Combined T-shaped rigid frame bridge combining box girders and gate-type piers
By combining the box girder and portal pier into a T-shaped rigid frame bridge structure, the problem of the large overall height of the portal pier viaduct was solved, and the optimization of the underbridge clearance and structural stiffness in the existing line crossing design was achieved to meet the needs of smaller bridge lanes.
Patent Information
- Application Number
- CN202422720373.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-08
- Publication Date
- 2025-09-23
- Estimated Expiration
- 2034-11-08
AI Technical Summary
The overall height of the existing portal pier viaduct structure is relatively large, which makes it difficult to design when crossing existing lines. In particular, when the width requirement of the bridge lane is relatively small, the design difficulty of matching the upper and lower structures increases.
A T-shaped rigid frame bridge structure is adopted, which is a combination of joint box beams and portal piers. The concrete box beam and cap beam are cast as a whole. The side piers are supported on the bottom of the concrete box beam. The junction of the portal main pier cap beam and the concrete box beam is cast as one piece. Prestressed steel strands enhance the bearing capacity, and the side piers provide support and restraint.
Under height restrictions, the height of the pier-beam combination can be reduced, the span can be increased, the clearance requirements under the bridge can be met, the structural stiffness and seismic performance can be improved, and the use of materials can be reduced.
Smart Images
Figure CN223373574U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of bridge construction, in particular to a combined T-shaped rigid frame bridge with a combined box beam and a portal pier. Background Art
[0002] With the continuous increase in bridge construction, more and more new bridges need to cross existing lines. In order to save investment, avoid special geological conditions or bridges are close to stations, it is often difficult to build bridges because the height of the new lines is too low.
[0003] As a structural form for crossing existing railways and highways, portal piers offer numerous advantages. They can span existing lines at a very narrow angle, even running parallel to them. This allows for strong spanning capabilities and minimal interference with operating lines. Their simplicity and cost-effectiveness have led to their widespread application in highway, railway, bridge, and water conservancy projects. Existing portal pier viaducts typically consist of portal piers, a cap beam, a main girder, and a carriageway. The portal piers are located on either side of the carriageway, the cap beam is located atop the portal piers, the main girder rests on the cap beam, and the carriageway is located on top of the main girder. In this structure, the main girder sits atop the cap beam, and the combined height of the two equals the sum of their respective heights. This results in a relatively high overall height, making design difficult when the clearance below the main girder is low. This makes it difficult to raise the line height, limiting the height required to cross the existing line, and complicating the design of the upper and lower structures. Furthermore, the spacing between the portal piers (the distance across the existing line), the width of the cap beam, the width of the main girder, and the width of the carriageway are kept relatively consistent, resulting in a carriageway width that is essentially the same as the distance across the existing line. However, for some actual working conditions, the design distance across the existing line is large, but the required width of the lane on the bridge is small, which increases the difficulty of matching the upper and lower structures.
[0004] Therefore, it is necessary to propose new measures to overcome the above-mentioned defects. Summary of the Invention
[0005] The purpose of the utility model is to provide a combined T-shaped rigid frame bridge with a combined box girder and a portal pier, so as to solve the problem of the overall height of the existing structure being relatively large, and the matching design problem of the upper and lower structures when the design distance across the existing line is large but the width requirement of the bridge lane is small.
[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the present utility model is:
[0007] A combined T-shaped rigid frame bridge with a box girder and a portal pier, the combined T-shaped rigid frame bridge comprising a concrete box girder, a portal main pier and side piers;
[0008] The portal main pier includes two pier bodies and a cap beam, wherein the two pier bodies are located on both sides of the existing line, and the cap beam is located above the existing line and intersects with the existing line;
[0009] The concrete box beam is arranged to intersect with the cap beam and is located above the cap beam. At the intersection of the cap beam and the concrete box beam, the top of the cap beam and the bottom of block 0 of the concrete box beam are cast as one piece.
[0010] The side piers are located on both sides of the existing line, and the side piers are arranged longitudinally and supported on the bottom of the concrete box girder.
[0011] Furthermore, at the intersection of the cap beam and the concrete box beam, the concrete box beam is embedded downwardly into the cap beam.
[0012] Furthermore, a support is provided on the top of the side pier, and the concrete box beam is supported on the support.
[0013] Furthermore, a portal pier pile foundation and a portal pier cap are provided below the pier body of the portal main pier.
[0014] Furthermore, a side pier pile foundation and a side pier cap are provided below the side pier.
