System-wide seismic vulnerability of aging multiple-span multiple-girder bridges in low-to-moderate seismic hazard regions

2021 ◽  
Vol 37 (1_suppl) ◽  
pp. 1626-1651
Author(s):  
John E Lens M.EERI ◽  
Mandar M Dewoolkar ◽  
Eric M Hernandez M.EERI
Keyword(s):  
United States ◽  
Seismic Hazard ◽  
Cross Sections ◽  
Seismic Vulnerability ◽  
Time History ◽  
The United States ◽  
National Database ◽  
Eastern United States ◽  
Girder Bridges ◽  
The Status

This article describes the approach, methods, and findings of a quantitative analysis of the seismic vulnerability in low-to-moderate seismic hazard regions of the Central and Eastern United States for system-wide assessment of typical multiple span bridges built in the 1950s through the 1960s. There is no national database on the status of seismic vulnerability of bridges, and thus no means to estimate the system-wide damage and retrofit costs for bridges. The study involved 380 nonlinear analyses using actual time-history records matched to four representative low-to-medium hazard target spectra corresponding with peak ground accelerations from approximately 0.06 to 0.3 g. Ground motions were obtained from soft and stiff site seismic classification locations and applied to models of four typical multiple-girder with concrete bent bridges. Multiple-girder bridges are the largest single category, comprising 55% of all multiple span bridges in the United States. Aging and deterioration effects were accounted for using reduced cross-sections representing fully spalled conditions and compared with pristine condition results. The research results indicate that there is an overall low likelihood of significant seismic damage to these typical bridges in such regions, with the caveat that certain bridge features such as more extensive deterioration, large skews, and varied bent heights require bridge-specific analysis. The analysis also excludes potential damage resulting from liquefaction, flow-spreading, or abutment slumping due to weak foundation or abutment soils.

Effects of temporal variations in seismicity on seismic hazard

1981 ◽  
Vol 71 (1) ◽  
pp. 321-334
Author(s):  
Robin K. McGuire ◽  
Theodore P. Barnhard
Keyword(s):  
United States ◽  
Seismic Hazard ◽  
Seismic Activity ◽  
Time Window ◽  
Hazard Analysis ◽  
The United States ◽  
Temporal Variations ◽  
Seismogenic Zone ◽  
Eastern United States ◽  
Ground Shaking

abstract The accuracy of stationary mathematical models of seismicity for calculating probabilities of damaging shaking is examined using the history of earthquakes in China from 1350 A.D. to 1949 A.D. During this time, rates of seismic activity varied periodically by a factor of 10. Probabilities of damaging shaking are calculated in 62 cities in North China using 50 yr of earthquake data to estimate seismicity parameters; the probabilities are compared to statistics of damaging shaking in the same cities for 50 yr following the data window. These comparisons indicate that the seismic hazard analysis is accurate if: (1) the maximum possible earthquake size in each seismogenic zone is determined from the entire seismic history rather than from a short-time window; and (2) the future seismic activity can be estimated accurately. The first condition emphasizes the importance of realistically estimating the maximum possible size of earthquakes on faults. The second indicates the need to understand possible trends in seismic activity where these exist, or to develop an earthquake prediction capability with which to estimate future activity. Without the capability of estimating future seismicity, stationary models provide less accurate but generally conservative indications of seismic ground-shaking hazard. In the United States, the available earthquake history is brief but gives no indication of changing rates of activity. The rate of seismic strain release in the Central and Eastern United States has been constant over the last 180 yr, and the geological record of earthquakes on the southern San Andreas Fault indicates no temporal trend for large shocks over the last 15 centuries. Both observations imply that seismic activity is either stationary or of such a long period that it may be treated as stationary for seismic hazard analyses in the United States.

Multicultural Assessment of Personality and Psychopathology in the United States: Still Art, Not Yet Science, and Controversial

1998 ◽  
Vol 14 (1) ◽  
pp. 62-70 ◽  
Author(s):  
Richard H. Dana
Keyword(s):  
United States ◽  
Racial Identity ◽  
The United States ◽  
Therapeutic Assessment ◽  
Culturally Competent ◽  
Research Attention ◽  
The Status ◽  
Training Research ◽  
Multicultural Assessment ◽  
Personality Description

This paper describes the status of multicultural assessment training, research, and practice in the United States. Racism, politicization of issues, and demands for equity in assessment of psychopathology and personality description have created a climate of controversy. Some sources of bias provide an introduction to major assessment issues including service delivery, moderator variables, modifications of standard tests, development of culture-specific tests, personality theory and cultural/racial identity description, cultural formulations for psychiatric diagnosis, and use of findings, particularly in therapeutic assessment. An assessment-intervention model summarizes this paper and suggests dimensions that compel practitioners to ask questions meriting research attention and providing avenues for developments of culturally competent practice.

scholarly journals Discursive Strategies and Sequenced Institutional Change: The Case of Marriage Equality in the United States

