Due to a high ratio between the radius and wall thickness, steel storage tanks are sensitive to stability. The thesis examines the standards used in the analysis of steel storage tank strength and stability, focusing on the API 579 Fitness-For-Service standard, which deals with the existing storage tanks. The stability of shell structures is considered to be strongly influenced by initial imperfections. An advanced analysis, as described in API 579, requires an accurate representation of imperfections,
which can be generated using the data obtained from laser scanners. The thesis includes a geometric and material nonlinear analysis of strength and stability of the existing storage tank conducted using the data collected from laser scanners. An advanced analysis was performed using the Wolfram Mathematica program and a package within the program that contains a finite element software environment called AceFEM. All analyses were further carried out in the SIMULIA Abaqus FEA program in order to verify the results.