Experimental behavior of dual steel system

A six-story eccentrically braced dual steel system (EBDS) was subjected to 24 earthquake ground motions with effective peak accelerations of up to 055 g on the earthquake simulator at the University of California at Berkeley The design construction dynamic characteristics and experimental behavior of this eccentrically braced system are discussed in this paper The EBDS was analyzed for its compliance with current earthquake-resistant regulations that include the 1985 Uniform Building Code (UBC) 1984 Applied Technology Council (ATC) 3-06 and 1986 Structural Engineers Association of California (SEAOC) A substantial overstrength of this dual system with respect to its nominal yielding strength was observed and this is discussed in terms of the response modification factors currently adopted by the ATC and SEAOC The lateral force distributions for the elastic level tests corresponded to the code-base design lateral force distributions but varied considerably for the collapse level tests The role of the ductile momentresisting space frame (DMRSF) in the EBDS is discussed in light of its performance uring the testing program Conclusions are drawn regarding the suitability of the EBDS for regions of high seismic risk and the response modification factors and lateral force distributions currently used or implied in the UBC ATC and SEAOC.