2021 ◽  
pp. 003232172110205
Author(s):  
Giulia Mariani ◽  
Tània Verge
Keyword(s):  
United States ◽  
Institutional Change ◽  
The United States ◽  
Marriage Equality ◽  
Agent Based ◽  
Discursive Strategies ◽  
Policy Debates ◽  
The Status ◽  
Private Actors

Building on historical and discursive institutionalism, this article examines the agent-based dynamics of gradual institutional change. Specifically, using marriage equality in the United States as a case study, we examine how actors’ ideational work enabled them to make use of the political and discursive opportunities afforded by multiple venues to legitimize the process of institutional change to take off sequentially through layering, displacement, and conversion. We also pay special attention to how the discursive strategies deployed by LGBT advocates, religious-conservative organizations and other private actors created new opportunities to influence policy debates and tip the scales to their preferred policy outcome. The sequential perspective adopted in this study allows problematizing traditional conceptualizations of which actors support or contest the status quo, as enduring oppositional dynamics lead them to perform both roles in subsequent phases of the institutional change process.

scholarly journals The status of neurology fellowships in the United States: clinical needs, educational barriers, and future outlooks

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Harini Sarva ◽  
Gustavo A. Patino ◽  
Mehmood Rashid ◽  
James W. M. Owens ◽  
Matthew S. Robbins ◽  
...  
Keyword(s):  
United States ◽  
American Academy ◽  
Neurodegenerative Disorders ◽  
Disease Burden ◽  
Neurological Diseases ◽  
The United States ◽  
Educational Barriers ◽  
The Status

AbstractThe need for subspecialty-trained neurologists is growing in parallel with increasing disease burden. However, despite the immense burden of neurological diseases, like headache and neurodegenerative disorders, recruitment into these subspecialties remains insufficient in the United States. In this manuscript, a group of educators from the American Academy of Neurology’s A.B. Baker Section on Neurological Education sought to review and discuss the current landscape of neurology fellowships in the United States, the factors driving fellowship recruitment and the educational barriers. Moreover, suggestions to potentially improve recruitment for under-selected fellowships, which can contribute towards an alignment between neurological education and neurological needs, and future educational scenarios are discussed.

scholarly journals THE EPIDEMIOLOGY OF PEDIATRIC MENISCAL ALLOGRAFT TRANSPLANTATION IN THE UNITED STATES

2021 ◽  
Vol 9 (7_suppl3) ◽  
pp. 2325967121S0004
Author(s):  
Haley E. Smith ◽  
Madeline M. Lyons ◽  
Neeraj M. Patel
Keyword(s):  
United States ◽  
Pediatric Population ◽  
The United States ◽  
National Database ◽  
Control Group ◽  
Meniscal Allograft Transplantation ◽  
Children's Hospitals ◽  
Allograft Transplantation ◽  
Meniscal Allograft ◽  
Children’S Hospitals

Background: Meniscal allograft transplantation (MAT) is an option to slow the progression of degenerative disease in the setting of substantial meniscal deficiency. This may be especially important in children and adolescents, but there is little literature on MAT in this population. Hypothesis/Purpose: The purpose of this study was to evaluate the epidemiology of MAT in the pediatric population, with specific attention to regional and demographic trends. Methods: The Pediatric Health Information System, a national database consisting of 49 children’s hospitals, was queried for all patients undergoing MAT between 2011 and 2018. Demographic information was collected for each subject as well as data regarding previous and subsequent surgeries. The database was also queried for all meniscus surgeries (including repairs and meniscectomies) performed during the study period. Demographic and geographic data from this control group were compared to that of children undergoing MAT. Univariate analysis was followed by purposeful entry multivariate regression to adjust for confounding factors. Results: A total of 27,168 meniscus surgeries were performed in 47 hospitals, with MAT performed 67 times in 17 hospitals. Twelve patients (18%) underwent a subsequent procedure after transplantation. In multivariate analysis, each year of increasing age resulted in 1.1 times higher odds of having undergone MAT rather than repair or meniscectomy (95% CI 1.03-1.1, p=0.002). Patients that underwent transplantation had 2.0 times higher odds of being female (95% CI 1.2-3.3, p=0.01) and 2.0 times higher odds of being commercially insured (95% CI 1.1-3.6, p=0.02). MAT was performed most frequently in the Northeast (4.9/1000 meniscus surgeries) and least often in the South (1.1/1000 meniscus surgeries, p<0.001). Furthermore, transplantation was more likely to be performed in larger cities. The median pediatric population of cities in which MAT was performed was 983,268 (range 157,253-3,138,870) compared to 662,290 (range 4,420-4,311,500) in cities where it was not (p=0.04). Conclusion: In the United States, patients that underwent MAT were older, more likely to be female, and have commercial insurance than those undergoing meniscus repair or meniscectomy. MAT was only done in 17/47 children’s hospitals that perform meniscus surgery and was most frequently performed in the Northeast and in larger cities. These trends highlight the need for further research, especially regarding differences along the lines of sex and insurance status.

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