Damage-Based Probabilistic Seismic Assessment of RC Frames

A conceptual framework for the probabilistic performance-based seismic assessment of building structures that considers both model uncertainty and response sensitivity to ground motion modification is presented in this paper. A new damage model is proposed for the assessment of building performance to seismic loads. The model is derived at the material level and combined at the element, story and structural level through the use of weighting factors. The damage model is used to assess the performance of a typical 12-story frame that has been designed to meet current ASCE-7 requirements for a high seismic zone. A series of nonlinear time history analyses of a simulation model of the building subjected to a large set of ground motions is carried out to extract demand measures which are then expressed as damage indices using the proposed model. A probabilistic approach is finally used to quantify the expected seismic performance of the building. Seismic risk and additional decision variables such as economic loss, repair cost, retrofit need, etc. can be determined by the fragility curve.