Response of pure-friction sliding structures to three components of earthquake excitation

This study has been conducted to evaluate the effects of three components of earthquake excitations on the response of the pure-friction base isolated structures. The structure is idealized as a three-dimensional single-storey building resting on the sliding support. The frictional forces mobilized at the sliding support are assumed to have the ideal Coulomb-friction characteristics. The response of this idealized system subjected to three components of El Centro 1940, Tabas 1978 and Northridge 1994 earthquakes is investigated. The effect of base vertical stresses on the lateral response of the system is illustrated by comparing the behaviour of the system subjected to three-component (including vertical component), two-component (excluding vertical component) and single-component (excluding vertical component and no interaction between the orthogonal directions) earthquake excitations. It is observed that the three-component earthquake can significantly affect the response of low period structures with the sliding support. Furthermore, it was found that the different input motions could highly influence the response of the system under three-component earthquake.