Modal pushover procedures for seismic evaluation of reinforced concrete structures: using new nonlinear single degree of freedom systems

This study performs a pushover procedure called Modified-UMRHA for seismic analysis of a reinforced concrete structure, based on the UMRHA (uncoupled modal response history analysis) procedure proposed by Chopra and Goel. The objective is to investigate three approaches for setting up nonlinear single degree of freedom systems drawn from modal pushover curves. These curves are obtained using a non-adaptive load pattern equal to the consistent mass matrix times the modal shape. These approaches are applied on the 14-storey Grenoble City Hall studied in the framework of the ARVISE French research program. The results obtained from the Modified-UMRHA using different proposed nonlinear single degree of freedom systems are compared with those from a rigorous nonlinear response history analysis.