Simplified direct displacement design of six-story NEESwood Capstone Building and pre-test seismic performance assessment

Abstract

This paper presents a simplified direct displacement design (DDD) procedure developed specifically for performance-based seismic design of multi-story woodframe buildings. In the proposed displacement-based design procedure, the Performance expectations are defined in terms of inter-story drift limits with specified non-exceedance probabilities coupled with prescribed seismic hazard levels. The DDD procedure was used to design shearwalls for a six-story woodframe test building (NEESWood Capstone Building). This NEESWood Capstone Building was designed to meet four Performance expectations: damage limitation, life-safety, far-field collapse prevention, and near-fault collapse prevention. To verify that design requirements were met, a series of nonlinear time-history analyses (NLTHA) were performed using both far-field and near-fault ground motion records. The distributions of inter-story drifts obtained from the NLTHA were used to verify the Performance of the Capstone Building and thereby validate the DDD procedure. Additionally, collapse analysis in accordance with the recently proposed ATC-63 methodology was performed (based on the 90% draft report). The results of incremental dynamic analyses confirmed that the Capstone Building designed using the DDD procedure has adequate capacity or margin against collapse. In summer of 2009, the test building was constructed and a series of full-scale earthquake tests were conducted using the E-defense (Miki) shake table in Japan. Comparison between the expected and the actual measured inter-story drifts of the test building will be discussed.