Abstract A state‐of‐the‐art seismic performance assessment is illustrated through application to a reinforced‐concrete moment‐frame building designed per current (2003) code provisions. Performance quantified in terms of economic losses and collapse safety. The includes site‐specific hazard analyses, nonlinear dynamic structural response simulations collapse, damage loss estimation. When selecting ground motion records for analyses that are consistent with target level expressed spectral...

This study applies nonlinear dynamic analyses to assess the risk of collapse RC special moment-frame (SMF) buildings quantify seismic safety implied by modern building codes. Thirty archetypical SMF buildings, ranging in height from 1 20 stories, are designed according ASCE 7-02 and ACI 318-05 for a high-seismic region. The results performance-based assessments show that, on average, these have an 11% probability under ground motion intensities with 2% exceedance 50 years. average mean...

This study examines the influence of ground motion duration on collapse capacities a modern five-story steel moment frame and reinforced concrete bridge pier. The effect is isolated from effects amplitude response spectral shape by assembling sets “spectrally equivalent” long short records employing them in comparative nonlinear dynamic analyses. For frame, estimated median capacity 29% lower when using set, as compared to set. pier, 17% lower. A comparison commonly used metrics indicates...

The self-centering rocking steel-braced frame is a high-performance system that can prevent major structural damage and minimize residual drifts during large earthquakes. It consists of braced steel frames are designed to remain elastic allowed rock off their foundation. Overturning resistance provided by post-tensioning, which provides reliable restoring force, replaceable fuses dissipate energy. design concepts this examined contrasted with other conventional seismic force resisting...

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 representative mild steels used civil engineering construction. Referred as stress modified critical strain (SMCS) model void growth (VGM), both integrate plastic strains triaxial stresses predict associated with mechanisms initiation, coalescence. The models suitable implementation through finite-element...

A new model is proposed to simulate ductile fracture initiation due large amplitude cyclic straining in structural steels, which often the governing limit state steel structures subjected earthquakes. Termed void growth (CVGM), technique an extension previously published models that caused by and coalescence under monotonic loading. The CVGM aims capture ultra low cycle fatigue (ductile fracture) behavior, characterized a few (generally, less than 20) reverse loading cycles inelastic strain...

A primary goal of seismic design requirements building codes is to protect the life safety inhabitants during extreme earthquakes. Fundamentally, this requires that likelihood structural collapse be at an acceptably low level. However, and standards are largely empirical in nature, such implied not known. The objective study quantitatively predict twelve modern reinforced concrete (RC) special moment frame (SMF) buildings designed according governing provisions 2003 IBC [ICC 2003], ASCE7-02...

Concrete encased composite column design provisions of the American Institute Code (ACI 318), AISC-LRFD Specification, and AISC Seismic Provisions are reviewed evaluated based on fiber section analyses that account for inelastic behavior steel concrete, including effects strength confinement concrete's stress-strain properties. Trial designs analyzed to evaluate their ductility as a function ratio structural gross area, nominal compression concrete by seismic hoop reinforcing. The highlight...

This study is the second of two companion papers to examine seismic collapse safety reinforced concrete frame buildings, and examines nonductile moment frames that are representative those built before mid-1970s in California. The probabilistic assessment relies on nonlinear dynamic simulation structural response calculate risk, accounting for uncertainties ground-motion characteristics modeling. evaluation considers a set archetypical RC structures varying height designed according...

Results from 18 large-scale tests of steel bracing members are presented to examine their inelastic buckling and fracture behavior as related the seismic design concentrically braced frames. The brace specimens include square hollow structural shapes (HSS), pipe, wide-flange sections. effect various parameters, including width–thickness slenderness ratios, cross-section shape, loading history, rate, grout fill on performance these braces is investigated. Among ratio shown have largest...

One of the challenges assessing structural collapse performance is appropriate selection ground motions for use in nonlinear dynamic simulation. The should represent characteristics extreme that exceed ground-motion intensities considered original building design. For modern buildings western United States, cause are expected to be rare high-intensity associated with a large magnitude earthquake. Recent research has shown have peaked spectral shape and scaling. method account this effect...

