چكيده لاتين :
In this paper the influence of the unit cost of steel, concrete and formwork and the characteristic strengths of steel and concrete on the optimum design of reinforced concrete flat slab buildings is investigated. Size optimization of flat slab buildings according to the
British Code of Practice is carried out. The objective function is the total cost of the building including the cost of floors, columns and foundations. The total cost ofthe building includes the cost of material and labour for concrete, reinforcement and formwork.
Excavation cost is also considered in the cost of foundations the optimization process is handled in two levels. In the first level the optimum cross-sectional dimensions of reinforced concrete elements is determined using a hybrid algorithm based on genetic algorithm . In the second level an exhaustive search is applied to seek the optimum size and number of steel bars for each individual type of structural elements. A practical example is given to demonstrate the achieved cost saving and sensitivity of the optimum design to unit cost items and the characteristic strengths of steel and concrete.
