ABSTRACT

This paper is to examine in detail the characteristics of vertical vibration effects on the structural responses. To this end, extensive numeric analysis of steel moment frames subjected to near-fault motions was carried out. Two and 12 stories steel moment frames were chosen as representative structures. Two sets of records (conventional set and near-fault set) were adopted as ground motions. Major findings obtained from this study are as follows. Effects of vertical motions on the maximum story drift are minimal. The SRSS approximation using the results of horizontal motion only and those of vertical motion only is applicable to estimate the axial forces of columns generated by horizontal and vertical vibration simultaneously. Beam maximum vertical accelerations can be estimated from the analysis with vertical motions only.