Loading...

3-D Seismic Evaluation of on Grade Cylindrical Flexible Storage Tanks Considering Soil-Structure Interaction

Andalib, Reza | 2012

1178 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 43546 (09)
  4. University: Sharif University of Technology
  5. Department: Civil Engineering
  6. Advisor(s): Rahimzadeh Rofooei, Fayaz
  7. Abstract:
  8. The circular flexible cylindrical liquid tanks usually are made of steel or aluminum and in majority of cases are built on grade due to its economic advantages. The most important part of a safe design of a storage tanks is the accurate estimation of the seismically induced lateral forces that should be transferred to its base through the tank shell and its support. Seismic behavior of liquid storage tanks is quite different from regular buildings and industrial structures due to its nonlinear behavior caused by complex distribution of hydrodynamic pressure, buckling of its walls, etc.. Moreover, the effect of rocking motion caused by the under laying soft soil, on its response parameters could be considerable. It should be noticed that arriving to an exact theoretical solution for the response of these tanks could be extremely difficult due to the effect of various parameters such as, soil-structure and liquid-structure interactions, large amplitude nonlinear sloshing, material yielding, plastic rotation of base plate and buckling of the tank shell. Therefore, numerical methods such as finite elements methods are used for their analysis since they offer a concise way of accurately considering all the aforementioned behaviors. Numerous studies have analyzed and investigated the dynamic behavior of fluid storage tanks; however, in most of these studies, it is assumed that the tank is located on a rigid ground. Thus, the effect of soil-foundation system on the dynamic behavior of the tank has not been taken into account. The main objectives of this thesis were to evaluate the seismic performance of tanks considering fluid-structure-soil interaction and to investigate the effect of different parameters influencing their dynamic behavior. Seven earthquake records which were applied simultaneously in three orthogonal directions and three different soil types of the under laying soil were considered in this study. The fluid-structure interaction was taken into account using ALE fluid FE approximation provided in general purpose program, ABAQUS. Finite element model with absorbing boundary was used to include soil-structure interaction effects. All the analyses were repeated for a half-filled tank for evaluating liquid height effects on the responses. It is found that the soil underlying the storage tank has a great influence on the behavior of the tank during the earthquake event such as increasing in the base shear and over turning moment with the softening of the under laying soil
  9. Keywords:
  10. Fluid-Structure Interaction ; Soil-Structure Interaction ; Absorbing Boundary ; Flexible Storage Tanks

 Digital Object List