One is concerned with the
design of the longitudinal
prestressing for highway bridge decks, with multiple
girders
in special those made with post-tensioned precast concrete. The major
point is to use an analysis methodology to be consistent through all
construction phases, since the first
prestressing at the plant until the
opening to traffic, with prestress losses considered. For this purpose, one
models the girder deck as a
grillage using the FEM. Moving loads are displaced step
by step over the slab, on the transversal and longitudinal directions, and a
stress envelop is generated. According to the construction phase the grillage
distribution is considered or not for the loads, including prestressing and its
losses. A computer program is developed to analyses the structure and to
calculate an appropriate girder prestressing.