Seismic Damage to Segmented Buried Pipe

2004 ◽  
Vol 20 (4) ◽  
pp. 1167-1183 ◽  
Author(s):  
Michael O'Rourke ◽  
Erik Deyoe
Keyword(s):  
Wave Propagation ◽  
Ground Deformation ◽  
Empirical Relation ◽  
Seismic Damage ◽  
Reliable Data ◽  
Ground Movement ◽  
Buried Pipe ◽  
The Past ◽  
Using Data ◽  
Permanent Ground Deformation

A fragility relation for buried segmented pipe subject to either the wave propagation or permanent ground deformation (PGD) hazard is presented. In the past, relations to estimate wave propagation damage to buried segmented pipe frequently use peak particle velocity (Vmax) to characterize the seismic hazard. For example, in 1993, O'Rourke and Ayala developed an empirical relation between damage (quantified by repairs per kilometer of pipe) and Vmax using data from four U.S. and two Mexican events. Existing fragility relations for PGD typically characterize the hazard by the amount of permanent ground movement. It is shown herein that for statistically reliable data, differences in estimated wave propagation repair rates become much smaller when the seismic shaking is characterized by ground strain as opposed to Vmax. Furthermore, damage rates for PGD are shown to be consistent with those for wave propagation when the PGD hazard is similarly characterized by ground strain. The combined wave propagation and PGD relation is quite consistent for four orders of magnitude of ground strain.

Towards Robust Fragility Relations for Buried Segmented Pipe in Ground Strain Areas

2015 ◽  
Vol 31 (3) ◽  
pp. 1839-1858 ◽  
Author(s):  
Michael O'Rourke ◽  
Evgueni Filipov ◽  
Eren Uçkan
Keyword(s):  
Wave Propagation ◽  
Linear Function ◽  
Ground Deformation ◽  
Unit Length ◽  
Ground Movement ◽  
Seismic Fragility ◽  
Ground Shaking ◽  
Permanent Ground Deformation

Seismic fragility relations of buried segmented pipelines are currently defined in terms of pipe repairs per unit length as a function of some measure of ground shaking or ground movement. In some current relations, both wave propagation (WP) and permanent ground deformation (PGD) damage are addressed by combining the hazard into a measure of ground strain. One troubling aspect of these fragility relations is that each new event seems to provide new data that in some cases, are significantly different from existing relations. Herein, we investigate the robustness of these expressions by using new data from the 1999 M = 7.4 Turkey earthquake. A methodology is presented to calculate ground strains, by considering relative PGD along the axis of the pipeline. Results indicate that, for the strain/damage range of interest, a linear function (on a log-log scale) provides a relatively robust fragility relation for buried segmented pipes.

Wave Propagation Versus Transient Ground Displacement as a Credible Hazard to Buried Oil and Gas Pipelines

2000 ◽  
Author(s):  
Douglas G. Honegger
Keyword(s):  
Wave Propagation ◽  
Southern California ◽  
Oil And Gas ◽  
Ground Deformation ◽  
Gas Pipeline ◽  
Tensile Failure ◽  
Northridge Earthquake ◽  
Research Activity ◽  
Research Project ◽  
Permanent Ground Deformation

In 1997, a research project was initiated by Southern California Gas Company, Pacific Gas and Electric Company, with support from Tokyo Gas, Osaka Gas, and Toho Gas, to investigate the cause of natural gas pipeline damage during the 1994 Northridge earthquake. As part of this research activity, extensive field and laboratory investigations were performed on a 1925 gas pipeline that suffered several girth weld failures in Potrero Canyon, a remote and unpopulated area just north of the Santa Susana Mountains. The pipeline is operated by the Southern California Gas Company, one of the principle sponsors of the gas utility research project. The investigations into the performance of the pipeline were largely prompted by questions regarding the cause of pipeline damage. Although ground cracking and sand boils were observed in Potrero Canyon following the Northridge earthquake, there were no clear signs of permanent ground deformation near the locations of pipeline damage. Pipeline damage, consisting predominantly of girth weld tensile failure and two instances of buckling of the pipe wall, indicated that significant relative pipe-soil deformation might have occurred. Field investigations were unable to identify surface evidence of permanent ground deformation near the locations of pipeline damage and attention focused on the possibility that the damage could have been caused by wave propagation. This focus was based on the assertions of past researchers that pipelines with poor-quality oxyacetylene girth welds are susceptible to damage from wave propagation. The detailed investigation of The pipeline has concluded that wave propagation was not a significant factor in the pipeline damage and raises questions regarding wave propagation effects as a causative mechanism for pipeline damage in past earthquakes. A simple analytical model of the transient ground deformation that may have occurred in the vicinity of the pipeline damage was found to provide insight into the cause of the ground cracking observed at the margins of Potrero Canyon, approximate magnitudes of differential ground displacements that may have occurred during the earthquake, and the reasons for the spatial distribution of pipeline damage. This model is proposed as the basis for identifying locations where similar earthquake effects can be identified in future hazard assessment studies.

