Structure-soil-structure interaction effects on structures retrofitted with tuned mass dampers

This paper investigates the dynamic structure-soil-structure interaction (SSSI) between two adjacent sway frames, replicating closely spaced residential buildings in an urban setting subjected to seismic input motions. The structures are considered with and without external damping mechanisms by means of tuned mass damper (TMD) configurations. Geotechnical centrifuge tests were conducted to address the current lack of experimental case studies into SSSI and uniquely explore the influences from the presence of TMDs and variations in their configurations on SSSI. SSSI was found to significantly alter the response of proximally located urban structures, as was evident from significantly larger rocking amplitudes and changes in frequency response spectra. TMD effects under SSSI were mostly found to amplify an adjacent structure's peak roof acceleration response and inter-storey drift - this was most aggravated when the damper was de-tuned. TMD effects were found to be relatively more pronounced under smaller earthquakes and could certainly cause occupational inconvenience or even damage in adjacent buildings.