A new type of large-span arch combined pier structure and construction method

Abstract

A novel large-span arch combined pier structure comprises a pier column and a cap beam arranged on the pier column, the pier column is arranged at both ends of the cap beam, and a pile foundation and a pedestal are arranged at the bottom of the pier column; a main arch ring and a hanger are arranged on the cap beam, the main arch ring is an arc-shaped structure with an opening facing downward, and the arch feet of the main arch ring are arranged at opposite ends of the cap beam; the upper end of the hanger is connected to the main arch ring, and the lower end of the hanger is connected to the cap beam; a main beam is arranged on the cap beam, and the positions of the hanger and the main beam do not interfere with each other; compared with the prior art, an arch system is adopted to provide multi-point elastic support for the cap beam through steel arch rings and hangers, and the load transmitted to the cap beam by the main beam of the upper structure is transmitted to the main arch ring by the hanger, which can reduce the bending moment of the cap beam, improve the rigidity of the cap beam, and greatly improve the span range of the cap beam, with high structural safety and wide applicability.

Description

Technical Field

[0001] The invention belongs to the technical field of road and bridge construction engineering structures, and in particular relates to a novel large-span arch combined pier structure and a construction method. Background Art

[0002] During the construction of bridges, it is inevitable to encounter ground obstacles such as rivers or roads. When the newly built bridge has a small skew angle with ground obstacles such as rivers or roads, two solutions are generally adopted: 1. Increase the span to cross the ground obstacle; 2. Set up portal piers and use the portal pier cap beam to cross the ground obstacle. Since the plan of increasing the span to cross the ground obstacle often greatly increases the cost of the bridge, it is a more appropriate choice to use the portal pier cap beam to cross the obstacle. However, when the width of the ground obstacle such as the river or the existing road is large, the portal pier needs to increase the span, and the conventional portal pier cannot meet the requirements. Therefore, it is necessary to develop a new type of portal pier structure to solve this type of engineering problem.

[0003] At present, the existing portal pier structure has limited spanning capacity and is not suitable for large-span structures. It mainly has the following disadvantages:

[0004] 1. As the span of the existing large-span prestressed concrete portal pier structure increases, the beam height needs to be increased to meet the stress requirements of the cap beam, which increases the deadweight of the structure, wastes the engineering work, and limits the span.

[0005] 2. The existing large-span prestressed concrete portal pier structure has a cap beam that is too high, affecting the clearance under the bridge. The bridge deck elevation needs to be further increased, affecting the overall cost of the bridge.

[0006] 3. The existing large-span prestressed concrete portal pier structure has a cap beam that is cast in place with a bracket. The bracket cast in place requires the erection of a bracket, which is inconvenient for construction. When crossing an existing road on the ground, traffic under the bridge needs to be closed, and the construction period is long. When crossing a river, a bracket needs to be erected in the river, which has a high construction cost.

[0007] 4. The existing steel cap beam portal pier structure adopts a steel box beam structure. The cap beam has low stiffness and large bridge deflection, which affects driving comfort. Summary of the invention

[0008] The present invention aims to overcome the defects in the prior art and provide a new type of arch combined pier structure and construction method suitable for large span and structural safety.

[0009] In order to achieve the above purpose, the technical solution adopted by the present invention is: a new type of large-span arch combined pier structure, including a pier column and a cap beam arranged on the pier column, the pier column is arranged at both ends of the cap beam, and the bottom of the pier column is provided with a pile foundation and a pedestal; a main arch ring and a hanger are provided on the cap beam, the main arch ring is an arc structure with an opening facing downward, and the arch feet of the main arch ring are arranged at opposite ends of the cap beam; the upper end of the hanger is connected to the main arch ring, and the lower end of the hanger is connected to the cap beam; a main beam is provided on the cap beam, and the positions of the hanger and the main beam do not interfere with each other.

[0010] As a preferred solution of the present invention, guardrails are arranged on both sides of the main beam, and the hanger is located in the central dividing strip of the main beam and outside the guardrails.

[0011] As a preferred solution of the present invention, the size of the top of the pier column gradually increases upward in the vertical direction, and a stiffening steel plate pier cap is provided on the top of the pier column, and the stiffening steel plate pier cap is welded and fixed to the cap beam.

