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Preliminary Experimental Study of Seismic Uplift of a Steel Frame.
Clough, R. W.; Huckelbridge, A. A.
National Science Foundation, Washington, D.C.; American Iron and Steel Inst., Washington, D.C., August 1977, 171 p.
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This study represents the preliminary portion of a research program into the effects of allowing column uplift in steel building frames responding to severe seismic loading. Included in this report are experimental and analytical results for a 3-story steel frame both with and without column uplift allowed. Uplift response results are presented for tests using 2 sets of impact elements with stiffnesses differing by approximately an order of magnitude. Allowing column uplift is shown for this frame to significantly reduce both the seismic loading and ductility demand, when compared to the fixed base response for a similar input motion. An analytical technique employing bilinear elastic foundation support elements, with no tensile capacity or stiffness in the upward direction, is shown to accurately predict the uplift response of this frame, even in the presence of large rigid body rotations. An analytical technique using concentrated bilinear plastic hinges is shown to accurately predict the nonlinear fixed base response, for moderately nonlinear response.
Seismic design; Columns (Supports); Earth movements; Dynamic response; Buildings; Earthquake engineering; Uplift response; Uplift pressure; Seismic response; Loads (Forces); Earthquakes