Conception of Post-Tensioning in Concrete Bridge Engineering using Optimization Methods – Basic and Examples

The process of finding the optimal run and force of prestressing strands within the entire length of prestressed concrete bridges is by now largely controlled by the experience of the planning engineer. Due to the strong influence of the particular parameters of prestressing on the longitudinal stresses of the whole structure, there is a demand for an elaborate, iterative search for an optimal prestressing, especially within statically indeterminate load-bearing systems of sectionally- constructed bridges. This paper shows how the conception of prestressing can be performed and at the same time, optimized through the use of non-linear numerical methods. With reference to planned bridges, the considerable potential of this numerical drafting method is demonstrated.