[0012] As a preferred solution of the present invention, the cap beam is a steel box beam structure, and the thickness at both ends of the cap beam is greater than the thickness in the middle of the cap beam.

[0013] As a preferred solution of the present invention, the main arch ring adopts a steel box structure or a steel pipe structure, and the arch foot of the main arch ring is welded and fixed to the cap beam.

[0014] A novel construction method for a large-span arch combined bridge pier structure, characterized in that it comprises the following steps:

[0015] Step A: Construction of pile foundation, cap and pier column. The pile foundation is set below the ground obstacle, the cap is set on the top of the pile foundation, the pier column is set on the cap, and the reinforced steel plate cap is pre-embedded on the top of the pier column;

[0016] Step B: The cap beam is processed in the factory, transported to the site for assembly, and hoisted onto the pier column as a whole. During installation, the cap beam is accurately positioned, and the stiffened steel plate cap on the top of the pier is welded and fixed to the cap beam;

[0017] Step C: The main arch ring is processed in the factory. The size of the main arch ring is set according to the size of the cap beam. It is transported to the site for assembly and hoisted on the cap beam as a whole. The arch foot is welded and fixed to the cap beam.

[0018] Step D: Hanger construction. Install the hanger inside the central dividing strip of the main beam and outside the outer guardrail. The upper end of the hanger is connected to the main arch ring, and the lower end is connected to the cap beam;

[0019] Step E: Main beam construction. The main beam is prefabricated in the factory and transported to the site and installed on the cap beam;

[0020] Step F: Bridge deck construction, including pavement and guardrail construction;

[0021] Step G: Adjust the suspension rod tension.

[0022] As a preferred solution of the present invention, the pile foundation adopts bored cast-in-place piles, and the pier columns are variable-section rectangular piers, which are cast using formwork.

[0023] As a preferred solution of the present invention, in step D, after the hanger is installed, the hanger is initially tensioned, and the hanger tension is adjusted to the design value of the construction stage to provide elastic support for the cap beam.

[0024] As a preferred solution of the present invention, in the process of erecting the beams, step E gradually tensions the hangers according to the load of the main beams and the internal force of the cap beams to ensure the safety of the cap beams.

[0025] As a preferred solution of the present invention, in step G, the cable force of the hanger is adjusted to the design value of the bridge completion stage according to the stress condition of the cap beam.

[0026] The beneficial effects of the present invention are as follows: compared with the prior art: the novel large-span arch combined pier structure of the present invention adopts an arch system, provides multi-point elastic support for the cap beam through steel arch rings and hangers, and the load transmitted to the cap beam by the main beam of the upper structure is transmitted to the main arch ring by the hanger, which can reduce the bending moment of the cap beam, improve the stiffness of the cap beam, and greatly increase the span range of the cap beam, with high structural safety and wide applicability.

[0027] The cap beam, arch ring and main beam of the present invention adopt steel structure, which are produced in the factory and spliced, erected and installed on site. No support is needed for construction, thus solving the technical problem of difficult support erection, shortening the traffic interruption time and accelerating the construction speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a cross-sectional schematic diagram of the present invention;

[0029] Figure 2 is a schematic elevation view of the present invention;

[0030] Figure 3 It is a plan view schematic diagram of the present invention;

[0031] Reference numerals in the figure: cap beam 101 , main beam 102 , stiffened steel plate pier cap 103 , guardrail 104 , main arch ring 201 , hanger 202 , pier column 301 , cap 302 , pile foundation 303 , ground obstacle 401 . DETAILED DESCRIPTION

[0032] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0033] like Figure 1-3As shown, a novel large-span arch combined pier structure includes a pier column 301 and a cap beam 101 arranged on the pier column 301, the pier column 301 is arranged at both ends of the cap beam 101, and a pile foundation 303 and a cap 302 are arranged at the bottom of the pier column 301; a main arch ring 201 and a hanger 202 are arranged on the cap beam 101, the main arch ring 201 is an arc structure with an opening facing downward, and the arch feet of the main arch ring 201 are arranged at opposite ends of the cap beam 101; the upper end of the hanger 202 is connected to the main arch ring 201, and the lower end of the hanger 202 is connected to the cap beam 101; a main beam 102 is arranged on the cap beam 101, and the positions of the hanger 202 and the main beam 102 do not interfere with each other.

