Coupled dynamic analysis of tall buildings isolated with friction pendulum bearings under three-dimensional wind loads

Base-isolated building as one of the effective measures of improving building seismic performance may be exposed to strong winds. On this condition, the building will undergo complicated nonlinear and coupled dy-namic response under synchronous three-dimensional (3D) wind loads. This study establishes an analysis framework for coupled dynamic response of tall buildings isolated with multiple friction pendulum bearings (FPBs) under 3D wind loads. A biaxial Bouc-Wen hysteresis model with a velocity-dependent friction coefficient is used to describe the coupled frictional forces of each individual bearing. The multi-correlated 3D wind loads on stories are modeled based on multiple point synchronous pressure measurement in a wind tunnel. The building top displacement and acceleration, and displacements of base slab and bearings are quantified under uniaxial (one of alongwind, crosswind and torsional), biaxial (both alongwind and crosswind), and triaxial (simultaneous alongwind, crosswind and torsional) wind loads. The distribution of friction-induced dissipation energy of the bearings is quantified. The dynamic response of corresponding fixed-base building is also evaluated for com-parison. The variation of structural responses with wind direction is also investigated. The influences of stiffness eccentricity and torsional frequency of the upper structure on corner acceleration of the top floor are further discussed to reveal the torsional coupling effect. This study sheds light on 3D nonlinear response characteristics of tall buildings isolated with FPBs, and helps to understand the coupled dynamic behavior as result of biaxial friction, structural eccentricity, and spatiotemporal wind loads.