Dynamic response of a tall building next to deep excavation considering soil–structure interaction

Abstract

Soil–structure interaction refers to the process in which a structure can change the response of underlying soil and a soil can change the response of structure. In the present study, the hardening soil model with small strain stiffness (HS-small) was used along with the software PLAXIS to analyze a 17-story building located next to a deep excavation with three approaches: using a fixed-based structure model, using a soil–structure interaction model, and using a soil–structure–excavation interaction model. Static analyses showed an upward deformation in the soil adjacent to excavation caused by strong post-tensioning force of the anchors, which may result in outward rotation of the adjacent structure. The results of seismic analysis suggested that the base shears in the two interaction models are lower than the base shear given by the fixed-based model. Although, the peak horizontal accelerations and the horizontal displacements in floors decrease significantly in interaction models but internal forces in some cases are higher than counterparts in the fixed-based model. The presence of deep excavation adjacent to a structure increases the permanent settlements after the earthquake and thus undermines the distribution of internal forces of the structure, which may lead to significant structural damage.