Seismic evaluation of flexible steel water storage tanks

Abstract

Cylindrical steel liquid storage tanks are widely used for water supply and industrial chemicals. The seismic response of these tanks differs from buildings as it stores liquid with different hydrodynamic characteristics. Steel tanks can be exposed to severe damages during earthquakes such as elephant’s foot buckling, diamond shape buckling, roof damage and failure of anchor bolts. This research investigates the seismic behavior of flexible steel water storage tanks using an analytical method. A series of parametric analyses are conducted for a typical liquid storage tank with different geometry properties and soil conditions. The effects of storage tank height, wall thickness, and subsoil type are investigated and their effects on the seismic response of the tank are evaluated and discussed. The results indicate that the soil type (representing shear wave velocity and shear modulus of the soil) has a profound impact on the base shear, overturning moment and hoop stress in the flexible tanks.