2021 |
Stewart MG, Li J, 'Risk-based assessment of blast-resistant design of ultra-high performance concrete columns', Structural Safety, 88 (2021) [C1]
© 2020 Elsevier Ltd In conventional structural protective design against blast loads conservative structural designs are anticipated. However, unknown factors that include threat ... [more]
© 2020 Elsevier Ltd In conventional structural protective design against blast loads conservative structural designs are anticipated. However, unknown factors that include threat uncertainty, blast load variation, construction methods, material quality, etc., could impact the accuracy of assessment and design, sometimes even leading to an overestimation of structural capacity to explosive blast effects or an underestimation of actual blast pressures. In the present study, structural safety and reliability analyses of Ultra-high Performance Concrete (UHPC) columns under varying blast scenarios are performed. The variation in column dimensions, steel reinforcement, UHPC material strength, explosive range and mass, and numerical and blast load model errors are considered. The peak reflected pressure and impulse from the selected blast scenarios are derived based on variation in the explosive mass and standoff distance. Failure probabilities of columns made of this emerging high performance concrete material are then estimated. It was found that for a UHPC column designed for blast the probability of major damage given an explosive blast load varies from 1 × 10-2 to 1 × 10-5 for explosive ordnance and terrorism blast scenarios. This provides a reasonable margin of safety against major structural damage. It was also found that the risk reducing benefit of blast-resistant UHPC columns can be considerable.
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2020 |
Qin H, Stewart MG, 'Risk-based cost-benefit analysis of climate adaptation measures for Australian contemporary houses under extreme winds', Journal of Infrastructure Preservation and Resilience, 1 (2020) [C1]
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2020 |
Ryan PC, Stewart MG, 'Regional variability of climate change adaptation feasibility for timber power poles', STRUCTURE AND INFRASTRUCTURE ENGINEERING, (2020)
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2020 |
Qin H, Stewart MG, 'Risk perceptions and economic incentives for mitigating windstorm damage to housing', Civil Engineering and Environmental Systems, (2020)
© 2020 Informa UK Limited, trading as Taylor & Francis Group. Mitigation measures such as window shutters can substantially reduce windstorm damage to housing. However, the ... [more]
© 2020 Informa UK Limited, trading as Taylor & Francis Group. Mitigation measures such as window shutters can substantially reduce windstorm damage to housing. However, the cost-effectiveness of wind mitigation measures remains unclear when considering influencing factors such as financial protection via insurance, individual risk perceptions and planning time horizons. Economic incentives may also be provided to motivate homeowners to invest in mitigation. In this study, the installation of cyclone-rated window shutters as a mitigation measure for homeowners in Australia is used as a case study. A life-cycle cost analysis in conjunction with a rank-dependent expected utility model are employed to identify economic incentives that are financially attractive to homeowners with different perceived risks and planning time horizons. The effect of home insurance is also taken into account. The results suggest that, as expected, the economic incentives needed to promote window shutters among homeowners decrease with the perceived storm damage risk and planning time horizon. A rebate for shutter installation cost or a discounted insurance premium have been found to be feasible economic incentives considering a typical planning time horizon of ten years. Statistical surveys are needed in future work to calibrate the parameters within the rank-dependent utility model to better represent the risk perceptions of different groups of homeowners.
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2020 |
Qin H, Stewart MG, 'Construction defects and wind fragility assessment for metal roof failure: A Bayesian approach', Reliability Engineering and System Safety, 197 (2020) [C1]
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2020 |
Thöns S, Stewart MG, 'On the cost-efficiency, significance and effectiveness of terrorism risk reduction strategies for buildings', Structural Safety, 85 (2020) [C1]
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2020 |
Stewart MG, Mueller J, 'Terrorism risks, chasing ghosts and infrastructure resilience', Sustainable and Resilient Infrastructure, 5 78-89 (2020) [C1]
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2020 |
Stewart MG, Netherton MD, 'Statistical variability and fragility assessment of ballistic perforation of steel plates for 7.62 mm AP ammunition', DEFENCE TECHNOLOGY, 16 503-513 (2020) [C1]
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2020 |
Qin H, Stewart MG, 'Wind and rain losses for metal-roofed contemporary houses subjected to non-cyclonic windstorms', Structural Safety, 86 (2020) [C1]
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2020 |
Hawchar L, Naughton O, Nolan P, Stewart MG, Ryan PC, 'A GIS-based framework for high-level climate change risk assessment of critical infrastructure', Climate Risk Management, 29 (2020) [C1]
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2020 |
Sielicki PW, Stewart MG, Gajewski T, Malendowski M, Peksa P, Al-Rifaie H, et al., 'Field test and probabilistic analysis of irregular steel debris casualty risks from a person-borne improvised explosive device', Defence Technology, (2020)
© 2020 The Authors Person-borne improvised explosive devices (PBIEDs) are often used in terrorist attacks in Western countries. This study aims to predict the trajectories of PBIE... [more]
© 2020 The Authors Person-borne improvised explosive devices (PBIEDs) are often used in terrorist attacks in Western countries. This study aims to predict the trajectories of PBIED fragments and the subsequent safety risks for people exposed to this hazard. An explosive field test with a typical PBIED composed of a plastic explosive charge and steel nut enhancements was performed to record initial fragment behaviour, including positions, velocity, and trajectory angles. These data were used to predict the full trajectory of PBIED fragments using a probabilistic analysis. In the probabilistic analyses a probability of fatality or serious injury was computed. Based on the results presented, many practical conclusions can be drawn, for instance, regarding safe evacuation distances if a person were exposed to a suspected PBIED.
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2020 |
Stewart MG, 'Professor Bruce R. Ellingwood - Mentor and Leader', STRUCTURAL SAFETY, 84 (2020)
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2020 |
Stewart MG, Netherton MD, Baldacchino H, 'Observed airblast variability and model error from repeatable explosive field trials', International Journal of Protective Structures, 11 235-257 (2020) [C1]
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2020 |
Faber MH, Miraglia S, Qin J, Stewart MG, 'Bridging resilience and sustainability - decision analysis for design and management of infrastructure systems', SUSTAINABLE AND RESILIENT INFRASTRUCTURE, 5 102-124 (2020) [C1]
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2019 |
Alterman D, Stewart MG, Netherton MD, 'Probabilistic assessment of airblast variability and fatality risk estimation for explosive blasts in confined building spaces', INTERNATIONAL JOURNAL OF PROTECTIVE STRUCTURES, 10 306-329 (2019) [C1]
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2019 |
Qin H, Stewart MG, 'System fragility analysis of roof cladding and trusses for Australian contemporary housing subjected to wind uplift', Structural Safety, 79 80-93 (2019) [C1]
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2019 |
Melhem MM, Caprani CC, Stewart MG, 'Reliability of Super-T PSC girders at serviceability limit state stresses across all span ranges', Structure and Infrastructure Engineering, 15 812-821 (2019) [C1]
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2019 |
Thöns S, Stewart MG, 'On decision optimality of terrorism risk mitigation measures for iconic bridges', Reliability Engineering and System Safety, 188 574-583 (2019) [C1]
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2019 |
Grant M, Stewart MG, 'Postal IEDs and risk assessment of work health and safety considerations for postal workers', International Journal of Risk Assessment and Management, 22 152-169 (2019)
© 2019 Inderscience Enterprises Ltd. Postal improvised explosive devices (IEDs) provide criminals and terrorists with a convenient mechanism for delivering an energetic payload to... [more]
© 2019 Inderscience Enterprises Ltd. Postal improvised explosive devices (IEDs) provide criminals and terrorists with a convenient mechanism for delivering an energetic payload to an intended victim with little operational risk. Postal IEDs formed 7% of IED attacks reported in the West between 1998-2015, are often dispatched in groups and can bring postal systems to a standstill. Nearly 30% of postal IED explosions occur in the postal worker environment and a third of the casualties caused by postal IEDs are postal workers. Postal IEDs are debatably a reasonably foreseeable cause of harm to postal workers and should be considered under the work health and safety (WHS) constructs of many Western nations. This paper considers this problem, using a probabilistic risk assessment model to inform a cost-benefit analysis considering potential risk reduction options for postal workers. It identifies that the control measures identified were not cost-effective where only the direct WHS costs pertaining to unintentional postal IED detonation within the mail delivery system were considered given the risk levels identified.
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2019 |
Stewart MG, Netherton MD, 'A probabilistic risk-acceptance model for assessing blast and fragmentation safety hazards', Reliability Engineering and System Safety, 191 (2019) [C1]
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2019 |
Stewart MG, Dorrough B, Netherton MD, 'Field testing and probabilistic assessment of ballistic penetration of steel plates for small calibre military ammunition', International Journal of Protective Structures, 10 421-438 (2019) [C1]
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2019 |
Stewart MG, 'Reliability-based load factors for airblast and structural reliability of reinforced concrete columns for protective structures', Structure and Infrastructure Engineering, 15 634-646 (2019) [C1]
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2018 |
Stewart MG, 'Reliability-based load factor design model for explosive blast loading', Structural Safety, 71 13-23 (2018) [C1]
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2018 |
Bjarnadottir S, Li Y, Reynisson O, Stewart MG, 'Reliability-based assessment of climatic adaptation for the increased resiliency of power distribution systems subjected to hurricanes', Sustainable and Resilient Infrastructure, 3 36-48 (2018) [C1]
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2018 |
Bayuaji R, Darmawan MS, Husin NA, Anugraha RB, Budipriyanto A, Stewart MG, 'Corrosion damage assessment of a reinforced concrete canal structure of power plant after 20 years of exposure in a marine environment: A case study', ENGINEERING FAILURE ANALYSIS, 84 287-299 (2018) [C1]
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2018 |
Mueller J, Stewart MG, 'Terrorism and Bathtubs: Comparing and Assessing the Risks', Terrorism and Political Violence, (2018)
© 2018, © 2018 Taylor & Francis Group, LLC. The likelihood that anyone outside a war zone will be killed by an Islamist extremist terrorist is extremely small. In the United... [more]
© 2018, © 2018 Taylor & Francis Group, LLC. The likelihood that anyone outside a war zone will be killed by an Islamist extremist terrorist is extremely small. In the United States, for example, some six people have perished each year since 9/11 at the hands of such terrorists¿vastly smaller than the number of people who die in bathtub drownings. Some argue, however, that the incidence of terrorist destruction is low because counterterrorism measures are so effective. They also contend that terrorism may well become more frequent and destructive in the future as terrorists plot and plan and learn from experience, and that terrorism, unlike bathtubs, provides no benefit and exacts costs far beyond those in the event itself by damagingly sowing fear and anxiety and by requiring policy makers to adopt countermeasures that are costly and excessive. This article finds these arguments to be wanting. In the process, it concludes that terrorism is rare outside war zones because, to a substantial degree, terrorists don¿t exist there. In general, as with rare diseases that kill few, it makes more policy sense to expend limited funds on hazards that inflict far more damage. It also discusses the issue of risk communication for this hazard.
