Large-span U-shaped beam prefabricating construction technology capable of realizing pre-tensioned and post-tensioned prestressed combined construction

Abstract

The invention relates to the field of concrete U-shaped beam prefabricating construction, in particular to a large-span U-shaped beam prefabricating construction technology capable of realizing pre-tensioned and post-tensioned prestressed combined construction. The technology mainly includes the following steps that bottom molds and side molds of a U-shaped beam are mounted and are bound into a steel reinforcement framework, impurities are cleaned, a support plate is mounted, collapse-proof embedded pieces are mounted, the steel reinforcement framework is hung, the steel reinforcement framework, steel strands and corrugated pipes are adjusted, end formworks are mounted, the prestress is adjusted preliminarily, embedded conduits are mounted, embedded pieces are mounted, overall tensioning is performed with the final tensioning stress, concrete pouring is performed, natural curing is performed, inner molds are dismounted, the side molds are loosened, the single end of a beam body is released synchronously, the steel strands are cut off mechanically, the end formworks are dismounted, the steel strands are bundled with the post-tensioning method, post-tensioned prestressed tensioning is performed, anchor sealing and beam storage are performed, and hole grouting, curing and the like are performed. According to the technology, a pre-tensioned and post-tensioned combined prestressed bridge is adopted, the stress and the deflection of the U-shaped beam and the control on cracks meet requirements, the prestressed steel reinforcement quantity and the equipment and the personnel investment are saved, the construction period is shortened, and the economic benefit is obtained.

Description

technical field [0001] The invention relates to the field of concrete U-shaped beam prefabricated construction, in particular to a large-span U-shaped beam prefabricated construction technology combined with successive tension and prestressing construction. Background technique [0002] Most of the domestic urban rail transit elevated parts are in the form of box girders, which have shortcomings such as excessive engineering structure height, complicated construction procedures, and high engineering costs. Some elevated structures have also begun to use segmental beams for assembly construction, but the assembly speed is relatively slow. In my country, the construction is intensive. Under the background of U-shaped beam, major cities in China are actively planning the development of rail transit in the future. The promotion of U-shaped beam technology is of great significance. Prestressed concrete bridges, but domestic U-beam application technology is still under development. ...

AI Technical Summary

Problems solved by technology

[0004] At present, the prestressed pretensioning method is the most commonly used in the construction of most beams for U-shaped beam prefabrication. However, not all beams with spans are suitable for pretensioning construction. Pre-tensioned steel strands, U-shaped beams, stress, deflection, cracks, etc. cannot meet the requirements of design and specifications, so large-span U-shaped beams are not suitable for pre-tensioned construction. Due to severe technical limitations, construction is difficult, resulting in large-span pre-tensioned Stress bridge cannot complete construction

For example, the patent number is: CN 201110235383.7, and the patent name is: a technology mentioned in the public document of the prefabricated construction technology of rail transit prestressed pretensioned concrete U-shaped beams. This technology is applied to realize concrete U-shaped beams in rail transit Prefabricated construction, but still subject to technical limitations, is limited to small-span beam construction, which is unfavorable to the application and development of large-tonnage prestressed bridges in the future