Comparison of European and American Standards for the preliminary design of an Oil Tank Foundation

Abstract

To develop a project in foreign countries, it is possible to use different standards or codes, which if are properly followed, give an acceptable level of reliability. However the different usage can generate different section dimensions and also reliability of the structure can differ. The thesis has the aim to compare the design of a foundation for an oil tank according to the European code and the American standard by pre-dimensioning the structural section. The thesis starts with a description of the methodologies used by the norms, in particular of the difference between each other in term of the method used. The API 650 uses the “old design method” called Allowable Stress Design (ASD) while the Eurocode uses the Limit State Design (LSD) method. Wind, seismic and dead loads acting on the foundations have been calculated. Regarding the earthquake and wind load, they have been calculated using the methods in the Eurocode and API 650 and comparing the results according to a case studied. The number of combination loads are also presented, because, in terms of number typology are different. Moreover three approaches of Limit State Design method considered have been evaluated. The possibility of the designer to picking one of them rather than the other, require discussing the results and making conclusions. The comparison has been done in according to the following structural parts: pre-dimension of the foundation section and longitudinal steel bars (for twisting and hoop stress only).