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2018 |
Stewart MG, Mueller J, 'Risk and economic assessment of U.S. aviation security for passenger-borne bomb attacks', JOURNAL OF TRANSPORTATION SECURITY, 11 117-136 (2018) [C1]
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2018 |
Stewart MG, Ginger JD, Henderson DJ, Ryan PC, 'Fragility and climate impact assessment of contemporary housing roof sheeting failure due to extreme wind', Engineering Structures, 171 464-475 (2018) [C1]
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2017 |
Li J, Masia MJ, Stewart MG, 'Stochastic spatial modelling of material properties and structural strength of unreinforced masonry in two-way bending', STRUCTURE AND INFRASTRUCTURE ENGINEERING, 13 683-695 (2017) [C1]
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2017 |
Zhi XD, Stewart MG, 'Damage and Risk Assessment for Single-Layer Reticulated Domes Subject to Explosive Blast Loads', INTERNATIONAL JOURNAL OF STRUCTURAL STABILITY AND DYNAMICS, 17 (2017) [C1]
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2017 |
Olmati P, Vamvatsikos D, Stewart MG, 'Safety factor for structural elements subjected to impulsive blast loads', INTERNATIONAL JOURNAL OF IMPACT ENGINEERING, 106 249-258 (2017) [C1]
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2017 |
Ryan PC, Stewart MG, 'Cost-benefit analysis of climate change adaptation for power pole networks', CLIMATIC CHANGE, 143 519-533 (2017) [C1]
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2017 |
Peng L, Stewart MG, Melchers RE, 'Corrosion and capacity prediction of marine steel infrastructure under a changing environment', STRUCTURE AND INFRASTRUCTURE ENGINEERING, 13 988-1001 (2017) [C1]
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2017 |
Stewart MG, Mueller J, 'Risk and economic assessment of expedited passenger screening and TSA PreCheck', JOURNAL OF TRANSPORTATION SECURITY, 10 1-22 (2017) [C1]
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2017 |
Grant MJ, Stewart MG, 'Benefit of Distributed Security Queuing for Reducing Risks Associated With Improvised Explosive Device Attacks in Airport Terminals', ASCE-ASME JOURNAL OF RISK AND UNCERTAINTY IN ENGINEERING SYSTEMS PART B-MECHANICAL ENGINEERING, 3 (2017) [C1]
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2017 |
Stewart MG, 'Risk of Progressive Collapse of Buildings from Terrorist Attacks: Are the Benefits of Protection Worth the Cost?', JOURNAL OF PERFORMANCE OF CONSTRUCTED FACILITIES, 31 (2017) [C1]
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2017 |
Grant MJ, Stewart MG, 'Modelling improvised explosive device attacks in the West - Assessing the hazard', RELIABILITY ENGINEERING & SYSTEM SAFETY, 165 345-354 (2017) [C1]
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2016 |
Alam M, Sanjayan J, Zou PXW, Stewart MG, Wilson J, 'Modelling the correlation between building energy ratings and heat-related mortality and morbidity', Sustainable Cities and Society, 22 29-39 (2016) [C1]
© 2016 Elsevier Ltd. All rights reserved. Climate change has led to an increase in the frequency and intensity of heatwaves as well as the risk of heat stress within buildings. To... [more]
© 2016 Elsevier Ltd. All rights reserved. Climate change has led to an increase in the frequency and intensity of heatwaves as well as the risk of heat stress within buildings. To provide habitable indoor conditions without air-conditioning during heatwave, residential building energy efficiency need to be upgraded. The aim of this research is to investigate the possible correlation of building energy rating upgrading with heat-related health hazard during heatwave, with case data drawing from Melbourne, Australia. Using building simulations, indoor heat stress conditions of different energy rated houses were calculated using wet bulb globe temperature and discomfort index under the Melbourne 2009 heatwave conditions. The results showed that during three days heatwave period, residents of 0.9 star energy rated house were exposed to extreme heat stress conditions for almost 25 h compared to only 6 h experienced by the occupants of 5.4 star energy rated house. Several robust empirical relationships were proposed to predict deaths, ambulance calls, emergency department presentations and after hour doctor calls during heatwave. It was concluded that mortality rate from a Melbourne 2009 type, as well as, future more intense heatwave may reduce by 90% if entire existing lower energy star rated houses can be upgraded to minimum 5.4 star energy rating.
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2016 |
Hajializadeh D, OBrien EJ, Stewart MG, 'The sensitivity of bridge safety to spatial correlation of load and resistance', Structures, 5 23-34 (2016) [C1]
© 2015 Elsevier B.V. Random Field theory has emerged in recent years to model the statistical correlation of resistance in concrete structures and to determine its influence on th... [more]
© 2015 Elsevier B.V. Random Field theory has emerged in recent years to model the statistical correlation of resistance in concrete structures and to determine its influence on the probability of structural failure. A major shortcoming in the work carried out to date is the spatial variability and corresponding correlation associated with applied traffic loads. In this paper the influence of spatial correlation of both traffic load and resistance is considered in the context of bridge safety assessment. The current study, explores, the nature of the problem by three theoretical examples. As a general trend, examples show that while traffic loads are weakly correlated, load effects are strongly correlated as the same heavy vehicle often causes extremes of load effect in different parts of the bridge which is due to the transverse sharing of load (measured here using a load sharing factor). It is found that the strength of correlation of load effect depends greatly on the load sharing factor which is treated in a simple way in many studies. In a more sophisticated beam-and-slab bridge example, load sharing factors are derived from a finite element analysis to assess transverse load sharing, and are shown to vary by girder number, girder segment and by load location. Despite the fact that load effect at points along the length of a bridge is strongly correlated, the combined influence of correlation in load and resistance on probability of failure is small.
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2016 |
Bastidas-Arteaga E, Stewart MG, 'Economic assessment of climate adaptation strategies for existing reinforced concrete structures subjected to chloride-induced corrosion', STRUCTURE AND INFRASTRUCTURE ENGINEERING, 12 432-449 (2016) [C1]
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2016 |
Stewart MG, Reid S, 'Decision-making in a changing climate', STRUCTURE AND INFRASTRUCTURE ENGINEERING, 12 431-431 (2016)
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2016 |
Mueller J, Stewart MG, 'The curse of the Black Swan', Journal of Risk Research, 19 1319-1330 (2016) [C1]
© 2016 Informa UK Limited, trading as Taylor & Francis Group. When unexpected and emotion-engaging events become Black Swans and carry an ¿extreme impact,¿ this derives not ... [more]
© 2016 Informa UK Limited, trading as Taylor & Francis Group. When unexpected and emotion-engaging events become Black Swans and carry an ¿extreme impact,¿ this derives not so much those qualities or from their intrinsic size or importance as from reaction, or overreaction, they generate; but one that is often as extreme and unpredictable as the event itself. Most consequential development in human history, however, stems not from such events, but from changes in thinking and behavior that are gradual and often little-noticed as they occur. In addition, when an unexpected, emotion-grabbing event becomes a Black Swan, the response is likely to become internalized, and getting people to re-evaluate through sensible risk analysis and risk communication is extremely difficult. As part of this, events that are aberrations are often unwisely taken instead to be harbingers ¿ and continue to be so even in the face of repeated disconfirming evidence. An examination of the 9/11 response in the US illustrates these points.
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2016 |
Mueller J, Stewart MG, 'Misoverestimating ISIS: Comparisons with Al-Qaeda', Perspectives on Terrorism, 10 32-41 (2016) [C1] |
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2016 |
Stewart MG, 'Climate change impact assessment of metal-clad buildings subject to extreme wind loading in non-cyclonic regions', SUSTAINABLE AND RESILIENT INFRASTRUCTURE, 1 32-45 (2016)
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2016 |
Chaves IA, Melchers RE, Peng L, Stewart MG, 'Probabilistic remaining life estimation for deteriorating steel marine infrastructure under global warming and nutrient pollution', Ocean Engineering, 126 129-137 (2016) [C1]
© 2016 Elsevier Ltd The longer-term serviceability and structural safety of steel infrastructure exposed to seawater conditions may be affected by global warming and by seawater n... [more]
© 2016 Elsevier Ltd The longer-term serviceability and structural safety of steel infrastructure exposed to seawater conditions may be affected by global warming and by seawater nutrient pollution. These may affect abiotic and biotic (microbial) corrosion. A model for long-term corrosion is developed from data obtained from steel piling exposed for 33 years in a seawater harbour. The effects on corrosion losses on the structural reliability of steel sheet piling as used in harbours world-wide were investigated as a function of seawater temperature rise from global warming and of seawater nutrient pollution. The results show that structural reliability is more sensitive to likely nutrient pollution than to predicted increases in seawater temperature, noting also that global warming also could increase nutrient pollution from anthropological sources.
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2016 |
Netherton MD, Stewart MG, 'Risk-based blast-load modelling: Techniques, models and benefits', International Journal of Protective Structures, 7 430-451 (2016) [C1]
© 2016, © The Author(s) 2016. There are many deterministic blast-load methods currently in use, such as (1) those for the ready calculation of explosive pressure, impulse and dura... [more]
© 2016, © The Author(s) 2016. There are many deterministic blast-load methods currently in use, such as (1) those for the ready calculation of explosive pressure, impulse and duration; (2) the derivation of explosive safety distances; or (3) the determination of safety hazards (and other consequences) following an explosive¿s detonation. In this article, we argue that deterministic blast-loading methods do not fully account for society¿s usual acceptance (or rejection) of the risks associated with damage, safety and/or injury as a result of an explosive blast-load. This article details the state of the art of probabilistic blast-load modelling that supports a quantitative calculation of risk, with respect to damage, safety and injury. The probabilistic models draw data from the literature and from our own field trials. The article details the benefits that flow from this form of blast-load characterisation and concludes with a discussion on how probabilistic methods be used to derive cost¿benefit advice with respect to any proposed risk mitigation solution.
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2016 |
Ryan PC, Stewart MG, Spencer N, Li Y, 'Probabilistic analysis of climate change impacts on timber power pole networks', INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS, 78 513-523 (2016) [C1]
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2016 |
Peng L, Stewart MG, 'Climate change and corrosion damage risks for reinforced concrete infrastructure in China', Structure and Infrastructure Engineering, 12 499-516 (2016) [C1]
© 2014 Taylor & Francis. A changing climate which leads to increases in atmospheric CO2 concentration, and changes in temperature and relative humidity (RH), especially in t... [more]
© 2014 Taylor & Francis. A changing climate which leads to increases in atmospheric CO2 concentration, and changes in temperature and relative humidity (RH), especially in the longer term, will accelerate the deterioration processes and consequently decline the safety, serviceability and durability of reinforced concrete (RC) infrastructure. This paper presents an investigation of carbonation-induced deterioration in three typical Chinese cities (Kunming, Xiamen and Jinan) under a changing climate. The changing trends of atmospheric CO2, local temperature and RH of typical Chinese cities are projected based on the latest CO2 emission scenarios. The time-dependent analysis is based on Monte Carlo simulation, and includes the uncertainty of climate projections, deterioration processes, material properties, dimensions and accuracy of predictive models. Deterioration of RC structures is represented by the probabilities of reinforcement corrosion initiation and damage. It was found that the mean carbonation depths by 2100 may increase by up to 45% for RC structures in China due to a changing climate. It was also found that climate change can cause an additional 7¿20% of carbonation-induced damage by 2100 for RC buildings in temperate or cold climate areas in China. The findings provide a basis for the development of climate adaptation strategies through the improved design of concrete structures.
