Abstract

This thesis presents a study of the effects of seismic loading on reinforced concrete liquid storage tanks. Stresses and displacements were computed by the finite element method to ascertain that they remain within an acceptable safety range when the tank is subjected to earthquake ground accelerations of varying intensities. In the analysis different parameters were considered. This included tank radius, liquid height, and shell thickness, loading conditions resulting from both hydrostatic and hydrodynamic pressures, and a variety of boundary conditions at the top and bottom of the tank, including a cover dome. The finite element package (ABAQUS) was used to model the shell by three-dimensional general shell elements under equivalent static seismic loads. To confirm the accuracy of the selected finite element modeling, the output of the three-dimensional shell element model under hydrostatic loading was compared with that of an axi-symmetric shell element model. For hydrodynamic loading, the results of the three-dimensional shell element model were compared with those of an axi-symmetric shell element model having asymmetric deformation. Such comparisons yielded nearly identical results, and confirmed both the accuracy and the repeatability of the displacement and stress output of the three­dimensional model. The parametric study showed that peak ground accelerations not exceeding 20% of the acceleration of gravity produce hydrodynamic pressures that do not induce stresses in the shell beyond the allowable. However, for higher peak accelerations, seismic loading may result in having stresss higher than the allowable stresses, i.e. unsafe conditions depending on the height-to-radius ratio of the tank. In these cases, it is recommended that seismic loading be considered in the initial phase of design of the tanks, or a retrofit technique be adopted if seismic loads are to be imposed on such tanks after construction.

School

School of Sciences and Engineering

Date of Award

6-1-2003

Online Submission Date

1-1-2002

First Advisor

Medhat A. Haroun

Committee Member 1

Sherif A. Mourad

Committee Member 2

Maher Y.A. Younan

Committee Member 3

Ezzat H. Fahmy

Document Type

Thesis

Extent

92 leaves :

Library of Congress Subject Heading 1

Concrete tanks

Rights

The author retains all rights with regard to copyright. The author certifies that written permission from the owner(s) of third-party copyrighted matter included in the thesis, dissertation, paper, or record of study has been obtained. The author further certifies that IRB approval has been obtained for this thesis, or that IRB approval is not necessary for this thesis. Insofar as this thesis, dissertation, paper, or record of study is an educational record as defined in the Family Educational Rights and Privacy Act (FERPA) (20 USC 1232g), the author has granted consent to disclosure of it to anyone who requests a copy.

Call Number

Thesis 2002/8

Location

mmbk

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Included in

Engineering Commons

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