Pipeline Geohazard Assessment: Bridging the Gap Between Integrity Management and Construction Safety Contexts

2018 ◽  
Author(s):  
Rodney S. Read
Keyword(s):  
Construction Safety ◽  
Worker Safety ◽  
Ground Movement ◽  
Pipeline Construction ◽  
Probability Estimates ◽  
Subject Matter Expertise ◽  
Management Context ◽  
Integrity Management ◽  
Geohazard Assessment

Geohazards are threats of a geological, geotechnical, hydrological, or seismic/tectonic nature that may negatively affect people, infrastructure and/or the environment. In a pipeline integrity management context, geohazards are considered under the time-independent threat category of Weather-related and Outside Force in the American standard ASME B31.8S. Geotechnical failure of pipelines due to ground movement is addressed in Annex H and elsewhere in the Canadian standard CSA-Z662. Both of these standards allow flexibility in terms of geohazard assessment as part of pipeline integrity management. As a result of this flexibility, many systems for identifying, characterizing, analyzing and managing geohazards have been developed by operators and geotechnical engineering practitioners. The evolution of these systems, and general expectations regarding geohazard assessment, toward quantitative geohazard frequency assessment is a trend in recent pipeline hearings and regulatory filings in Canada. While this trend is intended to frame geohazard assessment in an objective and repeatable manner, partitioning the assessment into a series of conditional probability estimates, the reality is that there is always an element of subjectivity in assigning these conditional probabilities, requiring subject matter expertise and expert judgment to make informed and defensible decisions. Defining a specific risk context (typically loss of containment from a pipeline) and communicating uncertainty are important aspects of applying these types of systems. Adoption of these approaches for alternate risk contexts, such as worker safety during pipeline construction, is challenging in that the specific geohazards and threat scenarios considered for long-term pipeline integrity may or may not adequately represent all credible threats during pipeline construction. This paper explores the commonalities and differences in short- and long-term framing of geohazard assessment, and offers guidance for extending geohazard assessment for long-term pipeline integrity to other contexts such as construction safety.

scholarly journals Transforming a Liability into an Asset: A System Dynamics Model for Free-Ranging Dog Population Management

Systems ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 56
Author(s):  
Urmila Basu Mallick ◽  
Marja H. Bakermans ◽  
Khalid Saeed
Keyword(s):  
System Dynamics ◽  
Social Integration ◽  
Unintended Consequences ◽  
System Dynamics Model ◽  
Dynamics Model ◽  
Innovative Strategies ◽  
Management Context ◽  
Free Ranging ◽  
Social Rewards

Using Indian free-ranging dogs (FRD) as a case study, we propose a novel intervention of social integration alongside previously proposed methods for dealing with FRD populations. Our study subsumes population dynamics, funding avenues, and innovative strategies to maintain FRD welfare and provide societal benefits. We develop a comprehensive system dynamics model, featuring identifiable parameters customizable for any management context and imperative for successfully planning a widescale FRD population intervention. We examine policy resistance and simulate conventional interventions alongside the proposed social integration effort to compare monetary and social rewards, as well as costs and unintended consequences. For challenging socioeconomic ecological contexts, policy resistance is best overcome by shifting priority strategically between social integration and conventional techniques. The results suggest that social integration can financially support a long-term FRD intervention, while transforming a “pest” population into a resource for animal-assisted health interventions, law enforcement, and conservation efforts.

