An alternative approach to lateral load analysis of framed type elevated water tank stagings

Abstract

Lateral load is believed to be acted at the centre of mass (CM) of elevated water tank whenever ground motion takes place. Lateral load induces axial force and horizontal shear force in all the columns and vertical shear force in all the braces of the tank staging which are associated with rigid link mechanism between CM and top nodal points of the staging frame. These forces in turn develop column moment and beam moments. Lateral load analysis and staging stiffness of elevated water tanks were found by earlier investigators through analytical methods of those having approximations. The present study aims at proposing a more realistic and simple analytical method to determine stiffness and member force owing to lateral load for any given configuration of elevated tank. The nodal displacements obtained from the proposed method were in line with existing methods. Furthermore, this study attempts to carry detailed analysis of tank staging configuration which consists of columns arranged in two concentric circles. The results of the lateral load analysis show that size of the radial beam has significant influence on the responses of the tank staging.