Optimum Diameter of Tapered Elevated RC Water Tank Staging

Water tank is used extensively for storing water, inflammable liquids and other chemicals. Generally, to provide water at large, tank is supported on frame or shaft (a vertical cylindrical shell). The staging with a single row of columns placed straight (vertical) along the periphery of circle or shaft, are generally adopted for elevated water tanks to support the tank container. Apart from verticality of staging, tapered (inclined) staging are also used to support the tank container. The aim of this paper is to understand the behavior of elevated water tank with frame and shaft type tapered staging in lateral earthquake loading using GSDMA guide line [6] and software SAP2000 [8]. The study have been assess, the optimum diameter of staging with reference to the diameter of container, and observed effect of staging batter. The study reveals that value of axial tension decreases with increase in tapering of staging as well as increase in diameter of staging. Optimum dimension of staging to fulfill the requirement of 'No Tension in column’ is with 70% and 80% diameter of staging in comparison with the container diameter for frame and shaft type staging respectively, in accordance with inclination of 6°. Keywords— Water, Intze Tank, Tapered Staging, Two mass model, Sloshing height