Novel joint for hogging moment area at box girder pier top

Abstract

The utility model relates to the field of box girders, and provides a novel joint for a hogging moment area at the top of a box girder pier, which is arranged at the joint of two box girders at the upper end of a pier and comprises a prestressed tendon and a steel stop block, anchor heads are arranged at two ends of the prestressed tendon to fixedly connect the upper ends of the box girders, and the steel stop block is arranged below the prestressed tendon to connect the box girders at two sides. The box girder pier has the advantages that the upper tension-bearing prestressed tendons are matched with the lower pressure-bearing steel check blocks, the mechanical property of a hogging moment area at the top of the box girder pier is greatly enhanced, the prestressed tendons bear and effectively disperse tension load from the upper portion in advance, the lower steel check blocks bear pressure of box girders on the two sides, and therefore the box girder pier is not prone to falling off. The mechanical property of the hogging moment area at the top of the box girder pier is greatly enhanced, so that the area can show more excellent bearing capacity and non-deformability when facing a complex and changeable load environment, and the bearing capacity and safety of the box girder are remarkably improved.

Description

Technical Field

[0001] The utility model relates to the technical field of box girders, and particularly relates to a novel joint in the negative moment area at the pier top of a box girder. Background Technique

[0002] As a bridge component with an intuitive structure and simple construction, precast box girders have occupied a pivotal position in large-scale transportation infrastructure projects such as urban viaducts and expressways due to their unique advantages. One of its greatest highlights is that precast box girders can be mass-produced efficiently in a specialized precast girder yard, which not only significantly shortens the construction period but also remarkably improves the standardization and regularization level of project construction. In addition, the construction process of precast box girders is relatively simple and fast, reducing the on-site workload and the interference to the surrounding environment, which conforms to the concept of modern green construction.

[0003] However, despite the many advantages of precast box girders, they also face some challenges in practical applications, especially in the negative moment area at the pier top. This area is subjected to complex mechanical actions from the bridge deck and vehicle loads, resulting in a complex and variable stress state of the structure, and the stability problem is particularly prominent. Especially under the long-term load, the risk of structural fatigue and damage in the negative moment area at the pier top increases, posing a potential threat to the overall safety and durability of the bridge. Therefore, how to solve the problems of large stress and insufficient structural stability in the negative moment area at the pier top of precast box girders while maintaining their original advantages has become an urgent technical problem to be solved in the current bridge engineering field. Content of the Utility Model

[0004] Aiming at the deficiencies of the prior art, to solve the problem that the negative moment area at the pier top of the precast box girder is subjected to complex mechanical actions from the bridge deck and vehicle loads, resulting in a complex and variable stress state of the structure and poor stability;

[0005] The utility model provides a novel joint in the negative moment area at the pier top of a box girder. The joint is arranged at the connection of two box girders at the upper end of the pier and includes prestressed tendons and steel retaining blocks. Anchor heads are arranged at both ends of the prestressed tendons to fixedly connect the upper ends of the box girders, and the steel retaining blocks are arranged below the prestressed tendons to connect the box girders on both sides.

[0006] As a preferred scheme, a plurality of structural steel bars are arranged on the prestressed tendons.

[0007] As a preferred scheme, the structural steel bars are arranged at equal intervals longitudinally along the anchor heads, and the structural steel bars are perpendicular to the axis of the box girder.

[0008] As a preferred scheme, the longitudinal spacing between adjacent structural steel bars is 8 - 12 cm.

[0009] As a preferred solution, the spacing between adjacent prestressed tendons is 8-12 cm.

[0010] The beneficial effects of the utility model are:

[0011] The utility model greatly enhances the mechanical properties of the negative bending moment zone at the box girder pier top through the cooperation of the upper tensile prestressed tendons and the lower compressive steel blocks. The prestressed tendons bear and effectively disperse the tensile load from above in advance, and the lower steel blocks bear the pressure of the box girders on both sides. This not only greatly enhances the mechanical properties of the negative bending moment zone at the box girder pier top, but also enables this area to show more outstanding bearing capacity and anti-deformation ability when facing complex and changeable load environments, thereby significantly improving the bearing capacity and safety of the box girder. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to make the content of the utility model easier to understand, the utility model is further described in detail below according to specific embodiments and in conjunction with the accompanying drawings, wherein:

[0013] Figure 1 It is a structural schematic diagram of the utility model.

