Soil-class effects on the seismic response of RC moment-resisting frames considering soil-structure interaction

In this study, the soil–structure interaction (SSI) effects are investigated on three selected structural models consisting of three, six, and nine story reinforced concrete (RC) moment resisting frame structures in conjunction with four different soil deposit classes suggested by the Algerian seismic design code RPA99/version 2003, taken as reference to choose the mechanical properties of the soil. The structures are modeled and analyzed under two different boundary conditions, namely, fixed-base and resting on soil medium. The strong ground motion recorded during the main shock of the Boumerdes 2003 earthquake (Mw = 6.8), matched to the design response spectrum associated with the different site categories, has been used as input motion. An elastic linear constitutive model was adopted for the soil and for the structural elements, and the analyses were carried out using a direct approach in the time domain by employing the finite difference software FLAC2D. The most significant effects of SSI on the seismic response of the selected frame structures are analyzed in terms of periods and modes of vibration of the structures, inter-story drifts, story shear forces, lateral displacements, and acceleration sensitive nonstructural elements. © 2023, The Author(s), under exclusive licence to Springer Nature Switzerland AG.