Effect of pounding on nonlinear seismic response of torsionally coupled steel structures resting on flexible soil

Abstract

The effects of earthquake induced pounding on the nonlinear response of torsionally coupled buildings resting on flexible soil are investigated in the current study. Three steel moment-resisting frame buildings with the same symmetric plan having 4, 7 and 10 stories are considered. Three-dimensional nonlinear models with different eccentricity ratios are created. The soil-structure interaction phenomenon is taken into account using the Winkler beam on nonlinear springs. The pair of adjacent structures spaced at different clear distances resting on a flexible soil are analyzed under a consistent set of ground motion records and the effects of seismic pounding, torsional eccentricity and soil-structure interaction are studied by comparison of nonlinear dynamic responses of buildings. The results show that the peripheral frames experienced the most critical conditions during earthquake-induced pounding and the combined effect of soil-structure interaction, torsional eccentricity and pounding results in the most severe nonlinear responses of the studied buildings in certain cases.