Review of Post-Fire Inspection Procedures for Concrete Tunnels

2021 ◽  
pp. 036119812110067
Author(s):  
Nick Menz ◽  
Simos Gerasimidis ◽  
Scott Civjan ◽  
John Czach ◽  
Joe Rigney
Keyword(s):  
United States ◽  
Experimental Studies ◽  
The United States ◽  
Concrete Members ◽  
Heating And Cooling ◽  
Fire Condition ◽  
Tunnel Inspection ◽  
Remaining Capacity ◽  
Departments Of Transportation ◽  
Loss Of Strength

It is well known that concrete structures can lose strength and long-term durability after a fire. The literature on the remaining capacity of tunnel structures after fire is quite scattered, however, and few published post-fire inspection guides exist. This paper reviews the available literature on the post-fire inspection and evaluation of concrete tunnels. The effects of fire on concrete and steel are discussed, including loss of strength, thermal spalling of concrete, and loss of strength in the bond between concrete and steel. In addition, studies on the residual strength of concrete members are presented. Available post-fire inspection strategies and methods are also discussed. Finally, the results of a survey of post-fire tunnel inspection practices at state Departments of Transportation and transit organizations across the United States are presented. Several models available in both structural building codes and experimental studies allow for the estimation of residual concrete compressive and steel tensile strength after heating and cooling from a given temperature. Furthermore, a variety of post-fire assessment methods are available, which include methods to assess the general post-fire condition of concrete tunnels, as well as methods to more directly assess the residual condition of concrete. Lastly, the review of literature and the survey of United States transit organizations revealed a lack of existing post-fire inspection procedures for concrete tunnels, and a need for further research on the subject.

Compatibility of Passenger Vehicles and Cable Median Barrier Systems

2017 ◽  
Author(s):  
Cody S. Stolle ◽  
John D. Reid
Keyword(s):  
United States ◽  
Kinetic Energy ◽  
The United States ◽  
Detailed Data ◽  
Factors Affecting ◽  
Passenger Vehicles ◽  
Complicating Factors ◽  
Departments Of Transportation ◽  
Severe Type ◽  
Trajectory Angle

Cross-median crashes are one of the most severe type of highway crashes. Many state Departments of Transportation (DOTs) install median barriers, such as cable median barriers (CMBs), to reduce the rate of cross-median crashes. Nonetheless, these barriers are not always successful. Approximately 20,000 cable barrier crashes throughout the United States spanning between 1999 and 2010 were examined, and detailed data was sufficient to determine the prevailing causes of 182 penetration crashes (i.e., barrier was breached). Penetration crashes involving CMBs were affected by: (1) impact conditions; (2) barrier placement and design; and (3) vehicle factors, including geometry and inertial properties. In general, CMB crashes occur at higher CG trajectory angles than with other roadside features. The 85th percentile CG trajectory angle for cable barriers was 39 degrees, compared to 25 degrees when all roadside features are considered. Approximately 2.2% of all CMB crashes were severe, although penetrations were between two and thirteen times more likely to be severe than non-penetration crashes. Vehicle factors such as weight and geometrical profile affected the likelihood of CMB penetrations. Headlights or taillights fractured or were damaged in approximately 80% of non-penetration crashes, but were damaged or fractured in less than 60% of penetration crashes, often by additional unrelated impacts. Lastly, heavier vehicles with more kinetic energy were more likely than similar, lighter vehicles to penetrate CMBs. Through better understanding of all of the complicating factors affecting CMB performance, better designs and guidelines can be prepared to maximize CMB effectiveness.

scholarly journals Rising Ethnic Diversity in the United States Accompanies Shifts Toward an Individualistic Culture

2020 ◽  
pp. 194855062096723
Author(s):  
Alex C. Huynh ◽  
Igor Grossmann
Keyword(s):  
United States ◽  
Ethnic Diversity ◽  
Experimental Studies ◽  
Ethnically Diverse ◽  
The United States ◽  
Living Alone ◽  
Individual Level ◽  
Relational Structures ◽  
Individualistic Culture ◽  
The Relationship