Integrity Management of Ground Movement Hazards

2016 ◽  
Author(s):  
Yong-Yi Wang ◽  
Don West ◽  
Douglas Dewar ◽  
Alex McKenzie-Johnson ◽  
Millan Sen
Keyword(s):  
Management Program ◽  
Ground Movement ◽  
Tensile Failure ◽  
Weld Strength ◽  
Factors Affecting ◽  
Ground Movements ◽  
Decision Points ◽  
Starting Point ◽  
Integrity Management ◽  
Girth Welds

Ground movements, such as landslides and subsidence/settlement, can pose serious threats to pipeline integrity. The consequence of these incidents can be severe. In the absence of systematic integrity management, preventing and predicting incidents related to ground movements can be difficult. A ground movement management program can reduce the potential of those incidents. Some basic concepts and terms relevant to the management of ground movement hazards are introduced first. A ground movement management program may involve a long segment of a pipeline that may have a threat of failure in unknown locations. Identifying such locations and understanding the potential magnitude of the ground movement is often the starting point of a management program. In other cases, management activities may start after an event is known to have occurred. A sample response process is shown to illustrate key considerations and decision points after the evidence of an event is discovered. Such a process can involve fitness-for-service (FFS) assessment when appropriate information is available. The framework and key elements of FFS assessment are explained, including safety factors on strain capacity. The use of FFS assessment is illustrated through the assessment of tensile failure mode. Assessment models are introduced, including key factors affecting the outcome of an assessment. The unique features of girth welds in vintage pipelines are highlighted because the management of such pipelines is a high priority in North America and perhaps in other parts of the worlds. Common practice and appropriate considerations in a pipeline replacement program in areas of potential ground movement are highlighted. It is advisable to replace pipes with pipes of similar strength and stiffness so the strains can be distributed as broadly as possible. The chemical composition of pipe steels and the mechanical properties of the pipes should be such that the possibility of HAZ softening and weld strength undermatching is minimized. In addition, the benefits and cost of using the workmanship flaw acceptance criteria of API 1104 or equivalent standards in making repair and cutout decisions of vintage pipelines should be evaluated against the possible use of FFS assessment procedures. FFS assessment provides a quantifiable performance target which is not available through the workmanship criteria. However, necessary inputs to perform FFS assessment may not be readily available. Ongoing work intended to address some of the gaps is briefly described.

International benchmarking for performance improvement in construction safety and health

2016 ◽  
Vol 23 (4) ◽  
pp. 916-936 ◽  
Author(s):  
Lance W. Saunders ◽  
Andrew P McCoy ◽  
Brian M. Kleiner ◽  
Helen Lingard ◽  
Tracy Cooke ◽  
...  
Keyword(s):  
Qualitative Data ◽  
Construction Safety ◽  
Study Data ◽  
Worker Safety ◽  
Potential Hazard ◽  
Content Type ◽  
Safety And Health ◽  
The Usa ◽  
Project Lifecycle

Purpose – The purpose of this paper is to advance knowledge on the advantages of integrating safety earlier in the construction project lifecycle. Design/methodology/approach – A case study approach is used to collect data from construction sites in the USA, which performs poorly in construction safety and health, and Australia (AU), which performs well in construction safety and health. Qualitative data are collected to determine how and when safety is considered in the project lifecycle in both countries, and then the results are benchmarked to determine the benefits of addressing safety earlier in the process. Findings – Data show that addressing a potential hazard earlier in the project lifecycle has performance benefits in terms of the level of hazard control. Research limitations/implications – The processes that are identified as possibly explaining the performance difference are just based on qualitative data from interviews. Targeted research addressing the relationship between these processes and safety outcomes is an opportunity for further research. Practical implications – The case study data are used to identify specific processes that are used in AU that might be adopted in the USA to improve performance by integrating safety earlier into the decision-making process. Social implications – This paper highlights the advantages of integrating safety as a decision factor early in the process. Worker safety is not just an issue in the construction industry, and thus the findings are applicable to all industries in which worker safety is an issue. Originality/value – This paper advances the safety in design literature by quantitatively supporting the link between when a hazard is addressed and performance. It also links the results to specific processes across countries, which advances the literature because most research in this area to data is within a single country.