[0015] Furthermore, prestressed steel strands are arranged inside the concrete box body of the concrete box beam.
[0016] Furthermore, the top width of the concrete box beam is smaller than the width of the cap beam.
[0017] Furthermore, the top of the pier body of the portal-type main pier gradually expands from bottom to top and transitions to the bottom of the cap beam of the portal-type main pier.
[0018] Furthermore, on both sides of block No. 0 of the concrete box beam are block No. 1, block No. 2 and a cast-in-place section.
[0019] Furthermore, prestressed steel strands are arranged in the No. 1 block, the No. 2 block and the cast-in-place section.
[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0021] This utility model provides a combined T-shaped rigid frame bridge with a box girder and portal piers. This bridge can reduce the combined height of the piers and beams when the line height is limited, thereby increasing the span and meeting the required clearance under the bridge. Furthermore, this utility model allows a new line to cross over an existing line at a very small intersection angle. The piers and beams are integrated, providing good integrity, reducing material usage, increasing structural rigidity and bearing capacity, and thus increasing the span and providing better seismic performance. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying any creative work, they can also obtain drawings of other embodiments based on these drawings.
[0023] Figure 1 It is an elevation view of a combined T-shaped rigid frame bridge in an embodiment of the present utility model.
[0024] Figure 2 It is a three-dimensional diagram of a combined T-shaped rigid frame bridge in an embodiment of the utility model.
[0025] Figure 3 yes Figure 1 Section II in .
[0026] Figure 4 yes Figure 3 Section II-II in the figure.
[0027] Figure 5 It is a construction step diagram of the box girder in this utility model.
[0028] The symbols in the figure are:
[0029] 1-superstructure, 2-substructure, 3-foundation, 4-concrete box girder, 5-portal main pier, 6-side pier, 7-side pier cap, 8-portal pier cap, 9-side pier pile foundation, 10-portal pier pile foundation, 11-support, 12-concrete box body, 13-prestressed steel strands, 14-existing line. DETAILED DESCRIPTION
[0030] To facilitate understanding of the present invention, a more comprehensive description of the present invention will be provided below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure of the present invention.
[0031] In the description of the present invention, it should be understood that the terms "middle", "upper", "lower", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.
[0032] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "connected" and "disposed" should be understood in a broad sense. For example, they may refer to fixed connection or disposition, detachable connection or disposition, or integral connection or disposition. Those skilled in the art will be able to understand the specific meanings of the above terms in this utility model based on specific circumstances.
[0033] It should also be noted that although the steps are described in order, in some cases they may be performed in an order different from that shown, and this should not be construed as limiting the order of the steps.
[0034] In a specific embodiment, the direction of the newly constructed line, that is, the length direction of the concrete box girder 4 is defined as the longitudinal direction, and the direction perpendicular thereto is defined as the transverse direction.
[0035] After the existing Line 14 is completed and operational, new routes will need to be planned and designed to intersect it based on increased traffic demand. Typically, a new bridge will be constructed to span the existing Line 14. Rigid frame bridges offer excellent integrity, with continuous beams and consolidated piers. They combine the advantages of a continuous beam, which has no expansion joints and provides smooth driving, with the advantages of a T-shaped rigid frame, which requires no supports and no conversion system. Furthermore, they offer significant longitudinal bending and lateral stiffness, meeting the load-bearing requirements of long-span bridges.
[0036] In actual construction, the clearance height under the bridge may be small, the overall height cannot be too high, and the road width does not need to be too large. To address the situation where new bridges have a small height limit and a small required width in actual construction, this utility model provides a combined T-shaped rigid frame bridge with a box girder and portal piers, which effectively controls the overall height and can adapt to box girder structures with smaller widths.
[0037] Specifically, such as Figure 1 and Figure 2 The composite T-shaped rigid frame bridge comprises a superstructure 1, a substructure 2, and a foundation 3. The superstructure 1 comprises a concrete box girder 4, the substructure 2 comprises a portal pier 5 and a side pier 6, and the foundation 3 comprises a pier pile foundation and a pier cap. Beneath the portal pier 5 are a portal pier pile foundation 10 and a portal pier cap 8, while beneath the side pier 6 are a side pier pile foundation 9 and a side pier cap 7.
