Seismic Behaviour Assessment of Steel Moment Resisting Frames Under Near-Field Earthquakes

Abstract

In this paper, some seismic factors, namely response modifiers, ductility, overstrength and deflection amplification, of steel moment resisting frames (MRFs) under near-field records are evaluated. To this purpose, two separate groups of near-field records (e.g., pulse-like and non-pulse-like) on the behaviour of MRFs are studied. In particular, four models with different storey heights (3-, 6-, 9-, and 12-storeys) are examined through IDA analyses under 20 pulse-like and 20 non-pulse-like ground motion records. Finally, the achieved results are compared with the recommendation values of the ASCE code to assess their reliability. According to the results, the MRF structures demonstrate better seismic behaviour under the non-pulse-like ground motions rather than pulse-like ones. The average response modification factor obtained from non-pulse-like ground motions is about 5.0, which is 1.19 times higher than the corresponding results achieved from pulse-like records.