scholarly journals Influence of Frost Heave and Thaw Settlement of Connected Aisle on Tunnel Structure

2019 ◽  
Vol 1176 ◽  
pp. 042027
Author(s):  
Yanxi Zhao
Keyword(s):  
Frost Heave ◽  
Tunnel Structure ◽  
Thaw Settlement

Permafrost Hazard of MoHe-DaQing Crude Oil Pipeline

2013 ◽  
Vol 734-737 ◽  
pp. 2659-2663
Author(s):  
Yun Bin Ma ◽  
Dong Jie Tan ◽  
Hong Yuan Jing ◽  
Quan Xue ◽  
Cheng Zhi Zhang
Keyword(s):  
Crude Oil ◽  
The Other ◽  
Frost Heave ◽  
Permafrost Soil ◽  
Buried Pipeline ◽  
Soil Frost ◽  
Plastic Deformations ◽  
Oil Pipeline ◽  
Thaw Settlement ◽  
Slope Instabilities

The crude oil pipeline from MoHe to DaQing (hereafter called Mo-Da pipeline) is part of China-Russia oil pipeline. Mo-Da pipeline is the first pipeline that through high latitude cold regions of China. The pipeline is in so complicated geography environment that many kinds of permafrost hazard are easily to happen including frost heave, thaw settlement, slope instabilities, and collapse and so on. The pipeline and the permafrost act and react upon one another. On one hand, soil frost heave and thaw settlement can produce extra stresses on pipe walls, which may result in centralized stresses and plastic deformations under certain conditions, even causes pipeline faults. On the other hand, buried pipeline will disturb ambient environment and then degrade the permafrost soil and finally impact safety of the pipeline. This paper mainly introduces the permafrost hazards of Mo-Da pipeline and demonstrates some methods for monitoring the influence of permafrost.

Influence of Moisture Content to the Freeze-Thaw Performance of Roadbed in High-Cold Areas

2013 ◽  
Vol 442 ◽  
pp. 342-345 ◽  
Author(s):  
Qiao Ling Wu ◽  
Yong Sheng ◽  
Feng Xie
Keyword(s):  
Moisture Content ◽  
Optimum Moisture Content ◽  
Frozen Soil ◽  
Frost Heave ◽  
Document Code ◽  
Freeze Thaw ◽  
Subgrade Soil ◽  
The Common ◽  
Thaw Settlement ◽  
The Stability

Frost-heave and thaw-settlement of roadbed soil in highway will influence directly the durability, safe traffic flow and construction & maintenance costs in high-cold areas, therefore, recognizing and analysing the common embankment technologies of highway roadbed in high-cold areas accurately is significant to the effective controlling of project invest and the highway construction with limited funds in minority areas. The relations of Moisture Content and the freeze-thaw performances of roadbed fillers, subgrade soil were got respectively by experiments, and the results shows: Moisture Content has larger influence on the frost-heave and thaw-settlement performance of the soil. During the embankment of roadbed, the Moisture Content of fillers should be controlled nearby the optimum Moisture Content. The frost-heave and thaw-settlement occurs mainly in the subgrade soil, controlling the Moisture Content of subgrade soil is very important to improve the up-limit of frozen-soil, keep the stability of frozen-soil, control the thaw-settlement of roadbed and get rid of the roadbed diseases. CLC: U416.1 Document code: B

scholarly journals Frost heave and thaw settlement of initially saturated-slurried and compacted-saturated materials

2020 ◽  
Vol 195 ◽  
pp. 03036
Author(s):  
Snehasis Tripathy ◽  
Osama Mahdi Al-Hussaini ◽  
Peter John Cleall ◽  
Stephen William Rees ◽  
Han-Lin Wang
Keyword(s):  
Laboratory Tests ◽  
Initial Conditions ◽  
Frost Heave ◽  
Freezing Process ◽  
Cement Kiln ◽  
Freezing And Thawing ◽  
Custom Made ◽  
Thawing Processes ◽  
Thaw Settlement ◽  
Study Laboratory

