Sensitivity Assessment using Genetic Algorithm for Optimal Design of RC Ring Wall Foundation of Liquid Storage Tanks

Hydrocarbons and chemical industries extensively use storage tanks made of steel for storing large quantities of liquids. These tanks are typically supported on a RC ring wall foundation. This paper presents a method to minimize the cost of RC Ring Wall Foundations and study the sensitivity of this cost towards the different design parameters. The optimization process is developed through the use of genetic algorithm which simulates the biological evolution for the fittest (optimized) organism Previous studies on use of genetic algorithm in structural engineering has been applied to different structures like frames beams, columns etc. This paper extends the use of genetic algorithm to ring wall foundations of liquid storage tanks. The objective function for optimization includes the costs of concrete, steel, formwork and excavation whose sensitivity is analysed for parameters like grade of steel, concrete, seismic and wind loading for different tank sizes. All the constraints functions are set to meet the design requirements as per Indian Standard Codes and construction industry practices. Eight cases of parametric study are considered in order to illustrate the applicability of the genetic algorithm design model. It is concluded that this approach is economically more effective compared to conventional methods for design and sensitivities of different design parameters can be quickly assessed. Additionally this design methodology can be extended to deal with other types of structures as well.