Seismic Evaluation of Existing high important steel structures according to the Seismic Rehabilitation of Existing Buildings No. 360

This paper evaluates the regulations of Instruction for Seismic Rehabilitation of Existing Buildings code (NO 360) and the Iranian code of practice for seismic resistant design of building (standard No.2800, 3nd.edittion) for the assessment of the seismic capacity of existing buildings via pushover analysis. A three-story and a five-story building with two different plans (symmetric and asymmetric) were utilised to compare the two different sets of assumptions. The considered buildings all have hospital application. If the comparison is performed in terms of initial stiffness or plastic deformation capacities, the different partial assumptions of the procedures lead to large discrepancies, while the opposite occurs when the comparison is performed in terms of structural performance levels at target displacements. Both procedures predicted that the structure would behave elastically during low-level excitation and that the structural performance level at target displacement for a high-level excitation would be between the Immediate Occupancy and Operational Performance levels.

Keywords:

Steel Structures , Performance-based seismic assessment , Non-linear procedures , Pushover analysis , Special Moment Frames