scholarly journals Disproportionate Collapse Mitigation in Tall Mass Timber Buildings

2019 ◽  
pp. 413-420
Author(s):  
Hossein Daneshvar ◽  
Ying Hei Chui
Keyword(s):  
Urban Areas ◽  
Structural Integrity ◽  
Tall Buildings ◽  
Case Scenario ◽  
Worst Case ◽  
Unique Type ◽  
Structural Robustness ◽  
Concrete Members ◽  
Disproportionate Collapse ◽  
Mass Timber

Tall buildings are a unique type of structure with their own characteristic behaviour. They are most often occupied by a large number of people; therefore, their damage, loss of functionality, or, in worst case scenario, collapse will lead to catastrophic consequences. There are methodologies intended to provide structural integrity or increase structural robustness in tall buildings, thereby making structures resistant to disproportionate collapse, which is characterized by a cascading progression of damage that is not proportionate to the initial failure. Tall buildings are commonly constructed with steel and concrete. As a result, most of the attempts at providing structural integrity are dedicated to mitigating the effect of disproportionate collapse in the steel and concrete members, connections, and their systems. On the other hand, with rising demand for new sustainable buildings in urban areas, tall mass timber buildings have attracted increased attention nationally and internationally. Ease of modularization and offsite construction is one of the greatest advantages of using mass timber in tall building construction in the congested urban areas of major cities. A major challenge facing the engineering community is the lack of research studies regarding the structural robustness required to mitigate the potential of disproportionate collapse. The current study seeks to begin the process of understanding the behaviour of mass timber components and assemblages, and make recommendations regarding their performance and possible means to mitigate the occurrence of disproportionate collapse. These recommendations would lead to safer structural performance in the event of localized damage that has the potential to spread to a disproportionately large part of the structure.

Slavery in Brazil: A Case Study of Diamantina, Minas Gerais

1988 ◽  
Vol 45 (1) ◽  
pp. 47-59 ◽  
Author(s):  
Donald Ramos
Keyword(s):  
Urban Areas ◽  
Living Conditions ◽  
Case Scenario ◽  
Worst Case ◽  
Men And Women ◽  
Mortality And Morbidity ◽  
Diamond Mining ◽  
Large Numbers ◽  
Special Case

The study of slave mortality and morbidity in Brazil has been very difficult because of the extreme paucity of sources. Techniques which have been useful in studying the lives of free men and women seldom are useful for analyzing their slaves. The use of parish records such as baptism and death registers is not possible because of the custom of listing only the slave's first name and the unimaginative choice of names which resulted in large numbers of Joãos, Josés, Manuels, Antônios, Antonias, Joanas, and, of course, Marias. Equally important, the types of plantation records available to students of U.S. slavery have seldom been found for Brazil.This essay is an examination of an isolated slave register, which, for a series of idiosyncratic reasons, provides information permitting a glimpse at mortality and morbidity in a distinct and carefully controlled slave population. Because the slaves involved were used in diamond mining under horrendous conditions it is probable that the conclusions reached in this essay represent a worst case scenario. Rather than typical, this is a special case where work and living conditions were probably worse than in plantation zones and certainly worse than in urban areas. It is this situation which makes the conclusions of this essay quite startling.

New Data on the Capacity of X-Joints Under Tension and Implications for Codes

2008 ◽  
Author(s):  
Adrian F. Dier ◽  
Philip Smedley ◽  
Gunnar Solland ◽  
Hege Bang
Keyword(s):  
Finite Element ◽  
Structural Integrity ◽  
Hot Spot ◽  
Case Scenario ◽  
Element Analysis ◽  
Worst Case ◽  
Numerical Work ◽  
Hot Spot Stress ◽  
Integrity Assessment ◽  
Existing Structures

This paper reviews available static strength data and presents results of finite element analyses on first crack loads and ultimate loads of X-joints in tension. A critique of existing guidance for such joints is given. An examination of hot spot stress for such joints is presented, together with new capacity formulations based on test data. The new formulations are verified with reference to new data from a finite element analysis. The new capacity formulations will be of interest to regulatory authorities, to designers of new offshore installations and to engineers carrying out assessments of existing structures. It is also expected that the formulations will be considered by code drafting committees, e.g. for API RP2A, ISO 19902 and NORSOK, during code revisions. The paper demonstrates that present guidance is unduly conservative in two respects: (1) high γ joints (i.e. thin-walled chords) in the range 0.7 ≤ β ≤ 0.9 joints (i.e. moderately high brace/chord diameter ratios), and (2) joints with β = 1.0 having low γ. However, it is shown that present guidance may be optimistic for low γ joints with β < 0.9. The new capacity formulations proposed in this paper correct these deficiencies. As one example, the new formulations give an increase of 60% in capacity compared to existing guidance for a joint with β = 1.0 and γ = 10, not untypical of many joints in service. In the near term, the paper may be most appreciated by those involved with structural integrity assessment studies. There have been some recent examples where existing guidance has indicated that some primary structural joints are under-strength. This has prompted extensive numerical work to prove the adequacy of the joints. A worst case scenario would be the implementation of unnecessary offshore strengthening work.