[0034] The position of the pier column 301 is set according to the position of the ground obstacle 401 such as a river or road. The pier column 301 is set on both sides of the ground obstacle 401 such as a river or road. The two sides of the ground obstacle 401 such as a river or road are provided with pier columns 301 arranged opposite to each other. The spacing between the pier columns 301 is set according to the actual width of the ground obstacle 401 such as a river or road. The spacing between the pier columns 301 is greater than the width of the ground obstacle 401 such as a river or road at the location.

[0035] The length of the cap beam 101 and the size of the main arch ring 201 are also set according to the actual distance between the oppositely arranged pier columns 301. The two ends of the cap beam 101 are erected on the top of the oppositely arranged pier columns 301. The cap beam 101 always keeps a horizontal state. The distance between the two arch feet of the main arch ring 201 corresponds to the length of the cap beam 101. The two arch feet of the main arch ring 201 are respectively set at the two ends of the cap beam 101.

[0036] Two parallel main beams 102 are arranged on the cap beam 101. The two main beams 102 form two lanes in opposite directions. The main beams 102 and the cap beam 101 are arranged crosswise, and the main beams 102 are placed on the cap beam 101. Guardrails 104 are arranged on both sides of the main beams 102. The guardrails 104 are located on both sides of the two main beams 102. The hangers 202 are located in the central dividing strip of the main beams 102 and outside the guardrails 104. Three hangers 202 are arranged between the main arch ring 201 and the cap beam 101. One hanger 202 is located between the two main beams 102, and the other two hangers 202 are located on both sides of the two main beams 102. The three hangers 202 are all arranged vertically, and the hangers 202 and the main beams 102 and the air above the main beams 102 do not interfere with each other.

[0037] The arch foot of the main arch ring 201 is set at the position of the cap beam 101 above the pier column 301. The main arch ring 201 and the cap beam 101 are consolidated to form a whole. The upper end of the hanger 202 is connected to the main arch ring 201, and the lower end of the hanger 202 is connected to the cap beam 101. The main arch ring 201 is arranged outside the clearance of the main beam 102 of the upper structure of the cap beam 101.

[0038] The size of the top of the pier column 301 gradually increases upward in the vertical direction. A stiffened steel plate pier cap 103 is provided on the top of the pier column 301. The stiffened steel plate pier cap 103 is welded and fixed to the cap beam 101 to facilitate the positioning and installation of the steel cap beam 101. The pier column 301 is a concrete rectangular pier to provide effective horizontal stiffness for the arch combined pier structure. The top area of ​​the pier column 301 gradually becomes larger, increasing the contact area between the pier column 301 and the cap beam 101.

[0039] The cap beam 101 is a steel box beam structure to ensure the overall force and structural safety of the cap beam 101. The steel box beam cap beam 101 can be processed in the factory and hoisted on site to shorten the construction period. The thickness of the two ends of the cap beam 101 is greater than the thickness of the middle part of the cap beam 101. The ends of the cap beam 101 are raised to improve the shear resistance of the cap beam 101.

[0040] The main arch ring 201 adopts a steel box structure or a steel pipe structure. The arch foot of the main arch ring 201 is welded and fixed to the cap beam 101. The height of the main arch ring 201 meets the clearance requirement of the vehicle on the main beam 102.

[0041] In actual production, the following steps are included:

[0042] Step A: Construction of pile foundation 303, cap 302 and pier column 301. Pile foundation 303 is set below the ground obstacle, cap 302 is set on the top of pile foundation 303, pier column 301 is set on cap 302, and a reinforced steel plate pier cap 103 is pre-embedded on the top of pier column 301.

[0043] The pile foundation 303 adopts bored cast-in-place piles. A pile hole is formed in the foundation soil at the construction site by mechanical drilling, steel pipe squeezing soil or manual excavation, and a steel cage is placed inside and concrete is poured to form a pile. Depending on the hole-forming method, the cast-in-place piles are selected as sinking pipe cast-in-place piles, bored cast-in-place piles and excavated cast-in-place piles.

[0044] The bridge pier column 301 is a variable cross-section rectangular bridge pier. The size of the top of the bridge pier column 301 gradually increases in the vertical upward direction. The bridge pier column 301 is cast using a template. Before casting, the garbage, soil in the template, oil stains on the steel bars and other debris should be cleaned up, and the cement mortar pads and plastic pads of the steel bars should be checked to see if they are properly padded. If a wooden template is used, water should be poured to moisten the template, and the cleaning opening of the column template should be closed after removing debris and accumulated water.

