The lateral static push analysis is performed to investigate the behavior of unanchored liquid storage tanks when subjected to lateral earthquake loads. As the tank is pushed in the lateral direction, it uplifts from its foundation and develops a similar uplifting mechanism to that occurred under earthquake excitations. As shown in Figure (5.28), a hydrodynamic pressure distribution was assumed on the tank wall as

(192) |

where

M | = | (193) | |

= | |||

= |

and similarly, if

Q | = | (194) | |

= | |||

= |

and accordingly

(195) |

Figures (5.29) and (5.30) show the finite element mesh used to model the broad and the tall tanks, respectively. The broad tank showed buckling at a value of OTM/WR=0.077 which indicates that the broad tank may have buckled during transient responses presented before. On the contrary, the tall tank did not experience buckling until it overturns. Figures (5.31) and (5.32) show that uplift displacements predicted from static analyses were larger than those predicted from dynamic analyses presented before. However, predicted axial stresses at the bottom of the tank shell were compared to those predicted from dynamic analyses.