Incremental dynamic analysis (IDA) is a parametric analysis method that has recently emerged in several different forms to estimate more thoroughly structural performance under seismic loads. It involves subjecting a structural model to one (or more) ground motion record(s), each scaled to multiple levels of intensity, thus producing one (or more) curve(s) of response parameterized versus intensity level. To establish a common frame of reference, the fundamental concepts are analysed, a unified terminology is proposed, suitable algorithms are presented, and properties of the IDA curve are looked into for both single-degree-of-freedom and multi-degree-of-freedom structures. In addition, summarization techniques for multi-record IDA studies and the association of the IDA study with the conventional static pushover analysis and the yield reduction R-factor are discussed. Finally, in the framework of performance-based earthquake engineering, the assessment of demand and capacity is viewed through the lens of an IDA study. Copyright © 2001 John Wiley & Sons, Ltd.

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Incremental dynamic analysis

(1991). Applied Linear Regression Models. Journal of Quality Technology: Vol. 23, No. 1, pp. 76-77.

Applied Linear Regression Models

Minimum Design Loads for Buildings and Other Structures provides requirements for general structural design and includes means for determining dead, live, soil, flood, wind, snow, rain, atmospheric ice, and earthquake loads, as well as their combinations, which are suitable for inclusion in building codes and other documents. This Standard, a revision of ASCE/SEI 7-05, offers a complete update and reorganization of the wind load provisions, expanding them from one chapter into six. The Standard contains new ultimate event wind maps with corresponding reductions in load factors, so that the loads are not affected, and updates the seismic loads with new risk-targeted seismic maps. The snow, live, and atmospheric icing provisions are updated as well. In addition, the Standard includes a detailed Commentary with explanatory and supplementary information designed to assist building code committees and regulatory authorities. Standard ASCE/SEI 7 is an integral part of building codes in the United States. Many of the load provisions are substantially adopted by reference in the International Building Code and the NFPA 5000 Building Construction and Safety Code. Structural engineers, architects, and those engaged in preparing and administering local building codes will find this Standard an essential reference in their practice. Note: New orders are fulfilled from the second printing, which incorporates the errata to the first printing.

Minimum Design Loads for Buildings and Other Structures

Estimation of fragility functions using dynamic structural analysis is an important step in a number of seismic assessment procedures. This paper discusses the applicability of statistical inferenc...

Efficient analytical fragility function fitting using dynamic structural analysis

Introduced in this paper are several alternative ground-motion intensity measures (IMs) that are intended for use in assessing the seismic performance of a structure at a site susceptible to near-source and/or ordinary ground motions. A comparison of such IMs is facilitated by defining the “efficiency” and “sufficiency” of an IM, both of which are criteria necessary for ensuring the accuracy of the structural performance assessment. The efficiency and sufficiency of each alternative IM, which are quantified via (i) nonlinear dynamic analyses of the structure under a suite of earthquake records and (ii) linear regression analysis, are demonstrated for the drift response of three different moderate- to long-period buildings subjected to suites of ordinary and of near-source earthquake records. One of the alternative IMs in particular is found to be relatively efficient and sufficient for the range of buildings considered and for both the near-source and ordinary ground motions.

Structure-specific scalar intensity measures for near source and ordinary earthquake ground motions

iii ACKNOWLEDGMENTS iv TABLE OF CONTENTS vii LIST OF FIGURES xvii LIST OF TABLES xxv

Assessing seismic collapse safety of modern reinforced concrete moment frame buildings

https://web.stanford.edu/~bakerjw/Publications/Liel_et_al_(2009)_model_uncertainties,_Structural_Safety.pdf

Incorporating modeling uncertainties in the assessment of seismic collapse risk of buildings

A state-of-the-art seismic performance assessment is illustrated through application to a reinforcedconcrete moment-frame building designed per current (2003) building code provisions. Performance is
quantified in terms of economic losses and collapse safety. The assessment includes site-specific seismic
hazard analyses, nonlinear dynamic structural response simulations to collapse, damage analyses, and loss
estimation. When selecting ground motion records for nonlinear dynamic analyses that are consistent with
a target hazard level expressed in terms of a response spectral value at the building’s fundamental period, it
is important to consider the response spectral shape, especially when considering higher hazard levels. This
was done through the parameter commonly denoted by e. Neglecting these effects during record selection
is shown to lead to a factor of 5–10 overestimation of mean annual collapse rate. Structural response
simulations, which properly account for uncertainties in ground motions and structural modelling, indicate
a 2–7% probability of collapse for buildings subjected to motions scaled to a hazard level equivalent
to a 2% probability of exceedance in 50 years. The probabilities of component damage and the means
and coefficients of variation of the repair costs are calculated using fragility functions and repair-cost
probability distributions. The calculated expected annual losses for various building design variants range
from 0.6 to 1.1% of the replacement value, where the smaller losses are for above-code design variants and
the larger losses are for buildings designed with minimum-code compliance. Sensitivity studies highlight
the impact of key modelling assumptions on the accurate calculation of damage and the associated repair
costs.

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Evaluation of the seismic performance of a code-conforming reinforced-concrete frame building—from seismic hazard to collapse safety and economic losses

This study applies nonlinear dynamic analyses to assess the risk of collapse of RC special moment-frame (SMF) buildings to quantify the seismic safety implied by modern building codes. Thirty archetypical RC SMF buildings, ranging in height from 1 to 20 stories, are designed according to ASCE 7-02 and ACI 318-05 for a high-seismic region. The results of performance-based seismic assessments show that, on average, these buildings have an 11% probability of collapse under ground motion intensities with a 2% probability of exceedance in 50 years. The average mean annual rate of collapse of 3.1×10-4 collapses per year corresponds to an average of 1.5% probability of collapse in 50 years. The study further examines the influence of specific design provisions on collapse safety. In particular, changes to the minimum seismic base shear requirement between 2002 and 2005 editions of ASCE 7 and variations in ACI 318 strong-column weak-beam (SCWB) design requirements are investigated. The study finds that the reduct...

Seismic Collapse Safety of Reinforced Concrete Buildings. I: Assessment of Ductile Moment Frames

Material tests and analyses are presented to investigate the accuracy of two micromechanics-based continuum criteria for predicting ductile crack initiation in low-carbon steels, which are representative of mild steels used in civil engineering construction. Referred to as the stress modified critical strain (SMCS) model and the void growth model (VGM), both criteria integrate plastic strains and triaxial stresses to predict crack initiation associated with the mechanisms of void initiation, growth and coalescence. The models are suitable for implementation through finite-element analyses to simulate fracture initiation in steel structures. Material tests and finite-element analyses of seven varieties of structural steels, including two new high-performance steels, are conducted to validate and calibrate the model parameters for practical structural engineering applications. Both models are shown to predict fracture accurately across the spectrum of steel samples and geometric configurations. However, application of the models to situations with high stress and strain gradients is shown to be quite sensitive to the characteristic length parameter of the models, which leads to large model variability in such cases. A strong empirical relationship between Charpy V-notch upper-shelf energy and the SMCS and VGM parameters is observed, which can be utilized to estimate the model parameters.

Gregory G. Deierlein

Papers

Assessing seismic collapse safety of modern reinforced concrete moment frame buildings

Incorporating modeling uncertainties in the assessment of seismic collapse risk of buildings

Evaluation of the seismic performance of a code-conforming reinforced-concrete frame building—from seismic hazard to collapse safety and economic losses

Seismic Collapse Safety of Reinforced Concrete Buildings. I: Assessment of Ductile Moment Frames

Void Growth Model and Stress Modified Critical Strain Model to Predict Ductile Fracture in Structural Steels