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2016 |
Hajializadeh D, Stewart MG, Enright B, OBrien E, 'Spatial time-dependent reliability analysis of reinforced concrete slab bridges subject to realistic traffic loading', STRUCTURE AND INFRASTRUCTURE ENGINEERING, 12 1137-1152 (2016) [C1]
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2016 |
Stewart MG, Foster S, Ahammed M, Sirivivatnanon V, 'Calibration of Australian Standard AS3600 concrete structures part II: reliability indices and changes to capacity reduction factors', Australian Journal of Structural Engineering, 17 254-266 (2016) [C1]
© 2016 Engineers Australia. Capacity reduction factors (¿) for flexure, shear and axial loadings are derived for reinforced concrete (RC) structures based on a reliability-based c... [more]
© 2016 Engineers Australia. Capacity reduction factors (¿) for flexure, shear and axial loadings are derived for reinforced concrete (RC) structures based on a reliability-based calibration of the Australian Concrete Structures Standard AS3600. The structural reliability analysis considers the bias and variability of material properties, dimensions, loads and model error. The target reliabilities (ßT) are selected based on consideration of past practice and Australian and international standards. The capacity reduction factors (¿) for the new code AS3600-2009 are selected using the most recent statistical parameters for material strengths for 20¿100 MPa strength concrete using Class N (ductile) 500N reinforcement. The reliability-based calibration found that the ¿-factor can be increased from 0.80 to 0.85 for members in bending, and increased from 0.60 to 0.65 for axial loading of short (stocky) columns where the ratio of the live load to the dead load is at least 0.25. No changes are recommended for shear or torsion, at this time, or for slender columns; further research is needed to better refine the design models for these cases and reduce the variation in their model error. The proposed increases in capacity reduction factors will result in up to an 8.3% increase in design strength that, in turn, provides efficiency in the use of materials. The proposed changes provide for modest savings in greenhouse gas emissions.
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2016 |
Foster SJ, Stewart MG, Loo M, Ahammed M, Sirivivatnanon V, 'Calibration of Australian Standard AS3600 Concrete Structures: part I statistical analysis of material properties and model error', Australian Journal of Structural Engineering, 17 242-253 (2016) [C1]
© 2016 Engineers Australia. Assessment of the reliability of design models developed for Australian Standards is of paramount importance for determination of public safety. Poorly... [more]
© 2016 Engineers Australia. Assessment of the reliability of design models developed for Australian Standards is of paramount importance for determination of public safety. Poorly calibrated models and safety factors can lead to overly safe and uneconomic construction or, worse, to an insufficient level of safety. This study investigates the reliability of the models used in the Australian Concrete Structures Standard AS3600¿2009 for the design of beams and slabs in bending and shear and columns under combined bending and axial loading. The study is in two parts; in Part I, strength and variability of over 20,000 concrete cylinders cured under standard conditions and tested at 28¿days are statistically analysed. The data were collected from all cities and regional areas in Australia and for all concrete strength grades; similarly, variability of reinforcement product is analysed. Next, reliable databases of laboratory tests for beams, slabs and columns were established for members failing in flexure, shear and compression and model errors, and their variability, determined for the code design models. It is concluded that improvements in the production of concrete and of bar products, over time, have led to reduced variability in their materials properties¿with potential for increasing code strength reduction factors and, thus, reducing excessive conservatism in design. This is assessed in Part II of this study.
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2016 |
Li J, Stewart MG, Masia MJ, Lawrence SJ, 'Spatial Correlation of Material Properties and Structural Strength of Masonry in Horizontal Bending', JOURNAL OF STRUCTURAL ENGINEERING, 142 (2016) [C1]
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2016 |
Stewart MG, Ryan PC, Henderson DJ, Ginger JD, 'Fragility analysis of roof damage to industrial buildings subject to extreme wind loading in non-cyclonic regions', Engineering Structures, 128 333-343 (2016) [C1]
© 2016 Elsevier Ltd A fragility analysis is conducted for loss of roof cladding for low rise metal-clad industrial buildings located in non-cyclonic regions of Australia. The stoc... [more]
© 2016 Elsevier Ltd A fragility analysis is conducted for loss of roof cladding for low rise metal-clad industrial buildings located in non-cyclonic regions of Australia. The stochastic analysis includes possible component and connection failures, load redistribution based on progressive failure, spatial distribution of wind load, and internal pressure variation caused by roof sheeting failure. This spatial and time-dependent reliability analysis will enable fragility curves to be developed that relate likelihood and extent of roof cover damage with wind speed. Industrial buildings representative of new construction in the Australian cities of Brisbane, Sydney and Melbourne are considered. Fragility functions are proposed for industrial buildings designed and constructed to existing codes, and also for improperly designed or constructed buildings where a roller door or other dominant opening prematurely fails during a storm for a building designed as nominally sealed. It was found that damage risks double if a roller door or other dominant opening prematurely fails during a storm.
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2015 |
Konthesingha KMC, Stewart MG, Ryan P, Ginger J, Henderson D, 'Reliability based vulnerability modelling of metal-clad industrial buildings to extreme wind loading for cyclonic regions', Journal of Wind Engineering and Industrial Aerodynamics, 147 176-185 (2015) [C1]
© 2015 Elsevier Ltd. This paper presents an approach for developing a vulnerability model to predict the probability and extent of damage to metal-clad industrial buildings due to... [more]
© 2015 Elsevier Ltd. This paper presents an approach for developing a vulnerability model to predict the probability and extent of damage to metal-clad industrial buildings due to extreme wind loading. Structural reliability-based methods that describe the spatially distributed wind load and component/connection strengths probabilistically are used in the model. Two failure mechanisms are considered for the roof envelop, namely; failure of roof cladding, and purlin failure. Interdependency between the failure mechanisms, load sharing effects due to connection/component failure, and internal pressure variation due to roof cladding failure are also considered. The industrial building examined in the study is a hot rolled structural steel, metal-clad, gable-end building designed for cyclonic regions in Australia. The likelihood and extent of roof damage for this buildings is presented using wind vulnerability curves obtained from the probabilistic model. It is found that internal pressure (e.g. an open door) and the use of cyclone washers has a significant effect on wind vulnerability. The utilisation of cyclone washers is found to reduce damage risks by over 70%.
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2015 |
Ginger J, Henderson D, Humphreys M, Konthesingha C, Stewart MG, 'Wind loads on the frames of industrial buildings', Australian Journal of Structural Engineering, 16 169-177 (2015) [C1]
© Institution of Engineers Australia, 2015. The structural response of typical, gable-end, low roof pitch industrial buildings, in a windstorm is dependent on the wind loads used ... [more]
© Institution of Engineers Australia, 2015. The structural response of typical, gable-end, low roof pitch industrial buildings, in a windstorm is dependent on the wind loads used in the design of cladding and the portal frame structure. Critical, structural wind load effects derived from wind loads measured on a wind tunnel model show that standards such as AS/NZS 1170.2 can produce unconservative design load effects on the heavily loaded fi rst internal frame. This paper forms part of wider study that assesses the vulnerability of hot rolled steel, industrial buildings to wind loads. The knee and ridge bending moments and horizontal and vertical reactions at the base of the frame are the critical load effects that are used in the design of structural members and connections of these types of buildings. This study found that some of these load effects based on external pressures are under-estimated by about 30%, when the building is located in a suburban environment. A dominant windward wall opening can effectively double the design load effects, thus signifi cantly increasing the vulnerability, especially if this scenario has not been considered by the designer.
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2015 |
Shi Y, Stewart MG, 'Spatial reliability analysis of explosive blast load damage to reinforced concrete columns', Structural Safety, 53 13-25 (2015) [C1]
© 2014 Elsevier Ltd. Columns are the key load-bearing elements in frame structures and exterior columns are probably the most vulnerable structural components to terrorist attack.... [more]
© 2014 Elsevier Ltd. Columns are the key load-bearing elements in frame structures and exterior columns are probably the most vulnerable structural components to terrorist attack. In this paper, a spatial reliability analysis is conducted to predict the damage for reinforced concrete (RC) columns subject to explosive blast loading. The spatial variability of material and dimensional properties of RC columns are modelled by stationary and non-stationary random fields. The variability of blast loading is also taken into consideration. Monte Carlo simulation and numerical methods are used to derive Blast Reliability Curves for RC columns under explosive loading for a number of terrorism threat scenarios, based on a high-fidelity physics-based computer programme LS-DYNA to estimate design and residual axial load-carrying capacity of RC columns. It was found that spatial variability has a significant effect on structural reliabilities and the spatial model will lead to more accurate predictions of damage and safety risks.
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2015 |
Stewart MG, 'Risk and economic viability of housing climate adaptation strategies for wind hazards in southeast Australia', Mitigation and Adaptation Strategies for Global Change, 20 601-622 (2015) [C1]
© 2013, Springer Science+Business Media Dordrecht. A changing climate and higher wind speeds means that residential construction is likely to receive more damage in the future if ... [more]
© 2013, Springer Science+Business Media Dordrecht. A changing climate and higher wind speeds means that residential construction is likely to receive more damage in the future if design standards are maintained at the current level. The vulnerability of residential construction may be reduced by an adaptation strategy that increases design wind speeds specified by Australian standards. The paper applies break-even analysis to compare the risks, costs and benefits of climate adaptation strategies for new housing in the three largest cities in Australia: Brisbane, Sydney and Melbourne. These cities are located in southeast Australia where wind hazard is dominated by synoptic winds (thunderstorms and east-coast lows). Break-even estimates of risk reduction and adaptation cost for designing new housing to enhanced standards were calculated for three synoptic wind pattern scenarios to 2070: (1) no change, (2) B1 and (3) A1FI emission scenarios. If the actual cost of adaptation exceeds the predicted break-even value, then adaptation is not cost-effective. It was found that this adaptation strategy can lead to risk reductions of 50¿80¿% at a cost of approximately 1¿% of house replacement value. If risk reduction is over 50¿%, discount rate is 4¿%, and there is no change of climate, the break-even analysis shows that adaptation is cost-effective for Sydney if the adaptation cost is less than 5¿9¿% of house replacement cost. Designing new housing to enhance wind classifications is also likely to be a cost-effective adaptation strategy for Brisbane and Melbourne.
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2015 |
Mojsilovic N, Stewart MG, 'Probability and structural reliability assessment of mortar joint thickness in load-bearing masonry walls', Structural Safety, 52 209-218 (2015) [C1]
© 2014 Elsevier Ltd. Mortar joint thickness has a significant effect on capacity of structural masonry. Data on mortar joint thickness (bed and head joints) were collected from tw... [more]
© 2014 Elsevier Ltd. Mortar joint thickness has a significant effect on capacity of structural masonry. Data on mortar joint thickness (bed and head joints) were collected from twelve typical storey-high walls at three different building sites and from four walls built in a research laboratory in Switzerland. The data obtained allowed an analysis of the spatial distribution of the joint thickness in each wall and the characterization of the probability distribution of joint thickness. The data has been statistically analysed and the results discussed: the central and dispersion measures were calculated and several probability distributions have been fitted to the sample data and subsequently tested using standard methods of statistical theory. Further, the results obtained from all four building sites have been compared, thus providing quantitative information about the quality of the work on different sites. The presented probabilistic information is then used to define reliability-based limit state specifications where the joint thickness acts as an important random variable. The reliability of the structural masonry subjected to a concentric normal force found that probabilistic modelling of bed joint thickness results in higher reliability indices.
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2015 |
Stewart MG, Deng X, 'Climate Impact Risks and Climate Adaptation Engineering for Built Infrastructure', ASCE-ASME Journal of Risk and Uncertainty in Engineering Systems, Part A: Civil Engineering, 1 04014001-04014001 (2015) [C1]
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2015 |
Stewart M, Netherton M, 'Preface', International Journal of Protective Structures, 6 iii (2015)
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2015 |
Stewart MG, Deng X, 'Closure to "Climate Impact Risks and Climate Adaptation Engineering for Built Infrastructure" by Mark G. Stewart and Xiaoli Deng', ASCE-ASME JOURNAL OF RISK AND UNCERTAINTY IN ENGINEERING SYSTEMS PART A-CIVIL ENGINEERING, 1 (2015)
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2015 |
Shi Y, Stewart MG, 'Damage and risk assessment for reinforced concrete wall panels subjected to explosive blast loading', International Journal of Impact Engineering, 85 5-19 (2015) [C1]
© 2015 Elsevier Ltd. All rights reserved. The structural integrity of reinforced concrete (RC) structures in blast events is important for critical facilities. In this paper, a st... [more]
© 2015 Elsevier Ltd. All rights reserved. The structural integrity of reinforced concrete (RC) structures in blast events is important for critical facilities. In this paper, a structural reliability analysis is conducted to predict the damage and risk reduction for RC wall panels subjected to explosive blast loading. Due to considerable uncertainties associated with material properties, dimensions, structural response, blast loading, as well as expected damage, probabilistic methods are used in quantifying the probability of damage for conventional and blast-resistant RC precast cladding wall panels by incorporating spatial and non-spatial variables. The variability of blast loading is also taken into consideration. Monte Carlo simulation and numerical methods are utilized to predict damage of RC wall panels subject to various threat scenarios, based on a physics-based computer programme LS-DYNA to estimate maximum support rotations. It was found that spatial variability of concrete compressive strength and concrete cover has little effects on the structural reliability for precast concrete panels, and the blast-resistant wall has 5%-100% lower probability of hazardous failure than the corresponding value for a conventional wall.
