Quantitative risk assessment of rock slope instabilities that threaten a highway near Canmore, Alberta, Canada: managing risk calculation uncertainty in practice

2020 ◽  
Vol 57 (3) ◽  
pp. 337-353 ◽  
Author(s):  
Renato Macciotta ◽  
Chris Gräpel ◽  
Tim Keegan ◽  
Jason Duxbury ◽  
Roger Skirrow
Keyword(s):  
Risk Assessment ◽  
Decision Making ◽  
Quantitative Risk Assessment ◽  
Environmental Concerns ◽  
Individual Risk ◽  
Total Risk ◽  
Economic Activities ◽  
Rock Falls ◽  
Risk Calculation ◽  
Fall Protection

We present a quantitative risk assessment (QRA) to guide decision-making for selection of rock fall protection strategies. The analysis corresponds to a section of highway near Canmore, Alberta, Canada; where rock falls are common. Environmental concerns, tourism, and economic activities overlap the project area, which increased the complexity of the decision-making process. QRA was adopted to improve highway user safety and minimize effects on natural, social, and economic environments. Uncertainty was associated with hazard and consequence quantification, and the study elicited plausible ranges of input variables for risk calculation. Expected and range in risk were calculated for current conditions and after mitigation. Individual risk to highway users was found to be low, following the limited exposure of any particular individual. Current total risk was calculated at 2.9 × 10−4probability of fatality and a plausible range between 2.0 × 10−5and 5.5 × 10−3. The slope protection configuration selected had a residual total risk between 9.0 × 10−4and 2.9 × 10−6, and a best estimate of 4.5 × 10−5. The risk levels were evaluated against criteria previously used in Canada and were considered an appropriate balance between project costs, public safety, environmental concerns, tourism, and economic activities after mitigation.

scholarly journals Biomechanical Rupture Risk Assessment

Aorta ◽  
2016 ◽  
Vol 04 (02) ◽  
pp. 42-60 ◽  
Author(s):  
T. Christian Gasser
Keyword(s):  
Risk Assessment ◽  
Decision Making ◽  
Validation Studies ◽  
Clinical Decision Making ◽  
Clinical Decision ◽  
Patient Treatment ◽  
Maximum Diameter ◽  
Individual Risk ◽  
Rupture Risk ◽  
Aneurysm Wall

AbstractAbdominal aortic aneurysm (AAA) rupture is a local event in the aneurysm wall that naturally demands tools to assess the risk for local wall rupture. Consequently, global parameters like the maximum diameter and its expansion over time can only give very rough risk indications; therefore, they frequently fail to predict individual risk for AAA rupture. In contrast, the Biomechanical Rupture Risk Assessment (BRRA) method investigates the wall’s risk for local rupture by quantitatively integrating many known AAA rupture risk factors like female sex, large relative expansion, intraluminal thrombus-related wall weakening, and high blood pressure. The BRRA method is almost 20 years old and has progressed considerably in recent years, it can now potentially enrich the diameter indication for AAA repair. The present paper reviews the current state of the BRRA method by summarizing its key underlying concepts (i.e., geometry modeling, biomechanical simulation, and result interpretation). Specifically, the validity of the underlying model assumptions is critically disused in relation to the intended simulation objective (i.e., a clinical AAA rupture risk assessment). Next, reported clinical BRRA validation studies are summarized, and their clinical relevance is reviewed. The BRRA method is a generic, biomechanics-based approach that provides several interfaces to incorporate information from different research disciplines. As an example, the final section of this review suggests integrating growth aspects to (potentially) further improve BRRA sensitivity and specificity. Despite the fact that no prospective validation studies are reported, a significant and still growing body of validation evidence suggests integrating the BRRA method into the clinical decision-making process (i.e., enriching diameter-based decision-making in AAA patient treatment).

scholarly journals Documentation of Individualized Preoperative Risk Assessment: A Multi-Center Study

2019 ◽  
Author(s):  
Joshua Aaron Bloomstone ◽  
Benjamin T Houseman ◽  
Evora Vicents Sande ◽  
Ann Brantley ◽  
Jessica Curran ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Decision Making ◽  
Shared Decision Making ◽  
Surgical Patients ◽  
Individual Risk ◽  
Shared Decision ◽  
Surgical Risk ◽  
Poor Outcomes ◽  
Multi Center Study ◽  
Cardiac Surgeons