scholarly journals Structural Integrity Assessment of Composites Plates with Embedded PZT Transducers for Structural Health Monitoring

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6148
Author(s):  
Tianyi Feng ◽  
M.H. Ferri Aliabadi
Keyword(s):  
Elastic Modulus ◽  
Lead Zirconate Titanate ◽  
Composite Structures ◽  
Structural Integrity ◽  
Fatigue Loading ◽  
Active Sensing ◽  
Case Scenario ◽  
Worst Case ◽  
Integrity Assessment ◽  
Compressive Tests

Active sensing using ultrasonic guided waves (UGW) is widely investigated for monitoring possible damages in composite structures. Recently, a novel diagnosed film based on a circuit-printed technique with piezoelectric lead zirconate titanate (PZT) transducers has been developed. The diagnostic film is a replacement for the traditional cable connection to PZT sensors and has been shown to significantly reduce the weight of the host structure. In this work, the diagnosed films were embedded into composite structures during manufacturing using a novel edge cut-out method during lay-up, which allowed for edge trimming after curing. In this paper, the effect of fatigue loading on the integrity of PZT transducers is initially investigated. The electro-mechanical impedance (EMI) properties at different fatigue loading cycles were used as the diagnostic measure for the performance of the sensors. At the same time, the behaviours of UGW were investigated at different fatigue loading cycles. It was found that the EMI properties and active sensing behaviours remained stable up to 1 million cycles for the force ranges of 0.5~5 kN and 1~10 kN. Next, the effect of embedding the diagnosed film on the mechanical properties of the host composite structure was investigated. Tensile and compressive tests were conducted and the elastic modulus of composite coupons with and without embedded PZT diagnosed films were compared. The elastic modulus of composite coupons with PZT diagnosed films embedded across the entire coupon reduced by as much as 20% for tensile tests and just over 10% for compressive tests compared to the coupons without embedded sensors. These reductions are considered the worst-case scenario, as in real structures the film would only be embedded in a relatively small area of the structure.

scholarly journals Noise Impact Assessment of Thermal Plant Facilities on Receptor Environments

2019 ◽  
Vol 2 (Issue 1) ◽  
Author(s):  
O.A Olu-Arotiowa ◽  
J.A Adeniran ◽  
R.O Yusuf ◽  
M.O Abdulraheem ◽  
A.S Aremu
Keyword(s):  
Power Generation ◽  
Power Plant ◽  
Urban Areas ◽  
Interpolation Method ◽  
Kriging Interpolation ◽  
Noise Levels ◽  
Noise Emission ◽  
Case Scenario ◽  
Worst Case ◽  
Kriging Interpolation Method

Noise pollution is considered as a serious environmental nuisance in the urban areas. This study has used the VDI code 2714 to investigate the impacts of the noise from all the power generation and ancilliary facilities in the proposed Independent Power Plant, Agbara, Ogun State receptor environment. Kriging interpolation method in SurferR 8.0 software to predict noise emission levels within the fence line of the proposed Independent Power Plant. Calculations of possible noise levels at some receptors locations around the plant were carried out using the VDI code 2714. Four operation scenarios were considered in this study. The scenarios considered include: Noise emission from power generation facilities only (Scenario 1); Noise from the use of Compressors and Transformers (Scenario 2); Noise emission from the operation of power generation and ancillary equipment (Scenario 3); and Noise emission from the use of Backup Generators (Scenario 4). The maximum noise from the four scenarios were 112.34, 114.58, 116.61 and 110.01 dB(A), respectively, which is above the 8-hour 90 dB(A) limit recommended by the Federal Ministry of Environment (FMEnv). The operation of the proposed power plant will not have significant impact on the receptor environments except for Karogbaji which receives less than 12 dB(A) for the worst-case scenario (Scenario 3). The modeling results show that the predicted noise levels generated by the proposed operation would generally be within the established noise criteria at all the receptor locations under all conditions.