We investigate the relationship between ethnic diversity and the rise of individualism in the United States during the 20th and 21st centuries. Tests of the historical rates of ethnic diversity alongside individualistic relational structures (e.g., adults living alone, single-/multi-child families) from the years 1950 to 2018 reveal that societal and regional rates of ethnic diversity accompanied individualistic relational structures. These effects hold above and beyond time-series trends in each variable. Further evidence from experimental studies ( N = 707) suggests that the presence of, and contact with, ethnically diverse others contributes to greater individualistic values (e.g., the importance of uniqueness and personal achievement). Converging evidence across societal-, regional-, and individual-level analyses suggests a systematic link between ethnic diversity and individualism. We discuss the implications of these findings for sociocultural livelihood in light of the rising rates of ethnic diversity across the globe.

Displays of emotion and citizen support for Merkel and Gysi

2017 ◽  
Vol 36 (2) ◽  
pp. 80-103 ◽  
Author(s):  
Oscar W. Gabriel ◽  
Lena Masch
Keyword(s):  
United States ◽  
Positive Emotions ◽  
Individual Recognition ◽  
Negative Emotions ◽  
Experimental Studies ◽  
The United States ◽  
Political Support ◽  
The Public ◽  
Positive Effects ◽  
The Impact

Emotional appeals have always been an important instrument in the mobilization of political support in modern societies. As found in several experimental studies from the United States, the emotions displayed by leading politicians in their televised public appearances have an impact on the political attitudes and behaviors of the public. Positive emotions such as joy or happiness, pride, and amusement elicit a more positive assessment of politicians, whereas showing negative emotions such as anger or outrage often diminishes the public’s support. This transfer of emotions from sender to recipient has been described as “emotional contagion.” However, under specific circumstances, emotions expressed by politicians can result in counter-empathic reactions among recipients. To examine the role of emotions between political leaders and the public in an institutional and cultural setting outside the United States, this article presents experimental findings on the impact of emotions expressed by two leading German politicians on the German public. The study used emotional displays by Chancellor Angela Merkel and former parliamentary leader of the Left Party, Gregor Gysi, observing how their assessments by the German public changed in response to these displays. Consistent with existing research, we discovered positive effects on the evaluation of both politicians when they displayed positive emotions. However, the impact of negative emotions is different for Merkel and Gysi and can be described as contagion in the former and counter-contagion in the latter case. Furthermore, we found that individual recognition of the expressed emotions modified the effect they had on the evaluation of some leadership characteristics.

scholarly journals Solar Energy in the United States: Development, Challenges and Future Prospects

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8142
Author(s):  
Sanzana Tabassum ◽  
Tanvin Rahman ◽  
Ashraf Ul Islam ◽  
Sumayya Rahman ◽  
Debopriya Roy Dipta ◽  
...  
Keyword(s):  
United States ◽  
Renewable Energy ◽  
Solar Energy ◽  
Financial Incentives ◽  
Power Plants ◽  
Solar Power ◽  
Renewable Energy Sources ◽  
The United States ◽  
Heating And Cooling ◽  
The U.S

The ambitious target of net-zero emission by 2050 has been aggressively driving the renewable energy sector in many countries. Leading the race of renewable energy sources is solar energy, the fastest growing energy source at present. The solar industry has witnessed more growth in the last decade than it has in the past 40 years, owing to its technological advancements, plummeting costs, and lucrative incentives. The United States is one of the largest producers of solar power in the world and has been a pioneer in solar adoption, with major projects across different technologies, mainly photovoltaic, concentrated solar power, and solar heating and cooling, but is expanding towards floating PV, solar combined with storage, and hybrid power plants. Although the United States has tremendous potential for exploiting solar resources, there is a scarcity of research that details the U.S. solar energy scenario. This paper provides a comprehensive review of solar energy in the U.S., highlighting the drivers of the solar industry in terms of technology, financial incentives, and strategies to overcome challenges. It also discusses the prospects of the future solar market based on extensive background research and the latest statistics. In addition, the paper categorizes the U.S. states into five tiers based on their solar prospects calculated using analytical hierarchy process and regression analysis. The price of solar technologies in the U.S. is also predicted up to 2031 using Wright’s law, which projected a 77% reduction in the next decade.

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