Experimental Studies of Pipeline Uplift Resistance in Frozen Ground

2004 ◽  
Author(s):  
Bill Liu ◽  
Jack Crooks ◽  
J. F. (Derick) Nixon ◽  
Joe Zhou
Keyword(s):  
Experimental Studies ◽  
Soil Surface ◽  
Mechanical Tests ◽  
Frozen Soil ◽  
Frost Heave ◽  
Frozen Ground ◽  
Frozen Soils ◽  
Uplift Resistance ◽  
Load Displacement ◽  
The Impact

A buried pipeline is subject to a variety of internal and external loads, one of which is the load induced by relative movements between the pipeline and the surrounding soils. Frost heave is one of the potential mechanisms that induce the relative movement for buried pipelines of chilled gas. The magnitude of the loads due to frost heave depends upon the amount of heaving and the load-displacement characteristics of the surrounding frozen soils, i.e., the uplift resistance of the frozen soils. Under the sponsorship of Pipeline Research Council International (PRCI), laboratory uplift tests have been carried out to study the load-displacement characteristics of a frozen soil and to assess the impact of loading rate, ice content and freezing direction. In addition to the measurements of the load and displacement of the pipe, deformations of the soil surface were also monitored at various locations. Parallel to the uplift tests, a series of laboratory geo-mechanical tests were conducted to define stiffness, tensile strain limits and time-dependent behavior of the frozen soil. Examples of the uplift test results are presented in the paper, together with detailed descriptions of soil material and test conditions. It is noted that quantitative data on uplift resistance are considered proprietary and will not be presented in this paper; however, detailed data may be obtained from technical publications of PRCI. Observations during the test with respect to the development of cracks in the frozen soil will be discussed. The load-displacement relationships measured in the uplift tests, together with the geo-mechanical properties of the frozen soil, will be used to the development and calibration of a numerical model, which will be presented in a separate technical paper to IPC2004.

Numerical Studies of Pipeline Uplift Resistance in Frozen Ground

2004 ◽  
Author(s):  
Bill Liu ◽  
Karen Moffitt ◽  
J. F. (Derick) Nixon ◽  
Joe Zhou ◽  
Yuxing Xiao
Keyword(s):  
Numerical Model ◽  
Design Tool ◽  
Frozen Soil ◽  
Frost Heave ◽  
Sensitivity Analyses ◽  
Relative Movement ◽  
Frozen Ground ◽  
Discontinuous Permafrost ◽  
Uplift Resistance ◽  
Load Displacement

A buried pipeline is subject to a variety of internal and external loads, one of which is the load induced by relative movement between the pipeline and the surrounding soils. Frost heave is one of the potential mechanisms that induce the relative movement for buried pipelines of chilled gas. The magnitude of the loads due to frost heave depends upon the amount of heaving and the load-displacement characteristics of the surrounding frozen soils, i.e., the uplift resistance of the soils. Under the sponsorship of Pipeline Research Council International (PRCI), laboratory uplift tests have been carried out to study the load-displacement characteristics of a frozen soil. In parallel, a series of laboratory geo-mechanical tests were conducted to define stiffness, tensile strain limits and time-dependent features of the frozen soil. A numerical model, using the geo-mechanical properties of the frozen soil as input parameters, has been developed. The numerical model is intended to be used as a tool primarily for sensitivity analyses and scaling of the results of the laboratory uplift tests to field operations, which are anticipated to have pipe diameters in a range of 5 to 10 times of the laboratory tests. A description of the numerical model is provided in the paper. The load-displacement relationships and failure mechanisms represented in the numerical model are compared with the measurements and observations made during the laboratory uplift tests (quantitative data on uplift resistance are considered proprietary and will not be presented, but detailed data may be obtained from technical publications of PRCI). After being calibrated, the numerical model can be used for sensitivity analyses, and also potentially used as a design tool for pipelines in discontinuous permafrost.

scholarly journals Experimental Studies on Frozen Soil

2021 ◽  
Author(s):  
Kshitij Gaur ◽  
Anil Kumar Sahu
Keyword(s):  
Room Temperature ◽  
Void Ratio ◽  
Experimental Studies ◽  
Soil Surface ◽  
Negative Temperature ◽  
Research Data ◽  
Frozen Soil ◽  
Soil Parameters ◽  
Frozen Soils ◽  
Zero Degree

Abstract Various studies have been carried out for soils at normal room temperature but the studies on frozen soils are meagre. For every construction, soil investigation is the most important and the primary step for a site. For constructions at normal room temperature, there are plenty of experimentation and research data on soil is available. But lack of research data for colder regions, where the ambient temperature is below zero degree Celsius for most of the time. It is therefore the need to study soil under iced condition to get a better idea about the behaviour of frozen soils. There are few research on construction and mechanical behaviour of frozen soil but no study on the very basic parameters of like void ratio, bulk density, porosity, and the degree of freezing and how these parameters change as the soil temperature changes from normal room temperature to negative values. The main emphasis is on the study and experimentation on frozen soil and to formulate different relationships between individual soil parameters at various temperatures. The methodology used is to model the soil surface (open grounds in colder regions) by taking sand as the soil after sieving. The model samples are taken into beakers with different bulk densities to replicate real site condition in the freezer. Then by calculating factors like density, porosity, void ratio, etc at negative temperature (-5, -10, -15, -20 degree Celsius) and forming relationship with same parameters with that on room temperature. The experimental data obtained is used in “Eureqa software” that will utilize the input so provided and will find mathematical relation that exist in the soil parameters.

