A comprehensive bridge abutment and its construction method, and a construction method for converting it into a bridge pier

Abstract

A combined abutment includes a combined pile foundation, a combined abutment, pier embedded steel bars, pile foundations, and an abutment body; the tops of multiple combined pile foundations jointly support the combined abutment, the top surface of the combined abutment is pre-embedded with multiple upright pier embedded steel bars and abutment body embedded steel bars, stirrups are tied to the multiple pier embedded steel bars, and more than one pile foundation is provided on both sides of the combined pile foundations and the combined abutment; the top surface of the combined abutment and the tops of the pile foundations on both sides jointly support the abutment body, the abutment body is connected to the combined abutment via the embedded steel bars in the abutment body, and the embedded steel bars in the piers are embedded within the abutment body. Also provided are a construction method for the combined abutment and a construction method for converting it into a pier. The present invention solves the problem of converting abutments into piers during the reconstruction of elevated bridges, effectively takes into account the needs of bridge reconstruction and construction, and avoids a large amount of abandoned projects of the upper and lower structures while meeting the structural stress and usage functions.

Description

Technical Field

[0001] The present invention belongs to the technical field of bridge engineering, and in particular relates to a comprehensive bridge abutment and a construction method thereof, as well as a construction method for converting the abutment into a bridge pier. Background Art

[0002] With the rapid development of urban bridge construction, the scale of investment in bridge construction is getting larger and larger. In order to maximize the economic and social benefits of infrastructure investment, bridge construction is often implemented in phases according to traffic demand.

[0003] For elevated urban expressways constructed in phases, in the near term, a combination of overpasses and ground roads can be employed. Specifically, overpasses will be used at intersections across transverse roads, while ground roads will be used for the remaining sections. When traffic volume reaches a certain level in the long term, these overpasses will be renovated into elevated bridges. This involves lifting the overpasses and connecting them with the newly constructed elevated bridges to form urban expressways.

[0004] In order to meet the bridge construction model that combines short-term and long-term goals, the abutments of cross-line bridges should be easy to be converted into piers of viaducts in the future. This requires an abutment that can adapt to this change, a construction method for the abutment, and a construction method for converting it into a pier. Summary of the Invention

[0005] In view of the above problems, the present invention provides a comprehensive abutment and a construction method thereof, as well as a construction method for converting the abutment into a pier.

[0006] The objectives of the present invention can be achieved through the following technical solutions: a combined abutment, comprising a combined pile foundation, a combined pedestal, pier embedded steel bars, pile foundations, and an abutment body; the tops of multiple combined pile foundations jointly support the combined pedestal, and the top surface of the combined pedestal is pre-embedded with multiple upright pier embedded steel bars and abutment body embedded steel bars, and stirrups are tied to multiple pier embedded steel bars, and more than one pile foundation is provided on both sides of the multiple combined pile foundations and the combined pedestal as a whole, and the top surface of the combined pedestal and the tops of the pile foundations on both sides jointly support the abutment body, and the abutment body is connected to the combined pedestal through the abutment body embedded steel bars, and the pier embedded steel bars are buried in the abutment body.

[0007] Furthermore, the pile foundation is a bored cast-in-place pile, a precast reinforced concrete pile, a prestressed concrete pipe pile or a steel pipe pile.

[0008] Furthermore, the abutment body adopts a reinforced concrete structure or a prestressed concrete structure.

[0009] Furthermore, the pre-embedded steel bars in the piers include long and short pre-embedded steel bars, which are arranged in a staggered pattern and bound with stirrups. Furthermore, the height difference between the tops of the long and short pre-embedded steel bars is greater than or equal to the larger of 35 times the diameter of the pre-embedded steel bars in the piers and 500 mm.

[0010] Furthermore, it also includes abutment ear walls, and the rear sides of the abutment body are both connected to the abutment ear walls.

[0011] A construction method for a comprehensive abutment includes the following steps:

[0012] (1) Consider the pile foundation in the middle and the pile foundations on both sides;

[0013] (2) Excavate the foundation pit, cast the bearing platform on the pile foundation, and pre-embed the steel bars of the piers and the abutment body;

[0014] (3) Cast the abutment body on the bearing platform and pile foundation, connect the pre-buried steel bars of the abutment body to each other, and embed the pre-buried steel bars of the pier inside the abutment body.

[0015] In the step (3), the abutment ear walls are cast simultaneously with the abutment body.

[0016] A construction method for converting a bridge abutment into a bridge pier, wherein the bridge abutment is the above-mentioned combined abutment, comprising the following steps:

[0017] (1) Lift the superstructure on the combined abutment to the design elevation and secure it to the temporary support;

[0018] (2) Dismantle the abutment body and the slab behind the abutment;

[0019] (3) Use pier extension steel bars to extend the pre-buried steel bars of the piers, tie the stirrups, and cast the piers.

[0020] In the step (3), the steel bar joints of the pre-embedded steel bars of the piers and the extended steel bars of the piers are staggered by 50%, and the staggered length is greater than or equal to the larger value of 35 times the diameter of the pre-embedded steel bars of the piers and 500 mm.