Abstract Background Individual surgical risk prediction tools that inform shared-decision making, strengthen the consent process and support clinical management are considered important tools to enhance patient experience and outcomes. Neither the use of individual pre-surgical risk assessment (ISRA) tools nor the rate of documented individual risk is known. The primary endpoint of this study was the rate of physician documented ISRAs within the records of patients with poor outcomes. Secondary endpoints included the effects of age, sex, race, ASA class, and time and type of surgery on the rate of documented presurgical risk.Methods The records of non-obstetric surgical patients within 22 hospitals in Arizona, Colorado, Nebraska, Nevada, and Wyoming, between January 1 and December 31, 2017 were evaluated. Logistic regression was used to analyze both individual and group effects associated with ISRA documentation.Results 756 of 140,756 inpatient charts met inclusion criteria [0.54%, 95% CI 0.50% to 0.58%]. ISRAs were documented by 16.08% of surgeons [p<0.0001; R-squared=68.23%] and 4.50% of anesthesiologists [p< 0.0001, R-squared 15.38%]. Cardiac surgeons documented ISRAs more frequently than non-cardiac surgeons (25.87% vs 16.15%) [p=0.0086, R-squared=0.970%]. Elective surgical patients were more likely than emergency surgical patients (19.57 vs 12.03%) to have risk documented [p=0.0226, R-squared=0.730%]. Patients over the age of 65 were more likely than patients under the age of 65 to have ISRA documentation (20.31 vs 14.61%) [p=0.0429, R-squared=0.580%].Conclusions The observed rate of documented individual surgical risk assessment in our sample was low. Surgeons were more likely than anesthesiologists to document individual presurgical risk. In-line with the Salzburg Statement on Shared-Decision Making, information regarding surgical risk represents the bedrock of presurgical decision making and informed consent. The rate and quality of risk documentation must be improved.

Quantitative Risk Assessment for Viral Contamination of Shellfish and Coastal Waters

1993 ◽  
Vol 56 (12) ◽  
pp. 1043-1050 ◽  
Author(s):  
JOAN B. ROSE ◽  
MARK D. SOBSEY
Keyword(s):  
Risk Assessment ◽  
Dose Response ◽  
Probability Model ◽  
Enteric Virus ◽  
Epidemiological Data ◽  
The United States ◽  
Hazard Identification ◽  
Quantitative Risk Assessment ◽  
Individual Risk ◽  
Viral Contamination

Human pathogenic viruses have been detected from approved shellfish harvesting waters based on the fecal coliform indicator. Until recently it was difficult to assess viral contamination and the potential impact on public health. Risk assessment is a valuable tool which can be used to estimate adverse effects associated with microbial hazards. This report describes the use of quantitative risk assessment for evaluating potential human health impacts associated with exposure to viral contamination of shellfish. The four fundamental steps used in a formal risk assessment are described within and include i) Hazard identification, ii) Dose-response determination, iii) Exposure assessment, and iv) Risk characterization. Dose-response models developed from human feeding studies were used to evaluate the risk of infection from contaminated shellfish. Of 58 pooled samples, 19% were found to be positive for viruses. Using an echovirus-12 probability model, the individual risk was determined for consumption of 60 g of raw shellfish. Individual risks ranged from 2.2 × 10−4 to 3.5 × 10−2. These data suggest that individuals consuming raw shellfish from approved waters in the United States may have on the average a 1 in 100 chance of becoming infected with an enteric virus. Using the rotavirus model which represents a more infectious virus, the risk rose to 5 in 10. The potential for use of a risk assessment approach for developing priorities and strategies for control of disease is immense. Epidemiological data have demonstrated the significance of shellfish-associated viral disease and, although limited, appropriate virus occurrence data are available. Additional information on virus occurrence and exposure is needed, and then scientific risk assessment can be used to better assure the safety of seafood.