[0014] The reference numerals in the accompanying drawings are:

[0015] 1-box girder; 2-bridge pier; 3-prestressed tendons; 4-structural reinforcement; 5-anchor head; 7-steel stopper. DETAILED DESCRIPTION

[0016] To illustrate the features of the present invention, the present invention is further described below with reference to the accompanying drawings and embodiments.

[0017] Example:

[0018] refer to Figure 1 This embodiment provides a new type of joint in the negative bending moment area at the top of the box girder pier, which solves the problem of low accuracy and durability of the current rolling tool micro-adjustment device; the joint is set at the connection of the two box girders 1 at the upper end of the pier 2, including prestressed tendons 3 and steel blocks 7, anchor heads 5 are set at both ends of the prestressed tendons 3 to fix the upper end of the box girder 1, and the spacing between adjacent prestressed tendons 3 is 10cm; the steel blocks 7 are set below the prestressed tendons 3 to connect the box girders 1 on both sides. Through the cooperation of the upper tensile prestressed tendons and the lower compressive steel blocks, the mechanical properties of the negative bending moment area at the top of the box girder pier are greatly enhanced. The prestressed tendons pre-bear and effectively disperse the load pressure from the top, and the lower steel blocks bear the pressure of the box girders on both sides, which not only greatly enhances the mechanical properties of the negative bending moment area at the top of the box girder pier, but also enables this area to show more outstanding bearing capacity and anti-deformation ability when facing complex and changeable load environments, so that the bearing capacity and safety of the box girder are significantly improved.

[0019] Preferably, in this embodiment, a plurality of construction steel bars 4 are provided on the prestressed tendon 3. The construction steel bars 4 are arranged at equal longitudinal intervals along the anchor head 5, and the construction steel bars 4 are perpendicular to the axis of the box girder 1. The longitudinal interval between adjacent construction steel bars 4 is 10 cm. By setting the construction steel bars, the compressive strength and shear strength of the concrete structure are significantly enhanced, thereby enhancing the bearing capacity of the overall structure, effectively preventing cracks from occurring, reducing cracks caused by drying shrinkage or load effects, maintaining the integrity and stability of the structure, and improving the safety of the prestressed box girder under extreme load conditions by reasonably arranging the steel bars.

[0020] The above embodiments and the accompanying drawings are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. The present invention has been described in detail with reference to the preferred embodiments. Those of ordinary skill in the art should understand that any changes, modifications, additions, or substitutions made by those of ordinary skill in the art within the scope of the essence of the present invention do not depart from the purpose of the present invention and should also fall within the scope of the claims of the present invention. Other related technical structures not exhaustively disclosed in the present invention are the prior art in this field.

Claims

1. A novel joint in the negative moment area at the top of the pier of a box girder. The joint is arranged at the connection of two box girders (1) at the upper end of a pier (2), and is characterized in that: It includes prestressed tendons (3) and steel stoppers (7). Anchor heads (5) are provided at both ends of the prestressed tendons (3) and fixedly connected to the upper ends of the box girders (1). The steel stoppers (7) are arranged below the prestressed tendons (3) and connected to the box girders (1) on both sides.

2. The novel joint in the negative moment area at the pier top of the box girder according to claim 1, wherein: A plurality of structural steel bars (4) are provided on the prestressed tendons (3).

3. The novel joint in the negative bending moment area at the pier top of the box girder according to claim 2, characterized in that: The structural steel bars (4) are arranged longitudinally at equal intervals along the anchor heads (5), and the structural steel bars (4) are perpendicular to the axis of the box girder (1).

4. The novel joint in the negative moment area at the pier top of the box girder according to claim 2, characterized in that: The longitudinal spacing between adjacent structural steel bars (4) is 8 - 12 cm.

5. The novel joint in the negative moment area at the pier top of the box girder according to claim 1, characterized in that: The spacing between adjacent prestressed tendons (3) is 8 - 12 cm.

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