Long term ground movement of TRISTAN synchrotron

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

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.

Observed ground and pile group responses due to tunneling in Bangkok stiff clay

2014 ◽  
Vol 51 (5) ◽  
pp. 479-495 ◽  
Author(s):  
Thayanan Boonyarak ◽  
Kullapat Phisitkul ◽  
Charles W.W. Ng ◽  
Wanchai Teparaksa ◽  
Zaw Zaw Aye
Keyword(s):  
Penetration Rate ◽  
Pile Group ◽  
Ground Movement ◽  
Pressure Balance ◽  
Soil Extraction ◽  
Influence Zone ◽  
Tunnel Face ◽  
Overburden Pressure ◽  
Stiff Clay

A 5.15 m diameter water diversion tunnel was driven into Bangkok stiff clay using an earth pressure balance shield. The tunnel was driven within a clear distance of 2 m from the closest pile of a 3 × 4 pile group supporting an expressway. During construction, tunnel driving parameters as well as induced ground and pile group responses were recorded. To avoid cutting the piles supporting the expressway, the alignment of the tunnel was adjusted and curved. As a result of this change in tunnel alignment, the tunnel advancing rate was reduced from an average 17 m/day for a straight drive to an average of only 6 m/day for the curved alignment, and the ratio between the tunnel face pressure and overburden pressure was changed from 0.5 to 0.4, accordingly. Due to the reduction of the tunnel face pressure, up to a 280% larger inward ground movement towards the tunnel was observed. As the shield penetration rate decreased, the torque required for tunnel driving was reduced by 33%, while the ratio between shield penetration rate and soil extraction was almost constant throughout the tunnel route. A transverse influence zone due to tunnel driving was identified to extend up to a distance that was twice the tunnel diameter radially from the longitudinal tunnel axis. The maximum tilting of the expressway pier and deduced differential settlement of the pile located within the influence zone were up to 1:2600 and 2.0 mm, respectively. Tilting of all the piers was mainly caused by long-term subsurface settlement having the tilting direction towards the tunnel. This long-term subsurface settlement was up to about 80% of the total.

Pipeline Maintenance in Geotechnically Unstable Areas: A Case Study

2000 ◽  
Author(s):  
Michelle L. Sorensen
Keyword(s):  
Risk Mitigation ◽  
Probability Distributions ◽  
Slope Instability ◽  
Ground Movement ◽  
Data Uncertainty ◽  
Strain Gauges ◽  
Mitigation Options ◽  
Soil Movement ◽  
Fort Mcmurray

The 22″ Alberta Oilsands Pipeline transports synthetic crude oil from Syncrude Canada Limited in Fort McMurray to Edmonton, Alberta. The pipeline crosses the House River approximately 100 kilometers south of Fort McMurray. The slope has been monitored since 1991 by three slope indicators. A finite element stress analysis indicated that total ground movement since installation in 1977 could correspond to pipeline compressive strains in excess of 0.32%, a level of risk unacceptable to the pipeline owner. A probability-based model was developed to determine cost and benefit of risk mitigation options. Parameters such as soil movement and pipe strain were input as probability distributions. The mitigation options included: reduce slope instability; reduce pipe stress; reduce pipe-to-soil interaction; implement long term monitoring; determine current pipe strain level (to decrease data uncertainty); do nothing. A Monte Carlo simulation was used to establish probability of failure and probable cost distributions for each option. The results were presented as a combined cost of failure and mitigation over 10 years. The analysis indicated that the optimum solution was to remove the existing soil traction loading on the pipe and mitigate long-term slope movement. The decision was made to relieve the pipe strain by excavating. Current pipe strain was measured in situ using residual strain measurement. Long term strain gauges were installed. Slope mitigation was deferred until the strain gauges indicate total pipeline strain levels approaching 0.32%.

