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

During large earthquakes, traditional seismic lateral resisting systems can experience significant damage distributed throughout the structural system, and residual drifts that make it difficult, if not financially prohibitive, to repair. Higher performance systems that allow a structure to be easily repaired after an earthquake represent a more sustainable method of construction. Controlled rocking of steel frames using replaceable energy dissipating fuses is a new technology which virtually eliminates residual drifts and concentrates the majority of structural damage in replaceable fuse elements, thus minimizing the amount of structural elements that require repair or replacement after an earthquake.

http://nees.illinois.edu/hosted/ControlledRocking/papers/080401%20Stanford-UIUC%20NEESR-SG%20Controlled%20Rocking%20--%20IABSE%202008%20Paper.pdf

Controlled Rocking of Steel Frames as a Sustainable New Technology for Seismic Resistance in Buildings

Verification of void growth-based exponential damage function for ductile crack initiation over the full range of stress triaxialities

Seismic isolation is a proven technology to protect structures from large earthquakes; however, it has not been extensively implemented in light-frame residential houses in the United State...

Parametric Study of Seismic Isolation Properties for Light-Frame Houses

Research has progressed near to the goal of directly simulating sidesway collapse for some types of structural systems. A complete collapse performance assessment involves many aspects such as directly modeling sidesway collapse, considering local collapse modes, and properly accounting for the numerous uncertainties involved in collapse prediction. Ideally, the collapse performance assessment should be based solely on scientific models and principles, but realistically many aspects of the assessment require significant judgment. Therefore, this paper proposes that the newly emerging models and methods be put thorough a consensus and codification process. This consensus process is critical to ensure that collapse assessment guidelines are not based on the judgment of a small number of individuals. This paper presents selected research advancements by the Pacific Earthquake Engineering Research that the authors hope can contribute to such a consensus process. Specifically, a calibrated reinforced-concrete beam-column element model is presented, which is capable of capturing the important modes of deterioration that precipitate sidesway collapse. Comparing this model and the FEMA 273/356 backbone curves against test data clearly shows that the new model provides a more realistic representation of observed response.

Toward the codification of modeling provisions for simulating structural collapse

A framework is proposed to assess the impact of safety cordons on the recovery of community functions after an earthquake, using high-resolution geospatial information to simulate the damage, cordons, and recovery trajectories for buildings in the affected area. Ground motion maps are developed to characterize shaking intensities for regional building-level engineering assessments of damage, repair times, and recovery times to quantify the impact of access restrictions associated with cordons around tall buildings with impaired collapse safety. The results are presented as recovery curves that quantify the cumulative loss in building functionality across the community as a function of time following an earthquake. A case study considers recovery of office space in Downtown San Francisco, following a Mw7.2 event on the San Andreas Fault. For this scenario, an average of 219 community days of office functionality are lost in the first year, representing about 60% of the total office space capacity. About one-third of the loss is attributed to access restrictions associated with cordons around older tall buildings. The proposed framework can be used to investigate the efficacy of various mitigation strategies to expedite recovery. While the most effective strategy for mitigating the overall impact of cordon restrictions is to seismically retrofit older tall buildings that trigger cordons, other less expensive preparedness measures are shown to be effective, depending on the recovery time frame of interest. Specifically, recovery preparedness measures are generally more effective when evaluated for longer-term recovery targets (e.g. recovery of function after 12 months) compared with short-term targets (e.g. recovery after 4 months).

Gregory G. Deierlein

Papers

Controlled Rocking of Steel Frames as a Sustainable New Technology for Seismic Resistance in Buildings

Verification of void growth-based exponential damage function for ductile crack initiation over the full range of stress triaxialities

Parametric Study of Seismic Isolation Properties for Light-Frame Houses

Toward the codification of modeling provisions for simulating structural collapse

High-resolution post-earthquake recovery simulation: Impact of safety cordons