A 3-Dimensional Continuum ALE Model for Soil-Pipe Interaction

2008 ◽  
Author(s):  
Abdelfettah Fredj ◽  
Aaron Dinovitzer ◽  
Joe Zhou
Keyword(s):  
Large Scale ◽  
Large Deformations ◽  
Ground Deformation ◽  
Ground Movement ◽  
Soil Movement ◽  
3 Dimensional ◽  
Ale Methods ◽  
Permanent Ground Deformation ◽  
Pipeline Design ◽  
Soil Pipe

Soil-pipe interactions when large ground movements occur are an important consideration in pipeline design, route selection, guide monitoring and reduce the risk of damage or failure. Large ground movement can be caused by slope failures, faulting, landslides and seismic activities. Such conditions induce large deformations of both the soil and pipe. Analyses of such behavior pose a significant challenge to capabilities of standard finite elements as the capability to analyze large deformations is required. This requirement is difficult to meet for Lagrangian-based code. New developments using ALE methods make it possible to determine soil and pipe deformation confidently for large displacements. This paper describes a study performed to investigate the mechanical behavior of a pipeline subjected to large soil movement. A 3D continuum modeling using an ALE (Arbitrary Eulerian Lagrangian) formulation was developed and run using LS-DYNA. The results are compared with published experimental data of large-scale test to verify the numerical analysis method. The analysis is further extended to analyze the soil-pipe interaction under permanent ground deformation such as those associated with surface fault rupture and landslides.

Failure Analysis Of Buried Gas Pipelines Crossing Seismic Faults

2020 ◽  
Vol 3 (2) ◽  
pp. 781-790
Author(s):  
M. Rizwan Akram ◽  
Ali Yesilyurt ◽  
A.Can. Zulfikar ◽  
F. Göktepe
Keyword(s):  
Ground Deformation ◽  
Warning System ◽  
Strike Slip ◽  
Gas Pipelines ◽  
Steel Pipes ◽  
Seismic Fault ◽  
Fault Parameters ◽  
Dip Angle ◽  
Permanent Ground Deformation ◽  
Recent Earthquakes

Research on buried gas pipelines (BGPs) has taken an important consideration due to their failures in recent earthquakes. In permanent ground deformation (PGD) hazards, seismic faults are considered as one of the major causes of BGPs failure due to accumulation of impermissible tensile strains. In current research, four steel pipes such as X-42, X-52, X-60, and X-70 grades crossing through strike-slip, normal and reverse seismic faults have been investigated. Firstly, failure of BGPs due to change in soil-pipe parameters have been analyzed. Later, effects of seismic fault parameters such as change in dip angle and angle between pipe and fault plane are evaluated. Additionally, effects due to changing pipe class levels are also examined. The results of current study reveal that BGPs can resist until earthquake moment magnitude of 7.0 but fails above this limit under the assumed geotechnical properties of current study. In addition, strike-slip fault can trigger early damage in BGPs than normal and reverse faults. In the last stage, an early warning system is proposed based on the current procedure. 

Increase associated risk of gynaecological cancer due to long-term exposure to high concentration of atmospheric SO2 industrial pollutant

2021 ◽  
pp. 1420326X2110036
Author(s):  
Qian Xu ◽  
Chan Lu ◽  
Rachael Gakii Murithi ◽  
Lanqin Cao
Keyword(s):  
Time Windows ◽  
Air Pollutant ◽  
Gynaecological Cancer ◽  
High Concentration ◽  
The Past ◽  
Short And Long Term ◽  
Using Data ◽  
Air Quality Monitoring Stations ◽  
Control Study

