OVERTURNING LIMIT OF A RIGID BLOCK CONSIDERING CUMULATIVE ENERGY LOSS DUE TO REPEATED SEISMIC POUNDINGS AND GROUND CONTACTS

This study focuses on the overturning behavior of rigid blocks placed near walls during seismic excitation, representing furniture inside buildings. A closed-form expression for the critical overturning condition is derived based on energy balance approach under variable-amplitude impulse inputs. The model accounts for cumulative energy loss from repeated wall impacts and ground contacts, allowing evaluation of critical input characteristics across a wide frequency range. A shaking table test using set of pulse-type input with asymmetric amplitudes is conducted to validate the proposed criteria. This approach enables comprehensive assessment of overturning limits considering block geometry and environmental factors.