Abstract:To investigate the seismic behaviors of frames in framewall structures (dual system), which may be different from those of frame structures, two framewall structures were designed conforming to current Chinese design codes. One is a twentyfourstory building on the Zone of Fortification Intensity 8 (0.3g), and the other is a thirtystory building on the Zone of Fortification Intensity 8 (0.2g). Then inelastic dynamic response analyses of the two structures were conducted with series of inputs of ground motions in a rare earthquake level. The seismic behaviors of the two structures were investigated preliminarily. It was found that the columns and beams of the frames in the framewall structures did not experienced yielding under strong earthquake, while coupled beams in walls were the major energydissipation elements with their postyielding plasticity. And the bases of some walls formed hinges as well. The reasons for the frames of dual system remained nonyielding states were analyzed and discussed from the aspects of their favorable loadcarrying state and strengthening measures for them in dual systems in Chinese design codes. A preliminary proposal was made that it may be feasible to loosen moderately some seismic fortification measures concerning the frame in the dual system with a height exceeding 60m on the Zone of Fortification Intensity 8.