Interlaced anchorage arrangement and construction method of super-long prestressed steel beams

Abstract

The invention discloses a stagger anchoring arrangement mode for overlong prestress steel cables and a construction method. A plurality of prestress short cables are included, the multiple prestress short cables are alternately distributed at the two sides of the position of the center cross section of a pier top, and one end of each cable is fixedly anchored on the cross section of an original cantilever end, and the other end of each cable is fixedly anchored on the cross section of the pier top at the opposite side of the cantilever end; and the ends, on the center cross section of the pier top, of the multiple prestress short cables are partially overlapped to form a stagger anchoring area of overlapped anchoring on the pier top. According to the stagger anchoring arrangement mode for the overlong prestress steel cables, the prestress steel cables are reasonably arranged and anchored, the long cables are properly changed to the short cables, and since prestress loss is closely linked to the length of the prestress steel cables, the prestress loss, caused by friction between steel strands and pipeline walls, looseness of steel bars and the like, of overlong prestress steel cables is decreased greatly, and therefore the mid-span deflection caused by the excessively large prestress loss is decreased.

Description

technical field [0001] The invention relates to an arrangement method and a construction method for super-long prestressed steel beams of a large-span continuous rigid frame bridge, in particular to an arrangement method and a construction method for interlaced anchoring of super-long prestressed steel tendons. Background technique [0002] The prestressed concrete continuous rigid frame bridge has the advantages of large spanning capacity, reasonable stress, smooth driving, convenient construction, and low maintenance cost. It has strong adaptability to mountainous areas with high mountains and steep slopes and narrow construction sites. China has built no less than 50 continuous rigid frame bridges with a main span of more than 200m, becoming the main bridge type of large and medium span girder bridges in my country. [0003] At present, the main defects of domestic long-span prestressed concrete continuous rigid frame bridges are excessive mid-span deflection of the main ...

AI Technical Summary

Problems solved by technology

Therefore, for the arrangement and anchoring of longitudinal prestressed steel tendons, the prestressed steel tendons are mainly anchored to the two cantilever ends of the symmetrical pouring section at present, that is, the overall length of the anchorage is as follows: figure 1 As shown, but with the increase of the length of the cantilever pouring section, the prestressed tendon will inevitably become longer and longer, and the prestressed loss is closely related to the length of the prestressed tendon

There is still no good solution for how to reasonably arrange the anchorage of the long prestressed beams, and how to properly transform the long prestressed beams into short beams, so as to improve the permanent prestress in the ultra-long prestressed steel beam body and reduce the loss of prestress. method

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