scholarly journals Climate Change, Migration, and Civil Strife

2020 ◽  
Vol 7 (4) ◽  
pp. 404-414
Author(s):  
Satchit Balsari ◽  
Caleb Dresser ◽  
Jennifer Leaning
Keyword(s):  
Climate Change ◽  
World War Ii ◽  
Urban Areas ◽  
Adaptation Strategy ◽  
Human Migration ◽  
Case Scenario ◽  
Worst Case ◽  
Climate Conditions ◽  
Civil Strife ◽  
Changing Climate

Abstract Purpose of Review In this article, we examine the intersection of human migration and climate change. Growing evidence that changing environmental and climate conditions are triggers for displacement, whether voluntary or forced, adds a powerful argument for profound anticipatory engagement. Recent Findings Climate change is expected to displace vast populations from rural to urban areas, and when life in the urban centers becomes untenable, many will continue their onward migration elsewhere (Wennersten and Robbins 2017; Rigaud et al. 2018). It is now accepted that the changing climate will be a threat multiplier, will exacerbate the need or decision to migrate, and will disproportionately affect large already vulnerable sections of humanity. Worst-case scenario models that assume business-as-usual approaches to climate change predict that nearly one-third of the global population will live in extremely hot (uninhabitable) climates, currently found in less than 1% of the earth’s surface mainly in the Sahara. Summary We find that the post–World War II regime designed to receive European migrants has failed to address population movement in the latter half of the twentieth century fueled by economic want, globalization, opening (and then closing) borders, civil strife, and war. Key stakeholders are in favor of using existing instruments to support a series of local, regional, and international arrangements to protect environmental migrants, most of whom will not cross international borders. The proposal for a dedicated UN agency and a new Convention has largely come from academia and NGOs. Migration is now recognized not only as a consequence of instability but as an adaptation strategy to the changing climate. Migration must be anticipated as a certainty, and thereby planned for and supported.

scholarly journals Welded joints as critical regions in pressure vessels -case study of vinyl-chloride monomer storage tank

2018 ◽  
Vol 72 (4) ◽  
pp. 177-182 ◽  
Author(s):  
Tamara Golubovic ◽  
Aleksandar Sedmak ◽  
Vesna Spasojevic-Brkic ◽  
Snezana Kirin ◽  
Emil Veg
Keyword(s):  
Vinyl Chloride ◽  
Pressure Vessel ◽  
Welded Joints ◽  
Storage Tank ◽  
Structural Integrity ◽  
Pressure Vessels ◽  
Vinyl Chloride Monomer ◽  
Case Scenario ◽  
Worst Case ◽  
Critical Regions

Welded joints are analysed as critical regions in a pressure vessel in respect to structural failure due to the elastic-plastic fracture/crack growth. To assess structural integrity of pressure vessels used in chemical industry the risk based procedure has been introduced and applied in the case of a large spherical pressure vessel used as a vinyl-chloride monomer (VCM) storage tank in HIP Azotara Pancevo. The risk matrix has been used, taking into account the basic definition of risk, being the product of the probability and consequence, and applied to different regions of welded joints, having different mechanical properties, i.e. crack resistance. To estimate probability, the failure assessment diagram (FAD) has been used, as an engineering tool, defined according to the position of the operating point for different regions of the welded joint, relative to the critical point on the limit curve. Generally speaking, consequence is estimated based on pressure vessel parameters, or by detailed analysis of health, safety, business and security issues, but in the analysed case, the worst case scenario is assumed, with the highest consequence due to potential disaster for environment and fatalities.

scholarly journals Global 1-km present and future hourly anthropogenic heat flux

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Alvin Christopher Galang Varquez ◽  
Shota Kiyomoto ◽  
Do Ngoc Khanh ◽  
Manabu Kanda
Keyword(s):  
Urban Areas ◽  
Radiative Forcing ◽  
Prediction Models ◽  
Population Distribution ◽  
Weather Prediction ◽  
Heat Emission ◽  
Anthropogenic Heat ◽  
Case Scenario ◽  
Worst Case ◽  
Anthropogenic Heat Flux

AbstractNumerical weather prediction models are progressively used to downscale future climate in cities at increasing spatial resolutions. Boundary conditions representing rapidly growing urban areas are imperative to more plausible future predictions. In this work, 1-km global anthropogenic heat emission (AHE) datasets of the present and future are constructed. To improve present AHE maps, 30 arc-second VIIRS satellite imagery outputs such as nighttime lights and night-fires were incorporated along with the LandScanTM population dataset. A futuristic scenario of AHE was also developed while considering pathways of radiative forcing (i.e. representative concentration pathways), pathways of social conditions (i.e. shared socio-economic pathways), a 1-km future urbanization probability map, and a model to estimate changes in population distribution. The new dataset highlights two distinct features; (1) a more spatially-heterogeneous representation of AHE is captured compared with other recent datasets, and (2) consideration of future urban sprawls and climate change in futuristic AHE maps. Significant increases in projected AHE for multiple cities under a worst-case scenario strengthen the need for further assessment of futuristic AHE.