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2015 |
Bastidas-Arteaga E, Stewart MG, 'Damage risks and economic assessment of climate adaptation strategies for design of new concrete structures subject to chloride-induced corrosion', Structural Safety, 52 40-53 (2015) [C1]
© 2014 Elsevier Ltd. Reinforced concrete (RC) structures are subject to environmental actions affecting their performance, serviceability and safety. Among these actions, chloride... [more]
© 2014 Elsevier Ltd. Reinforced concrete (RC) structures are subject to environmental actions affecting their performance, serviceability and safety. Among these actions, chloride ingress leads to corrosion initiation and its interaction with service loading could reduce its operational life. Experimental evidence indicates that chloride ingress is highly influenced by weather conditions in the surrounding environment and therefore by climate change. Consequently, both structural design and maintenance should be adapted to these new environmental conditions. This work focuses on the assessment of the costs and benefits of two climate adaptation strategies for new RC structures placed in chloride-contaminated environments under various climate change scenarios. Their cost-effectiveness is measured in terms of the benefit-to-cost ratio (BCR) and the probability that BCR exceeds unity - i.e., Pr(BCR. > 1). It was found that increasing concrete strength grade is more cost-effective than increasing design cover. The results also indicate that the cost-effectiveness of a given adaptation strategy depends mainly on the type of structural component, exposure conditions and climate change scenarios.
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2015 |
Stewart MG, Mueller J, 'Responsible policy analysis in aviation security with an evaluation of PreCheck', Journal of Air Transport Management, 48 13-22 (2015) [C1]
© 2015 Elsevier Ltd. Officials serving the public are tasked at the most fundamental level to spend funds in a manner that most effectively and efficiently keeps people safe. To d... [more]
© 2015 Elsevier Ltd. Officials serving the public are tasked at the most fundamental level to spend funds in a manner that most effectively and efficiently keeps people safe. To do otherwise is irresponsible. In the case of counterterrorism policy-making, it is important, then, to evaluate the degree to which any gains in security afforded by counterterrorism measures are great enough to justify their cost. Risk analysis is an aid to responsible decisionmaking that does exactly that. We deal with four elements central to this approach-the cost per saved life, acceptable risk, cost-benefit analysis, and risk communication-and we discuss the degree to which risk analysis has been applied within the government to evaluate counterterrorism measures. We summarize our findings when this approach is used to assess the cost-effectiveness of airline and airport security measures, and then conclude by applying it to PreCheck, a measure that seems likely to bring considerable efficiencies to the screening process and great benefits to passengers, airports, and airlines while actually enhancing security somewhat.
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2015 |
Stewart MG, Netherton MD, 'Reliability-based design load factors for explosive blast loading', Journal of Performance of Constructed Facilities, 29 (2015) [C1]
© 2014 American Society of Civil Engineers. Reliability-based design allows the decision maker to select the level of reliability for a specific blast loading scenario and key to ... [more]
© 2014 American Society of Civil Engineers. Reliability-based design allows the decision maker to select the level of reliability for a specific blast loading scenario and key to this is an understanding of airblast uncertainty. Hence, explosive field trials have been conducted in Australia that measured the variability of free-field blast loading caused by military standard plastic explosives. The results have revealed a high level of variability of peak incident pressure, impulse, and time of positive phase duration for repeatable tests where variability would be expected to be a minimum. The accuracy of predictive blast load models (model error) was also assessed. A probabilistic blast load computer model is revised to capture these observed variabilities. The effect of a 20% mass-increase safety factor typically applied to explosive mass on the probability of exceeding a design blast load is assessed. Reliability-based load factors are calculated where the nominal load is multiplied by the load factor to ensure that the actual load is equal to the reliability level. Reliability-based load factors are estimated for reliability levels of 0.05-0.99, for a range of scaled distances for military munitions. The load factor can be as low as 0.66 for a 0.05 reliability level and as high as 1.30 for a 0.99 reliability level.
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2015 |
Grant M, Stewart MG, 'Probabilistic risk assessment for improvised explosive device attacks that cause significant building damage', Journal of Performance of Constructed Facilities, 29 (2015) [C1]
© 2014 American Society of Civil Engineers. Most vulnerability assessments assume that an improvised explosive device (IED) will reach maximum TNT equivalency, and that the IED wi... [more]
© 2014 American Society of Civil Engineers. Most vulnerability assessments assume that an improvised explosive device (IED) will reach maximum TNT equivalency, and that the IED will successfully detonate. These assumptions will tend to overestimate actual blast-load effects. The paper develops an IED probabilistic risk-assessment model using a systems model for IED attacks based on the reliability of IEDs and by characterizing the human aspects of an IED attack's operational effectiveness from existing databases of terrorist incidents. The analysis includes estimates of the probability of threat, hazard, and loss for large commercial buildings in the United States. It was found that annual fatality risk for building occupants is similar to acceptable risk criteria. This suggests that strengthening buildings against progressive collapse may not be warranted unless there is a specific threat against a building.
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2015 |
Salman AM, Li Y, Stewart MG, 'Evaluating system reliability and targeted hardening strategies of power distribution systems subjected to hurricanes', Reliability Engineering and System Safety, 144 319-333 (2015) [C1]
© 2015 Elsevier Ltd. All rights reserved. Over the years, power distribution systems have been vulnerable to extensive damage from hurricanes which can cause power outage resultin... [more]
© 2015 Elsevier Ltd. All rights reserved. Over the years, power distribution systems have been vulnerable to extensive damage from hurricanes which can cause power outage resulting in millions of dollars of economic losses and restoration costs. Most of the outage is as a result of failure of distribution support structures. Over the years, various methods of strengthening distribution systems have been proposed and studied. Some of these methods, such as undergrounding of the system, have been shown to be unjustified from an economic point of view. A potential cost-effective strategy is targeted hardening of the system. This, however, requires a method of determining critical parts of a system that when strengthened, will have greater impact on reliability. This paper presents a framework for studying the effectiveness of targeted hardening strategies on power distribution systems subjected to hurricanes. The framework includes a methodology for evaluating system reliability that relates failure of poles and power delivery, determination of critical parts of a system, hurricane hazard analysis, and consideration of decay of distribution poles. The framework also incorporates cost analysis that considers economic losses due to power outage. A notional power distribution system is used to demonstrate the framework by evaluating and comparing the effectiveness of three hardening measures.
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2015 |
Mueller J, Stewart MG, 'Terrorism, counterterrorism, and the Internet: The American cases', Dynamics of Asymmetric Conflict: Pathways toward Terrorism and Genocide, 8 176-190 (2015) [C1]
© 2015 Taylor & Francis. This article assesses the cases that have come to light since 9/11 of Islamist extremist terrorism, whether based in the United States or abroad, in... [more]
© 2015 Taylor & Francis. This article assesses the cases that have come to light since 9/11 of Islamist extremist terrorism, whether based in the United States or abroad, in which the United States itself has been, or apparently has been, targeted. Information from them is used to evaluate how the Internet (including various forms of electronic communication) has affected several aspects of the terrorism enterprise in the United States: radicalization, communication, organization, and the gathering of information. In general, it is found that the Internet has not been particularly important. Although it has been facilitating in some respects, it has scarcely ever been necessary. In some respects, the Internet more fully aids efforts to police terrorism ¿ although this is mainly due to the incompetence and amateurishness of would-be terrorists. In other respects, however, the Internet, and the big data compilations it makes possible, greatly increase the costs and complications of the counterterrorism quest.
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2014 |
Mueller J, Stewart MG, 'Evaluating counterterrorism spending', Journal of Economic Perspectives, 28 237-248 (2014) [C1]
© 2014, American Economic Association. All rights reserved. In this article, we present a simple back-of-the-envelope approach for evaluating whether counterterrorism security mea... [more]
© 2014, American Economic Association. All rights reserved. In this article, we present a simple back-of-the-envelope approach for evaluating whether counterterrorism security measures reduce risk sufficiently to justify their costs. The approach uses only four variables: the consequences of a successful attack, the likelihood of a successful attack, the degree to which the security measure reduces risk, and the cost of the security measure. After measuring the cost of a counterterrorism measure, we explore a range of outcomes for the costs of terrorist attacks and a range of possible estimates for how much risk might be reduced by the measure. Then working from this mix of information and assumptions, we can calculate how many terrorist attacks (and of what size) would need to be averted to justify the cost of the counterterrorism measure in narrow cost-benefit terms. To illustrate this approach, we first apply it to the overall increases in domestic counterterrorism expenditures that have taken place since the terrorist attacks of September 11, 2001, and alternatively we apply it to just the FBI's counterterrorism efforts. We then evaluate evidence on the number and size of terrorist attacks that have actually been averted or might have been averted since 9/11.
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2014 |
Li J, Masia MJ, Stewart MG, Lawrence SJ, 'Spatial variability and stochastic strength prediction of unreinforced masonry walls in vertical bending', Engineering Structures, 59 787-797 (2014) [C1]
The flexural bond strength of unreinforced masonry (URM) is a key material property affecting wall out-of-plane lateral load capacity. It is well known that the unit flexural bond... [more]
The flexural bond strength of unreinforced masonry (URM) is a key material property affecting wall out-of-plane lateral load capacity. It is well known that the unit flexural bond strength (defined here as the flexural strength of the bond between the brick and lower mortar bed joint associated with any given masonry unit (brick)) varies considerably between units, and that this spatial variability might significantly affect the structural performance and reliability of URM walls in flexure. The paper develops a computational method to predict the strength for non-load bearing single skin URM walls subject to one-way vertical bending considering unit-to-unit spatial variability of flexural bond strength. We characterise the probability distributions of wall strength and examine how spatial variability in unit flexural bond strength affects the variability of base cracking load, mid-height cracking load, peak load and behaviour of clay brick URM walls. This is done using 3-D non-linear Finite Element Analyses (FEA) and stochastic analysis in the form of Monte Carlo simulations. Varying COVs (0.1, 0.3 and 0.5) of unit flexural bond strength are considered. The mean and variance of wall strength are estimated to show the effect of spatial variability of flexural bond strength on wall strength. The failure modes of the wall are compared to show the significant differences between non-spatial and spatial analyses. © 2013.
