Pushover Analysis

Pushover analysis is a nonlinear static procedure in which a structure is subjected to gravity loads and then a monotonically increasing lateral load pattern, while modelling the nonlinear (plastic-hinge) behaviour of members, until a target displacement or collapse. It produces the capacity curve (base shear vs. roof displacement) and reveals the sequence of plastic-hinge formation, the failure mechanism, and the displacement/ductility demand — information that an elastic analysis cannot give.

It is the core tool of performance-based and displacement-based seismic evaluation, used to assess whether an existing or designed building meets target performance levels (e.g. immediate occupancy, life safety, collapse prevention) at given hazard levels. In Indian practice it underpins seismic evaluation and retrofit of existing buildings (IS 15988) and supplements the IS 1893 force-based design for important/irregular structures, identifying soft storeys, weak columns and strong-beam/weak-column problems. Its limitations — a single invariant load pattern, approximate treatment of higher modes and torsion — mean it is complemented by nonlinear response-history analysis for complex or tall structures.