Preliminary ranking of alternative scalar and vector intensity measures of ground shaking

In Performance-Based Earthquake Engineering, seismic demand in structures is predicted by building probabilistic seismic demand models that link measures of earthquake intensity (IMs) to measures of structural demand. Investigations are carried out herein for evaluating the predictive capability of a wide range of commonly-used scalar and vector-valued IMs for different peak-related demand parameters. To accomplish this goal, both efficiency and sufficiency of the candidate IMs are taken into account. The latter is evaluated with the recently-proposed “relative sufficiency measure”. This measure, which is derived based on information theory concepts, quantifies the amount of information gained (on average) by an IM relative to another about the demand parameter of interest. Evaluation of the IMs, herein, uses two sets of ground motions consisting of ordinary and pulse-like near-fault records. Two-dimensional RC frame structures, both fixed and isolated at the base, are selected. The most suitable IMs for predicting the considered different demand parameters and types of structure are identified in terms of both efficiency and sufficiency. The use of these most informative IMs is suggested to build improved probabilistic demand models.