Stress Analysis of Lifting and Lowering-In Process

2014 ◽  
Author(s):  
Fan Zhang ◽  
Ming Liu ◽  
Yong-Yi Wang ◽  
William A. Bruce
Keyword(s):  
Vertical Plane ◽  
Ground Movement ◽  
Lateral Movement ◽  
Combined Stress ◽  
Acceptance Criteria ◽  
Element Analysis ◽  
Bending Stresses ◽  
Cross Country ◽  
Potential Damage

For typical cross-country pipelines not expected to experience ground movement hazards, the longitudinal stresses experienced during lifting and lowering-in are typically the highest that they experience in their entire service life. Vertical bending stresses are produced by the curvature created from the upward lifting forces of the sidebooms and the downward force of the pipe weight. Horizontal bending stresses are produced due to the lateral movement of the pipe when the pipe string is moved from its support position on the side of trench to the center of the trench. It is critical to limit the stresses during lifting and lowering-in so that potential damage to the pipeline is avoided. For pipelines constructed using an engineering critical assessment (ECA) based flaw acceptance criteria, stresses must be controlled below the limit established during the development of the flaw acceptance criteria. However, there is little in the way of formal guidance in current codes and standards for controlling stresses during the lifting and lowering-in process. This paper is part of a long-term effort being sponsored primarily by Pipeline Research Council International (PRCI) to develop general construction guidelines that can be used to manage lifting and lowering-in stresses during pipeline construction. In this paper, the stresses during lifting and lowering-in on normally flat terrain were studied. The component of stress due to bending in the horizontal plane was determined through an analytical method. The component of stress due to the bending in the vertical plane was studied by finite element analysis (FEA). The FEA determined the stresses under various profiles. Recommended lifting profiles in the format of lifting height ranges were developed. The combined stress was then determined from the two components. In addition, FEA was used to simulate the lifting and lowering-in process of a pipe string including a field side bend. The results show that the side bend produces a very slight increase in the stress level. More work is being performed to investigate various other scenarios of field and pipe string conditions.

scholarly journals Modeling of land subsidence caused by groundwater withdrawal in Konya Closed Basin, Turkey

2020 ◽  
Vol 382 ◽  
pp. 397-401
Author(s):  
Ahmed Wedam Ahmed ◽  
Ekrem Kalkan ◽  
Artur Guzy ◽  
Mine Alacali ◽  
Agnieszka Malinowska
Keyword(s):  
Groundwater Flow ◽  
Land Subsidence ◽  
Underground Mining ◽  
Model Development ◽  
Ground Movement ◽  
Groundwater Withdrawal ◽  
Local Conditions ◽  
Closed Basin ◽  
Fine Grained

Abstract. Land subsidence is a threat that occurs worldwide as a result of the withdrawal of fluid and also underground mining. The subsidence is mainly due to excessive groundwater withdrawal from certain types of rocks, such as fine-grained sediments. Mitigating the effects of land subsidence generally requires careful observations of the temporal change in groundwater level and ideally modeling of groundwater flow and subsidence. In Turkey, land subsidence is a crucial issue in the Konya Closed Basin. When simulating the effect of long-term groundwater withdrawal on the spatial variation of subsidence rates, various coupled numerical groundwater-flow and subsidence models have been used. Also, GPS, InSAR and ENVISAT SAR images have been used for verification of the models' parameters. In the work reported here, a novel numerical solution based on consolidation theory was developed in MATLAB to predict the land subsidence of the Konya Closed Basin. In order to adjust the model to the local conditions, historical data from the study area for the years 2011–2014 were used. The presented solution allowed for subsidence model development which can support the prediction of the ground movement for the Konya Closed Basin in Turkey.