The Contribution of In-Line IMU Inspection to Geohazard and Crack Management Strategies

2021 ◽  
Author(s):  
Andy Young ◽  
Andrew Wilde ◽  
Ivan Grosmann
Keyword(s):  
Management Practices ◽  
Load Capacity ◽  
Management Strategies ◽  
High Strength ◽  
Ground Movement ◽  
Ground Subsidence ◽  
Measurement Unit ◽  
External Loading ◽  
Integrity Management ◽  
The Right

Abstract Geohazards and external loads are a significant threat to the integrity of pipelines in hilly terrain, at river crossings and where ground subsidence is taking place. Well designed pipelines can tolerate strains that exceed the nominal strain of 0.5% that corresponds specified minimum yield strengths, however the presence of weld defects and stress corrosion cracking can reduce the load capacity dramatically. Welds that are to specification but are under-matched on actual strength to the adjacent parent pipe have also been recognised as potentially vulnerable to low strain failures in high strength pipes. Modern pipelines in terrain susceptible to geohazards normally include design studies to identify and avoid or mitigate the threats. Surveillance of the right-of-way is also routinely carried out for pipelines with good integrity management practices, and particularly for major strategic lines. In-line inspection using an inertial measurement unit (IMU) is a well-known method to detect ground movement loads and contributes to the integrity management of pipelines. In this paper we illustrate : 1. How IMU inspection is an important tool in the management of geohazards and how it compliments other methods of geohazard assessment. 2. How locations of elevated pipe strain are identified and evaluated for external loading threats, and can be aligned with other data sets that indicate the pipeline load capacity. 3. How the locations of bending strain can be prioritised for further action. 4. How the loading profile in the pipeline can be incorporated into crack management strategies in order prioritise locations for further investigation or assessment.

Overview of Pipeline Geohazard Assessment Approaches and Strategies

2013 ◽  
Author(s):  
Moness Rizkalla ◽  
R. S. (Rod) Read
Keyword(s):  
Risk Assessments ◽  
Pipeline System ◽  
Mechanistic Models ◽  
Fitness For Purpose ◽  
Site Specific ◽  
Integrity Management ◽  
Hazard And Risk ◽  
Geohazard Risk ◽  
Geohazard Assessment ◽  
Do So

Undertaking a systematic pipeline geohazard assessment may be driven by the design and regulatory permitting needs for proposed new pipelines or as an input to the integrity management of operating pipeline assets. Yet the leading international pipeline codes do not provide explicit direction on undertaking such assessments, rather providing considerable latitude in the guidance to do so which in turn provides several options. The methods for identifying and assessing the potential likelihood and severity of geohazards vary significantly, from purely expert judgment-based approaches relying largely on visual observations of geomorphology to analytically-intensive methods incorporating phenomenological and/or mechanistic models and route, pipeline properties and, where applicable, operational monitoring data. Each of these methods can be used to assess hazard and risk associated with specific geohazards in terms of qualitative, semi-quantitative or quantitative approaches provided that associated underlying assumptions are clearly understood. Some of these methods are better suited to provide a continuous contiguous geohazard risk assessment for a pipeline system while others are better suited for localized site-specific risk assessments. Following a brief review of pipeline codes, this paper provides an overview of the range of pipeline geohazard assessment approaches and explores the “fitness for purpose” strategy that allows for continuing improvement during design stages and into operations.

A Bayesian Machine Learning Approach for Efficient Integrity Management of Steel Lazy Wave Risers

2020 ◽  
Author(s):  
Rasoul Hejazi ◽  
Andrew Grime ◽  
Mark Randolph ◽  
Mike Efthymiou
Keyword(s):  
Machine Learning ◽  
Fatigue Failure ◽  
Learning Process ◽  
Predictive Models ◽  
Structural Integrity ◽  
Degradation Mechanism ◽  
Data Driven ◽  
Practical Implementation ◽  
Integrity Management

