Assessment of nonlinear static (pushover) analysis procedures using field experience

Download
2013
Dilsiz, Abdullah
Recently, many nonlinear analysis procedures have been proposed for earthquake response determination of the structures. Although, the nonlinear response history analysis (NRHA) is accepted as the most accurate source of information for nonlinear seismic response, nonlinear static procedures (NSP) may also provide reasonable estimates of seismic demand and inelastic behavior. However, all proposed NSPs have limitations, due to the certain approximations and simplifications, such as invariable load pattern and single mode consideration. This study is concentrated on the “NSPs” which are generally compared with the “exact results” of NRHA. The current widely used NSPs’ results were compared with the results of both NRHA and the “real” results (real building performance records or experimental results). The results of observations of real structures which are subjected to strong ground motions were used for the assessment. In addition, the buildings were evaluated using nonlinear static and nonlinear dynamic detailed assessment procedures of the current codes. Considering “If I had known that this Earthquake would happen 1 day before the occurrence of the earthquake, could I estimate the damage states, using the widely used NSPs?” moderately and heavily damaged building samples have been collected from Adapazarı and analytical models formed. According to the results of NSPs and NRHA of studied buildings, there is no clear result that any of the procedures used can identify the performance point suitably for each condition. Most of the analyses results could not predict the level of damage accurately. Using these results it is not possible to determine the seismic response and the damage of the buildings before the occurrence of earthquake. The expectations obtained from the NSPs also do not comply with the results of NRHA. Thus; there is no safety for the compatibility of pushover procedures as well as the code specifications with field observations, yet. Considering the high effort given for the computation and post-process of the analyses results, global seismic performance of the buildings were assessed by preliminary assessment procedures. In contrary with the detailed assessment results, the vulnerable buildings studied could be evaluated successfully and qualified according to moderate or severe damage experienced during the earthquake by some preliminary assessment procedures. The valuable information about the seismic behavior of RC buildings obtained from the tests should be supported with more data obtained from the field. This strikes a pessimistic tone because if the inconsistencies between field data and assessment procedures described in guidelines on account of fluctuations of material properties, geometries, ground motion variations and many other parameters considered then a clear need exists to be sanguine about the predictive powers of these methods.

Suggestions

Linear modal combination procedure for structural dynamics
Tanışer, Sadun; Sucuoğlu, Haluk; Department of Civil Engineering (2013)
Earthquake engineering practice utilizes different analysis procedures in the estimation of seismic demands on structures. These procedures are mainly divided into two groups as static and dynamic procedures. Dynamic procedures are more accurate than the static procedures since they include the entire history of any response parameter during the ground motion. Nevertheless, there are also approximate but much simpler static analysis procedures that overcome high computational demands and inherent difficulti...
Experimental evaluation of geomembrane / geotextile interface as base isolating system
Taheri Bonab, Amin; Gülerce, Zeynep; Kalpakcı, Volkan; Department of Civil Engineering (2016)
The objective of this study is to evaluate the effect of the composite liner seismic isolation system on the seismic response of small-to-moderate height structures. For this purpose, a building model with the natural frequency of 3.13 Hz (representing 3-4 story structures) was tested with and without the addition of composite liner system using the shaking table test set-up by employing harmonic and modified/ scaled ground motions. Experiment results showed that the composite liner seismic isolation system...
A Predictive model for maximum interstory drift ratio (MIDR) and its implementation in probability-based design and performance assessment procedures g
Eroğlu Azak, Tuba; Akkar, Sinan; Department of Civil Engineering (2013)
Estimating nonlinear deformation demands is important for the implementation of rational seismic design and assessment methodologies to ensure the safe and reliable response of existing and new buildings against seismic action. The nonlinear deformation demand estimations should consider the variability inground motions as well as the uncertainties involved in structural response. This study presents probability-based seismic design and assessment procedures for code-confirming low- and mid-rise reinforced ...
Effect of ground motion selection on seismic response of buildings
Karakütük, Özge; Yakut, Ahmet; Department of Civil Engineering (2015)
In this study, effects of ground motion selection and scaling procedure given in different earthquake design codes were investigated. To observe differences between the scaling procedures defined in various seismic design codes, these procedures are applied employing the response spectra defined in these specifications. Four reinforced concrete moment resisting frame buildings were used in the analyses. These buildings have 3, 4, 6 and 8 stories. This way, effects of scaling on low-rise and mid-rise buildin...
Seismic testing of a scaled roller-compacted-concrete gravity dam
Gharibdoust, Ali; Binici, Barış; Department of Civil Engineering (2016)
Within the last half-century, seismic response analysis of concrete gravity dams has been extensively studied. Studies reveal that two types of failure modes prevail in the form of dam body cracking or base slide. The literature lacks the conditions that clearly differentiate the two failure types. In this context a state of the art single degree of freedom pseudo-dynamic testing was developed to assess the gravity dam response on smooth foundation interface. Three different hazard levels of earthquake name...
Citation Formats
A. Dilsiz, “Assessment of nonlinear static (pushover) analysis procedures using field experience,” Ph.D. - Doctoral Program, Middle East Technical University, 2013.