Multiple inelastic mechanisms analysis (MIMA): A simplified method for the estimation of the seismic response of RC frame buildings

In this paper, an alternative approach, referred to as Multiple Inelastic Mechanisms Analysis (MIMA), based on the principles of the Displacement-based Assessment (DBA) method, is proposed in the attempt of reducing the complexity related to NRHAs, while maintaining a sufficient accurateness in the estimation of expected losses. MIMA is a practice-oriented approach that provides the seismic response of a structure at different intensity levels. The most important novelties of MIMA with respect to the current state-of-the-art are the possibility of accounting for the contribution of different inelastic mechanisms, the record-to-record variability, and the effects of infills and stairs. In the current version, the proposed approach is specialized for pre-70 RC frame buildings. However, it could be extended to other building types with minor efforts. In this paper, MIMA is applied on a six-stories building, representative of typical RC frame buildings realized in Italy (and other European countries) in the 60's and 70's. A good accordance between approximate predictions and accurate results (from NRHAs) is observed.