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2014 |
Peng L, Stewart MG, 'Spatial time-dependent reliability analysis of corrosion damage to RC structures with climate change', Magazine of Concrete Research, 66 1154-1169 (2014) [C1]
The environment around concrete structures may be influenced by a changing climate, especially in the long run, leading to an acceleration of deterioration. Therefore, the safety,... [more]
The environment around concrete structures may be influenced by a changing climate, especially in the long run, leading to an acceleration of deterioration. Therefore, the safety, serviceability and durability of concrete infrastructure may decline at a faster rate than expected. Carbonation-induced deterioration to concrete structures constructed in Sydney, Australia and Kunming, China under a changing climate is investigated in this paper. Two emissions scenarios are considered - RCP 8.5 and RCP 4.5, representing high and medium greenhouse gas emissions scenarios respectively. The spatial time-dependent reliability analysis includes time-dependent climate scenarios and deterioration processes, as well as a large number of random variables and spatial random fields of material properties and dimensions. The surface of concrete structures is discretised into a large number of elements and the likelihood and extent of corrosion damage is calculated by tracking the evolution of the corrosion process of each element using Monte Carlo simulations. The results show that a changing climate could cause the extent of damage to increase by up to 6% for reinforced concrete infrastructure in Kunming. The findings may be used to assess climate adaptation measures in the design stage, as well as a cost-benefit analysis of climate adaptation measures.
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2014 |
Stewart MG, Mueller J, 'Cost-benefit analysis of airport security: Are airports too safe?', JOURNAL OF AIR TRANSPORT MANAGEMENT, 35 19-28 (2014) [C1]
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2014 |
Peng L, Stewart Mark G, 'Climate change effects on carbonation-induced corrosion and damage risks of RC infrastructure in China', Tumu Gongcheng Xuebao/China Civil Engineering Journal, 47 61-69 (2014) [C1]
Climate change may increase atmospheric CO2 concentration and temperature, change relative humidity (RH), and consequently change RC infrastructures' surrounding environment.... [more]
Climate change may increase atmospheric CO2 concentration and temperature, change relative humidity (RH), and consequently change RC infrastructures' surrounding environment. Especially in the long run, the decline of the safety, serviceability and durability of RC structures may be accelerated. Carbonation induced corrosion damage of RC infrastructure in Xiamen and Shaoguan under a changing climate is investigated for time period 2010~2100. The projection of atmospheric CO2 concentration, temperature and RH in both cities are based on the representative concentration pathways (RCPs). The time-dependent reliability analysis was conducted by Monte Carlo simulation and includes the uncertainty of dimensions, material properties, climate projections, and predictive models. The corrosion damage risks of RC structures are represented by the probability of severe cracking of concrete cover. Results show that climate change may increase mean carbonation depth by 8 mm by 2100. Moreover, carbonation-induced damage risk for RC buildings in temperate areas can be increased by 12%~19%. This research provides a reference for impacts of future climate change on RC structures and development of climate adaptation strategies.
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2014 |
Mueller J, Stewart MG, 'Terrorism and counterterrorism in the US: the question of responsible policy-making', International Journal of Human Rights, 18 228-240 (2014) [C1]
Officials serving the public are tasked at the most fundamental level to spend funds in a manner that most effectively and efficiently keeps people safe. To do otherwise is irresp... [more]
Officials serving the public are tasked at the most fundamental level to spend funds in a manner that most effectively and efficiently keeps people safe. To do otherwise is irresponsible and, because human lives are at stake, immoral. In the case of counterterrorism policy-making, it is important to evaluate the degree to which any gains in security afforded by counterterrorism measures have been great enough to justify their cost. Risk analysis is an aid to responsible decision-making that does exactly that. We deal with four issues central to this approach, applying them to the hazard presented by terrorism: the cost per saved life, acceptable risk, cost-benefit analysis, and risk communication. We also assess the degree to which risk analysis has been coherently applied to counterterrorism efforts in the US in making or evaluating decisions that have cost taxpayers many hundreds of billions of dollars over the past dozen years. © 2014 Taylor & Francis.
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2014 |
Stewart MG, Wang X, Willgoose GR, 'Direct and indirect cost-and-benefit assessment of climate adaptation strategies for housing for extreme wind events in Queensland', Natural Hazards Review, 15 (2014) [C1]
© 2014 American Society of Civil Engineers. The intensity of tropical cyclones and severe storms is likely to increase due to climate change. Brisbane and the northeast coast of Q... [more]
© 2014 American Society of Civil Engineers. The intensity of tropical cyclones and severe storms is likely to increase due to climate change. Brisbane and the northeast coast of Queensland are regions where design wind specifications may be inadequate under either current or likely future climate conditions. An appropriate adaptation strategy may be one that increases wind classifications for new houses, which leads to a reduced vulnerability of new construction. The present paper will assess the damage risks, adaptation costs, and cost-effectiveness of these adaptation measures for residential construction in Cairns, Townsville, Rockhampton, and South East Queensland, assuming time-dependent changes in the frequency and intensity of cyclonic and noncyclonic winds to 2100. Loss functions are also developed for direct and indirect losses. It was found that increasing design wind loads for new houses in Brisbane and South East Queensland will lead to a net benefit [net present value (NPV)] of up to $10.5 billion by 2100, assuming a discount rate of 4%, which includes approximately 95% of a direct benefit and 5% of an indirect benefit. The benefits are highest for Brisbane due to its large population and the high vulnerability of existing residential construction, and have a 90-100% likelihood of achieving a net benefit by 2100.
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2014 |
Bjarnadottir S, Li Y, Stewart MG, 'Risk-based economic assessment of mitigation strategies for power distribution poles subjected to hurricanes', Structure and Infrastructure Engineering, 10 740-752 (2014) [C1]
This paper presents a risk-based framework to assess the hurricane damage risks to distribution poles, and investigates the risks, costs and benefit of different mitigation strate... [more]
This paper presents a risk-based framework to assess the hurricane damage risks to distribution poles, and investigates the risks, costs and benefit of different mitigation strategies. It is estimated that power outages due to storms cause approximately $270 million in repair/replacement costs annually in the USA. Hurricane Irene alone left approximately 6 million residents without power along the east coast of the USA in 2011, causing an estimated $5-$7 billion in damages. These high repair/replacement costs warrant an investigation of mitigation strategies that may aid in reducing replacement and damage costs. This paper describes the reliability analysis of typical timber distribution poles and probabilistic wind models to determine failure probabilities for specific locations. Furthermore, in order to more accurately portray the behaviour of distribution poles, the proposed framework includes the degradation and service-proven reliability of timber distribution poles. Four mitigation strategies are developed, and the cost effectiveness of each strategy is evaluated. In order to assess the cost effectiveness, a life cycle cost analysis is conducted for each mitigation strategy. This paper finds that appropriate mitigation strategies can reduce replacement costs of distribution poles associated with hurricane wind by 2060. © 2013 © 2013 Taylor & Francis.
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2014 |
Bjarnadottir S, Li Y, Stewart MG, 'Regional loss estimation due to hurricane wind and hurricane-induced surge considering climate variability', Structure and Infrastructure Engineering, 10 1369-1384 (2014) [C1]
© 2013, © 2013 Taylor & Francis. This paper presents a framework to assess the potential hurricane damage risks to residential construction. Studies show that hurricane wind... [more]
© 2013, © 2013 Taylor & Francis. This paper presents a framework to assess the potential hurricane damage risks to residential construction. Studies show that hurricane wind, frequency and/or hurricane-induced surge may change as a result of climate change; therefore, hurricane risk assessments should be capable of accounting for the impacts climate change. The framework includes a hurricane wind field model, hurricane-induced surge height model and hurricane vulnerability models. Three case study locations (Miami-Dade County, FL; New Hanover County, NC and Galveston County, TX) are presented for two types of analyses: annual regional loss estimation and event-based regional loss estimation. Demographic information, such as median house value and changes in house numbers, and distribution of houses for different exposures, is used to estimate the time-dependent probability of damage with or without possible climate change-induced change in wind speed, frequency and/or surge height. Through both analyses, it was found that climate change may have a significant impact on regional hurricane damage losses.
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2014 |
Stewart MG, Mueller J, 'Terrorism risks for bridges in a multi-hazard environment', International Journal of Protective Structures, 5 275-289 (2014) [C1]
The paper will assess terrorist threats to new and existing bridges and the cost-effectiveness of protective counter-terrorism measures. This analysis will consider threat likelih... [more]
The paper will assess terrorist threats to new and existing bridges and the cost-effectiveness of protective counter-terrorism measures. This analysis will consider threat likelihood, cost of security measures, risk reduction and expected losses to compare the costs and benefits of protective measures to bridges to decide which protective measures are cost-effective. In this paper, a break-even cost-benefit analysis determines the minimum probability of an attack, absent the protective measures, that is required for the benefit of the protective measures to equal their cost for new and existing bridges. It was found that unless terrorist threat probabilities are high, then typical protective measures are not cost-effective. Bridges and other critical infrastructure are subject to a range of natural and man-made hazards, and terrorism is most likely not as important a threat as natural hazards. It was found that economic risks to bridges from floods, earthquakes, and ship impact are higher than threats from terrorism.
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2014 |
Ryan PC, Stewart MG, Spencer N, Li Y, 'Reliability assessment of power pole infrastructure incorporating deterioration and network maintenance', Reliability Engineering & System Safety, 132 261-273 (2014) [C1]
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2013 |
Netherton MD, Stewart MG, 'What are some of the problems associated with the current methods of calculating explosive blast loads?', 10th International Conference on Shock and Impact Loads on Structures 2013, 65-74 (2013)
The most common methods for calculating explosive blast loads are deterministic; in that, the output will always be the same for given model-inputs. However, a statistical analysi... [more]
The most common methods for calculating explosive blast loads are deterministic; in that, the output will always be the same for given model-inputs. However, a statistical analysis of actual explosive blast loading field (test) data reveals a high level of variability of peak reflected pressure, impulse and time of positive phase duration from repeated tests where variability would be expected to be a minimum. Given that blast-loads from similar events are highly variable, and that the most common blast-load models do not account for such circumstances, the question we should now be asking is this: How can we improve our methods for predicting blast loads, such that (known) variability and uncertainty is appropriately considered, to ensure that we continue to give useful, usable and robust information to decision makers? In other words: What exactly is the best available method for giving your Boss advice on the risks associated with explosive blast loads? This paper explores the deterministic nature of commonly used blast-load models and discusses their limitations with respect to matters such as: explosive safety distances, the design loads on protective structures and the military's deliberate use of munitions. We argue that deterministic models do not adequately account for society's usual acceptance (or rejection) of the risks associated with damage and/or injury. A new probabilistically based blast-load model is developed which does take into account the observed (and very real) variability of explosive blast loads. Following which, new forms of risk-based advice are presented. This new probabilistic blast-load model uses statistical and probabilistic information taken from the literature as well as from our own explosive trials. Explosive scenarios of future interest could be from blast-loads resulting from (possible) terrorist activity, or, from current in-service military munitions. In either case, we argue that these new forms of risk-based advice (eg: the most probable blast-load or cost-effective mitigation) provides additional - and unique - utility for decision makers involved in the production, storage and operational use of explosives. The paper concludes with a discussion on how the new probabilistic blast-loading model can improve a decision maker's confidence with respect to explosive safety distances, magazine design, protective structures design, weaponeering and collateral damage estimation.
