Abstract: The foundation of storage tank is the basic structure in petrochemical plants. Characterized by huge size and load, storage tank has high requirements for its foundation. Ring wall reinforced concrete foundation is often adopted due to its advantages of great stiffness, high resistance to uneven settlement, less land occupation and good economics. Based on the engineering practice of the foundation of a 20,000 m3 heavy oil storage tank, this paper discusses the differences between SH/T3036-2007 Specification for Design of Steel Storage Tanks Subgrade and Foundation in Petrochemical Industry and GB 50473-2008 Code for Design of Steel Tank Foundation in the calculation conditions, calculation formula and parameter values of foundation as well as their effects on calculation results. CFG pile composite foundation is successfully used for this heavy load storage tank built on soft soil. The project has been running well for many years

Key words: cement fly-ash gravel pile, composite foundation, large heavy oil storage tank, ring wall foundation