Accelerations of Nonstructural Components during Nonlinear Seismic Response of Multistory Structures

A simple method is presented for determining the peak horizontal acceleration of nonstructural components attached to the floor system of multistory structures subjected to strong ground motions. The procedure was developed for nonstructural components based on shake-table data measured on the floor diaphragms of 30 small-scale reinforced concrete test structures. The observed response led to a general expression that directly accounts for the level of inelastic response of the structures. Floor acceleration data from existing instrumented buildings during strong seismic events were used to test the validity of the method. The method was also assessed analytically using acceleration data calculated after nonlinear dynamic analyses of 6- and 12-story reinforced concrete frames subjected to a suite of 10 ground motions scaled to three intensity levels to cause varied degrees of inelastic response in the frame elements. These analyses allowed the inclusion of flexible nonstructural components in the assessment. The formulation involved may be easily incorporated into the framework of modern seismic design provisions for nonstructural components. It is shown that the proposed method outperforms the one in modern model building codes. (C) 2012 American Society of Civil Engineers.