[0021] Compared with existing technologies, this invention offers the following advantages: it solves the challenge of converting abutments into piers during elevated bridge reconstruction, effectively meeting the demands of bridge reconstruction and construction. While ensuring structural strength and usability, it avoids the need for extensive abandonment of both the upper and lower structures, thereby improving practicality. This comprehensive abutment, its construction method, and its conversion into piers offer broad application prospects in bridge construction, with significant economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1This is a cross-sectional diagram of a combined abutment.

[0023] Figure 2 This is a plan diagram of a combined abutment.

[0024] Figure 3 for Figure 1 Cross-section of AA.

[0025] Figure 4 A schematic cross-sectional view of the bridge pier.

[0026] Figure 5 This is a plan view of the bridge pier.

[0027] Figure 6 This is a schematic elevation diagram of the bridge pier.

[0028] The parts in the figure are numbered as follows:

[0029] 1. Considering pile foundation

[0030] 2. Taking into account the foundation

[0031] 3. Pre-embedded steel bars in piers

[0032] 301 long embedded steel bars

[0033] 302 short embedded steel bars

[0034] 4 pile foundation

[0035] 5. Bridge abutment

[0036] 6Abutment ear wall

[0037] 7Superstructure

[0038] 8 rear panels

[0039] 9 Bridge pier extension steel bars

[0040] 10 bridge piers

[0041] 11. Build a new superstructure. DETAILED DESCRIPTION

[0042] The following describes the specific embodiments of the present invention in detail in conjunction with the accompanying drawings so that those skilled in the art can more clearly understand how to practice the present invention. Although the present invention has been described in conjunction with its preferred embodiments, these embodiments are merely illustrative, rather than limiting, the scope of the present invention.

[0043] See also Figures 1 to 3 A comprehensive bridge abutment includes a comprehensive pile foundation 1, a comprehensive bearing platform 2, pre-embedded steel bars in the pier 3, a pile foundation 4, and a bridge abutment body 5.

[0044] The plurality of said combined pile foundations 1 are arranged in a rectangular array or a plum blossom-shaped array, and the tops of the plurality of said combined pile foundations 1 jointly support a combined pedestal 2, and the top surface of the said combined pedestal 2 is pre-embedded with a plurality of upright pier pre-embedded steel bars 3 and abutment body pre-embedded steel bars, and the plurality of said pier pre-embedded steel bars 3 are tied with stirrups, and the plurality of said combined pile foundations 1 and the combined pedestal 2 are provided with more than one pile foundation 4 on both sides of the whole, and the top surface of the combined pedestal 2 and the tops of the pile foundations 4 on both sides jointly support abutment body 5, and the abutment body 5 is connected to the combined pedestal 2 through the pre-embedded steel bars of the abutment body, and the pre-embedded steel bars of the pier 3 are buried in the abutment body 5.

[0045] The pile foundations 1 and 4 may be bored cast-in-place piles, precast reinforced concrete piles, prestressed concrete pipe piles or steel pipe piles.

[0046] The abutment 2 is a reinforced concrete structure used to transfer the internal force of the abutment to the pile foundation 4.

[0047] The abutment body 5 is an integral abutment body, which adopts a reinforced concrete structure or a prestressed concrete structure, and is used to support the bridge superstructure 7 and resist the backfill behind the abutment.

[0048] In this embodiment, the number of the combined pile foundations 1 is 8, and the 8 combined pile foundations 1 are arranged in a 2*4 array.

[0049] In this embodiment, the pier embedded steel bars 3 include long embedded steel bars 301 and short embedded steel bars 302. Multiple long embedded steel bars 301 and multiple short embedded steel bars 302 are arranged into two groups of pier embedded steel bars. The two groups are symmetrically distributed along the transverse centerline of the bridge, taking into account the bridge cap 2. Each group of pier embedded steel bars 3 is staggered in a rectangular arrangement of long embedded steel bars 301 and short embedded steel bars 302. Stirrups are attached to both groups of pier embedded steel bars. The height difference between the tops of the long embedded steel bars 301 and the short embedded steel bars 302 should be greater than or equal to the larger of 35 times the diameter of the pier embedded steel bars 3 and 500 mm.

[0050] It also includes abutment ear walls 6. Both sides of the rear of the abutment body 5 are connected to the abutment ear walls 6 to constrain the backfill behind the abutment. The abutment ear walls 6 can also be replaced by retaining walls or slopes according to actual site conditions.

[0051] The construction steps of the combined abutment are as follows:

[0052] (1) Construction of the middle pile foundation 1 and the two side pile foundations 4;

[0053] (2) Excavate the foundation pit, tie the steel bars of the bridge cap 2 on the pile foundation 1 in the foundation pit, embed the pre-embedded steel bars 3 of the pier and the pre-embedded steel bars of the abutment body, and pour concrete to form the bridge cap 2;

[0054] (3) Tie the steel bars of the abutment body 5 and the steel bars of the abutment ear wall 6 on the bearing platform 2 and the pile foundation 4 in the foundation pit, pour concrete to form the abutment body 5 and the abutment ear wall 6, connect the abutment body 5 with the pre-embedded steel bars of the abutment body, and bury the pre-embedded steel bars 3 of the pier in the abutment body 5.

