Dynamic response of concrete tanks under far-field, long-period earthquakes

The dynamic responses of rectangular concrete liquid-storage tanks under near-field and far-field, long-period (FFLP) earthquakes were comparatively studied using a shaking table. The effects of different seismic reduction methods were compared and the influence of limiting devices on sliding isolation was evaluated. Under a FFLP earthquake, the results showed that liquid sloshing was more likely to exhibit non-linear behaviour. Greater sloshing occurred in tanks with rubber isolation and sliding isolation with the spring limiting device than in the other types of tank. These two damping measures actually increased the sloshing height. Sliding isolation with the steel-bar limiting device significantly reduced the sloshing height, and sliding isolation produced greater horizontal displacement. However, the influence of a FFLP earthquake on other liquid sloshing responses was not remarkable. Sliding isolation with the steel-bar limiting device was found to have the most beneficial effect.