Model Tests on Sloshing of a Floating Roof in a Cylindrical Liquid Storage Tank Under Seismic Excitation

Shaking table tests are carried out to validate the analytical solutions for the sloshing of a floating roof in a cylindrical liquid storage tank under seismic excitation. The experimental tank is a 1/100 scaled model of typical oil-storage tank of 100,000m3 capacity, made of acrylic tube of 800mm in diameter. The tests are performed using three types of floating roof model: (1) a roof composed of a pontoon ring only, (2) a roof composed of uniform isotropic plate, and (3) a single-deck type roof composed of an inner deck and an outer pontoon. The motion capture system using high-speed micro cameras is employed to measure the roof displacement over the whole roof surface. The test results are compared with the analytical solutions based on linear potential theory. Overall agreement is confirmed between theory and experiment, while nonlinear bi-harmonic resonance oscillation is observed to occur in certain cases.