DYNAMICS OF STRUCTURES WITH UPLIFT AND SLIDING

A structure incorporating the mechanism of sliding, as used in seismic isolation, along with the mechanism of uplift, but at a different ele vation, is proposed to study the possible beneficial effects on the re sponse of the structure, as compared to allowing partial base uplift o nly. A two-mass model of system uplift and sliding is established. The equations of motion for both the phase of full contact and the phase of base uplift are derived. The criteria governing the transformation of these two phases are given. Both the time history and the response spectrum results show that the structure with both uplift and sliding mechanisms is superior to that with only the uplift mechanism. Not onl y is the response of the structure lessened, but also the amount of up lift is greatly reduced because of the added sliding mechanism.