Abstract In-service integrity management (IM) of steel lazy wave risers (SLWRs) can benefit significantly from quantitative assessment of the overall risk of system failure as it can provide an effective tool for decision making. SLWRs are prone to fatigue failure within their touchdown zone (TDZ). This failure mode needs to be evaluated rigorously in riser IM processes because fatigue is an ongoing degradation mechanism threatening the structural integrity of risers throughout their service life. However, accurately evaluating the probability of fatigue failure for riser systems within a useful time frame is challenging due to the need to run a large number of nonlinear, dynamic numerical time domain simulations. Applying the Bayesian framework for machine learning, through the use of Gaussian Processes (GP) for regression, offers an attractive solution to overcome the burden of prohibitive simulation run times. GPs are stochastic, data-driven predictive models which incorporate the underlying physics of the problem in the learning process, and facilitate rapid probabilistic assessments with limited loss in accuracy. This paper proposes an efficient framework for practical implementation of a GP to create predictive models for the estimation of fatigue responses at SLWR hotspots. Such models are able to perform stochastic response prediction within a few milliseconds, thus enabling rapid prediction of the probability of SLWR fatigue failure. A realistic North West Shelf (NWS) case study is used to demonstrate the framework, comprising a 20” SLWR connected to a representative floating facility located in 950 m water depth. A full hindcast metocean dataset with associated statistical distributions are used for the riser long-term fatigue loading conditions. Numerical simulation and sampling techniques are adopted to generate a simulation-based dataset for training the data-driven model. In addition, a recently developed dimensionality reduction technique is employed to improve efficiency and reduce complexity of the learning process. The results show that the stochastic predictive models developed by the suggested framework can predict the long-term TDZ fatigue damage of SLWRs due to vessel motions with an acceptable level of accuracy for practical purposes.

Vulnerability of Buried Pipelines to Landslides

2016 ◽  
Author(s):  
Gerald Ferris ◽  
Sarah Newton ◽  
Michael Porter
Keyword(s):  
Ground Movement ◽  
Buried Pipelines ◽  
Large Numbers ◽  
Vulnerability Model ◽  
Cause Of Failure ◽  
Integrity Management ◽  
Pipeline Failure ◽  
As Stress ◽  
Pipeline Failures ◽  
Landslide Movement

The movement of a mass of rock, debris or earth down a slope is a landslide, which in the pipeline industry is often referred to as ground movement. Landslides continue to cause pipeline failures throughout the industry, sometimes as the singular cause of failure and in others cases as a contributing factor to failures (such as stress corrosion cracking on slopes). Landslides can originate on slopes above a pipeline and cause impact loads; they can originate below a pipeline and cause unintended spans; and they can encompass the ground crossed by a pipeline, which can lead to high compressive (or tensile) strains and pipeline buckling. This paper focuses on the latter scenario. Similar to the approach recently outlined for watercourses [1], the term ‘vulnerability’ refers to the conditional probability of pipeline failure given that landslide movement spatially impacts a pipeline. This paper presents the development of a statistical and judgment-based vulnerability model for pipeline crossings of slopes that are subject to landslides that can be used to rank the relative importance of slopes at a screening level of assessment. The model is based on case histories where this type of landslide scenario caused pipeline failures (defined as holes, leaks and ruptures), or buckling of pipelines that resulted in the need for immediate repairs. Vulnerability has two main uses: on its own to help prioritize large numbers of slope crossings for further investigation; and, once combined with estimates of the probability of landslide movement, to provide a probability of pipeline failure estimate that can be used to guide integrity management programs.

Long term ground movement of TRISTAN synchrotron

2003 ◽  
Author(s):  
K. Endo ◽  
Y. Ohsawa ◽  
M. Miyahara
Keyword(s):  
Ground Movement

The Dose of CD34+ Cells Negatively Impacts the Outcome of Patients Treated with Genoidentical Allo SCT Prepared with a Reduced Intensity Conditioning (RIC).

