Analytical Study of Elevated Service Reservoir with Water Baffles Under Seismic Loading

Abstract

Around the world earthquakes occur often causing some serious damages to property and life. Earthquakes weaken the structure and cause it to fail suddenly. Elevated Water tanks are such structures which have heavier mass suspended at a height supported on slender staging. When earthquake is induced in the tanks, it generates wave sloshing, the motion of the water induced due to seismic excitation. This sloshing of the water inside the tank will move in relative direction the seismic excitation causing structural instability. The water inside the tank will also act as tuned liquid mass damper and absorbs most of the energy created during seismic excitation. In this paper we have analysed various arrangement of baffle walls inside the tank in order to determine the stresses and displacements induced by the sloshing motion of the water tank. The water inside the tank will also act as tuned liquid mass damper where it will reduce the energy generated due to seismic excitation. During sloshing motion, there is an increase in lateral pressure applied over the tank walls which has adverse effect on the displacement of the system. The displacement of the system increases due to sloshing activity. By providing baffle walls we can reduce this displacement induced due to sloshing and thereby reduce the stresses generated on the supporting structure. From this analytical work the latter said was very evident.