Impact of In Situ Soil Shear-Wave Velocity Profile on the Seismic Design of Tall Buildings on End-Bearing Piles

Abstract

In this study, a numerical investigation into how the shear wave velocity profile affects the seismic performance of tall buildings and foundations was carried out using FLAC3D software. The in situ soil profile and equivalent average soil profile, which reflect the actual soil shear wave velocity profile and the corresponding uniform time-averaged soil shear wave profile based on the actual profile, respectively, were studied. Overconsolidated soil near the ground surface was considered in the in situ soil profile. A 20-story building supported by an end-bearing pile foundation was designed and simulated. A fully coupled nonlinear dynamic analysis was carried out in the time domain to evaluate the seismic response of the structure and foundation system under strong earthquakes. The variations of the interface parameters with depth around the piles were considered according to the variations in the stiffness of surrounding soil with depth in the numerical model when the in situ soil profile was used. The predicted shear forces, maximum lateral deformation, and maximum interstory drifts of the building are presented and discussed, as are the maximum shear forces, maximum bending moments, and the maximum lateral deformation of the piles. The results indicate that the use of an actual shear wave velocity profile instead of an equivalent average profile gives design engineers the opportunity to optimize their design and achieve cost-effective solutions.