jacking load of multiple closure sections 3 of the main beams in the middle span.

[0043] S4. After the horizontal jacking load at the cantilever end of the main beam 1 in the middle span of the main beam closure section 3 reaches the calculation requirements, weld the first steel pipe 11 and the third steel pipe 13 at all the main beam closure sections 3, and weld the second steel pipe 12 and the third steel pipe 13; weld the stiffening frame 8 in the side span main beam closure section 4, so as to weld the embedded steel plate on the top plate of the first end of the main beam 1 away from the first steel pipe 11 and the embedded steel plate above the main beam 2 of the side span cast-in-place section together, and weld the embedded steel plate on the top plate of the last end of the main beam 1 away from the second steel pipe 12 and the embedded steel plate above the main beam 2 of the side span cast-in-place section together.

[0044] Among them, the rigid frame 8 is generally made of large-size steel;

[0045] S5. Install all the hangers for the closure segment 3 of the mid-span main beam, the formwork for the closure segment 3 of the mid-span main beam, the hangers for the closure segment 4 of the side-span main beam, and the formwork for the closure segment 4 of the side-span main beam. Tie the reinforcing bars and start pouring the closure segment concrete at the same time. Gradually remove the closure weights 6 and 5 of the side-span main beam and the closure weights 5 of the mid-span main beam. After the concrete pouring is completed, the rapid closure construction of the multi-span prestressed concrete continuous rigid frame bridge is completed.

[0046] S6. Lightweight high-strength concrete is poured into the first steel pipe 11, the second steel pipe 12, and the third steel pipe 13 inside the concrete box girder to form a steel-concrete composite arch structure. The long-term deflection problem of the main beam in the middle span of the continuous rigid frame bridge is solved by utilizing the advantage of the large vertical stiffness of the arch structure.

[0047] Through the above technical solutions, and through reasonable theoretical calculations and construction planning, the separate and batch closure method used for multi-span continuous rigid frame bridges (multi-span refers to 4 spans or more) is optimized to the simultaneous closure of the side spans and all middle spans, which greatly improves the closure construction speed of multi-span continuous rigid frame bridges.

[0048] The present invention provides a multi-span prestressed concrete continuous rigid frame bridge with a simple structure, which shortens the connection construction time. Furthermore, the rapid closure construction method adopted can reduce the closure construction cycle of the continuous rigid frame bridge from [(number of spans / 2, rounded up) × one closure] to one closure time, which greatly improves the construction speed of the continuous rigid frame bridge and saves construction time and costs.

[0049] The above are merely preferred embodiments of the present utility model and do not constitute any limitation on the technical scope of the present utility model. Therefore, any minor modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model shall still fall within the scope of the technical solution of the present utility model.

Claims

1. A multi-span prestressed concrete continuous rigid frame bridge, characterized in that, include: Multiple central span main beams are arranged sequentially; adjacent central span main beams are connected by a central span main beam closure section; the bottom of each central span main beam is fixedly connected to a main pier; a fixing unit is disposed within the central span main beam and connected to it; two side span cast-in-place main beams are provided, one side span cast-in-place main beam is connected to the first central span main beam, and the other side span cast-in-place main beam is connected to the last central span main beam; the bottom of each side span cast-in-place main beam is fixedly connected to a side pier. The fixing unit includes a first steel pipe, a second steel pipe, and multiple transverse diaphragms; the multiple transverse diaphragms are spaced apart within the mid-span main beam and fixedly connected to the mid-span main beam; the first steel pipe and the second steel pipe are symmetrically arranged within the mid-span main beam about the main pier; the first end of the first steel pipe is connected to the mid-span main beam; the second end of the first steel pipe passes through the transverse diaphragm and extends into the closure section of the mid-span main beam, and the first steel pipe is fixedly connected to the transverse diaphragm through a shear-resistant connector; the first end of the second steel pipe is connected to the mid-span main beam; the second end of the second steel pipe passes through the transverse diaphragm and extends into the closure section of the mid-span main beam, and the second steel pipe is fixedly connected to the transverse diaphragm through the shear-resistant connector; in two adjacent mid-span main beams, the second ends of the first steel pipe and the second ends of the second steel pipe are connected by a third steel pipe to form an arch structure.

2. The multi-span prestressed concrete continuous rigid frame bridge according to claim 1, characterized in that, The cross-sections of the first steel pipe, the second steel pipe, and the third steel pipe are all circular.

3. The multi-span prestressed concrete continuous rigid frame bridge according to claim 1, characterized in that, The two ends of the closure section of the mid-span main beam are provided with closure counterweights to apply vertical downward counterweights to the mid-span main beam at both ends of the closure section.

4. The multi-span prestressed concrete continuous rigid frame bridge according to claim 1, characterized in that, The main beam of the side span and the main beam of the middle span are connected by the closure section of the side span main beam.

5. The multi-span prestressed concrete continuous rigid frame bridge according to claim 4, characterized in that, The two ends of the side span main beam closure section are provided with side span main beam closure counterweights to apply vertical downward counterweights to the middle span main beam and the side span cast-in-place main beam at both ends of the side span main beam closure section.

6. The multi-span prestressed concrete continuous rigid frame bridge according to claim 4, characterized in that, A stiffening frame is provided on the closure section of the side span main beam; one end of the stiffening frame is fixedly connected to the middle span main beam, and the other end is fixedly connected to the side span cast-in-place main beam.

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