[0038] The portal main pier 5 includes two pier bodies and a cap beam. The two pier bodies are located on both sides of the existing line 14 and can cross the existing line at a very small angle. The cap beam is located above the existing line 14 and intersects with the existing line 14. The top of the pier body of the portal main pier 5 gradually expands from bottom to top and transitions to the bottom of the cap beam of the portal main pier 5, improving the load-bearing performance at the node. The concrete box beam 4 is arranged to intersect with the cap beam and is located above the cap beam. At the intersection of the cap beam and the concrete box beam 4, the top of the cap beam and the bottom of the No. 0 block of the concrete box beam 4 are cast as one piece, that is, rigidly connected. The side piers 6 are located on both sides of the existing line 14. The side piers 6 are arranged longitudinally and supported on the bottom of the concrete box beam 4. The portal main pier 5, the portal pier cap 8 and the portal pier pile foundation 10 do not interfere with the existing line. The side piers 6, the side pier cap 7 and the side pier pile foundation 9 do not interfere with the existing line. The portal pier cap 8 and the side pier cap 7 transmit the forces transmitted from the portal main pier 5 and the side pier 6 to the portal pier pile foundation 10 and the side pier pile foundation respectively.
[0039] like Figure 3 In this structure, the concrete box girder 4 is embedded downwards into the cap girder at the intersection of the cap girder and the concrete box girder 4. The combined height of the cap girder and concrete box girder 4 is less than the sum of their actual heights, significantly reducing the overall height. Furthermore, since the concrete box girder 4 is embedded downwards into the cap girder, the top width of the concrete box girder 4 is less than the cap girder width. This makes it suitable for box girder structures with smaller widths, eliminating the need to construct a box girder and road surface of the same width as the cap girder.
[0040] like Figure 4 The concrete box girder 4 comprises a concrete box 12 and prestressed steel strands 13. The prestressed steel strands 13 extend through the concrete box 12 and are located within its top and web plates. The prestressed steel strands 13 provide prestressing and tightly bond with the concrete box 12, imparting compressive stress to the concrete box 12 and significantly increasing the beam's load-bearing capacity.
[0041] The tops of the side piers 6 are equipped with supports 11, which support the concrete box girder 4 and constrain its lateral movement. The portal piers 5 provide intermediate, consolidated support for the concrete box girder 4. The side piers 6, through the supports 11, provide movable support for the concrete box girder 4, restraining its lateral displacement and preventing it from toppling. Releasing the longitudinal constraints allows the concrete box girder 4 to expand and contract freely under the influence of temperature changes.
[0042] The above-mentioned combined box girder and portal pier T-shaped rigid frame bridge is constructed using the following construction methods:
[0043] First, it is necessary to determine the angle between the new line and the existing line, as well as the height difference with the existing line, lay out the lines to determine the positions of the portal pier pile foundation 10 and the side pier pile foundation 9, and level the site and access road. Then, construction can begin:
[0044] S1: Construction Foundation 3, including:
[0045] S101: Excavate portal pier foundation pits and side pier foundation pits on both sides of the existing line 14, construct portal pier pile foundations 10 and side pier pile foundations 9 by drilling and pouring, and then construct portal pier caps 8 and side pier caps 7;
[0046] S102: Before excavation, drainage work should be done on the top and bottom of the foundation pit, 1 to 2 water collection wells should be made at the corners of the foundation pit, and cushion layer concrete should be poured. The top surface elevation should not be higher than the design elevation of the bottom of the pedestal.
[0047] S2: After measuring the line height, a formwork is erected on the foundation 3, steel bars are tied, and the pier body of the portal main pier 5 and the side pier 6 are cast and constructed.
[0048] S3: After the pier body of the portal-type main pier 5 is constructed to the pier top, the bracket and the cap beam formwork of the portal-type main pier 5 are set up, and the cap beam of the portal-type main pier 5 is cast. A groove for the junction position is reserved on the middle top surface and the steel bars are exposed.
[0049] S4: At the intersection of the concrete box girder 4 and the portal pier 5 cap beam, structural reinforcement needs to be set in the middle position of the portal pier cap beam, so that the portal pier 5 reinforcement enters the concrete box girder 4, and the concrete box girder 4 reinforcement enters the portal pier 5, and the formwork is erected to cast block No. 0 of the concrete box girder 4, so that the bottom of block No. 0 and the top of the cap beam are cast as a whole, and are embedded in each other from top to bottom.
[0050] S5: Continue to construct the concrete box beam 4 by cantilever casting, tensioning the prestressed steel tendons 13 in batches with a certain length as a section, until the end is cast to form a T-shaped rigid frame stress form, such as Figure 5 ,include:
[0051] S501: After pouring block 0, a hanging basket is set up on block 0, and blocks 1 on both sides are cantilevered and prestressed steel tendons of the top plate are tensioned;
[0052] S502: Then move the hanging basket to block No. 1, cantilever cast blocks No. 2 on both sides and tension the top plate prestressed steel tendons;
[0053] S503: Finally, set up the support and formwork to cast the cast-in-place box girder to the side pier position. After the concrete reaches the required strength, remove the formwork and support.