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2013 |
Bastidas-Arteaga E, Schoefs F, Stewart MG, Wang X, 'Influence of global warming on durability of corroding RC structures: A probabilistic approach', ENGINEERING STRUCTURES, 51 259-266 (2013) [C1]
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2013 |
Stewart MG, Mueller J, 'Terrorism Risks and Cost-Benefit Analysis of Aviation Security', RISK ANALYSIS, 33 893-908 (2013) [C1]
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2013 |
Stewart MG, Mueller J, 'Aviation Security, Risk Assessment, and Risk Aversion for Public Decisionmaking', JOURNAL OF POLICY ANALYSIS AND MANAGEMENT, 32 615-+ (2013) [C1]
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2013 |
Stewart MG, O'Callaghan D, Hartley M, 'Review of QTRA and risk-based cost-benefit assessment of tree management', Arboriculture and Urban Forestry, 39 165-172 (2013) [C1]
Quantified Risk Assessment (QRA) has been in wide use in risk management since the 1960s for systems ranging from aviation, nuclear power, and offshore platforms to medical treatm... [more]
Quantified Risk Assessment (QRA) has been in wide use in risk management since the 1960s for systems ranging from aviation, nuclear power, and offshore platforms to medical treatment and pharmaceuticals. The Quantified Tree Risk Assessment (QTRA) system is examined considering the principles of QRA. A case study of 14 fig trees in Newcastle, Australia, illustrates some limitations of the QTRA process, and extrapolating risks for a single tree to a group of trees. There is a need for any risk management process involving trees, not only to assess the risk, but to weigh the benefits provided by trees by a risk-based cost-benefit analysis. Tree risk assessors should rely on benchmarks to ensure that their assessment is not outside of the realms of reality or scientific rigor. © 2013 International Society of Arboriculture.
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2013 |
Bjarnadottir S, Li Y, Stewart MG, 'Hurricane Risk Assessment of Power Distribution Poles Considering Impacts of a Changing Climate', JOURNAL OF INFRASTRUCTURE SYSTEMS, 19 12-24 (2013) [C1]
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2012 |
Chernin L, Val DV, Stewart MG, 'Prediction of cover crack propagation in RC structures caused by corrosion', Magazine of Concrete Research, 64 95-111 (2012) [C1]
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2012 |
Oven KJ, Curtis SE, Reaney S, Riva M, Stewart MG, Ohlemuller R, et al., 'Climate change and health and social care: Defining future hazard, vulnerability and risk for infrastructure systems supporting older people's health care in England', Applied Geography, 33 16-24 (2012) [C1]
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2012 |
Mueller J, Stewart MG, 'The terrorism delusion: America's overwrought response to September 11', International Security, 37 81-110 (2012) [C1]
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2012 |
Stewart MG, Wang X, Nguyen MN, 'Climate change adaptation for corrosion control of concrete infrastructure', Structural Safety, 35 29-39 (2012) [C1]
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2012 |
Mueller J, Stewart MG, 'Civil liberties, fear and terrorism', Notre Dame Journal of International and Comparative Law, 3 282-288 (2012) [C2] |
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2012 |
Stewart MG, O'Connor A, 'Probabilistic risk assessment and service life performance management of load bearing biomedical implants', Reliability Engineering and System Safety, 108 49-55 (2012) [C1]
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2012 |
Zhai X, Zhong Z, Stewart MG, 'Structural reliability for reinforced concrete block masonry walls in shear force', Journal of Harbin Engineering University, 33 313-319 (2012) [C2]
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2012 |
Mullard JA, Stewart MG, 'Life-cycle cost assessment of maintenance strategies for RC structures in chloride environments', Journal of Bridge Engineering, 17 353-362 (2012) [C1]
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2012 |
Stewart MG, Netherton MD, Shi Y, Grant M, Mueller J, 'Probabilistic terrorism risk assessment and risk acceptability for infrastructure protection', Australian Journal of Structural Engineering, 13 1-17 (2012) [C1]
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2012 |
Correa MRS, Masia MJ, Stewart MG, Heffler LM, 'An experimental and statistical analysis of the flexural bond strength of masonry walls', Australian Journal of Structural Engineering, 13 139-148 (2012) [C1]
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2012 |
Stewart MG, Hao H, 'Security and protective structures research in Australia', Australian Journal of Structural Engineering, 13 i (2012) [C6] |
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2012 |
Zhai X, Zhong Z, Stewart MG, 'Model error and structural reliability for reinforced concrete block masonry walls in shear', Advances in Structural Engineering, 15 389-398 (2012) [C1]
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2012 |
Stewart MG, 'Spatial and time-dependent reliability modelling of corrosion damage, safety and maintenance for reinforced concrete structures', Structure and Infrastructure Engineering, 8 607-619 (2012) [C1]
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2012 |
Grant MJ, Stewart MG, 'A systems model for probabilistic risk assessment of improvised explosive device attacks', International Journal of Intelligent Defence Support Systems, 5 75-93 (2012) [C1] |
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2011 |
Li Y, Stewart MG, 'Cyclone damage risks caused by enhanced greenhouse conditions and economic viability of strengthened residential construction', Natural Hazards Review, 12 9-18 (2011) [C1]
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2011 |
Stewart MG, Mueller J, 'Cost-benefit analysis of advanced imaging technology full body scanners for airline passenger security screening', Journal of Homeland Security and Emergency Management, 8 1-18 (2011) [C1]
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2011 |
Mueller J, Stewart MG, 'Balancing the risks, benefits, and costs of Homeland Security', Homeland Security Affairs, 7 16 (2011) [C1] |
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2011 |
Stewart MG, 'Life-safety risks and optimisation of protective measures against terrorist threats to infrastructure', Structure and Infrastructure Engineering: Maintenance, Management, Life-Cycle Design and Performance, 7 431-440 (2011) [C1]
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2011 |
Mueller J, Stewart MG, 'Witches, communists and terrorists: Evaluating the risks and tallying the costs', Human Rights, 38 20-22 (2011) [C3] |
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2011 |
Al-Harthy AS, Stewart MG, Mullard J, 'Concrete cover cracking caused by steel reinforcement corrosion', Magazine of Concrete Research, 63 655-667 (2011) [C1]
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2011 |
Mueller J, Stewart MG, 'The price is not right: The U.S. spends too much money to fight terrorism', Playboy, 58 149-150 (2011) [C3] |
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2011 |
Stewart MG, Wang X, Nguyen MN, 'Climate change impact and risks of concrete infrastructure deterioration', Engineering Structures, 33 1326-1337 (2011) [C1]
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2011 |
Wang X, Stewart MG, Nguyen M, 'Impact of climate change on corrosion and damage to concrete infrastructure in Australia', Climatic Change, 110 941-957 (2011) [C1]
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2011 |
Bjarnadottir S, Li Y, Stewart MG, 'A probabilistic-based framework for impact and adaptation assessment of climate change on hurricane damage risks and costs', Structural Safety, 33 173-185 (2011) [C1]
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2011 |
Mullard JA, Stewart MG, 'Corrosion-induced cover cracking: New test data and predictive models', ACI Structural Journal, 108 71-79 (2011) [C1]
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2011 |
Bjarnadottir S, Li Y, Stewart MG, 'Social vulnerability index for coastal communities at risk to hurricane hazard and a changing climate', Natural Hazards, 59 1055-1075 (2011) [C1]
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2011 |
Lawrence S, Stewart MG, 'Model error and structural reliability for unreinforced masonry walls in vertical bending', Masonry International, 24 23-30 (2011) [C1] |
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2011 |
Stewart MG, Lawrence S, 'When buildings are too safe', MATERIALS WORLD, 19 30-31 (2011) [O1] |
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2011 |
Stewart MG, Mueller J, 'Assessing the risks, costs, and benefits of counter-terrorism protective measures for infrastructure', The CIP Report, 10 3-5, 31 (2011) [C3] |
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2011 |
Stewart MG, Ellingwood BR, Mueller J, 'Homeland security: A case study in risk aversion for public decision-making', International Journal of Risk Assessment and Management, 15 367-386 (2011) [C1]
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2010 |
Stewart MG, 'Risk-informed decision support for assessing the costs and benefits of counter-terrorism protective measures for infrastructure', International Journal of Critical Infrastructure Protection, 3 29-40 (2010) [C1]
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2010 |
Hao H, Stewart MG, Zhong-Xian L, Shi Y, 'RC column failure probabilities to blast loads', International Journal of Protective Structures, 1 571-591 (2010) [C1]
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2010 |
Netherton MD, Stewart MG, 'Blast Load Variability and Accuracy of Blast Load Prediction Models', International Journal of Protective Structures, 1 543-570 (2010) [C1]
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2010 |
Stewart MG, 'Acceptable Risk Criteria for Infrastructure Protection', International Journal of Protective Structures, 1 23-40 (2010) [C1]
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2010 |
Mueller J, Stewart MG, 'Hardly existential: Thinking rationally about terrorism', Foreign Affairs, 1-5 (2010) [C2] |
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2010 |
Zhai X, Stewart MG, 'Structural reliability analysis of reinforced grouted concrete block masonry walls in compression', Engineering Structures, 32 106-114 (2010) [C1]
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2010 |
Wei X, Stewart MG, 'Model validation and parametric study on the blast response of unreinforced brick masonry walls', International Journal of Impact Engineering, 37 1150-1159 (2010) [C1]
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2010 |
Stewart MG, 'Reliability safety assessment of corroding reinforced concrete structures based on visual inspection information', ACI Structural Journal, 107 671-679 (2010) [C1]
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2010 |
Stewart MG, Peng J, 'Life cycle cost assessment of climate change adaptation measures to minimise carbonation-induced corrosion risks', International Journal of Engineering Under Uncertainty: Hazards, Assessment and Mitigation, 2 35-46 (2010) [C2] |
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2010 |
Stewart MG, Li Y, 'Methodologies for economic impact and adaptation assessment of cyclone damage risks due to climate change', Australian Journal of Structural Engineering, 10 121-135 (2010) [C1]
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2009 |
Stewart M, Reid S, 'Disaster & hazard mitigation', Australian Journal of Structural Engineering, 9 (2009) |
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2009 |
Stewart MG, Suo Q, 'Extent of spatially variable corrosion damage as an indicator of strength and time-dependent reliability of RC beams', Engineering Structures, 31 198-207 (2009) [C1]
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2009 |
Stewart MG, 'Mechanical behaviour of pitting corrosion of flexural and shear reinforcement and its effect on structural reliability of corroding RC beams', Structural Safety, 31 19-30 (2009) [C1]
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2009 |
Netherton MD, Stewart MG, 'Probabilistic modelling of safety and damage blast risks for window glazing', Canadian Journal of Civil Engineering, 36 1321-1331 (2009) [C1]
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2009 |
Val DV, Chemin L, Stewart MG, 'Experimental and numerical investigation of corrosion-induced cover cracking in reinforced concrete structures', Journal of Structural Engineering, 135 376-385 (2009) [C1]
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2009 |
Mullard JA, Stewart MG, 'Stochastic assessment of timing and efficiency of maintenance for corroding RC structures', Journal of Structural Engineering, 135 887-895 (2009) [C1]
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2009 |
Netherton MD, Stewart MG, 'The effects of explosive blast load variability on safety hazard and damage risks for monolithic window glazing', International Journal of Impact Engineering, 36 1346-1354 (2009) [C1]
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2009 |
Suo Q, Stewart MG, 'Corrosion cracking prediction updating of deteriorating RC structures using inspection information', Reliability Engineering & System Safety, 94 1340-1348 (2009) [C1]
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2009 |
Val DV, Stewart MG, 'Reliability assessment of ageing reinforced concrete structures: Current situation and future challenges', Structural Engineering International, 19 211-219 (2009) [C1]
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2009 |
Stewart MG, Reid S, 'Preface: Disaster & hazard mitigation', Australian Journal of Structural Engineering, 9 i (2009) [C3] |
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2009 |
Lawrence S, Stewart MG, 'Reliability-based calibration of the capacity reduction factor for design of masonry in compression to AS3700', Australian Journal of Structural Engineering, 9 97-110 (2009) [C1]
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2008 |
Stewart MG, Mueller J, 'A risk and cost-benefit assessment of Australian aviation security measures', Security Challenges, 4 45-61 (2008) [C1]
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2008 |
Stewart MG, Mueller J, 'A risk and cost-benefit assessment of United States aviation security measures', Journal of Transportation Security, 1 143-159 (2008) [C1]
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2008 |
Stewart MG, O'Rourke A, 'Probabilistic risk assessment of mine subsidence', Australian Geomechanics, 43 1-12 (2008) [C1]
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2008 |
Stewart MG, 'Cost effectiveness of risk mitigation strategies for protection of buildings against terrorist attack', Journal of Performance of Constructed Facilities, 22 115-120 (2008) [C1]
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2008 |
Heffler LM, Stewart MG, Masia MJ, Correa MRS, 'Statistical analysis and spatial correlation of flexural bond strength for masonry walls', Masonry International: Journal of the International Masonry Society, 21 59-70 (2008) [C1]
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2008 |
