ElsevierMartínez Martín, FJ.; Hospitaler Pérez, A.; Yepes Piqueras, V. (2010). Heuristic optimization of RC bridge piers with rectangular hollow sections. Computers and Structures. 88:375-386. doi:10.1016/j.compstruc.2009.11 Keywords: structural design, economic optimization, ant colony optimization, concrete structures.
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IntroductionThe design of bridge piers is crucial for the design of prestressed concrete viaducts. The piers make up between 20% and 50% of the total cost of the viaduct depending on pier heights and foundation conditions. Rectangular hollow cross-sections as described in the present paper are most frequently used. Current designs of such reinforced concrete (RC) structures are highly conditioned by the experience of structural engineers. Design procedures usually adopt cross-section dimensions and material grades based on commonly sanctioned practice. Once the geometry and materials of the structure are specified, the reinforcement of the pier is tentatively defined according to experience. The first-order stress resultants are analyzed and second-order (buckling) stress resultants are then estimated according to simplified and conservative formulae or following a more general method that accounts for second-order deformations and includes the non-linear stiffness of the column. Tentative passive reinforcement must then satisfy the limit states prescribed by concrete codes. Should the dimensions, the material grades or the reinforcement be insufficient, the structure is redefined on a trial-and-error basis. This process leads to safe designs, but the cost of the RC pier is, consequently, highly dependent upon the experience of the structural designer. In contrast to designs based on experience, artificial intelligence has been applied to a variety of fields including the solution of constrained problems. The design of RC structures is a problem of selecting design variables as subject to structural constraints for which artificial intelligence is aptly suited. These methods involve simple algorithms, but they also require a considerable computational effort, since they include a large number of iterations in which the objective function is evaluated and the structural constraints are checked. The rectangular hollow section piers object of this study are those commonly used in the construction of cast-in-place prestressed concrete road and railway viaducts. The objective of this study is to examine the heuristic optimization of this type of RC structure. The method followed consisted in developing an evaluation computer module in which cross-section dimensions, materials and steel reinforcement are taken as discrete variables. This module computes the cost of a solution and checks all the relevant limit states. ACO, GA and TA algorithms are then used to search the solution space. It is important to note that the present study is an updated and revised version of the conference 6 study by Martinez et al. [21], which was an initial analysis that concentrated on ACO algorithms and did not includ...