A framework is presented for incorporating probabilistic building performance limit states in the assessment of community resilience to earthquakes. The are defined on basis their implications postearthquake functionality and recovery. They include damage triggering inspection, occupiable with loss functionality, unoccupiable damage, irreparable collapse. Fragility curves developed linking earthquake ground motion intensity probability exceedance each states. characteristic recovery path...

SUMMARY This study examines the expected cost of repairing earthquake damage in a set 30 archetype reinforced concrete moment frame buildings. Varying height from 1 to 20 stories, these buildings are representative office with special RC frames, designed according modern seismic codes. Economic losses associated repair computed using performance‐based engineering framework, which integrates site‐specific hazard, structural response, building components and contents, resulting costs. Results...

Controlled rocking braced steel frames are seismic lateral-force resisting systems that utilize column-uplifting mechanisms, high-strength post-tensioning, and replaceable energy-dissipating fuses to enhance performance. This paper describes seven quasi-static cyclic tests of half-scale were conducted investigate the behavior system its components, validate analysis models, establish performance limit states, develop evaluate construction details. Design parameters investigated include...

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Nonlinear static and dynamic analyses are utilized by engineers for performance-based seismic risk evaluation of new existing structures. In this context, nonlinear component modeling criteria typically based on ASCE 41 guidelines. Experiments wide-flange steel columns suggest that the 41-13 models do not adequately reflect expected column behavior under cyclic loading. To help bridge gap between state-of-the-art research engineering practice, paper proposes first-cycle envelope monotonic...

Abstract A new type of seismic resistant structural steel braced‐frame system is introduced that employs controlled rocking, elastic post tensioning, and replaceable fuses to resist earthquake shaking with limited damage. Through the use capacity design principles, inelastic energy dissipation confined while rocking tensioning provide self‐centering action eliminate residual drift. Quasi‐static cyclic tests dynamic shake table large‐scale specimens confirm can sustain extreme ground story...

Cost-benefit assessment is used to evaluate the effectiveness of various seismic retrofit strategies address concerns about earthquake safety and damage older concrete frame buildings. The benefits mitigation are quantified in monetary terms by assessing reductions risk building (repairs) occupant fatalities. When evaluated considering repair costs only, maximum cost retrofitting that offers a positive rate return 10% 30% replacement value. Since retrofits generally more than this, this...

Summary Robust estimation of collapse risk should consider the uncertainty in modeling structures as well variability earthquake ground motions. In this paper, we illustrate incorporation structural model parameters nonlinear dynamic analyses to probabilistically assess story drifts and buildings. Monte Carlo simulations with Latin hypercube sampling are performed on ductile non‐ductile reinforced concrete building archetypes quantify influence uncertainties how it is affected by ductility...

Abstract Hospital systems play a critical role in treating injuries during disaster emergency responses. Simultaneously, natural disasters hinder their ability to operate at full capacity. Thus, cities must develop strategies that enable hospitals’ effective operations. Here, we present methodology evaluate response based on model assesses the loss of hospital functions and quantifies multiseverity as result earthquake damage. The proposed can design plans for patient transfers allocation...

In areas of high seismicity in the United States, design many existing tall buildings followed guidelines that do not provide an explicit understanding performance during major earthquakes. This paper presents assessment seismic and strategies for increased resilience a case study city, San Francisco, where archetype building is designed based on inventory stock. A 40-story moment-resisting frame system selected as representative building. The rectangular plan represents state construction...

Increasingly, engineers are designing composite and mixed building systems of structural steel reinforced concrete to produce more efficient structures than realized using either material alone. Recent literature has pointed out a need for greater understanding the interaction in such systems. In this paper, behavior beam‐column connections is examined through results an experimental research program where 15 two‐thirds scale joint specimens were tested under monotonic cyclic loading. Such...