A Realization Method of Sectional Temporary Prestress of Bridge Segment

Abstract

The invention discloses a section temporary pre-stress implement method of bridge segments. The method includes the steps that a winding hoist machine is adopted to hoist a segment to be mounted in place, after trail assembly is correctly conducted, the segment to be mounted is disconnected, and an adhesive is used for smearing the section of a mounted segment; the segment to be mounted is assembled in place, a temporary pre-stress device is mounted on top plates of the two segments and exerts first extrusion force, a bending moment generated by the first extrusion force on the centroids of the segment sections serves as a first bending moment, resultant force of the gravity of the segment to be mounted and tensile force of the winding hoist machine serves as a second bending moment, a bending moment generated by second extrusion force on the centroids of the segment sections serves as a second bending moment, and the tensile force of the winding hoist machine is reduced to make the first bending moment equal to the second bending moment. The first bending moment is equal to the second bending moment, and extrusion stress formed by the first extrusion force evenly acts on the segment sections; the situation is avoided that pressure on the upper end of a joint is high, and pressure on the lower end of the joint is low; the construction quality of the glued joint is ensured.

Description

technical field [0001] The invention relates to the technical field of bridge construction, in particular to a method for realizing temporary prestressing of bridge sections. Background technique [0002] For bridges constructed by the cantilever assembly process, the segmental joints are generally glued joints, and a certain thickness of adhesive needs to be applied to the section of the segment to play the roles of lubrication, riveting, waterproofing, and stress transmission. The application of extrusion force is generally realized by a temporary prestressing device installed on the segmental beam, and the weight of the segment itself is generally borne by the cantilever assembly equipment. Temporary prestressing devices generally include tensioning pedestals and precision-rolled rebars, which are characterized by easy operation and repeated durability. [0003] In order to ensure the effective use of prestress, it is usually required that the line of action of temporary...

AI Technical Summary

Problems solved by technology

At this time, we can only rely on the top temporary pre-stressing device to apply extrusion force, which will inevitably lead to high pressure at the upper end of the joint and lower pressure at the lower end. Tensile force is required (in order to ensure the safety of tensioning, the size of the tensioning pedestal must be increased and the anchoring measures must be strengthened), which eventually leads to the compressive stress of the section being large at the top and small at the bottom, which cannot be uniformly compressed, thus affecting the construction quality of the glued joint. leave a hidden danger

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