Soils and industrial waste in various geotechnical engineering applications are expected to experience freezing and thawing processes in various regions of the world where the winter and summer temperatures fluctuate between sub-zero and positive ambient temperatures. In this study laboratory tests were undertaken on three materials (Speswhite kaolin, Pegwell Bay soil and a cement kiln dust). A custom-made test set up was used to carry out the laboratory tests involving freezing and thawing processes. Initially saturated-slurried and compacted-saturated samples of the selected materials were subjected to one cycle of freezing and thawing to study the influence of material type and initial conditions on the one-dimensional frost heave and thaw settlement. The test results showed that the type of material and the initial conditions of the materials prior to the freezing process influenced the frost heave, frost heave rate, velocity of water flow, segregation potential, and thaw settlement. Compacted-saturated materials showed a tendency to exhibit a greater magnitude of frost heave as compared to their saturated-slurried counterparts.

scholarly journals Stability of the Foundation of Buried Energy Pipeline in Permafrost Region

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Yan Li ◽  
Huijun Jin ◽  
Zhi Wen ◽  
Xinze Li ◽  
Qi Zhang
Keyword(s):  
Mitigation Strategies ◽  
Slope Instability ◽  
Frost Heave ◽  
Mitigation Measures ◽  
Formation Mechanisms ◽  
Permafrost Region ◽  
Buried Pipelines ◽  
Foundation Soil ◽  
Thaw Settlement ◽  
Permafrost Regions

During operation, a buried pipeline is threatened by a variety of geological hazards, particularly in permafrost regions, where freezing-thawing disasters have a significant influence on the integrity and safety of the buried pipelines. The topographical environmental conditions along the pipeline, as well as the influence of frost heave and thaw settlement on the pipeline’s foundation soil, must be considered in the design and construction stage. Theoretical analysis, numerical modeling, field testing, and mitigation measures on vital energy pipelines in permafrost have been widely documented, but no attempt has been made to review the freezing-thawing disasters, current research methodologies, and mitigation strategies. This article reviews the formation mechanisms and mitigation measures for frost hazards (e.g., differential frost heave, thaw settlement, slope instability, frost mounds, icing, river ice scouring, and pipeline floating) along buried pipelines in permafrost regions and summarizes and prospects the major progress in the research on mechanisms, analysis methods, model test, and field monitoring based on publications of studies of key energy pipelines in permafrost regions. This review will provide scholars with a basic understanding of the challenging freezing-thawing hazards encountered by energy pipelines in permafrost regions, as well as research on the stability and mitigation of pipeline foundation soils plagued by freezing-thawing hazards in permafrost regions under a warming climate and degrading permafrost environment.

Pipelines in permafrost: geotechnical issues and lessons 12010 R.M. Hardy Address, 63rd Canadian Geotechnical Conference.

2011 ◽  
Vol 48 (9) ◽  
pp. 1412-1431 ◽  
Author(s):  
James M. Oswell
Keyword(s):  
Slope Stability ◽  
Frost Heave ◽  
Terrain Mapping ◽  
Upheaval Buckling ◽  
Technical Developments ◽  
History Of ◽  
Key Issues ◽  
Thaw Settlement ◽  
Design Construction ◽  
Permafrost Regions

Geotechnical input to the design, construction, and operations of pipelines in permafrost may differ significantly from that for pipelines in temperate terrain. The general remoteness and terrain fragility of permafrost regions are key issues that challenge the geotechnical input. Specific geotechnical issues that necessitate input include pipeline routing, slope stability, thaw settlement and frost heave, ditching, buoyancy control, upheaval buckling. and others. This paper examines the history of pipeline development in Canada north of the 60th latitude and highlights some key design issues and some of the technical developments over the past 40 years of design, construction, and operations of pipelines in permafrost regions. Advances have been made in areas such as geothermal modeling, slope stability assessments, terrain mapping technologies, thaw settlement and frost heave prediction, and predicting and monitoring pipeline strain demand.