Technical safety: use of concept risk assessment for field development certainty

2019 ◽  
Vol 59 (2) ◽  
pp. 549
Author(s):  
Colin Crowley ◽  
Dave Ashton
Keyword(s):  
Risk Assessment ◽  
Design Feature ◽  
Safety Performance ◽  
Quantitative Risk Assessment ◽  
Individual Risk ◽  
Field Development ◽  
Risk Levels ◽  
Wide Range ◽  
Rule Sets ◽  
Risk Reduction Measures

As technology advances and field development possibilities grow, the need for earlier guidance on the safety performance of concept designs is greater than ever. The SNC-Lavalin concept risk assessment (CRA) tool is a transparent and rapidly deployable model that is based on sound, industry-accepted quantitative risk assessment (QRA) principles. From the earliest stages of field development, when conceptualisation may be vague and data sparse, a wide range and variety of design options can still be assessed effectively and ranked on their safety performance. The CRA tool is proprietary software initially developed with BP and Shell. The model was first calibrated against 10 detailed QRAs, but is regularly benchmarked and updated with the most current failure rate data and has been used on nearly 50 projects globally. The database now incorporates established rule sets from hundreds of detailed QRAs performed, including floating liquefied natural gas and floating storage regasification units. This paper presents a CRA case study for a generic remote offshore field with a range of development options from conventional to minimal offshore facilities. The model calculates the associated risks for the options considered and is presented in terms of individual risk per annum, temporary refuge impairment frequency and potential loss of life. The results highlight the effects of each individual design feature on risk levels by comparison of similar options side by side, noting the main risk contributors and allowing investigation of the benefits of risk reduction measures. This enables identification of the best design features from each of the options and allows an optimised design to be carried forward.

Implementation of Quantitative Risk Assessment: Case Study

2014 ◽  
Author(s):  
David Mangold ◽  
W. Kent Muhlbauer ◽  
Jim Ponder ◽  
Tony Alfano
Keyword(s):  
Risk Assessment ◽  
Decision Making ◽  
Risk Management ◽  
The United States ◽  
Management Program ◽  
Quantitative Risk Assessment ◽  
Management Decision ◽  
Classical Statistics ◽  
Wide Range

Risk management of pipelines is a complex challenge due to the dynamic environment of the real world coupled with a wide range of system types installed over many decades. Various methods of risk assessment are currently being used in industry, many of which utilize relative scoring. These assessments are often not designed for the new integrity management program (IMP) requirements and are under direct challenge by regulators. SemGroup had historically used relative risk assessment methodologies to help support risk management decision-making. While the formality offered by these early methods provided benefits, it was recognized that, in order to more effectively manage risk and better meet the United States IMP objectives, a more effective risk assessment would be needed. A rapid and inexpensive migration into a better risk assessment platform was sought. The platform needed to be applicable not only to pipeline miles, but also to station facilities and all related components. The risk results had to be readily understandable and scalable, capturing risks from ‘trap to trap’ in addition to risks accompanying each segment. The solution appeared in the form a quantitative risk assessment that was ‘physics based’ rather than the classical statistics based QRA. This paper will outline the steps involved in this transition process and show how quantitative risk assessment may be efficiently implemented to better guide integrity decision-making, illustrated with a case study from SemGroup.

QUANTITATIVE RISK ASSESSMENT FOR COLLISIONS INVOLVING DOUBLE HULL OIL TANKERS

2021 ◽  
Vol 156 (A2) ◽  
Author(s):  
S A M Youssef ◽  
S T Ince ◽  
Y S Kim ◽  
J K Paik ◽  
F Chang ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Structural Damage ◽  
Human Life ◽  
Quantitative Risk Assessment ◽  
Environmental Damage ◽  
Total Risk ◽  
Formal Safety Assessment ◽  
Environmental Damages ◽  
Oil Tankers ◽  
Double Hull

In recent decades, the safety of ships at sea has become a major concern of the global maritime industries. Ships are rarely subject to severe accidents during their life cycle. Collision is one of the most hazardous accidents, with potentially serious consequences such as the loss of human life, structural damage and environmental damage, especially if large tankers, LNG and/or nuclear-powered vessels are involved. This study presents a Quantitative Risk Assessment (QRA) for double hull oil tankers that have collided with different types of ships. The methodology used to perform the QRA is based on the International Maritime Organization’s (IMO) definition of a Formal Safety Assessment (FSA). Using probabilistic approaches, ship-ship collision scenarios are randomly selected to create a representative sample of all possible scenarios. The collision frequency is then calculated for each scenario. As this is a virtual experiment, the LS-DYNA nonlinear finite element method (NLFEM) is used to predict the structural consequences of each scenario selected. In addition, the environmental consequences are estimated by calculating the size of each scenario’s oil spill. To assess the economic consequences, the property and environmental damages are calculated in terms of monetary units. The total risk is then calculated as the sum of the resultant structural and environmental damages. Exceedance curves are established that can be used to define the collision design loads in association with various design criteria.

