Influence of water fill condition on the seismic response of ground supported circular water tanks
Keywords:
Ground supported cylindrical water tank; fluid – structure interaction; aspect ratio; modal analysis; water fill condition; time history analysis.Abstract
The dynamic behaviour of cylindrical ground supported concrete water tanks with different aspect ratios is investigated by performing coupled acoustic structural Finite Element (FE) analysis. The influence of water fill condition on the natural impulsive frequency of tanks with different aspect ratio from FE analysis is compared with the values obtained from standard codes. The parametric study on tanks of aspect ratio varying from 0.2 to 2.0 necessitates to incorporate the water fill condition for the determination of impulsive frequency. Time history analyses for full fill and half fill conditions are carried out for tanks with different aspect ratio in response to past three major earthquakes of varying frequency content. The responses of the tank such as hoop stress, normal stress and radial displacement to seismic loading depend not only on the frequency content of earthquake, but also on the tank dimensions and its water fill conditions.