Enbridge Northern Pipeline: 25 Years of Operation, Successes and Challenges

2010 ◽  
Author(s):  
Ingrid Pederson ◽  
Millan Sen ◽  
Andrew Bidwell ◽  
Nader Yoosef-Ghodsi
Keyword(s):  
Crude Oil ◽  
Ground Movement ◽  
Oil Pipeline ◽  
Ground Temperatures ◽  
Geotechnical Monitoring ◽  
Discontinuous Permafrost ◽  
Long Term Trends ◽  
Slope Instabilities ◽  
Successes And Challenges

Enbridge Pipelines Inc. has operated a 324 mm diameter, 870 km crude oil pipeline from Norman Wells, Northwest Territories to Zama, Alberta since 1985. This pipeline is the first completely buried oil pipeline constructed within the discontinuous permafrost zone of Canada. This pipeline was constructed over two winter seasons, and since 1985 has transported roughly 200 million barrels of crude oil to southern markets without significant interruption. This paper will review the design, construction, and operational challenges of this pipeline through the past 25 years. Unique and innovative aspects of this pipeline include measures taken during construction to minimize thermal disturbance to the soil, insulating permafrost slopes to minimize post-construction thaw, operating at temperatures that minimize thermal effects on the surrounding ground, accommodating ground movement caused by frost heave/thaw and slope instabilities, and evaluating the effects of moving water bodies adjacent to the pipeline right-of-way. The use of in-line inspection tools (GEOPIG) has been valuable as a supplement to conventional geotechnical monitoring, for the evaluation and assessment the effects of ground movement to the pipeline. Finite element pipe/soil interaction models have been developed for selected sites in order to assess the potential for slope movement to generate strains in the buried pipeline that exceed the strain capacity. This paper will review new monitoring data and findings since previous publications. In addition, the implications of long-term trends of increasing ground temperatures and associated changes to the geotechnical and permafrost conditions along the pipeline route will also be discussed and are relevant to other proposed pipeline and linear infrastructure projects along the Mackenzie Valley.

Structured Response Plan After a Ground Movement Event

2020 ◽  
Author(s):  
Yong-Yi Wang ◽  
Dunji Yu ◽  
Mike Cook
Keyword(s):  
Phase 1 ◽  
Ground Movement ◽  
Specific Information ◽  
Buried Pipelines ◽  
Phase 3 ◽  
Response Plan ◽  
A Company ◽  
Term Management ◽  
Full Pressure

Abstract The vast majority of buried pipelines are not designed to accommodate significant localized ground movement caused by landslides, earthquakes, or subsidence/settlement. When a ground movement event occurs along the ROW of a buried pipeline, it is imperative that the pipeline operator determine whether the ground movement is a threat to pipeline integrity to protect those responding to the event, those living near the affected ROW, and the environment. This paper covers the development of a response plan that provides guidance to pipeline operators responding to a ground movement event while considering the unique conditions associated with such events. The response plan covers some critical decisions after an event, including, but not limited to (1) whether the event affects the pipeline, the local ROW, or those living adjacent to the ROW, (2) control of flow, i.e., the need for shutdown or pressure reduction, and (3) work needed to return the line to full-pressure service. The overall response plan is presented in three main phases: • Phase 1: Immediate Response, • Phase 2: Follow-on Assessment and Actions, and • Phase 3: Long-term Management. The structured response plan and associated guidance are presented in a self-contained stand-alone document available from PRCI. Parts of the document or the entire document can be adopted by operators, depending on the extent of existing procedures an operator may have. Alternatively, company-specific information and procedures can be added to the document to form a company-specific SOP.

Therapy and prevention for mental health: What if mental diseases are mostly not brain disorders?

2019 ◽  
Vol 42 ◽  
Author(s):  
John P. A. Ioannidis
Keyword(s):  
Mental Health ◽  
Mental Disease ◽  
Brain Disorders ◽  
Social Stressors ◽  
Labor Education ◽  
Mental Diseases ◽  
Long Term Follow Up ◽  
Political Decisions

AbstractNeurobiology-based interventions for mental diseases and searches for useful biomarkers of treatment response have largely failed. Clinical trials should assess interventions related to environmental and social stressors, with long-term follow-up; social rather than biological endpoints; personalized outcomes; and suitable cluster, adaptive, and n-of-1 designs. Labor, education, financial, and other social/political decisions should be evaluated for their impacts on mental disease.

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