Bridge type structure of large-diameter pile integrated continuous rigid frame bridge

Abstract

The utility model discloses a bridge type structure of a large-diameter pile-column integrated continuous rigid frame bridge, which aims at solving the problems of low efficiency, high risk, high cost and the like caused by the fact that a traditional rigid frame bridge needs a bearing platform and underwater steel cofferdam construction, and adopts a pile-column integrated design and a continuous rigid frame girder collaborative system. The main pier is formed by directly connecting a large-diameter socketed pile foundation and a cylindrical pier, and a bearing platform and underwater operation are omitted; and the pier top and the main beam 0 # block are anchored in a prestressed mode through a top straining beam, and a flexible pier-beam cooperative stress system is formed. The main beam is a single-box single-chamber variable cross-section continuous rigid frame box beam and is provided with a three-way prestress system. Through structure optimization, the construction process is remarkably simplified, underwater potential safety hazards are eliminated, material consumption is reduced, meanwhile, the anti-seismic property and environmental adaptability of the bridge are improved, and the structure is particularly suitable for large-span bridge construction under deepwater and complex geological conditions.

Description

Technical Field

[0001] This utility model relates to the field of bridge engineering technology, specifically a bridge structure for a large-diameter integrated pile and column continuous rigid frame bridge. Background Technology

[0002] Traditional rigid frame bridges in deep-water environments and long-span bridge construction commonly employ a structural system of "pile foundation + abutment + double-limb thin-walled pier + No. 0 block". This scheme distributes the load through the pile foundation, transfers the superstructure's forces to the piles through the abutment, provides vertical support through the double-limb thin-walled pier, and achieves pier-beam consolidation in conjunction with the No. 0 block. However, the construction of the pile foundation requires underwater steel cofferdam installation and blasting operations, resulting in a long construction period, limitations imposed by hydrological conditions, and high risks associated with underwater operations, especially in deep-water environments where the stability of the cofferdam is difficult to guarantee, easily leading to safety accidents. Furthermore, the abutment construction requires additional formwork and concrete pouring, increasing construction steps and costs, complicating construction, and posing safety hazards. Simultaneously, the combination of the double-limb thin-walled pier and abutment leads to material redundancy, increasing the structural self-weight, and the poor matching of pier stiffness with the main beam stiffness easily causes stress concentration. Moreover, the abutment, as an intermediate force-transfer component, consumes a large amount of concrete and steel reinforcement, resulting in resource waste and insufficient structural efficiency and economy. Finally, due to the high stiffness of traditional piers and their rigid connection with the main beam, they are prone to excessive displacement at the pier top or cracking of the beam under earthquakes or vehicle dynamic loads, affecting the structural durability. Summary of the Invention

[0003] The technical problem to be solved by this utility model is to provide a bridge structure for a large-diameter integrated continuous rigid frame bridge with piles and columns, which simplifies the deep-water construction process, reduces safety risks, and also achieves pier-beam stiffness matching, thereby improving overall economy and seismic performance.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is: a large-diameter pile-column integrated continuous rigid frame bridge structure, including a continuous rigid frame main beam and integrated pile piers, wherein the continuous rigid frame main beam and the continuous box girders located at both ends of it form a three-span continuous rigid frame structure.

[0005] The integrated pile pier consists of a bottom rock-socketed pile foundation and an upper pier column directly connected together.

[0006] The integrated pile pier has a top tie beam at the upper end of the pier column. The top tie beam is fixed to the No. 0 block of the main beam through prestressed tendons, forming a flexible pier-beam collaborative force-bearing system.

[0007] In a preferred embodiment, the rock-socketed pile foundation is embedded in moderately weathered rock strata, with an embedding depth of not less than three times the pile diameter.

[0008] In the preferred embodiment, the continuous rigid frame main beam is a single-box, single-cell variable cross-section box girder, and the beam height gradually decreases from the root to the mid-span according to a quadratic parabola.

[0009] In the preferred embodiment, the thickness of the web plate in the continuous rigid frame main beam gradually decreases from 100cm to 50cm, the thickness of the top plate is 30cm, and the thickness of the bottom plate gradually decreases from 150cm to 32cm.

