Effect of Strength Parameters on Seismic Performance of Elevated Tanks by Probabilistic Analysis

Considering the importance of the effect of elevated tank body strength on the seismic performance of model during an earthquake, this research evaluated the effect of Young Modulus of body concrete and foundation as strength parameters on seismic performance of elevated tanks and examines the responses to achieve the optimal body stiffness using probabilistic analysis as an effective method to know the effect of different parameters on the output responses. The system is modeled and analyzed by ANSYS software based on the finite element method. The applied approaches included the Newark method for time integration of the dynamic analysis and the probabilistic analysis using the Latin Hypercube sampling method (LHS). Accordingly, first, the modulus of the elasticity of the tank body and foundation were considered as the input parameters. Seismic responses of the model due to Manjil earthquake ground motions are compared with each other. Obtained results illustrated the capability of presented finite element model. The obtained results of the probabilistic analysis indicate the sensitivity of responses to the variation of the flexibility of the tank foundation. Increasing the modulus of elasticity of concrete enhances the principle stresses on tank body and decreases tank displacement. According to the diagrams, changes in the modulus of the elasticity of the tank have a significant effect on the response values, and the percentage of response variations is high. However, the variations in modulus of the elasticity have little effect on the values of the output responses.