Parametric study on seismic demand assessment of acceleration-sensitive nonstructural components of RC frames

Abstract

Nonstructural components (NSCs) are earthquake-vulnerable structures, and damage to the NSCs induced by earthquakes may cause tremendous loss. However, seismic design of NSCs by current building codes is usually based on experience rather than rigorous seismic theory. By numerical simulations, this paper begins with a study of the floor amplification factor (FAF) of reference structures, followed by a derivation of the component amplification factor (CAF) of acceleration-sensitive NSCs. Taking eight RC frames as the reference structures, this study investigates the floor response spectrum (FRS) by linear and nonlinear analysis. Defined as the ratio of peak floor acceleration (PFA, acceleration at period 0 s of the FRS) to PGA, the FAF is fitted by polynomials, in which the earthquake intensity ratio(Ru), relative height (z/h) of the floor and the fundamental period of the reference structure (T1) are considered as explanatory variables. Then the CAF, defined as the ratio of the peak component acceleration (PCA) over PFA is fitted by functions with shape of the frequency response function (FRF), whereRu,T1 and the ratio of period of NSCs (Ta) to the nonlinear period of the reference structure (Tp) are used to explain the CAF. Finally, the proposed formulas of FAF and CAF are compared with three major codes and peer studies. The proposed FAF and CAF formulas are more comprehensive as major influence variables are all considered, and are expected to be more accurate to predict the seismic amplification of floors and NSCs.