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1086-1086
Author(s):  
Didier Blaise ◽  
Laure Farnaut ◽  
Catherine Faucher ◽  
Sabine Furst ◽  
Jean El Cheikh ◽  
...  
Keyword(s):  
Hematopoietic Cell Transplantation ◽  
Cox Model ◽  
Disease Status ◽  
Probability Estimates ◽  
Cd34 Cells ◽  
Comorbidity Index ◽  
And Function ◽  
Donor Source

Abstract While RIC are presently commonly used, most of the reports suffer from insufficiencies limiting knowledge acquisition: small populations, short follow-up, heterogeneities in the RIC intensity or the donor source. We report here 100 patients with hematological malignancies (HM) treated with geno-identical SCT after the same RIC in a single center from 2000 until 2006. All patients received oral busulfan (8mg/m2), thymoglobulin (2.5 mg/kg) and Fludarabine (150 to 180 mg/m²) (FBT conditioning). All grafts were PBSC from a match sibling donor. All grafts were monitored for CD34, CD3, CD4, CD8, CD19 and CD56+ cells (notably CD34= 5.6 (1.5–22) × 10e6/kg; CD3= 317 (112–887) × 10e6/kg). Median age was 50 (18–64). Hematopoietic cell transplantation comorbidity index (HCT-CI) was 0, 1–2 and > 2 in 31, 39 and 23 of the 93 evaluable patients. All patients received post-graft CSA. Diagnoses included acute leukemia (39%), Myeloid (16%) or Lymphoid (45%) malignancies. 53, 14 and 33 pts were in CR, progression or stable disease. Minimal and median follow-up are respectively 6 and 34 months. All but one engrafted reaching full lymphoid donor chimerism prior to day 100 in 85% of the cases. 55 pts presented aGVHD (G1: 12; G2: 22; G3: 12; G4: 9) for a cumulative incidence (CI) of G2–4 aGVHD of 43% (33–53); 91 patients were evaluable for cGVHD with a 79% (71–87) CI (Lim= 20%; Ext: 80%). In a multivariate analysis cGVHD occurrence could be predicted by 2 independent factors: lower dose of CD34 (but no impact of CD3, CD4, CD8, CD19 or CD56) (odd ratio (OR): 0.79 (0.69–0.90)) and grade 2–4 aGVHD (OR: 1.16 (1.01–1.32)). TRM CI was respectively 5%, 14% and 19% (11–27) at 3, 12 months and overall. TRM was strongly associated with aGVHD occurrence (TRM CI: grade 2–4 aGVHD: 37% (23–51); grade 0–1 aGVHD: 7% (0–14): p<.01). Relapse CI was 15% (8–22) at a median of 169 days (30–769). Disease control was significatively associated with cGVHD occurrence (Relapse CI: cGVHD: 10% (3–17); no cGVHD: 42% (14–70): p=.01). 5 year overall survival (OS) and LFS probability estimates are 62% (50–72) and 60% (48–72) with a plateau starting after 3.5 years. Outcome was similar for the patients above or under 50 and for the different diagnoses. HCT-CI did not show any influence on outcome. In a Cox model analysis, LFS was independently affected by only 2 pre-transplant variables: disease status (CR vs. no CR) (OR=0.45; p=.022) and the dose of infused CD34+ cells (> or < 5.6 × 10e6 CD34+ cells) (OR: 2.04; p=.039). In accordance with above, patients with higher CD34+ cells presented less cGVHD (cGVHD CI: CD34 < 5.6: 98% (94–100); CD34 > 5.6: 76% (64–88) ; p<0.01). These data confirm that FBT RIC, combining myeloablation (Busulfan) and limited Thymoglobulin, is efficient in a wide population in term of age and diagnosis conducting to sustained long term OS and EFS with limited TRM. They suggest also that after RIC, graft composition and function probably in relation with G-CSF mobilization might impact allogeneic effect and invite revisiting this subject in this context.

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