Performance Based Seismic Design of Multistorey RCC Buildings with Diaphragm Discontinuity

A Performance Based Seismic Design is aimed at controlling the structural damage under the action of earthquake forces, based on precise estimation of proper response parameters using Nonlinear Pushover Analysis. It is a highly iterative process needed to meet designer specified and code requirements. Openings in the floors (diaphragm discontinuity) reduce the rigidity of the diaphragm and affect the distribution of lateral load to the lateral load resisting element and causes stress concentration near discontinued joints. The assessment of the seismic vulnerability of such structures is very complex. Hence, there is a need for an accurate evaluation of the seismic response beyond linear behavior. This paper presents a Performance Based Seismic Design of RCC Buildings with different shapes of opening Diaphragm under the Design Basis Earthquake (DBE) and Maximum considered Earthquake (MCE) by choosing performance criteria in terms of Inter-storey Drift (IDR) and Inelastic Displacement Demand Ratio (IDDR). The Capacity Spectrum Method of Pushover Analysis is performed in SAP 2000, based on FEMA 365 [4] and ATC 40 [3] guidelines, to study the performance of RC buildings designed as per IS 1893:2002 [1], with diaphragm discontinuity. The results shows that opening in diaphragm reduce the capacity and produce higher drift at performance point.