Dynamic response of buildings to ground rotational motion

Abstract

Torsional motion in a building subjected to earthquake force is often attributed to an eccentricity between the centres of mass and resistance of the building. However, a more direct cause of torsional response is the presence of a rotational component in the earthquake motion. The effect of such a rotational motion on the response of both a symmetric and an unsymmetric single storey building model is studied. It is shown that the rotational component of excitation may have a very significant effect on the response, and that this effect may at times be more pronounced than the effect of torsion resulting from translational motion combined with plan eccentricity.