SEISMIC RESPONSE OF SLIDING STRUCTURES TO BIDIRECTIONAL EARTHQUAKE EXCITATION

Seismic response of a one-storey structure with sliding support to bid irectional (i.e. two horizontal components) earthquake ground motion i s investigated. Frictional forces, which are mobilized at the sliding support, are assumed to have ideal Coulomb-friction characteristics. C oupling effects due to circular interaction between the frictional for ces are incorporated in the governing equations of motion. Effects of bidirectional interaction of frictional forces on the response are inv estigated by comparing the response to two-component excitation with t he corresponding response produced by the application of single-compon ent excitations in each direction independently. It is observed that t he response of the sliding structure is influenced significantly by th e bidirectional interaction of frictional forces. Further, it is shown that the design sliding displacement may be underestimated if the bid irectional interaction of frictional forces is neglected and the slidi ng structures are designed merely on the basis of single-component exc itation.