[0045] Step B: The cap beam 101 is processed in a factory, transported to the site for assembly, and hoisted as a whole onto the pier column 301. During installation, after the cap beam 101 is accurately positioned, the stiffened steel plate pier cap 103 on the top of the pier is welded and fixed to the cap beam 101.

[0046] The cap beam 101 is a steel box beam structure, which is connected by a full welding method with a top plate, a bottom plate, a web plate, a transverse diaphragm, a longitudinal diaphragm and stiffening ribs. The top plate is an orthogonal anisotropic bridge deck composed of a cap plate and longitudinal stiffening ribs. The steel plate box beam is a commonly used structural form in engineering. In order to study the influence of the spacing of transverse diaphragms on the distortion of simply supported steel box beams under concentrated loads, simply supported steel box beams with different numbers of transverse diaphragms are set, and the distortion effect and rigid torsion effect under concentrated loads are compared to obtain the maximum distortion effect curve with the number of transverse diaphragms. A concentrated load is applied to the top of the box beam web, and the load decomposition method is used to calculate according to four working conditions: distortion, rigid torsion, symmetrical bending and eccentric load.

[0047] Step C: The main arch ring 201 is produced and processed in a factory. The size of the main arch ring 201 is set according to the size of the cap beam 101. The main arch ring 201 is transported to the site for assembly and hoisted on the cap beam 101 as a whole. The arch foot is welded and fixed to the cap beam 101.

[0048] The main arch ring 201 is an arc-shaped structure with an opening facing downward, and the main arch ring 201 is also a steel box girder structure, which is connected by a top plate, a bottom plate, a web plate, a transverse diaphragm, a longitudinal diaphragm and stiffening ribs through full welding, wherein the top plate is an orthogonal anisotropic bridge deck composed of a cover plate and longitudinal stiffening ribs.

[0049] Step D: Construction of the hanger 202. The hanger 202 is installed inside the central dividing zone of the main beam 102 and outside the outer guardrail 104. The upper end of the hanger 202 is connected to the main arch ring 201, and the lower end is connected to the cap beam 101. After the hanger 202 is installed, the hanger 202 is initially tensioned, and the tension of the hanger 202 is adjusted to the design value at the construction stage to provide elastic support for the cap beam 101.

[0050] Step E: Construction of main beam 102. The main beam 102 is prefabricated in the factory and transported to the site, and installed on the cap beam 101. During the beam erection process, the hanger rod 202 is gradually tensioned according to the load of the main beam 102 and the internal force of the cap beam 101 to ensure the safety of the cap beam 101.

[0051] Step F: bridge deck construction, including pavement layer and guardrail 104 construction.

[0052] Step G: Adjust the cable force of the hanger 202 to the design value at the bridge completion stage according to the stress condition of the cap beam 101.

[0053] The upper end of the hanger 202 is connected to the main arch ring 201, and the lower end is connected to the cap beam 101. It is arranged inside the central dividing zone of the main beam 102 and outside the outer guardrail 104 to provide elastic support for the cap beam 101 to reduce the bending moment of the cap beam 101 and improve the structural rigidity.

[0054] The hanger 202 is used to transfer the load of the bridge deck system to the suspension cable, and can be made of round steel, eye rod or steel strand rope.

[0055] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention; therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0056] Although this article uses the following terms more frequently: cap beam 101, main beam 102, stiffened steel plate pier cap 103, guardrail 104, main arch ring 201, hanger 202, pier column 301, pedestal 302, pile foundation 303, ground obstacle 401, etc., it does not exclude the possibility of using other terms; these terms are used only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional limitations is contrary to the spirit of the present invention.

