Closure to 'Base-Isolated FCC Building: Impact Response in Northridge Earthquake' by Satish Nagarajaiah and Xiaohong Sun

摘要

The writers are thankful to the discussers for their interest in the paper, and for the comments. The writers regret the omission of the reference on the study by the discussers (Maison and Ventura 1992), which is a correlative response analysis of base isolated Foothill Communities Law and Justice Center (FCLJC) building based on the modeling approach for fixed base structures, formulation, and computer program developed by Maison and Kasai (1990) that the writers have referred to. As the title suggests the main objective of the study by the writers was to evaluate the seismic response of base-isolated Fire Command and Control (FCC) building in Los Angeles, during the 1994 Northridge earthquake, and to model the three-dimensional behavior with nonproportional damping, one-sided eccentric impact with energy dissipation, and time-dependent gap see Eqs. (1)-(7) and (13)-(16). The two- and three-dimensional formulation and the solution procedures for base-isolated structures, with nonlinearities and sudden changes in stiffness due to impact and with time-dependent gap, developed by the writers are new and accurate; the system identification, and the impact response features presented by the writers are new (see Figs. 4-9). The response due to impact is a nonlinear-also, time dependent in the study by the writers-phenomenon; hence, careful verification of the computed response is necessary. The computed responses, in the writers' study, are verified using the observed or recorded impact response of base isolated FCC in 1994 Northridge earthquake.