Construction method of PK fracture surface prestressed concrete box girder

Abstract

The invention provides a construction method of a PK fracture surface prestressed concrete box girder. The method comprises the steps that firstly prefabrication is carried out in a ground prefabrication site; then a prefabricated girder segment is lifted to a sliding and moving bracket; the prefabricated girder segment is moved to the design position on the sliding and moving bracket, and long-term storage is realized; and after a gluing period is reached, gluing is completed. A short line method is used in ground prefabrication. The construction method is simple in principle and convenient to operate, economical and reasonable are realized, and the construction method can be widely used in prefabrication and splicing construction of various types components, labor can be effectively saved, and uncertainty brought by manual operation can be avoided.

Description

technical field [0001] The invention belongs to the technical field of bridge construction, and in particular relates to a construction method of a PK section prestressed concrete box girder. Background technique [0002] In the field of engineering construction at home and abroad, the number of prestressed concrete box girder bridges with PK sections is relatively small, and the cast-in-place method of brackets is generally used for construction. However, due to the super-wide, over-weight, and weak torsional rigidity in the transverse bridge direction, the cast-in-place method has always had the following defects: [0003] 1. The cast-in-place method has inconsistent restraint stiffness in all directions of the beam body, which leads to a large number of shrinkage cracks or even cracks in the process of concrete hardening; [0004] 2. A large amount of support system and formwork system are required, and generally do not have the conditions for multiple use, and the econo...

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Problems solved by technology

[0003] 1. The cast-in-place method has inconsistent restraint stiffness in all directions of the beam body, which leads to a large number of shrinkage cracks or even cracks in the process of concrete hardening;

[0004] 2. A large amount of support system and formwork system are required, and generally do not have the conditions for multiple use, and the economy is extremely poor;

[0005] 3. The line shape of the bracket cast-in-place method completely depends on the stiffness of the bracket system and the formwork system, but the long-term geological conditions and support conditions in actual projects are very different, and the stiffness of the entire bracket and formwork system varies greatly. According to the current domestic and foreign cast-in-place construction Case, linear control is extremely poor;

[0006] 4. The above-mentioned 3rd linear error causes the overall stress system of the bridge to be inconsistent with the design, and there are a large number of cracks and cracks, which in turn greatly reduces the service life of the bridge, and a large amount of repair work will be generated in the later operation stage

[0007] The construction of segmental prefabrication method, which is rare in the prior art, also has many deficiencies due to the inadequacy of analysis and treatment of key issues, and urgently needs to be improved.

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