  This paper presents a multi-objective formulation for optimization of arch
dams. The objective is to simultaneously minimize the concrete volume and
stress state of the dam body. Instead of a single design, the multi-objective
problem provides a set of Pareto solutions in which a decision maker approach
can select best answer according to its preferences. To solve this new problem,
a multi-objective charged system search as an efficient meta-heuristic is also
developed. The proposed algorithm is evaluated on a real-size double curvature
arch dam. The computational results show that the proposed methodology is
highly competitive with existing arch dam optimization algorithms.
