Investigation the Influence of Earthquake Accelogram Direction to Steel Moment-Resisting Frame Structures

In recent years, the discussion of nonlinear behavior in seismic evaluation of structures has been raised. One of the best and newest methods of evaluating buildings is the use of nonlinear dynamic analysis. This type of analysis shows a comprehensive behavior of structures in the linear to nonlinear domain. In this study, in addition to nonlinear dynamic analysis, in order to match the reality, seismic components with different angles have been applied to the structure to show a more accurate seismic evaluation of the structure. In this research, steel buildings with intermediate moment-resisting frame was modelled in three dimensional state in SAP2000 software with 8 and 12 stories and square and rectangular planes and their seismic performances have been studied and compared according to the angle of 8 pairs of accelograms (16 accelograms) under near and far-fault earthquakes (0, 30, 60 and 90 degree) using nonlinear dynamic time history analysis. The results showed that the performance of the structures at angles of 60 and 90 degree was more critical due to the larger seismic responses. Also, in most accelograms, the height of the structure was more effective than the plan shape on seismic responses. In addition, the studied structures had more critical seismic responses due to near-fault earthquakes compared to far-fault earthquakes.