Stewart MG, Al-Harthy A, 'Pitting corrosion and structural reliability of corroding RC structures: Experimental data and probabilistic analysis', Reliability Engineering & System Safety, 93 373-382 (2008) [C1]
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2008 |
Stewart MG, Netherton MD, 'Security risks and probabilistic risk assessment of glazing subject to explosive blast loading', Reliability Engineering and System Safety, 93 627-638 (2008) [C1]
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2008 |
Stewart MG, 'Risk acceptability and cost-effectiveness of protective measures against terrorist threats to built infrastructure considering multiple threat scenarios', Transactions of Tianjin University, 14 313-317 (2008) [C1]
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2007 |
Stewart MG, Lawrence S, 'Model error, structural reliability and partial safety factors for structural masonry in compression', Journal of the British Masonry Society Masonry International, 20 107-116 (2007) [C1] |
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2007 |
Stewart MG, Mullard JA, Drake BJ, Al-Harthy AS, 'Utility of spatially variable damage performance indicators for improved safety and maintenance decisions of deteriorating infrastructure', Civil Engineering and Environmental Systems, 24 149-163 (2007) [C1]
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2007 |
Darmawan MS, Stewart MG, 'Effect of pitting corrosion on capacity of prestressing wires', Magazine of Concrete Research, 59 131-139 (2007) [C1]
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2007 |
Stewart MG, Mullard JA, 'Spatial time-dependent reliability analysis of corrosion damage and the timing of first repair for RC structures', Engineering Structures, 29 1457-1464 (2007) [C1]
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2007 |
Darmawan MS, Stewart MG, 'Spatial time-dependent reliability analysis of corroding pretensioned prestressed concrete bridge girders', Structural Safety, 29 16-31 (2007) [C1]
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2006 |
Stewart MG, 'Risk assessment and optimization of blast mitigation strategies for design and strengthening of built infrastructure', Transactions of Tianjin University, 12 8-15 (2006) [C1]
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2006 |
Darmawan MS, Stewart MG, 'Effect of spatially variable pitting corrosion on structural reliability of prestressed concrete bridge girders', Australian Journal of Structural Engineering, 6 147-158 (2006) [C1] |
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2006 |
Stewart MG, Netherton MD, 'Performance, reliability and security risks of glazing subject to explosive blast loading', Australian Journal of Structural Engineering, 7 23-36 (2006) [C1] |
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2006 |
Stewart MG, Netherton MD, Rosowsky DV, 'Terrorism risks and blast damage to built infrastructure', Natural Hazards Review, 7 114-122 (2006) [C1]
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2006 |
Stewart MG, 'Spatial variability of damage and expected maintenance costs for deteriorating RC structures', Structure and Infrastructure Engineering, 2 79-90 (2006) [C1]
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2006 |
Stewart MG, Mullard JA, 'Reliability based assessment of the influence of concrete durability on the timing of repair for RC bridges', Proceedings of the 3rd International Conference on Bridge Maintenance, Safety and Management - Bridge Maintenance, Safety, Management, Life-Cycle Performance and Cost, 519-520 (2006)
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2005 |
Vu KAT, Stewart MG, 'Predicting the likelihood and extent of reinforced concrete corrosion-induced cracking', Journal of Structural Engineering, 131 1681-1689 (2005) [C1]
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2005 |
Stewart MG, Love A, 'Uncertainty, Economic Risk Analysis And Risk Acceptance Criteria For Mine Subsidence', Australian Geomechanics, 40 79-89 (2005) [C1]
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2005 |
Vu K, Stewart MG, Mullard JA, 'Corrosion-induced cracking: Experimental data and predictive models', ACI Structural Journal, 102 719-726 (2005) [C1]
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2005 |
Val DV, Stewart MG, 'Decision analysis for deteriorating structures', Reliability Engineering & System Safety, 87 377-385 (2005) [C1]
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2004 |
Stewart MG, 'Spatial Variability Of Pitting Corrosion And Its Influence On Structural Fragility And Reliability Of RC Beams In Flexure', Structural Safety, Vol. 26 453-470 (2004) [C1]
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2004 |
Stewart MG, Estes AC, Frangopol DM, 'Bridge Deck Replacement For Minimum Expected Cost Under Multiple Reliability Constraints', Journal of Structural Engineering, Vol. 130 1414-1419 (2004) [C1]
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2004 |
Epaarachchi DC, Stewart MG, 'Human Error And Reliability Of Multistory Reinforced-Concrete Building Construction', Journal of Performance of Constructed Facilities, 18 12-20 (2004) [C1]
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2004 |
Stewart MG, 'Risk Assessment As A Decision-Making Tool To Mitigate Blast Damage To Built Infrastructure', Australian Journal of Multi-Disciplinary Engineering, Not Known 1-11 (2004) [C1] |
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2004 |
Epaarachchi DC, Stewart MG, 'Human Error and Reliability of Multistory Reinforced-Concrete Building Construction', Journal of Performance of Constructed Facilities, 18 12-20 (2004)
Copyright © 2004 American Society of Civil Engineers. This paper develops probabilistic and human reliability models to estimate the probability of structural collapse (system ris... [more]
Copyright © 2004 American Society of Civil Engineers. This paper develops probabilistic and human reliability models to estimate the probability of structural collapse (system risk) during the construction of typical multistory reinforced-concrete buildings in the presence of human error. Results obtained from the human reliability analysis suggest that errors related to concrete cover and concreting workmanship are more detrimental to system risk than any other errors. Errors related to reinforcement area have a minor effect on system risk, provided that the existing effectiveness of engineering inspections is maintained. The results also show that errors related to installation of steel shores/reshores do not significantly affect the system risk. © 2004
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2003 |
Stewart MG, Rosowsky DV, Huang Z, 'Hurricane Risks And Economic Viability Of Strengthened Construction', Natural Hazards Review, Vol. 4 12-19 (2003) [C1]
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2003 |
Val DV, Stewart MG, 'Life-Cycle Cost Analysis Of Reinforced Concrete Structures In Marine Environments', Structural Safety, 25 343-362 (2003) [C1]
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2003 |
Stewart MG, 'Cyclone Damage And Temporal Changes To Building Vulnerablity And Economic Risks For Residential Construction', Journal Of Wind Engineerng And Industrial Aerodynamics, Vol. 91 671-691 (2003) [C1]
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2003 |
Faber M, Stewart MG, 'Risk Assessment For Civil Engineering Facilities: Critical Overview And Discussion', Reliability Engineering and System Safety, Vol. 80 173-184 (2003) [C1]
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2003 |
Stewart MG, Val DV, 'Multiple Limit States And Expected Failure Costs For Deteriorating Reinforced Concrete Bridges', Journal Of Bridge Engineering, Vol. 8 405-415 (2003) [C1]
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2002 |
Epaarachchi DC, Stewart MG, Rosowsky DV, 'Structural Reliability of Multistory Buildings During Construction', Journal of Structural Engineering, Vol. 128, No. 2 205-213 (2002) [C1]
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2002 |
Val DV, Stewart MG, 'Safety Factors For Assessment of Existing Structures', Journal of Structural Engineering, Vol. 128, No. 2 258-265 (2002) [C1]
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2002 |
Stewart MG, Lawrence S, 'Structural Reliability of Masonry Walls in Flexure', Masonry International, Vol. 15, No. 2 48-52 (2002) [C1] |
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2002 |
Pukl R, Teply B, Novak D, Stewart MG, 'Modeling Of Precast Prestressed Bridge Girder Under Corrosion Attack', Beton TKS, 3/2002 5 (2002) [C3] |
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2002 |
Hossain NB, Stewart MG, 'Serviceability Reliability and Expected Costs of RC Beams Designed to Serviceability Specifications of AS3600', Australian Journal of Structural Engineering, Vol. 4, No. 1 17-27 (2002) [C1] |
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2001 |
Khor EH, Rosowsky DV, Stewart MG, 'Probabilistic analysis of time-dependent deflections of RC flexural members', Computers & Structures, 79 1461-1472 (2001) [C1]
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2001 |
Stewart MG, Rosowsky DV, Val DV, 'Reliability-based bridge assessment using risk-ranking decision analysis', Structural Safety, 23 397-405 (2001) [C1]
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2001 |
Stewart MG, 'Effect of Construction and Service Loads on Reliability of Existing RC Buildings', Journal of Structural Engineering, 127 1232-1235 (2001) [C1]
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2001 |
Rosowsky DV, Stewart MG, 'Probabilistic Construction Load Model for Multistory Reinforced-Concrete Buildings', Journal of Performance of Constructed Facilities, 15 145-152 (2001) [C1]
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2001 |
Hossain NB, Stewart MG, 'Probabilistic Models of Damaging Deflections for Floor Elements', Journal of Performance of Constructed Facilities, 15 135-140 (2001) [C1]
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2001 |
Stewart MG, 'Reliability-based assessment of ageing bridges using risk ranking and life cycle cost decision analyses', Reliability Engineering & System Safety, 74 263-273 (2001) [C1]
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2000 |
Faber MH, Val DV, Stewart MG, 'Proof load testing for bridge assessment and upgrading', Engineering Structures, Vol 22 1677-1689 (2000) [C1]
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2000 |
Vu KAT, Stewart MG, 'Structural reliability of concrete bridges including improved chloride-induced corrosion models', Structural Safety, Vol 22 313-333 (2000) [C1]
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2000 |
Rosowsky DV, Stewart MG, Khor EH, 'Early-Age Loading and Long-Term Deflections of Reinforced Concrete Beams', ACI Structural Journal, No.97, No. 3 517-524 (2000) [C1]
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2000 |
Val DV, Stewart MG, Melchers RE, 'Life-cycle performance of reinforced concrete bridges: probabilistic approach', Computer-Aided Civil and Infrastructure Engineering, 15 14-25 (2000) [C1]
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2000 |
Epaarachchi DC, Stewart MG, Rosowsky DV, 'Design, Workmanship and System Risk of Multi-Storey Buildings During Construction', Australian Journal of Structural Engineering, Vol. 3 Nos. 1& 2 43-53 (2000) [C1] |
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2000 |
Stewart MG, 'Risk-based optimisation of repair strategies for concrete structures considering life-cycle cost analysis', Concrete in Australia, Vol 26, No. 2 21-25 (2000) [C3] |
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1999 |
Stewart MG, Val DV, 'Role of load history in reliability-based decision analysis of aging bridges', Journal of Structural Engineering, July 1999 776-783 (1999) [C1]
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1999 |
Stewart MG, Attard MM, 'Model Errors and Structural Reliability for High Strength Concrete Column Design', Australian Journal of Structural Engineering, Vol. SE1, No. 3 167-177 (1999) [C1] |
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1999 |
Stewart MG, Attard MM, 'Reliability and model accuracy for high-strength concrete column design', Journal of Structural Engineering, March 1999 290-300 (1999) [C1]
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1998 |
Attard MM, Stewart MG, 'A Two Parameter Stress Block for High-Strength Concrete', ACI Structural Journal, VOl. 95, No. 3 305-317 (1998) [C1]
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1998 |
Val DV, Stewart MG, Melchers RE, 'Effect of reinforcement corrosion on reliability of highway bridges', Engineering Structures, Vol. 20, No.11 1010-1019 (1998) [C1]
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1998 |
Stewart MG, Rosowksy DV, 'Structural Safety and Serviceability of Concrete Bridges subject to corrosion', Journal of Infrastructure Systems, Vol. 4 146-155 (1998) [C1]
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1998 |
Stewart MG, 'Reliability-based bridge design and assessment', Progress in Structural Engineering and Materials, Vol. 1 No. 2 214-222 (1998) [C1] |
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1998 |
Stewart MG, Rosowsky DV, 'Time-dependent reliability of deteriorating reinforced concrete bridge decks', Structural Safety, Vol. 20 91-109 (1998) [C1]
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1997 |
Stewart MG, 'Time-dependent reliability of existing RC structures', JOURNAL OF STRUCTURAL ENGINEERING-ASCE, 123 896-902 (1997)
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1997 |
Stewart MG, 'Concreting workmanship and its influence on serviceability reliability', ACI MATERIALS JOURNAL, 94 501-509 (1997)
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1996 |
Stewart MG, 'Optimization of serviceability load combinations for structural steel beam design', STRUCTURAL SAFETY, 18 225-238 (1996)
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1996 |
Stewart MG, 'Optimization of serviceability load combinations for structural steel beam design', Structural Safety, 18 225-238 (1996)
In Australia, typical design load combinations for serviceability are ¿sQ and G + ¿sQ (D and D + L in the US) where G and Q are design dead and live loads, respectively, and ¿s is... [more]
In Australia, typical design load combinations for serviceability are ¿sQ and G + ¿sQ (D and D + L in the US) where G and Q are design dead and live loads, respectively, and ¿s is a short-term live load factor. Code calibration is conducted herein for Australian and US serviceability load combinations, for structural steel beams in flexure. The effects that office, retail, domestic and car parking loads and tributary areas have on serviceability reliability is described. It was found that serviceability reliabilities for different floor uses vary considerably for Australian and US serviceability load combinations; whereas the differences between serviceability reliabilities for one year and duration of a single tenancy reference periods were not great. Short-term live load factors for most floor uses were adjusted (sometimes significantly) to ensure that serviceability reliabilities exceed the minimum target level of 1.65. Consequently, the present paper provides suggested values for short-term live load factors that may be used in Australian and possibly in US codes. Copyright © 1996 Elsevier Science Ltd.
