The Effect of Near-Field Earthquakes on the Seismic Response of Rectangular Concrete Water Tanks, Considering the Flexibility of Walls

Constructing concrete water tanks to supply the water pressure needed in cities is inevitable. In Iran, many cities, including metropolises, are near active faults, and in some cases, the fault even passes through them; while the near-field earthquakes' effect on the seismic behavior of tanks has not been thoroughly investigated. Therefore, the effect of the vertical component of pulse-like and non-pulse-like near-fault earthquakes on the lateral hydrodynamic force acting on the tank's wall and the sloshing response of rectangular concrete tanks are numerically studied in this paper. The finite element method is used to model the tank and liquid, and the results of the numerical method employed in this study are compared and verified by the experimental results. Subsequently, eight seismic records derived from four near-field earthquakes are used for two and three-component seismic analyzes.It is found that the maximum sloshing response occurring at the corner of the tank's wall can be higher than that of the middle of the tank's wall by up to 81.6 percent. In other words, the corner of the tank's wall is the critical point for the sloshing response in all cases studied in this paper. In addition, the vertical component of near-fault earthquakes has been indicated to have a negligible effect on the sloshing response while considering this component increases the hydrodynamic force acting on the concrete tank's wall by up to 58.2 percent. On the other hand, near-field pulse-like earthquakes may alter the dynamic force response in rectangular concrete tanks. This alteration can be seen in the force distribution pattern along the tank's wall, which changes under such ground motions.