Seismic strengthening of liquid-storage tanks with energy-dissipating anchors

The seismic performance of liquid-storage steel tanks can be improved by anchoring them to their foundations with energy-dissipating devices rather than with conventional anchors. Case studies of two tanks are presented-one broad and one slender tank, both anchored with torsional-beam steel dampers, which dissipate seismic energy by inelastic deformations induced by uplifting of the tank wall. Numerical results show that tanks anchored with steel dampers experience significantly less foundation overturning moment than similar fully anchored tanks. Relative to unanchored tanks, the tanks anchored with steel dampers experience small values of base uplift, plastic rotation at the plate boundary, hoop stress in the wall, and radial separation between the plate and foundation. In general, tanks anchored with dampers exhibit performance superior to that of similar unanchored or fully anchored tanks. Due to savings in the material of tank wall, foundation, and full base anchorage, the use of energy dissipating anchors is likely to be cost-effective.