A cohort case–control study was conducted in XiangYa Hospital, Changsha, China, which involved 305 patients and 399 healthy women, from June 2010 to December 2018, to evaluate the association between Chinese women’s short- and long-term exposure to industrial air pollutant, SO2 and gynaecological cancer (GC). We obtained personal and family information from the XiangYa Hospital electronic computer medical records. Using data obtained from the air quality monitoring stations in Changsha, we estimated each woman’s exposure to the industrial air pollutant, sulphur dioxide (SO2), for different time windows, including the past 1, 5, 10 and 15 years before diagnosis of the disease. A multiple logistic regression model was used to assess the association between GC and SO2 exposure. GC was significantly associated with long-term SO2 exposure, with adjusted odds ratio (95% confidence interval) = 1.56 (1.10–2.21) and 1.81 (1.07–3.06) for a per interquartile range increase in the past 10 and 15 years, respectively. Sensitivity analysis showed that different groups reacted in different ways to long-term SO2 exposure. We concluded that long-term exposure to high concentration of industrial pollutant, SO2 is associated with the development of GC. This finding has implications for the prevention and reduction of GC.

Sexual harassment and psychological complaints: student- and class-level associations

2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
S Brolin Låftman ◽  
Y Bjereld ◽  
B Modin ◽  
P Löfstedt
Keyword(s):  
School Climate ◽  
Sexual Harassment ◽  
Linear Regression Analysis ◽  
Well Being ◽  
Negative Effects ◽  
School Class ◽  
School Aged Children ◽  
The Past ◽  
Class Level ◽  
Using Data

Abstract Background Students who are subjected to sexual harassment at school report lower psychological well-being than those who are not exposed. Yet, it is possible that the occurrence of sexual harassment in the school class is stressful also for those who are not directly targeted, with potential negative effects on well-being for all students. The aim was to examine whether sexual harassment at the student- and at the class-level was associated with students' psychological complaints. Methods Data from the Swedish Health Behaviour in School-aged Children (HBSC) of 2017/18 was used, with information from students aged 11, 13 and 15 years (n = 3,720 distributed across 209 classes). Psychological complaints were constructed as a summative index of four items capturing how often the student had felt low, felt irritable or bad tempered, felt nervous, or had difficulties to fall asleep, during the past six months (Cronbach's alpha=0.78). Sexual harassment at the student-level was measured by one item concerning bullying at school: “Other students have exposed me to sexual jokes”. Students who reported that this had happened at least “2 or 3 times a month” were classified as exposed to sexual harassment at school. Sexual harassment at the class-level was defined as the school class proportion of students exposed to sexual harassment, reported in per cent. Two-level linear regression analysis was applied. Results Students who had been exposed to sexual harassment had higher levels of psychological complaints (b = 2.74, p < 0.001). The proportion of students in the school class who had been exposed to sexual harassment was also associated with higher levels of psychological complaints, even when adjusting for sexual harassment at the student-level, gender and grade (b = 0.03, p = 0.015). Conclusions Sexual harassment is harmful for those who are exposed, but may also affect other students negatively. Thus, a school climate free from sexual harassment will profit all students. Key messages Using data collected among students aged 11, 13 and 15 years, this study showed that sexual harassment at the student- and class-level was associated with higher levels of psychological complaints. Sexual harassment is harmful for those who are exposed, but may also affect other students negatively. Thus, a school climate free from sexual harassment will profit all students.

Estimation of Construction Waste Generation and Management in Taiwan

2011 ◽  
Vol 243-249 ◽  
pp. 6292-6295 ◽  
Author(s):  
Rong Yau Huang ◽  
Li Hsu Yeh ◽  
Hao Hsien Chen ◽  
Jyh Dong Lin ◽  
Ping Fu Chen ◽  
...  
Keyword(s):  
Decision Tree ◽  
Cross Correlation ◽  
Expert Interviews ◽  
Waste Generation ◽  
Valid Conclusion ◽  
Construction Waste ◽  
Composition Ratio ◽  
The Past ◽  
Highly Correlated ◽  
Using Data

This study examines construction waste generation and management in Taiwan. We verify the factors probable affecting the output of construction wastes by using data for the output of declared construction wastes produced from demolition projects in Taiwan in the last year, expert interviews, and research achievements in the past, and find “ on-site separation” is the factor with effects on the output of construction wastes via cross-correlation by algorithms such as K-Means and Decision Tree C5.0. It can be seen that the output (0.092(t/M3) with on-site separation or 0.329(t/M3) without on-site separation is highly correlated with the composition ratio of construction wastes and referred to as a valid conclusion.

