Evaluation of the Ground Motion Record Selection Method for Structure Groups In Case Of Generic Steel Moment-Resisting Frames

Rapid growth of performance-based earthquake engineering has caused increasing interest in Non-linear Time History Analysis (NLTHA) as an effective tool for the estimation of engineering demand parameters (EDPs) and capacity. Focusing on the selected set of strong ground motions (SGMs) as an important source of uncertainty on the results; there are a variety of studies, the purpose of which is to introduce a standard scheme for efficient selection of appropriate SGMs as the input of NLTHA. A part of existing differences, most of these methods suffer from a common limitation that is the application of simplifying assumptions in their contextual framework that may not be correct always. Although, the use of such simplifications is unavoidable, the effect of them on the reliability of the results estimated by performing NLTHA under proposed set of SGMs by method must be evaluated. In this paper, a recently proposed structure-specific record selection method is investigated in terms of its ability to keep the claimed efficiency in case of structures that may challenge the correctness of reducing a MDOF nonlinear system to an equal SDOF. Among different influencing parameters that are considered in this study such as the type and pattern of irregularities, as well as, initial stiffness of the frames; the results confirm that ductility plays the chief role on the selection output. Also, the application of the proposed subsets by the selection method does not necessarily result in the reduction of the statistical dispersion in the estimated EDPs.