Effects of dynamic soil-structure interaction on the performance of structures equipped with viscous dampers

Viscous dampers are common energy dissipation devices installed in superstructures to minimise seismic induced story shears and drifts. Most of the experimental research into the performance of buildings with viscous dampers fail to capture the realistic behaviour of soil-structure interaction (SSI) in the field. This paper presents one of the first experimental attempts to investigate the effects of SSI on the performance of damped sway frames through dynamic centrifuge testing. The paper will show the successful application of model oil dampers in the centrifuge and compare the response of a model damped frame to a similar frame without dampers. The degree of SSI was varied by varying the intensity of the input motions. Hysteretic damping of soil beneath the foundations is found to increase the effective damping in both damped and undamped frames. The ground compliance triggers global rocking in the damped frame which can limit damper performance.