[0054] S6: Set up the support and cast the concrete box beam 4 to the side pier 6 in the formwork. After the concrete reaches the required strength, remove the formwork and support.
[0055] S7: Install support 11 on the top of side pier 6. Support 11 provides upward support force and lateral displacement constraint, so that the whole structure forms a T-shaped rigid frame stress state and completes the bridge state.
[0056] In the above method, the concrete box girder 4 and the portal pier 5 are integrally cast using a vertical formwork method, thereby connecting them to form a single unit. This connection allows for the transfer of bending moments, shear forces, and axial forces between the concrete box girder 4 and the portal pier 5. This favorable load-bearing condition increases the span of the structure. The combination of the concrete box girder 4 and the portal pier 5 requires precise positioning. The clearance under the bridge is controlled according to the design size to determine the position of the concrete box girder 4. A formwork is then developed for the joint position to achieve simultaneous pouring.
[0057] The combined T-shaped rigid frame bridge of the combined box girder and the portal pier provided by the utility model has the advantage of greater rigidity and increased driving comfort compared to ordinary T-shaped rigid frame bridges; compared to the traditional structural form of portal piers plus simply supported beams, the combined T-shaped rigid frame bridge of the combined box girder and the portal pier can cross the existing line when the line is lower, and has good integrity and good seismic resistance.
[0058] The above examples are used to illustrate the present invention, which are only used to help understand the present invention and are not intended to limit the present invention. Those skilled in the art of the present invention can make some simple deductions, modifications or substitutions based on the concept of the present invention.
Claims
1. A combined T-shaped rigid frame bridge with a box girder and portal piers, characterized by: The combined T-shaped rigid frame bridge comprises a concrete box girder (4), a portal main pier (5) and a side pier (6); The portal main pier (5) includes two pier bodies and a cap beam, the two pier bodies are located on both sides of the existing line (14), and the cap beam is located above the existing line (14) and intersects with the existing line (14); The concrete box beam (4) is arranged to intersect with the cap beam and is located above the cap beam. At the intersection of the cap beam and the concrete box beam (4), the top of the cap beam and the bottom of block 0 of the concrete box beam (4) are cast as one piece. The side piers (6) are located on both sides of the existing line (14), and the side piers (6) are arranged longitudinally and supported on the bottom of the concrete box beam (4).
2. The T-shaped rigid frame bridge with a combined box girder and portal piers according to claim 1, characterized in that: At the intersection of the cap beam and the concrete box beam (4), the concrete box beam (4) is embedded downwardly into the cap beam.
3. The T-shaped rigid frame bridge with combined box beams and portal piers according to claim 1, characterized in that: A support (11) is provided on the top of the side pier (6), and the concrete box beam (4) is supported on the support (11).
4. The T-shaped rigid frame bridge with combined box beams and portal piers according to claim 1, characterized in that: A portal pier pile foundation (10) and a portal pier cap (8) are provided below the pier body of the portal main pier (5).
5. The T-shaped rigid frame bridge with combined box beams and portal piers according to claim 1, characterized in that: A side pier pile foundation (9) and a side pier cap (7) are provided below the side pier (6).
6. The T-shaped rigid frame bridge with combined box beams and portal piers according to claim 1, characterized in that: Prestressed steel strands (13) are arranged inside the concrete box body (12) of the concrete box beam (4).
7. The T-shaped rigid frame bridge with combined box beams and portal piers according to claim 1, characterized in that: The top width of the concrete box beam (4) is smaller than the width of the cap beam.
8. The T-shaped rigid frame bridge with combined box beams and portal piers according to claim 1, characterized in that: The top of the pier body of the portal-type main pier (5) gradually expands from bottom to top and transitions to the bottom of the cap beam of the portal-type main pier (5).
9. The T-shaped rigid frame bridge with combined box beams and portal piers according to claim 1, characterized in that: Block No. 0 of the concrete box beam (4) is followed by block No. 1, block No. 2 and a cast-in-place section.
10. The T-shaped rigid frame bridge with combined box beams and portal piers according to claim 9, characterized in that: Prestressed steel strands (13) are arranged in the No. 1 block, the No. 2 block and the cast-in-place section.