Simultaneous Cross Section and Launching Nose Optimization of Incrementally Launched Bridges

Abstract

The conventional design process of the launching nose of an incrementally launched bridge is usually based on parametric models with great limitations and the use of a trial and error technique to improve the design. Facing the disadvantages of traditional approaches, the use of numerical optimization techniques permits the development of objective, rigorous, and complete formulations. This work solves the design optimization problem of an incrementally launched prestressed concrete bridge during construction, searching simultaneously for the optimum cross section dimensions and the prestressing forces of the concrete deck, as well as the most adequate characteristics of the launching nose for the best economic solution. A computer code that allows the generation of a deck was developed, under real design constraints similar to those a bridge designer may encounter in practice. This code is very useful for preliminary phases of a project. The results obtained with this innovative formulation show the benefit of considering numerical optimization tools.