Structural performance evaluation of innovative prestressed concrete floating fuel storage tanks

Abstract

Prestressed concrete (PC) tanks have been widely used in industrial applications and are commonly constructed as base-supported structures. In land–space constrained cities, it may be viable to construct such facilities as floating structures on sea areas. Several innovative conceptual designs of floating fuel storage tanks, including double- and single-hull structures, are first proposed in this paper. For this new type of fuel storage facility, the self-weight and in-fill fuel are balanced by buoyancy forces, and there is no need for massive foundations. Due to the absence of specific guidelines, many design concerns have to be addressed before a fully functional PC floating fuel storage facility can be designed and operated economically. In this study, finite-element analyses are performed to investigate the structural behavior of floating fuel storage tanks of various design options. To mobilize the buoyancy and hydrostatic load effects during filling operations, water ballasting and the use of in-fill expanded polystyrene foam were examined to optimize the performance of proposed concepts. Analysis results indicate that single-hull tanks show better performance than double-hull tanks because the hydrostatic pressure on the tank wall due to outside seawater and in-fill fuel are balanced to a great extent. Following the principles of load-balancing and allowable stress design approach, prestressing steel requirements are determined for the selected tank concept.