Claims

1. A novel large-span arch combined pier structure, comprising a pier column (301) and a cap beam (101) arranged on the pier column (301), wherein the pier column (301) is arranged at both ends of the cap beam (101), and a pile foundation (303) and a cap (302) are arranged at the bottom of the pier column (301); characterized in that: The cap beam (101) is provided with a main arch ring (201) and a suspension rod (202); the main arch ring (201) is an arc-shaped structure with an opening facing downward, and the arch feet of the main arch ring (201) are arranged at opposite ends of the cap beam (101); the upper end of the suspension rod (202) is connected to the main arch ring (201), and the lower end of the suspension rod (202) is connected to the cap beam (101); the cap beam (101) is provided with a main beam (102), and the positions of the suspension rod (202) and the main beam (102) do not interfere with each other; the cap beam (101) is a steel box beam structure, and the thickness of the two ends of the cap beam (101) is greater than that of the cap beam (101). The thickness of the middle part of the beam (101); the main arch ring (201) adopts a steel box structure or a steel pipe structure, and the arch foot of the main arch ring (201) is welded and fixed to the cap beam (101); the arch foot of the main arch ring (201) is arranged at the position of the cap beam (101) above the pier column (301), the main arch ring (201) and the cap beam (101) are consolidated to form a whole, the upper end of the hanger (202) is connected to the main arch ring (201), and the lower end of the hanger (202) is connected to the cap beam (101), and the main arch ring (201) is arranged outside the clearance of the main beam (102) of the upper structure of the cap beam (101).

2. The novel large-span arch combined pier structure according to claim 1 is characterized in that: Guardrails (104) are arranged on both sides of the main beam (102), and the suspension rod (202) is located in the central dividing zone of the main beam (102) and outside the guardrails (104).

3. The novel large-span arch combined pier structure according to claim 1 is characterized in that: The size of the top of the pier column (301) gradually increases upward in the vertical direction. A stiffening steel plate pier cap (103) is provided on the top of the pier column (301). The stiffening steel plate pier cap (103) is welded and fixed to the cap beam (101).

4. A construction method of a novel large-span arch combined bridge pier structure, based on the novel large-span arch combined bridge pier structure as claimed in any one of claims 1 to 3, characterized in that: The following steps are involved: Step A: Construction of pile foundation (303), capping platform (302) and pier column (301), wherein the pile foundation (303) is arranged below the ground obstacle, the capping platform (302) is arranged on the top of the pile foundation (303), the pier column (301) is arranged on the capping platform (302), and a reinforced steel plate pier cap (103) is pre-embedded on the top of the pier column (301); Step B: The cap beam (101) is processed in a factory, transported to the site for assembly, and hoisted as a whole onto the bridge pier column (301). During installation, after the cap beam (101) is accurately positioned, the stiffened steel plate pier cap (103) on the top of the bridge pier is welded and fixed to the cap beam (101); Step C: The main arch ring (201) is processed in a factory, the size of the main arch ring (201) is set according to the size of the cap beam (101), and the main arch ring (201) is transported to the site for assembly, hoisted on the cap beam (101) as a whole, and the arch foot is welded and fixed to the cap beam (101); Step D: Construction of the suspension rod (202), installing the suspension rod (202) inside the central dividing strip of the main beam (102) and outside the outer guardrail (104), wherein the upper end of the suspension rod (202) is connected to the main arch ring (201), and the lower end is connected to the cap beam (101); Step E: Construction of the main beam (102), the main beam (102) is prefabricated in the factory and then transported to the site and installed on the cap beam (101); Step F: bridge deck construction, including pavement and guardrail (104) construction; Step G: adjusting the cable force of the suspension rod (202).

5. The construction method of a novel large-span arch combined bridge pier structure according to claim 4 is characterized in that: The pile foundation (303) is a bored cast-in-place pile, and the pier column (301) is a variable-section rectangular pier, which is cast using a formwork.

6. The construction method of a novel large-span arch combined bridge pier structure according to claim 4 is characterized in that: In the step D, after the installation of the hanger (202) is completed, the hanger (202) is initially tensioned, and the tension of the hanger (202) is adjusted to the design value of the construction stage to provide elastic support for the cap beam (101).

7. The construction method of a novel large-span arch combined bridge pier structure according to claim 4 is characterized in that: In the step E, during the beam erection process, the suspension rod (202) is gradually tensioned according to the load of the main beam (102) and the internal force of the cap beam (101), so as to ensure the safety of the cap beam (101).

8. The construction method of a novel large-span arch combined bridge pier structure according to claim 4 is characterized in that: In the step G, the cable force of the hanger (202) is adjusted to the design value at the bridge completion stage according to the stress condition of the cap beam (101).

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