[0010] In the preferred embodiment, the continuous rigid frame main beam is equipped with a three-dimensional prestressing system in the longitudinal, transverse and vertical directions to ensure uniform stress distribution on the box girder as a whole.

[0011] In a preferred embodiment, the prestressed anchorage node between the top beam and the No. 0 block of the main beam is connected by prestressed tendons to form a rigid connection node.

[0012] In the preferred embodiment, the pier column and the rock-socketed pile foundation of the integrated pile pier adopt a uniform cross-section transition, and the diameter of the rock-socketed pile foundation is 5cm larger than the diameter of the pier column to ensure uniform stress transmission in the pile-pier connection area.

[0013] The large-diameter pile-column integrated continuous rigid frame bridge structure provided by this utility model has the following beneficial effects by adopting the above structure:

[0014] (1) The traditional construction process of the pier and underwater steel cofferdam has been eliminated, which completely eliminates high-risk operations such as underwater blasting and cofferdam installation in deep water environment, and greatly reduces the safety risks of construction personnel and the probability of engineering accidents.

[0015] (2) The design of direct connection of large-diameter piles is adopted to avoid redundant structure of pile cap and double-limb thin-walled pier, reduce intermediate links in the force transmission path, make the load transmission more direct, and significantly enhance the integrity and stability of the structure.

[0016] (3) The flexible pier-beam co-force system effectively absorbs the energy generated by earthquakes and vehicle dynamic loads by adjusting the stiffness matching between the pier column and the main beam, reducing the displacement of the pier top and the stress concentration of the beam, and improving the seismic performance and long-term durability of the bridge. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0018] Figure 1 This is a schematic diagram of the main bridge structure of this utility model.

[0019] Figure 2 This utility model Figure 1 Detailed diagram.

[0020] Figure 3 This is a schematic diagram of the integrated pile pier structure of this utility model.

[0021] In the diagram: 1. Continuous rigid frame main beam, 2. Rock-socketed pile foundation, 3. Pier column, 4. Top tie beam. Detailed Implementation

[0022] Example 1:

[0023] like Figure 1-3 Among them, a large-diameter pile-column integrated continuous rigid frame bridge structure includes a continuous rigid frame main beam 1 and integrated pile piers. The continuous rigid frame main beam 1 and the continuous box girders located at both ends of it form a three-span continuous rigid frame structure.

[0024] The integrated pile pier is composed of a bottom rock-socketed pile foundation 2 and an upper pier column 3 directly connected together;

[0025] The pier column 3 in the integrated pile pier is provided with a top tie beam 4 at the upper end. The top tie beam 4 is fixed to the main beam block 0 through prestressed tendons to form a flexible pier-beam collaborative force-bearing system.

[0026] In the preferred embodiment, the rock-socketed pile foundation 2 is embedded in the moderately weathered rock layer, with an embedding depth of not less than three times the pile diameter.

[0027] In the preferred embodiment, the continuous rigid frame main beam 1 is a single-box single-cell variable cross-section box beam, and the beam height gradually decreases from the root to the mid-span according to a quadratic parabola.

[0028] In the preferred embodiment, the thickness of the web plate in the continuous rigid frame main beam 1 gradually decreases from 100cm to 50cm, the thickness of the top plate is 30cm, and the thickness of the bottom plate gradually decreases from 150cm to 32cm.

[0029] In the preferred embodiment, the continuous rigid frame main beam 1 is equipped with a three-dimensional prestressing system in the longitudinal, transverse and vertical directions to ensure that the box girder is subjected to uniform stress.

[0030] In the preferred embodiment, the prestressed anchorage node of the top beam 4 and the main beam block 0 is connected by prestressed tendons to form a rigid connection node.

[0031] In the preferred embodiment, the pier column 3 of the integrated pile pier and the rock-socketed pile foundation 2 adopt an equal cross-section transition, and the diameter of the rock-socketed pile foundation 2 is 5cm larger than the diameter of the pier column 3, to ensure uniform stress transmission in the pile-pier connection area.

[0032] Example 2:

[0033] Based on Example 1, the integrated construction process for large-diameter piles in deep-water environments includes:

[0034] (1) Pile foundation construction

[0035] A steel platform was erected in the deep water area as a pile foundation construction platform, with the platform elevation 1.5m above the highest water level;

[0036] The prefabricated steel casing (315cm in diameter) was hoisted in sections and connected section by section using underwater welding technology, and then sunk to the design elevation.