Case study: frost heave and thaw settlement under an ice rink

2017 ◽  
Vol 4 (2) ◽  
pp. 103-112 ◽  
Author(s):  
Gowthaman Sinnathamby ◽  
Henry Gustavsson ◽  
Leena Korkiala-Tanttu ◽  
Carles Perez Cervera ◽  
Mirva Koskinen
Keyword(s):  
Frost Heave ◽  
Thaw Settlement

Norman Wells pipeline settlement and uplift movements

1999 ◽  
Vol 36 (1) ◽  
pp. 119-135 ◽  
Author(s):  
JF (Derick) Nixon ◽  
Margo Burgess
Keyword(s):  
Structural Model ◽  
Strain Analysis ◽  
Frost Heave ◽  
Low Density ◽  
Oil Pipeline ◽  
The North ◽  
Bending Strain ◽  
Uplift Zone ◽  
Thaw Depth ◽  
Thaw Settlement

The Norman Wells oil pipeline has been operating successfully since 1985. The pipe was designed to operate as an ambient-temperature pipeline and accommodate up to 0.8 m of thaw settlement in inorganic terrain. The pipeline has settled close to this amount in some areas, without excessive straining of the pipe. An average thaw strain for the soil back-calculated from the thaw depth and resulting thaw settlement at several sites gives average values of 16-20%. At one location (kilometre post 5.2), the pipeline has experienced uplift of 1.1 m or more. The mechanism for pipe movement is likely a combination of high axial stresses and some small initial frost heave, which triggered uplift buckling of the pipe. Low-density thawed soils contributed to this behavior. An internal profiling device (Geopig) has been run through the pipe in recent years. Analysis of the profiles indicates excellent agreement with manual surveys at the site. The pipe is experiencing about 0.3% bending strain in the uplift zone, and about 0.4% strain in a settling area immediately to the north. Pipe strain analysis using a structural model indicates that about 0.2 m of frost heave would be required to initiate uplift buckling over a critical heave length of 22-25 m.

Pipeline Geohazards Unique to Northern Climates

2006 ◽  
Author(s):  
Rupert G. Tart
Keyword(s):  
Active Layer ◽  
Heat Removal ◽  
Heat Pipes ◽  
Large Earthquake ◽  
Frost Heave ◽  
Near Surface ◽  
Slope Movements ◽  
Discontinuous Permafrost ◽  
Thaw Settlement ◽  
The Impact

Pipelines in northern climates can be impacted by geohazards that are unique to cold regions. Some of these include frost heave, thaw settlement, solifluction, icings, glaciers, ice-rich slopes, and others. This paper will discuss most of these geohazards as they have been monitored, mitigated, and managed along the Trans Alaska Pipeline (TAPS) and other pipelines in Alaska and Russia. Early analyses of frost heave and thaw settlement of piles concluded that frost heave and thaw settlement would be controlled by installing passive heat removal devices (heat pipes). In permafrost areas heat pipes have generally worked well. In unfrozen terrain or discontinuous permafrost the heat pipes have not been able to maintain stability. Examples of each of these situations will be discussed. Steep rolling terrain makes up a significant part of the TAPS route. Some of the slopes are in permafrost and others are in thawed ground. For the past 15 years, surveillance and monitoring of some of the slopes along the pipeline route has documented the response of slopes in frozen ground. Warmer (that is near 0 degrees C) ice-rich slopes can creep. An example of this is documented on a slope instrumented with inclinometers and thermistors. Other slope movements related to pore pressure increases caused by active layer containment of unfrozen groundwater flows will be discussed. The impact of solifluction zones on pipeline construction and routing will be addressed as it has been managed along the TAPS. Other near surface slope movements that appear to be similar to solifluction have been observed along the pipeline right-of-way on the workpad. This paper will address an interrelationship of these observed slope behaviors. In doing this the interaction of slope seeps and the freeze front as it forms in fall and then recedes in spring and summer is compared to observations of engineered projects. Icings can be observed in several locations along TAPS. In some cases these can be related to slope movements. In other cases the icings have reached the aboveground and caused maintenance issues. TAPS was designed to avoid future surges of several large glaciers. In most years these glaciers have retreated and have not been a significant issue. A recent large earthquake caused a landslide on the largest glacier near TAPS and resulted in some review of the activity on that glacier. In 2002 a large earthquake centered near TAPS caused liquefaction in some areas, breakage of ice in lakes in some locations, and sand boils very close to the pipe. These observations will be related to the thinly frozen active layer over a deep talik during the earthquake.

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