Time history analysis of a steel water tank with pinned and fixed foundations under varying ground perturbations

Earthquake is a natural phenomenon which is caused by sudden release of energy in the Earth's crust that creates seismic waves. Seismic response of an overhead water tank with varying foundation types subjected to five different earthquake accelerograms was simulated using Time History Analysis. Tank responses observed includes the base shear, base moment and displacement at some joints. The maximum base shear obtained was 9.521E+03 kN and 1.093E+04 kN for pinned and fixed foundations respectively. The maximum displacements at three selected joints labelled as joint 12, joint 22 and joint 32 were 3.67E-01m, 4.349E-01 m and 3.67E-01 m for pinned foundation and 8.68E-02m, 1.119E-01 m and 8.68E-01 m when the foundations were fixed. The results revealed that using a fixed foundation increased the base shear but reduced displacements at the selected joints when compared to when a pinned foundation was used.