scholarly journals Origins of Risk Assessment in Food Safety Decision Making

1988 ◽  
Vol 7 (4) ◽  
pp. 539-542 ◽  
Author(s):  
Joseph V. Rodricks
Keyword(s):  
Risk Assessment ◽  
Decision Making ◽  
Human Exposure ◽  
Driving Forces ◽  
Quantitative Risk Assessment ◽  
Regulatory Agencies ◽  
Decision Making Process ◽  
Commercially Important ◽  
Exposure Levels ◽  
Almost All

FDA's efforts during the early 1970s to establish acceptable food exposure levels for carcinogenic animal drugs such as diethylstilbestrol (DES) led the agency to incorporate quantitative risk assessment into its decision-making process. During the nearly two decades since FDA first introduced risk assessment as a regulatory tool, its uses have been expanded to almost all areas of chemical regulation. The major driving forces behind this expansion have been (1) the need to deal systematically with the large number of commercially important chemicals that have been identified as animal carcinogens and that have been found to occur widely in the environment and (2) the large number of laws that now require regulatory agencies to establish limits on human exposure to these substances.

scholarly journals Quantitative Risk Assessment for Aerospace Facility According to Windrose

Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 189
Author(s):  
Hee Jin Kim ◽  
Kyeong Min Jang ◽  
In Seok Yeo ◽  
Hwa Young Oh ◽  
Sun Il Kang ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Wind Direction ◽  
Fire Frequency ◽  
Quantitative Risk Assessment ◽  
Individual Risk ◽  
Wind Rose ◽  
Minimum Risk ◽  
Failure Data ◽  
Degree Of Damage ◽  
The Individual

Wind direction and speed are the most important factors that determine the degree of damage caused by a jet fire. In this study, the metal hose used to extract/supply fuel was identified as the component with the highest risk for a jet fire occurring at an aerospace facility. A risk assessment was performed to evaluate the individual risk of a jet fire from the metal hose according to the wind direction and speed. HSE failure data was applied for calculating the jet fire probability including metal hose failure, ignition frequency, and jet fire frequency. Which was 3.0 × 10−4. The individual risk of different fatality probabilities was calculated according to the wind rose data for the aerospace facility. The individual risk from jet fire in the aerospace facility was calculated with a maximum risk of 3.35 × 10−5 and a minimum risk of 1.49 × 10−6. The individual risk satisfied HSE ALARP criteria. In addition, firewalls, extinguishing systems, and an emergency shut off system were enhanced, and it was thought that the risk from jet fire could satisfy acceptable criteria.

Safety Risk Acceptance Criteria for Pipelines

2020 ◽  
Author(s):  
Maher Nessim ◽  
Shahani Kariyawasam
Keyword(s):  
Risk Assessment ◽  
Oil And Gas ◽  
Task Force ◽  
Quantitative Risk Assessment ◽  
Background Information ◽  
Individual Risk ◽  
Acceptance Criteria ◽  
Safety Risk ◽  
Wide Range ◽  
Societal Risk

Abstract The lack of established acceptance criteria has been one of the key challenges to the application of quantitative risk assessment (QRA) techniques in the Canadian pipeline industry. While a wide range of such criteria have been developed and published, it remains difficult for most operators to commit to specific criteria because such criteria may not be acceptable to all stakeholders. Recognizing this limitation, the Canadian Standards Association formed a Risk Management Task Force (RMTF) under the Technical Committee for the Z662 Standard on the Oil and Gas Pipeline Systems to propose criteria for potential inclusion in its non-mandatory Annex on Risk Assessment. This paper describes the criteria that have been developed by the RMTF and provides the background information needed for users to understand and use them correctly. The discussion includes: a summary of the measures used to quantify the safety risk associated with an ignited product release; a summary of established international and Canadian criteria that have been considered; a description and interpretation of the ALARP (As Low As Reasonably Practicable) principle; and the rationale used by the RMTF to select specific individual risk and societal risk criteria for CSA Z662. The proposed criteria are also compared to the criteria underpinning other risk-based parts of the Z662 Standard, including Annexes C and O. Guidance is provided on the analysis assumptions, methods and parameters required to ensure that the risk calculations produce results that are consistent with the definition and intent of the criteria. Key issues addressed by the guidance include the definition of individual risk (i.e. location risk versus personal risk), the pipeline length over which the frequency versus number of fatalities (F-N) relationship representing societal risk is calculated, and the effect of population density averaging over the pipeline length.

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