EARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS Earthquake Engng Struct. Dyn. 2009; 00:1–16 Prepared using eqeauth.cls [Version: 2002/11/11 v1.00] Fast Performance Uncertainty Estimation via Pushover and Approximate IDA‡

Approximate methods based on the static pushover are introduced to estimate the seismic performance uncertainty of structures having non-deterministic modeling parameters. At their basis lies the use of static pushover analysis to approximate Incremental Dynamic Analysis (IDA) and estimate the demand and capacity epistemic uncertainty. As a testbed we use a nine-storey steel frame having beam hinges with uncertain moment-rotation relationships. Their properties are fully described by six, randomly distributed, parameters. Using Monte Carlo simulation with latin hypercube sampling, a characteristic ensemble of structures is created. The Static Pushover to IDA (SPO2IDA) software is used to approximate the IDA capacity curve from the appropriately post-processed results of the static pushover. The approximate IDAs allow the evaluation of the seismic demand and capacity for the full range of limit-states, even close to global dynamic instability. Moment estimating techniques such as Rosenblackth’s point estimating method and the first-order, second-moment (FOSM) method are adopted as simple alternatives to obtain performance statistics with only a few simulations. The pushover is shown to be a tool that combined with SPO2IDA and moment estimating techniques can supply the uncertainty in the seismic performance of first-mode dominated buildings for the full range of limit-states, thus replacing semi-empirical or code tabulated values (e.g. FEMA-350), often adopte