Response of Pure-Friction Sliding Structures to Three Components of Earthquake Excitation Considering Variations in the Coecient of Friction


Department of Civil Engineering,Amirkabir University of Technology


In the present study, the in
uence of the coecient of friction on the seismic response
of sliding base isolated structures is investigated. The building is modeled as a simpli ed single-story
structure resting on a group of sliding supports. The frictional forces mobilized at the sliding supports
are assumed to have a hysteretic plasticity behavior. Bilateral interaction between the sti ness of the
two horizontal orthogonal directions of the isolators has been taken into consideration. The results show
that the variations of the coecient of friction in
uence the response of a sliding base isolated building.
E ects of vertical excitation on the normal and frictional forces are considered too. The in
uence of
the bi-directional interaction of frictional forces and vertical excitation on the response is investigated by
comparing the response of the system to mono-directional (excluding vertical component and no interaction
between the two horizontal orthogonal directions), bi-directional (excluding vertical component) and tridirectional
earthquake excitations. It is demonstrated that the response of the sliding isolated structures
is in
uenced signi cantly by the bi-directional interaction of frictional forces and by incorporation of the
vertical component. Further, the base shear response may be underestimated if the e ects of the vertical
component are neglected and the sliding structures are designed merely on the basis of single-component
or two-component excitation.