The Launching of the Pavilion Bridge, Zaragoza, Spain

Abstract

through pods and noncontinuous ones in the lateral pods.A lower chord was formed by a box girder, just below the lowest platform, and lateral trusses between both chords, upper and lower, called "diagrid", the latter showing some discontinuities to allow for windows.The structure is modulated lengthwise into 3,60 m equally spaced cross sections, and at each of them, and within the lower box girder, there exist transverse diaphragms from which "ribs" extend out reaching for, and connecting to, the upper chords. Diagrid panels were installed between those ribs. South Structure Launching, General SchemeTh e southern portion of the structure, 140 m long and 21 MN in weight, was assembled at the right margin of the Ebro River, that is, the southern side. It had to be moved 123 m up to its final position. This was the most complex and spectacular part of the construction of the Pavilion Bridge.The launched element was curved plan wise, of variable width and height and fu lly asymmetric.The launching project, jointly developed by the alternative structural designer and the contractor technical services, started by determining the center of gravity of the structure. Actions on the permanent structure and auxiliary elements during launching were sensitive to the center of gravity position.Launching was organized into three phases, according to where movement was driven from: -First phase: the structure was supported on hydraulic jacks capable of skidding and guided by two sliding railing paths. The total distance to traverse was 44 m longitudinally and 9 m transversely. During launching, the structure was simply supported on two skidding lines, front and rear, which were fi xed with respect to the structure. -Seco nd phase: this phase used the same skidding elements used previously. As the frontal cantilever kept AbstractThis article describes the construction method of a singular structure, half pavilion and half bridge.Th e Pavilion Bridge is a curvaceous complex structure, architecturally influenced in its design as a combination of a building for exhibitions and a footbridge over a major river.The construction method was essentially chosen to meet a tight deadline. It basically consisted of working in parallel in two sites, one at each river bank. The northern site was built by a more common method. The southern site accommodated the assembling of the rest of the structure, that is, the main span to be launched.Launching this structure was a most unusual maneuver, even for this experienced team, who were used to complex construction methods.