Effect of Supporting System on Dynamic Buckling of Elevated Water Tanks: A Case Study

Abstract

The elevated water tanks are high importance structures for the humanity lifelines. These elevated tanks are considered as very sensitive structures for seismic movement conditions. Among the reasons for the damage and failure of elevated tanks is the design of its support systems. For this reason, several theoretical and experimental researchers studied the performance of this type of structure under seismic loading. The present study aims to demonstrate the supporting system effect on dynamic buckling of the elevated water tank, using three dimensional finite element technique the seismic response of two elevated water tanks was established taking into account the following factors; the fluidstructure Interaction (FSI), the wall flexibility, different nonlinear time histories analysis, and the material and geometric nonlinearity. Indeed, the application of three different instability criteria for the critical PGA estimate using two seismic excitations, namely El Centro and San Fernando earthquake. The numerical values are compared and no significant effect is found of the supporting system for convective fundamental frequency; however, strongly disturbed impulsive fundamental frequency. In addition, the effect of supporting system and the frequency content of the earthquake on PGAcr are clearly shown. A percent increase of PGAcr can reach up to 37.48%.