| Adjacent buildings with small or no spacing between them suffered from considerable damage during previous earthquakes due to pounding. Supplemental viscous damping devices, installed across the gap between these types of buildings, were considered for seismic retrofit to mitigate building pounding. Applicability of the supplemental viscous damping device for pounding mitigation was studied through earthquake simulator testing, using a model of two steel frames with various gap configurations between the frames. This test represents the first effort to experimentally study the effectiveness of viscous dampers installed across the gap between two adjacent buildings to reduce the pounding response. Based on the experimental results, a finite element model was developed and calibrated. The calibrated model was used to perform a series of numerical simulations to develop a database of pounding responses both before and after the retrofit. Results from earthquake simulator testing and numerical simulations indicate that viscous damping devices significantly reduce the seismic pounding response without inducing new seismic demands on either frame. The damping devices were found to be more effective under earthquake excitation with higher intensities and for buildings with small gaps rather than with no gap spacing. As a result of this study, simplified design guidelines were established for retrofitting these buildings. |
