AbstractThe performance of base‐isolated buildings during collision with a retaining wall is examined via shaking table experiments, and a simplified numerical simulation method is proposed to predict structural response. Input ground motions are scaled to various amplitudes to examine the pounding effect of the superstructure under different collision velocities. The influence of wall rigidity on the superstructure response is examined by replacing rubber member attachments on the retaining wall with pads that have different rubber hardness values. Factors influencing the response of the superstructure during collision are identified from experimental results. A numerical simulation method that uses impulse forcing function to replace the collision simulation is evaluated. Time history analysis of a lumped‐mass model considering an impulse at the expected time and location of the collision are shown to efficiently predict the maximum floor acceleration and story shear force of the superstructure during collision without employing a collision analysis model. This research contributes towards developing simplified procedures for estimating the effects of collision in base isolated structures.