Berechnung des Abhebens von verankerten Flüssigkeitsbehältern unter Erdbebeneinwirkung

Uplift analyses of anchored liquid storage tanks under earthquake excitation.

Horizontal earthquake excitations may lead to an uplift of the base plate of liquid storage tanks. The uplift results in additional axial forces on the opposite site of the tank wall and rotational deformations in the base plate. Especially the rotation of the tank base plate is critical for the verification of the earthquake resistance. Anchorages can effectively restrict the uplift while ring foundation or piles bear the appearing tensile forces. In the present paper the effect of anchorages is analysed on the overall system of tank wall and base plate. The tank shell is modelled by flat shell elements. The anchor bolts are considered as spring elements with nonlinear material behaviour. The dynamic pressure of the anchored tank due to horizontal excitation is applied incrementally to the tank shell. The uplift and the material nonlinearity are considered by iterative calculations at every load step. The results are compared with the specifications of EC 8, part 4, appendix A.