Effects of Soil-Structure in High-Rise Buildings by Means of Dimensionless Analysis and a Simplified Model

In this paper simplified expressions for assessing fundamental frequency and modal damping of high-rise buildings taking into account the soil-structure interaction (SSI) are proposed. To this end, several steps have been followed. First, a 3DoF model is formulated making use of dimensionless parameters. Second, the 3DoF model is simplified into an equivalent 1DoF system. Finally, cancelling high-order and cross-terms and making some mathematical manipulations a simplified expression for fundamental frequency and modal damping is obtained. Results of the equivalent 1DoF are compared with those of the 3DoF to check the accuracy. Furthermore, the influence of the foundation in the overall system is studied making use of several pile configurations and foundation layout.