Superposition of Manoeuvres and Load Spectra Extrapolation

2006 ◽  
Vol 5-6 ◽  
pp. 255-262 ◽  
Author(s):  
Angela Cerrini ◽  
P. Johannesson ◽  
Stefano Beretta
Keyword(s):  
Structural Integrity ◽  
Working Life ◽  
Service Operations ◽  
Extreme Value Statistics ◽  
Case Scenario ◽  
Worst Case ◽  
Integrity Assessment ◽  
Load Spectra ◽  
Increasing Demand ◽  
Load Conditions

To face the increasing demand for long lasting, versatile and performing machines, a detailed analysis of the load conditions is required especially when structural integrity assessment has to be achieved. Usually acquisitions of load histories are shorter than the machine working life and an extrapolation of the signal for the total service life is needed. Traditional methods for load spectra extrapolation are based on conservative choices in terms of worst case scenario. Methods based on extreme value statistics have been developed. The problem addressed in this paper concerns the extrapolation of load histories on a welded boom in which different manoeuvres are superimposed. Different ways of extrapolating the load measurement have been derived, both in time domain and in Markov domain, in order to account for the superposition of bigger and more damaging cycles and smaller cycles caused by two different service operations.

scholarly journals Feasibility Study of a Building-Integrated PV Manager to Power a Last-Mile Electric Vehicle Sharing System

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Manuel Fuentes ◽  
Jesús Fraile-Ardanuy ◽  
José L. Risco-Martín ◽  
José M. Moya
Keyword(s):  
Public Transportation ◽  
Urban Areas ◽  
Positive Energy ◽  
Energy Storage Devices ◽  
Case Scenario ◽  
Total Energy Consumption ◽  
Worst Case ◽  
Last Mile ◽  
Mobility System ◽  
Electric Bicycle

Transportation is one of the largest single sources of air pollution in urban areas. This paper analyzes a model of solar-powered vehicle sharing system using building-integrated photovoltaics (BIPV), resulting in a zero-emission and zero-energy mobility system for last-mile employee transportation. As a case study, an electric bicycle sharing system between a public transportation hub and a work center is modeled mathematically and optimized in order to minimize the number of pickup trips to satisfy the demand, while minimizing the total energy consumption of the system. The whole mobility system is fully powered with BIPV-generated energy. Results show a positive energy balance in e-bike batteries and pickup vehicle batteries in the worst day of the year regarding solar radiation. Even in this worst-case scenario, we achieve reuse rates of 3.8 people per bike, using actual data. The proposed system manages PV energy using only the batteries from the electric vehicles, without requiring supportive energy storage devices. Energy requirements and PV generation have been analyzed in detail to ensure the feasibility of this approach.

Jordan and Syrian Refugees: Avoiding the Worst Case Scenario

2015 ◽  
Vol 7 (3) ◽  
pp. 319-335
Author(s):  
Doris Carrion
Keyword(s):  
International Development ◽  
Urban Areas ◽  
Refugee Crisis ◽  
Case Scenario ◽  
Worst Case ◽  
Current Trends ◽  
Political Effect ◽  
Development Support ◽  
Perceived Impact ◽  
Competition For Resources

Civil war in Syria has provoked a major refugee crisis in neighbouring Jordan, raising the latter’s population by 8 per cent. For Jordanians, the highly visible presence of many thousands of refugees living in their midst – mostly in urban areas, rather than camps – raises fears over competition for resources and opportunities. Host communities have partly benefited from the presence of refugees, but many Jordanians feel they are worse off because of the Syrians. The refugee crisis has hit the most vulnerable people in their country hardest. Local inhabitants feel increasingly disenfranchised and neglected by both their government and international donors due to a real and perceived impact on rents, prices, public services and public order. If current trends continue, resentment and alienation in the northern governorates are likely to increase in the coming years. Local discontent may subside if Syrians are given more opportunities to earn a living legally, which would mean that Jordan would benefit more from their presence. In order to minimize a negative political effect, a more open livelihood policy should be accompanied by a significant increase in international development support for host communities. It does not look like refugees will be able to return to Syria any time soon, no matter how hard life in Jordan becomes. Jordan and the international community should take the difficult but necessary steps to prevent the crisis from making life even worse for the country’s most vulnerable residents.

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