Example application of the FEMA P695 (ATC-63) methodology for the collapse performance evaluation of wood light-frame systems

This paper describes an example application of the newly developed FEMA P695 (ATC-63) methodology for the collapse performance evaluation of wood lightframe construction, an existing lateral-force-resisting system of ASCE/SEI 7-05. The example includes all the steps required in the application of the FEMA P695 (ATC-63) methodology including: the identification and design of wood lightframe archetype configurations, the development of nonlinear numerical models for these archetype configurations, the execution of nonlinear incremental dynamic analyses of these archetype configurations using the far-field ground motions set of the FEMA P695 (ATC-63) methodology, and the collapse performance evaluation of these archetype configurations considering composite uncertainties in the ground motions, design requirements, numerical models and quality of the test data. The results of this example shows that current seismic provisions for engineered wood light-frame construction included in the ASCE/SEI 7-05 are adequate to provide an acceptable level of collapse safety. It is also recognized that the collapse safety of actual engineering wood light-frame construction is higher than calculated in this example because of the beneficial effects of interior and exterior wall finishes. These wall finishes were not included in this example because they are not defined as part of the lateral structural system, and therefore are not governed by the seismic design provisions.