[0037] Use an impact drill to drill a hole inside the steel casing until it is embedded in the moderately weathered rock layer to a depth of 945cm (3 times the pile diameter). After cleaning the hole, a high-strength steel cage is inserted.

[0038] C40 concrete was poured in layers up to the top of the pile to form a rock-socketed pile foundation.

[0039] (2) Pier construction

[0040] C50 concrete was poured into the top of the pile foundation to form a cylindrical pier with a diameter of 310cm. The verticality error of the pier body was controlled within 1 / 1000.

[0041] A 360cm×310cm reinforced concrete top tie beam is installed on the pier top, with prestressed ducts and anchorages pre-embedded.

[0042] (3) Main beam block 0 is fixed

[0043] The No. 0 block of the main beam is cast in place on the tie beam at the top of the pier. The prestressed steel strands (strength 1860MPa) are tensioned by post-tensioning to anchor the tie beam and the No. 0 block into a whole, forming a rigid connection node between the pier and the beam.

[0044] Example 3:

[0045] Based on Example 1, the control of the flexible pier-beam cooperative force-bearing system includes:

[0046] Through finite element model analysis, the cross-sectional dimensions and reinforcement ratio of the pier column were adjusted to control the ratio of the longitudinal stiffness of the pier column to the stiffness of the main beam within the range of 1:16 to 1:43.

[0047] The limit for horizontal displacement at the top of the pier is 1 / 1000 of the span length L (120m) (i.e., ≤120mm).

[0048] Dampers are installed at the connection nodes between the top beam and the main beam to absorb vibration energy caused by earthquakes or vehicle loads.

[0049] Regularly monitor the displacement at the pier top and the stress in the beam to ensure the long-term stability of the flexible coupling system.

Claims

1. A bridge structure for a large-diameter integrated pile-column continuous rigid frame bridge, characterized in that: It includes a continuous rigid frame main beam (1) and an integrated pile pier, wherein the continuous rigid frame main beam (1) and the continuous box beams located at both ends thereon form a three-span continuous rigid frame structure; The integrated pile pier is composed of a bottom rock-socketed pile foundation (2) and an upper pier column (3) directly connected; The pier column (3) in the integrated pile pier is provided with a top tie beam (4) at the upper end. The top tie beam (4) is fixed to the No. 0 block of the main beam through prestressed tendons to form a flexible pier-beam cooperative force-bearing system.

2. The bridge structure of a large-diameter integrated pile-column continuous rigid frame bridge according to claim 1, characterized in that: The rock-socketed pile foundation (2) is embedded in the moderately weathered rock layer, with an embedding depth of not less than three times the pile diameter.

3. The bridge structure of a large-diameter integrated pile-column continuous rigid frame bridge according to claim 1, characterized in that: The continuous rigid frame main beam (1) adopts a single-box single-cell variable cross-section box beam, and the beam height gradually decreases from the root to the middle of the span according to a quadratic parabola.

4. The bridge structure of a large-diameter integrated pile-column continuous rigid frame bridge according to claim 3, characterized in that: In the continuous rigid frame main beam (1), the thickness of the web plate gradually changes from 100cm to 50cm, the thickness of the top plate is 30cm, and the thickness of the bottom plate gradually changes from 150cm to 32cm.

5. The bridge structure of a large-diameter integrated pile-column continuous rigid frame bridge according to claim 1, characterized in that: The continuous rigid frame main beam (1) is equipped with a three-dimensional prestressing system in the longitudinal, transverse and vertical directions to ensure that the box girder is subjected to uniform stress.

6. The bridge structure of a large-diameter integrated pile-column continuous rigid frame bridge according to claim 1, characterized in that: The prestressed anchorage node of the top beam (4) and the main beam No. 0 block is connected by prestressed tendons to form a rigid connection node.

7. The bridge structure of a large-diameter integrated pile-column continuous rigid frame bridge according to claim 1, characterized in that: The integrated pile pier adopts an equal cross-section transition between the pier column and the rock-socketed pile foundation (2). The diameter of the rock-socketed pile foundation (2) is 5cm larger than the diameter of the pier column (3) to ensure uniform stress transmission in the pile pier connection area.

Images