Effects of Multi-Directional Seismic Input on Non-Linear Static Analysis of Existing Reinforced Concrete Structures

Recent studies have shown the importance of including seismic input directionality in nonlinear analyses for an accurate prediction structural demand on frame structures. This paper proposes a new method that includes multi-directionality forces Nonlinear Static Analyses (NSAs). Conventionally, pushover (PO) apply monotonically increasing lateral loads two directions typically correspond with building X and Y directions, case rectangular plan are parallel to sides. Since general direction is priori unknown, effects applying PO load patterns along varying angles studied this paper. Two non-code-conforming reinforced concrete buildings used as study. They identical design but first one doubly symmetric while second has significant asymmetry due translation center mass. applied both structures at between 0° 360° 15° increments. The results NSAs compared those multi-directional NHAs same angles. demands show more conservative than conventional NSAs, especially corners asymmetric- where they can yield significantly higher demands. base shear capacities decrease intermediate interaction responses be captured thanks columns’ fiber section discretization. On average closer NHAs, even though generally lower.