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1995 |
STEWART MG, 'WORKMANSHIP AND ITS INFLUENCE ON PROBABILISTIC MODELS OF CONCRETE COMPRESSIVE STRENGTH', ACI MATERIALS JOURNAL, 92 361-372 (1995)
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1993 |
STEWART MG, 'STRUCTURAL RELIABILITY AND ERROR CONTROL IN REINFORCED-CONCRETE DESIGN AND CONSTRUCTION', STRUCTURAL SAFETY, 12 277-292 (1993)
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1993 |
STEWART MG, 'MODELING HUMAN-PERFORMANCE IN REINFORCED-CONCRETE BEAM CONSTRUCTION', JOURNAL OF CONSTRUCTION ENGINEERING AND MANAGEMENT-ASCE, 119 6-22 (1993)
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1992 |
STEWART MG, 'A HUMAN RELIABILITY-ANALYSIS OF REINFORCED-CONCRETE BEAM CONSTRUCTION', CIVIL ENGINEERING SYSTEMS, 9 227-247 (1992)
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1992 |
Stewart MG, 'Simulation of human error in reinforced concrete design', Research in Engineering Design, 4 51-60 (1992)
Available statistical data suggest that human error in design causes a significant proportion of performance failures; namely, structural failure, cost overruns, and delays. A Hum... [more]
Available statistical data suggest that human error in design causes a significant proportion of performance failures; namely, structural failure, cost overruns, and delays. A Human Reliability Analysis (HRA) model has been developed to simulate the effect of human error on the design computations of a reinforced concrete beam. The proposed HRA model incorporates the effect of "self-corrections"; this is a process where tasks are re-evaluated if the result appears to be not within "reasonable" expectations. Calculation, table look-up, chart look-up, and table ranking microtasks were incorporated into the proposed HRA model; human perormance data are described for each of these microtasks. It was found that human error, particularly multiple errors, lead to a significant loss of structural safety. © 1992 Springer-Verlag New York Inc.
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1992 |
STEWART MG, 'MODELING HUMAN ERROR RATES FOR HUMAN RELIABILITY-ANALYSIS OF A STRUCTURAL DESIGN TASK', RELIABILITY ENGINEERING & SYSTEM SAFETY, 36 171-180 (1992)
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1991 |
STEWART MG, 'PROBABILISTIC RISK ASSESSMENT OF QUALITY-CONTROL AND QUALITY ASSURANCE MEASURES IN STRUCTURAL DESIGN', IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS, 21 1000-1007 (1991)
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1991 |
STEWART MG, 'SAFE LOAD TABLES - A DESIGN AID IN THE PREVENTION OF HUMAN ERROR', STRUCTURAL SAFETY, 10 269-282 (1991)
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1991 |
STEWART MG, MELCHERS RE, 'THE CHOICE OF OPTIMAL CHECKING STRATEGIES FOR ERROR CONTROL IN STRUCTURAL-ENGINEERING', CIVIL ENGINEERING SYSTEMS, 8 59-59 (1991)
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1991 |
STEWART MG, MELCHERS RE, 'CHECKING MODELS IN STRUCTURAL DESIGN - CLOSURE', JOURNAL OF STRUCTURAL ENGINEERING-ASCE, 117 2188-2189 (1991)
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1991 |
Stewart MG, 'Human dimension and risk analysis in structural design', Transactions of the Institution of Engineers, Australia. Civil engineering, CE33 195-202 (1991)
The 'human dimension' is the unpredictable nature of human behaviour. In structural engineering tasks it can be shown that human errors result from this behaviour, for t... [more]
The 'human dimension' is the unpredictable nature of human behaviour. In structural engineering tasks it can be shown that human errors result from this behaviour, for the incidence of design error is a major cause of structural failure. A Probabilistic Risk Analysis (PRA) model has been developed to simulate the effects of human error on a typical design task. The design task considered is the design of a flexural member. A computer simulation technique and event-tree methods were employed. This model provides the basis for an investigation into the efficiency of two quality management measure; namely, (i) design checking and (ii) the use of safe load tables as a design aid. Comparisons between the efficiency of design checking and the use of safe load tables will be made. It is indicated that a designer using safe load tables (or similar design aids) will be more 'cost-effective' and less prone to error than designers not using such design aids.
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1990 |
STEWART MG, 'HUMAN ERROR IN STEEL BEAM DESIGN', CIVIL ENGINEERING SYSTEMS, 7 94-101 (1990)
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1990 |
Stewart MG, 'Prevention and control of human errors in structural design', National Conference Publication - Institution of Engineers, Australia, 156-160 (1990)
Reviews of statistical surveys of structural failures indicate that human error is a major cause of failure. These surveys show that human error may occur in the planning, design,... [more]
Reviews of statistical surveys of structural failures indicate that human error is a major cause of failure. These surveys show that human error may occur in the planning, design, construction, or utilisation of a structure. However, the available data suggest that design error causes a significant proportion of structural failures. An investigation of the efficiency of a quality control measure (e.g., design checking) is reported which includes design checking guidelines for the structural engineering profession. The use of safe load tables (for steel member design) as a quality assurance measure is also investigated. It is indicated that a designer using safe load tables (or similar design aids) will be more 'cost effective' and less prone to error than designers not using such design aids. Comparisons between the efficiency of design checking and the use of safe load tables will be made.
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1990 |
Page AW, Kleeman PW, Stewart MG, Melchers RE, 'Structural aspects of the Newcastle earthquake', National Conference Publication - Institution of Engineers, Australia, 305-312 (1990)
On 28 December, 1989 the city of Newcastle was struck by a magnitude 5.6 earthquake killing 12 people and causing losses estimated at $1000 million. It was the first time a major ... [more]
On 28 December, 1989 the city of Newcastle was struck by a magnitude 5.6 earthquake killing 12 people and causing losses estimated at $1000 million. It was the first time a major Australian city has been so extensively damaged as a result of an earthquake, and the first time that deaths have occurred. With a few exceptions, most of the damage was to older loadbearing masonry construction or to infill masonry in modern framed construction. There was relatively little structural damage to modern buildings, industrial facilities and lifelines. This paper reviews the damage to structures and brings out the main points to be considered in future design and construction.
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1989 |
Stewart MG, Melchers RE, 'Structural design and design checking', Civil engineering transactions, CE31 63-69 (1989)
The process of structural design has received very little attention from the research community despite its centralness in day-to-day structural engineering. Much of the research ... [more]
The process of structural design has received very little attention from the research community despite its centralness in day-to-day structural engineering. Much of the research which has been done has been carried out in Australia over a number of years and with the co-operation of many structural engineers. The present paper reviews the reasons for being engaged in this relatively unusual research activity and provides an overview of the work to date. A review is given of the incidence and type of errors made in basic design tasks such as calculations, table look-up and table interpolation, and how these errors relate to results obtained for more comprehensive tasks such as loading determination and member design. One of the outcomes of the work has been to suggest areas in certain current design codes which are prone to misinterpretation by practitioners. Preliminary results related to design computation checking and inspection are also reviewed. This work potentially has major implications for quality assurance programmes.
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1989 |
STEWART MG, MELCHERS RE, 'ERROR CONTROL IN MEMBER DESIGN', STRUCTURAL SAFETY, 6 11-24 (1989)
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1989 |
Stewart MG, Melchers RE, 'Decision model for overview checking of engineering designs', International Journal of Industrial Ergonomics, 4 19-27 (1989)
Overview checking occurs whenever an engineering design is reviewed by another engineer without specifically carrying out checking calculations or following through the design pro... [more]
Overview checking occurs whenever an engineering design is reviewed by another engineer without specifically carrying out checking calculations or following through the design process in detail. Results are reported herein of a survey examining the effectiveness of overview checking. The respondents were requested to assess whether a structural design should be considered "undersized", "correct" or "oversized". Using the responses as a basis, a decision model is proposed for the effectiveness of overview checking as a function of error magnitude and of checker's experience. It is concluded that correct assessment of a design as "safe" is not a function of experience. However, it appears that more experience is beneficial in selecting economical designs. © 1989.
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1989 |
STEWART MG, MELCHERS RE, 'OPTIMIZATION OF STRUCTURAL DESIGN CHECKING', JOURNAL OF STRUCTURAL ENGINEERING-ASCE, 115 2448-2460 (1989)
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1989 |
STEWART MG, MELCHERS RE, 'CHECKING MODELS IN STRUCTURAL DESIGN', JOURNAL OF STRUCTURAL ENGINEERING-ASCE, 115 1309-1324 (1989)
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1988 |
STEWART MG, MELCHERS RE, 'SIMULATION OF HUMAN ERROR IN A DESIGN LOADING TASK', STRUCTURAL SAFETY, 5 285-297 (1988)
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1985 |
Melchers RE, Stewart MG, 'DATA-BASED MODELS FOR HUMAN ERROR IN DESIGN. 51-60 (1985)
To predict the reliability of structures it is necessary to make reasonable allowances in the assessment for the influence of human error in the design, construction and use of th... [more]
To predict the reliability of structures it is necessary to make reasonable allowances in the assessment for the influence of human error in the design, construction and use of the structure. The present paper deals with an attempt to model mathematically the human errors introduced into the structural design process and the effect they may have on structural safety. Preliminary data collection for use in the model is reported, and an outline of the model being developed is given.
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