Seismic response sensitivity analysis of intake towers interacting with dam, reservoir and foundation

Hydraulic engineering

In this paper, parameter sensitivity analysis of the dynamic response of cylindrical intake towers interacting with the concrete dam, foundation, internal and surrounding water is performed. The tower is modelled and verified using three-dimensional finite elements according to the Eulerian-Lagrangian approach in the time domain. In order to carry out a parametric study, the Taguchi optimization method is employed to distinguish the most influential parameters. Thus, the iteration algorithm and number of numerical tests are designed. The models are tested under longitudinal horizontal excitation of selected reference accelerograms for either hard soil or hard rock. The evaluation of the results indicated that the two parameters, i.e. tower’s slender ratio, and the surrounding water depth are the most effective factors on both intake tower’s top drift and the base shear coefficient under seismic excitations on hard soil. It is observed that the elasticity modulus of the foundation is another influential factor in the seismic response, as the tower’s drift increases with the foundation’s flexibility. Furthermore, the effect of dam interaction on the tower drift reduces as the distance from the dam increases and stays relatively constant for any distance higher than twice the tower’s height. Interesting to note that the intake tower did not show notable sensitivity to the reference hard rock ground motion compared with that of the hard soil ground motion.