Cannabis Growers in the United States: Findings From a National Household Survey 2010−2014

2021 ◽  
pp. 002204262110004
Author(s):  
Alejandro Azofeifa ◽  
Rosalie L. Pacula ◽  
Margaret E. Mattson
Keyword(s):  
Logistic Regression Model ◽  
Geographical Location ◽  
Household Survey ◽  
The United States ◽  
Multivariable Logistic Regression Model ◽  
Chi Square ◽  
Prevention Education ◽  
The Past ◽  
National Household Survey ◽  
Using Data

Given the rapidly changing U.S. cannabis legislation landscape, the aim of this article is to describe individuals who self-reported growing cannabis in the past year by selected characteristics and geographical location. Using data from 2010 to 2014 National Survey on Drug Use and Health, we conducted bivariate chi-square tests and ran a multivariable logistic regression model to examine the indicators associated with growing cannabis. Approximately, 484,000 individuals aged 12+ self-reported growing cannabis in the past year (1.6% of marijuana users). Predictors of growing cannabis included being male and self-reported reporting using cannabis for a greater number of days. Data showed differences in the proportion of cannabis growers by the state of residence. Obtaining a baseline estimate of cannabis growing practices prior to recreational cannabis markets emerging (2014) is important because such practices may undermine efforts to discourage diversion to youth. Tracking these acquisition patterns will better inform content for public health messaging and prevention education, particularly those targeting youth.

scholarly journals The Economic Impact of Inflammatory Bowel Disease in Canada

2004 ◽  
Vol 18 (4) ◽  
pp. 255-257
Author(s):  
Robert Hilsden
Keyword(s):  
Inflammatory Bowel Disease ◽  
Bowel Disease ◽  
Labour Force ◽  
Incidence Rates ◽  
Age Group ◽  
Group Level ◽  
The Past ◽  
Inflammatory Bowel ◽  
Using Data ◽  
Very High

Longobardi and colleagues examined the effect of inflammatory bowel disease (IBD) on employment, using data from 10,891 respondents aged 20 to 64 years from the 1998 cycle of the Canadian National Population Health Survey (NPHS) (1). This sample included 187 (1.7%) subjects who self-reported IBD or a similar bowel disorder. A significantly greater proportion of IBD than non-IBD respondents reported that they were not in the labour force (28.9% versus 18.5%). Even after adjusting for other factors (age group, level of pain, etc), subjects with IBD had a 2.9% higher nonparticipation rate (21.4%). For example, among people not hospitalized within the past year and with no limitation of activities due to pain, IBD subjects were 1.2 times more likely to be unemployed than those without IBD. Subjects who reported high levels of pain had a very high probability of being out of the labour force. Based on Canadian annual compensation data for all employed persons in Canada, and age- and sex-specific prevalence, and incidence rates for IBD, the authors estimated that there are 119,980 IBD patients between the ages of 20 and 64 years in Canada and that this group includes 3479 people who are not in the labour force. This translates into lost wages of $104.2 million, or $868 per IBD patient

Chapter 7.1 Deception Island

2021 ◽  
pp. M55-2018-56
Author(s):  
A. Geyer ◽  
D. Pedrazzi ◽  
J. Almendros ◽  
M. Berrocoso ◽  
J. López-Martínez ◽  
...  
Keyword(s):  
Ground Deformation ◽  
South Shetland Islands ◽  
Deception Island ◽  
Research Activity ◽  
Proper Understanding ◽  
Volcanic Unrest ◽  
Origin And Evolution ◽  
Shetland Islands ◽  
The Past ◽  
Scientific Disciplines

AbstractDeception Island (South Shetland Islands) is one of the most active volcanoes in Antarctica, with more than 15 explosive eruptive events registered over the past two centuries. Recent eruptions (1967, 1969 and 1970) and volcanic unrest episodes in 1992, 1999 and 2014–15 demonstrate that the occurrence of future volcanic activity is a valid and pressing concern for scientists, logistic personnel and tourists that are visiting or are working on or near the island. Over the last few decades, intense research activity has been carried out on Deception Island to decipher the origin and evolution of this very complex volcano. To that end, a solid integration of related scientific disciplines, such as tectonics, petrology, geochemistry, geophysics, geomorphology, remote sensing, glaciology, is required. A proper understanding of the island's evolution in the past, and its present state, is essential for improving the efficiency in interpreting monitoring data recorded during volcanic unrest periods and, hence, for future eruption forecasting. In this chapter, we briefly present Deception Island's most relevant tectonic, geomorphological, volcanological and magmatic features, as well as the results obtained from decades of monitoring the island's seismic activity and ground deformation.

Sign in / Sign up

Export Citation Format

Share Document