Bridge at Hagen

Abstract

The bridge at Hagen-Eskesy, in Germany, was destroyed during the last war, and its reconstruction is part of a local improvement plan. The initial bridge was metallic, but it has now been decided to build a main tied arch, consisting of a box section arch, of 93 m span, and two lateral spans, each 33 m long. These two are open girders, whose top and bottom chords are also hollow box sections. Both the tie members and the main bridging structures are prestressed. The twin arches, from which the deck hangs, are independent. This has made it necessary to attach the arches very rigidly to the stabilising structure, to withstand the powerful effect of the wind forces. Owing to the large dimensions, the possible effect of torsion and buckling under the prestressing forces had to be carefully considered. The twin arches are 12.90 m from each other, and their section is 1.2x1.2 m at the springers, 2x2 m at the quarter span, and 2.4x1.7 at the crown. During the loading and overloading tests, oscilographs were used, to record the effect of mobile loads, and of the increasing overloads. To simulate the effect of running over uneven surfaces, timber beams were placed across the pavement, and loaded vehicles were made to run over them.