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.