Comparison of Nonlinear Static Methods for the Seismic Assessment of Plan Irregular Frame Buildings with Non Seismic Details

The use of Nonlinear Static Procedures (NSPs) for the seismic assessment of plan irregular buildings is challenging. The most common pushover-based approaches have led to adequate results in regular buildings, and hence, there is a need to verify the validity of such methods on the assessment of irregular structures. In this article, four commonly used nonlinear static procedures (CSM, N2, MPA, ACSM) are applied on the assessment of two existing five- and eight-story plan-asymmetric buildings in Turkey. The accuracy of the different NSPs is evaluated through comparisons with the results derived from nonlinear dynamic analyses. The results are presented in terms of interstory drifts, normalized top displacements, lateral displacement profiles, chord rotations, base shear, and top displacement ratios. The performance of such procedures in evaluating the damage limitation according to the Eurocode8 is also verified. Special attention is given to the ACSM (Adaptive Capacity Spectrum Method) whose performance in 3D plan irregular buildings has recently been tested. Conclusions about the performance of each NSP are outlined at the end of the article.