Elevated storage tanks play an important role in transmitting water at longer distances and storing water for emergency situations. In elevated water tanks, the whole mass is directly supported on columns, hence the columns are responsible for resisting lateral forces, so designing columns in such a way that a columns will face less structural damage is most important. In this paper, elevated circular water tank is analyzed in Staad.Pro by using a time history analysis method. Here, the structure is analyzed for an empty condition for ordinary columns and with some modification in whole slender column. In this paper, the major concern is about frame of modified elevated tank, where a wing slab is attached with column. The capacity of both tanks is 500 m3 with a 4 m bracing interval. Through time history analysis by using El-Centro earthquake time-acceleration data, the authors have checked the force distribution, stress contours in columns and beams of both the structures, and the time-displacement and time-velocity graphs at same nodes in both structures at 4 m interval and compared them. Also, they have checked the mode shapes in terms of frequency, time period and mass participation for both the structures. Hence, lower non-linearity is obtained for less time period, of seconds as compared to ordinary tank.