[0055] After this, the construction of the overpass includes the following steps:

[0056] (4) Fill the back of the construction platform behind the abutment 5 to 1 / 3 of the total height;

[0057] (5) Constructing the superstructure 7 in front of the abutment body 5. The superstructure 7 may be an integral box girder structure such as a concrete box girder, a steel box girder, or a steel-concrete composite box girder, as required;

[0058] (6) Fill the back of the construction platform behind the abutment 5 to the total height;

[0059] (7) A rear slab 8 is constructed behind the abutment body 5 and on the upper surface of the backfill behind the abutment.

[0060] In this way, the construction of the abutments of the overpass and the superstructure thereon is completed.

[0061] The construction steps for transforming the combined abutment into a pier are as follows:

[0062] (1) Lift the superstructure 7 on the combined abutment to the design elevation and fix it on the temporary support;

[0063] (2) Dismantle the abutment body 5, abutment ear wall 6 and abutment back slab 8;

[0064] (3) The pier pre-embedded steel bars 3 are extended with pier extension steel bars 9, and stirrups are tied, and concrete is poured to form the pier 10. The steel bar joints of the pier pre-embedded steel bars 3 and the pier extension steel bars 9 are staggered by 50%, and the staggered length should be greater than or equal to the larger value of 35 times the diameter of the pier pre-embedded steel bars 3 and 500 mm.

[0065] This is followed by the construction of the viaduct, which includes the following steps:

[0066] (4) Construct the bridge support at the top of pier 10;

[0067] (5) Place the superstructure 7 on the bridge support;

[0068] (6) Construction of new superstructure of adjacent span 11.

[0069] Thus, the construction of the viaduct pier 10 and the superstructure thereon is completed. Figures 4 to 6 .

[0070] It should be noted that the present invention, having been fully described, is susceptible to numerous variations and modifications, and is not limited to the specific embodiments described above. The foregoing embodiments are intended to illustrate the present invention, not to limit it. In short, the scope of protection of the present invention encompasses any such variations, substitutions, and modifications as would be apparent to one of ordinary skill in the art.

Claims

1. A comprehensive abutment, characterized in that: It includes a combined pile foundation, a combined pedestal, pier embedded steel bars, pile foundation, and abutment body; the tops of multiple combined pile foundations jointly support the combined pedestal, and the top surface of the combined pedestal is pre-embedded with multiple upright pier embedded steel bars and abutment body embedded steel bars, and multiple pier embedded steel bars are tied with stirrups. There is more than one pile foundation on both sides of the multiple combined pile foundations and the combined pedestal, and the top surface of the combined pedestal and the tops of the pile foundations on both sides jointly support the abutment body, and the abutment body is connected to the combined pedestal through the embedded steel bars of the abutment body, and the embedded steel bars of the piers are buried in the abutment body; the combined pile foundation and pile foundation adopt bored cast-in-place piles, precast reinforced concrete piles, prestressed concrete pipe piles or steel pipe piles.

2. The comprehensive abutment according to claim 1, characterized in that: The abutment body adopts a reinforced concrete structure or a prestressed concrete structure.

3. The comprehensive abutment according to claim 1, characterized in that: The pre-embedded steel bars of the bridge pier include long pre-embedded steel bars and short pre-embedded steel bars, which are arranged alternately one by one and tied with stirrups.

4. The comprehensive abutment according to claim 3, characterized in that: The height difference between the top ends of the long embedded steel bars and the short embedded steel bars is greater than or equal to the larger value of 35 times the diameter of the pier embedded steel bars and 500 mm.

5. The combined abutment according to any one of claims 1 to 4, characterized in that: It also includes abutment ear walls, and both sides of the rear side of the abutment body are connected to the abutment ear walls.

6. A construction method for a comprehensive abutment, characterized in that: The following steps are included: (1) constructing the middle pile foundation and the pile foundations on both sides; (2) Excavate the foundation pit, cast the bearing platform on the pile foundation, and pre-embed the steel bars of the piers and the abutment body; (3) Cast the abutment body on the bearing platform and pile foundation, connect the pre-buried steel bars of the abutment body to each other, and embed the pre-buried steel bars of the pier inside the abutment body.

7. The construction method of the comprehensive abutment according to claim 6, characterized in that: In the step (3), the abutment ear walls are cast simultaneously with the abutment body.

8. A construction method for transforming a bridge abutment into a bridge pier, characterized in that: The abutment is a comprehensive abutment according to any one of claims 1 to 4, comprising the following steps: (1) Lift the superstructure on the combined abutment to the design elevation and secure it to the temporary support; (2) Dismantle the abutment body and the slab behind the abutment; (3) Use pier extension steel bars to extend the pre-buried steel bars of the piers, tie the stirrups, and cast the piers.

9. The construction method for transforming abutments into piers according to claim 8, characterized in that: In the step (3), the steel bar joints of the pre-embedded steel bars of the piers and the extended steel bars of the piers are staggered by 50%, and the staggered length is greater than or equal to the larger value of 35 times the diameter of the pre-embedded steel bars of the piers and 500 mm.

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