Experimental studies on the seismic performance of reduced beam section moment connections to deep wide flange columns in steel MRF systems

The use of reduced beam section (RBS) moment connections has become popular in the U.S. for the seismic resistant design of steel special moment resisting frames (SMF). Drift criteria often controls the design of these types of structural systems. Consequently, the use of deep wide flange steel columns in steel SMFs is desirable because they offer more economical inter-story drift control compared to shallower columns (e.g., W12 or W14 sections). There is a lack of knowledge about the behavior of RBS connections to a deep column under seismic loading conditions. A research project was therefore conducted to investigate the seismic performance of these types of connections to a deep column. The parameters in the study included: column section size; beam section size; composite floor slab; and supplemental lateral bracing at end of the RBS.