en Optimal design Optimal design پژوهشي Research This study presents shape optimization of a gravity dam imposing stability and principal stress constraints. A gravity dam is a large scale hydraulic structure consisting of huge amount of concrete material. Hence, an optimum design gives a cost-benefit structure due to the fact that small changes in shape of dam cross-section leads to large saving of concrete volume. Three recently developed meta-heuristics are utilized for optimizing the structure. These algorithms are charged system search (CSS), colliding bodies optimization (CBO) and its enhanced edition (ECBO). This article also provides useful formulations for stability analysis of gravity dams which can be extended to further researches. gravity dam, structural optimization, stability analysis of dam, charged system search, colliding bodies optimization, meta-heuristics. 419 431 http://ijoce.iust.ac.ir/browse.php?a_code=A-10-66-76&slc_lang=en&sid=1 A. Kaveh 18003194753284600867 18003194753284600867 Yes P. Zakian 18003194753284600868 18003194753284600868 No