Strength and Stability Analysis of Double-Deck Floating Roof Under Wind Load

Double-deck floating roof has gained more and more popularity in large oil storage tanks. Wind load is one of the main factors that cause failure of the floating roofs. Because of complexity of structure and difficulty in theoretical calculation, wind load on double-deck floating roof has not been considered into the general design standards. An engineering calculation method based on finite element method for the strength and stability of double-deck floating roof under wind load is established. The relation between pressure distribution on floating roof and liquid height is studied when the double-deck floating roof locates at different levels. Results show that pressure difference on the roof reaches maximum when the liquid height is 100%. The finite element model of double-deck floating roof is established based on large deformation theory, the overall displacement, deformation and stress are obtained by applying pressure distribution on the roof. The first anti-sinking criterion and axial compression stability criterion of long bar are selected to verify the strength and stability of floating roofs under wind load. Results show that the engineering calculation method presented can be effectively used to analyze the strength and stability of double-deck floating roof under wind load.