Repairable Seismic Moment Frames with Bolted WT Connections: Part I

A moment frame lateral load-resisting system was developed in which inelastic deformations due to seismic loading were intended to be isolated to easily replaceable WT components. Fully bolted connections were utilized to facilitate simple component installation and replacement. In Part I of this series, WT components for the moment frame system were modeled using finite element analysis. Full-scale component testing was performed to verify analytical results. Parameters taken from modeling and testing results were used to develop design provisions. In Part II of this series, an example building was designed using the provisions developed and analyzed under simulated earthquake accelerations to develop appropriate seismic performance factors. WT components designed using recommended geometric parameters resulted in desirable behavior. Recommended design equations correlated well to experimental test results. Experimental results suggested WT components designed using the recommended provisions exhibit adequate low-cycle fatigue performance and deflection capacity to be used with wide flange beams up to a nominal depth of 30 in. (762 mm). Nonlinear time-history analysis suggests seismic performance factors currently published for steel special moment frame systems are appropriate for the proposed WT moment frame system.