TOWARD A PERFORMANCE-BASED PROCEDURE FOR DIRECT DISPLACEMENT DESIGN OF ENGINEERED WOODFRAME STRUCTURES

摘要

This paper reports on a study to extend a recently proposed direct displacement design (DDD) procedure for mid-rise engineered wood-frame structures and develop a set of factors for use in the procedure to meet specified performance levels with certain target probabilities. The archetype buildings, originally designed using current force-based design procedures, were re-designed using the simplified DDD procedure with a range of non-exceedance probability adjustment factors (CNE). Nonlinear time-history analysis was performed for each archetype structure under the 2%/50 year seismic hazard level and peak inter-story drift distributions were developed. The non-exceedance probability at the 4% drift limit was then plotted against building height and design charts were developed for each different value of CNE. Using design charts of this type, engineers/designers are able to specify a target drift limit as well as a target non-exceedance probability when using the simplified DDD procedure. Thus, a true performance-based procedure for the seismic design of mid-rise wood-frame structures is described.