A geometric programming method for cost-optimal design of a modular floor system

Geometric programming has been found suitable for optimal design of many engineering systems. This paper presents a method based on geometric programming for cost-optimal design of a modular floor system with precast prestressed slab units simply supported on steel beams. Both voided and solid slab constructions are considered. The objective function of the optimization problem includes cost of fabrication including concrete, formwork, prestressing and steel beams and cost of erecting the structure. The constraints are formulated based on allowable stresses, deflections and geometry of the structural systems. The optimization problem is solved to obtain the optimal values of the design variables. Sensitivity analyses are then performed to determine the effect of changes in the imposed load on the optimum values of the design variables.