Seismic Analysis of Elevated Water Tank with Different Staging Configuration

Abstract

Reinforced concrete elevated water tanks are very important structures. They are considered
as main lifeline elements during and after earthquakes. An elevated water tank behaves like
an inverted pendulum, which consist of huge water mass at the top of a slender staging. This
is most critical consideration for the failure of the tank during earthquakes. Basically,
supporting system, so called staging is formed by a group of columns and horizontal braces
provided at intermediate levels to reduce the effective length of the column. Staging is
responsible for lateral resistance of complete structure. The objective of this study is, to
understand the behavior of different staging system, under different tank conditions.
Response Spectrum Analysis is carried out on three different types of bracing systems of
elevated water tank in all zones by using STAAD Pro V8i 2007. Comparison of base shear
and nodal displacements of elevated water tank for empty and full condition is done. The
spring mass model as per IS 1893:2002 Part 2 has been used for the analysis.