Evaluation of Nonlinear Static Procedures in the Assessment of Building Frames

Abstract

In recent years a number of nonlinear static procedures (NSPs) have been developed and proposed. Such pushover-based seismic assessment procedures are relatively straightforward to employ and are generally chosen over nonlinear dynamic analysis, especially within the realm of design office application. Parametric comparisons between the different NSPs available, however, are still somewhat sparse. In this work, five commonly employed NSPs (the N2 method, capacity spectrum method, modal pushover analysis, adaptive modal combination procedure, and the adaptive capacity spectrum method) are applied in the assessment of 16 frames subjected to a large number of input motions with a view to assess the accuracy level of such approaches through comparison with nonlinear dynamic analysis results. The evaluation shows that all the NSPs are able to accurately predict displacements and to produce reasonable estimates for other response parameters, with limited dispersion. Even though no single NSP tested led to consistently superior results, modal pushover analysis and the adaptive capacity spectrum method seemed to perform slightly better.

Seismic Response of Rc Bridges Using Generalised Force Vectors

“…Finally, the target displacements for the "relative-displacement based approach" is simply defined according to Equation (16).…”

“…6. Target Displacement Demand: Target total displacement demand for the j 'th pier or the j 'th deck node is computed from Equation (12) whereas the target relative displacement of the j 'th pier with respect to the (j-1) 'th pier, or the j 'th deck node with respect to the (j-1) 'th deck node is computed from Equation (16). If improved accuracy is sought, the spectral contribution corresponding to the first mode can be replaced by its inelastic counterpart.…”

“…Correspondingly, the NSPs that incorporate higher mode effects provide a response that is more accurate, especially in structures where higher mode contributions are expected to be important [13][14][15]. Single mode based NSPs on the other hand typically present shortcomings for structures where higher mode effects are important, but they do tend to provide acceptable or good estimates for regular structures and may represent a good compromise for large scale assessment studies [16][17].…”

Spectral reduction factors evaluation for seismic assessment of frame buildings

“…already been established through a number of parametric studies using different structural forms, such as bridges [12,37], planar building frames with/without vertical irregularity [36], plan-irregular buildings [7]. This procedure, which primarily depends on the employment of a spectral reduction factor, incorporates the effects of higher vibration modes and varying dynamic characteristics during inelastic excursions via a displacement-based adaptive pushover analysis proposed by Antoniou and Pinho [4] with an equally adaptive conversion of pushover to capacity curve of an equivalent SDOF system utilising the substitute structure concept proposed originally by Gulkan and Sozen [21] and improved later to incorporate the direct displacement-based design concepts proposed by Priestley and Calvi [38].…”

Earthquake Risk Assessment: Present Shortcomings and Future Directions

“…Pinho et al 2013;Silva et al 2013b). Hence, the use of vulnerability functions based on nonlinear dynamic analysis and derived in terms of elastic scalar intensity measures would both simplify the hazard modelling required in the risk assessment (at least for homogeneous portfolios, as discussed in Sect.…”