Construction technology of prestressed oblique beam with variable cross-section

Abstract

The invention relates to a variable cross-section pre-stress cant beam and a construction process thereof. The variable cross-section pre-stress cant beam is characterized by comprising a cant beam body, a lower end of the cant beam body is poured and connected to the upper end of a first layer of layer, the central part and the upper end of the cant beam body are poured and connected to a Y-shaped column; an I-shaped stiff steel rib and a pre-stress bellows are arranged in the cant beam body, the stiff steel rib is positioned at the center of the cant beam body, the number of the pre-stress bellows is four and the pre-stress bellows are respectively positioned at four angels of the stiff steel rib, the stiff steel rib is pulled by each pre-stress bellow; the cross section of the cant beam body is varied, width of the connection part of the cant beam body and the first layer of the column, the connection part of the connection part of the cant beam body and a third layer of the column, the connection part of the connection part of the cant beam body and a fourth layer of the column, the connection part of the center part and the cant beam body, the connection part of the cant beam body and the Y-shaped column, and the connection part of the cant beam body and the upper end part keeps consistency, and the thickness is determined according to the angle of the cant beam body, number of picking ear in each layer, tand he first layer of column and the Y-shaped column. The construction process guarantees the convenience of the pulling of the bellows and the pulling quality of pre-stress rib.

Description

technical field [0001] The invention belongs to the technical field of prestressed construction of variable-section prestressed oblique beams, and in particular relates to a variable-section prestressed oblique beam and a construction process thereof. Background technique [0002] The 15,000-seat main stadium project of Wuhan Optics Valley International Tennis Center is a "bowl-shaped" stadium composed of 32 Y-shaped columns supporting the inclined beams of the stands. The engineering structure is relatively complicated. Because the stands are in the form of steps, there are many forms of lower supporting structures. The supporting structure of the tennis hall stands in this project is a cantilevered large inclined beam on a Y-shaped column. The stand is high from the ground and has a large span. The design size of inclined beam section is large. The oblique beam itself is an oblique member, and the overweight oblique member in space will generate a large horizontal thrust ...

AI Technical Summary

Problems solved by technology

The oblique beam itself is an oblique member, and the overweight oblique member in space will generate a large horizontal thrust due to its own weight and construction load, and the horizontal thrust generated by the oblique beam will increase with the increase of the inclination angle. The increase is particularly unfavorable to the force of the scaffolding (that is, the full frame) system

If the inclination angle of the inclined beam is too small, it will affect the viewing effect of the audience in the upper stand

[0003] During the traditional prestressing construction, the corrugated pipe is threaded at one time. During the construction process, the corrugated pipe is likely to be damaged or blocked, making it difficult or impossible to thread the prestressed tendons in the later stage.

The prestressed tendons threading step is to thread the prestressed tendons after the corrugated pipe is installed, and pour concrete. However, in this project, the oblique beam is long and has a variable cross section. The prestressed tendon curves are inconsistent. Prestressed tendons, resulting in long prestressed tendons reserved, the latter section of the bellows cannot be threaded, and it is easy to cause problems such as pollution, bending, and breakage of prestressed tendons

[0004] In the construction of traditional inclined beams, lugs are generally used as secondary structure construction: 1. It is not conducive to the integrity of the lug structure; 2. It is not conducive to the construction period

However, the inclined beam is regarded as a beam for formwork installation: 1. It is not conducive to concrete pouring; 2. The requirements for the formwork frame are high, which is not conducive to the overall load bearing of the formwork frame; 3. The concrete on the upper surface of the inclined beam is prone to floating Pulp has a certain impact on the quality of the project

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