scholarly journals Experimental Studies on Frozen Soil

2021 ◽  
Author(s):  
Kshitij Gaur ◽  
Anil Kumar Sahu
Keyword(s):  
Room Temperature ◽  
Void Ratio ◽  
Experimental Studies ◽  
Soil Surface ◽  
Negative Temperature ◽  
Research Data ◽  
Frozen Soil ◽  
Soil Parameters ◽  
Frozen Soils ◽  
A Site

Abstract Various studies have been carried out for soils at normal room temperature but the studies on frozen soils are meagre. For every construction, soil investigation is the most important and the primary step for a site. For constructions at normal room temperature, there is plenty of experimentation and research data on soil is available. But lack of research data for colder regions, where the ambient temperature is below zero degrees Celsius for most of the time. It is therefore the need to study soil under the iced condition to get a better idea about the behaviour of frozen soils. There is little research on the construction and mechanical behaviour of frozen soil but no study on the very basic parameters like void ratio, bulk density, porosity, and the degree of freezing and how these parameters change as the soil temperature changes from normal room temperature to negative values. The main emphasis is on the study and experimentation of frozen soil and the formulation of different relationships between individual soil parameters at various temperatures. The methodology used is to model the soil surface (open grounds in colder regions) by taking sand as the soil after sieving. The model samples are taken into beakers with different bulk densities to replicate real site conditions in the freezer. Then by calculating factors like density, porosity, void ratio, etc at negative temperature (-5, -10, -15, -20 degree Celsius) and forming a relationship with the same parameters as that on room temperature. The experimental data obtained is used in “Eureqa software” that will utilize the input so provided and will find mathematical relations that exist in the soil parameters.

scholarly journals Experimental Studies on Frozen Soil

2021 ◽  
Author(s):  
Kshitij Gaur ◽  
Anil Kumar Sahu
Keyword(s):  
Room Temperature ◽  
Void Ratio ◽  
Experimental Studies ◽  
Soil Surface ◽  
Negative Temperature ◽  
Research Data ◽  
Frozen Soil ◽  
Soil Parameters ◽  
Frozen Soils ◽  
Zero Degree

Abstract Various studies have been carried out for soils at normal room temperature but the studies on frozen soils are meagre. For every construction, soil investigation is the most important and the primary step for a site. For constructions at normal room temperature, there are plenty of experimentation and research data on soil is available. But lack of research data for colder regions, where the ambient temperature is below zero degree Celsius for most of the time. It is therefore the need to study soil under iced condition to get a better idea about the behaviour of frozen soils. There are few research on construction and mechanical behaviour of frozen soil but no study on the very basic parameters of like void ratio, bulk density, porosity, and the degree of freezing and how these parameters change as the soil temperature changes from normal room temperature to negative values. The main emphasis is on the study and experimentation on frozen soil and to formulate different relationships between individual soil parameters at various temperatures. The methodology used is to model the soil surface (open grounds in colder regions) by taking sand as the soil after sieving. The model samples are taken into beakers with different bulk densities to replicate real site condition in the freezer. Then by calculating factors like density, porosity, void ratio, etc at negative temperature (-5, -10, -15, -20 degree Celsius) and forming relationship with same parameters with that on room temperature. The experimental data obtained is used in “Eureqa software” that will utilize the input so provided and will find mathematical relation that exist in the soil parameters.

scholarly journals Experimental Studies on Frozen Soil

2021 ◽  
Author(s):  
Kshitij Gaur ◽  
Anil Kumar Sahu
Keyword(s):  
Room Temperature ◽  
Void Ratio ◽  
Experimental Studies ◽  
Soil Surface ◽  
Negative Temperature ◽  
Research Data ◽  
Frozen Soil ◽  
Soil Parameters ◽  
Frozen Soils ◽  
A Site

Abstract Various studies have been carried out for soils at normal room temperature but the studies on frozen soils are meagre. For every construction, soil investigation is the most important and the primary step for a site. For constructions at normal room temperature, there is plenty of experimentation and research data on soil is available. But lack of research data for colder regions, where the ambient temperature is below zero degrees Celsius for most of the time. It is therefore the need to study soil under the iced condition to get a better idea about the behaviour of frozen soils. There is little research on the construction and mechanical behaviour of frozen soil but no study on the very basic parameters like void ratio, bulk density, porosity, and the degree of freezing and how these parameters change as the soil temperature changes from normal room temperature to negative values. The main emphasis is on the study and experimentation of frozen soil and the formulation of different relationships between individual soil parameters at various temperatures. The methodology used is to model the soil surface (open grounds in colder regions) by taking sand as the soil after sieving. The model samples are taken into beakers with different bulk densities to replicate real site conditions in the freezer. Then by calculating factors like density, porosity, void ratio, etc at negative temperature (-5, -10, -15, -20 degree Celsius) and forming a relationship with the same parameters as that on room temperature. The experimental data obtained is used in “Eureqa software” that will utilize the input so provided and will find mathematical relations that exist in the soil parameters.

scholarly journals Experimental Studies on Frozen Soil

2021 ◽  
Author(s):  
Kshitij Gaur ◽  
Anil Kumar Sahu
Keyword(s):  
Room Temperature ◽  
Void Ratio ◽  
Experimental Studies ◽  
Soil Surface ◽  
Negative Temperature ◽  
Research Data ◽  
Frozen Soil ◽  
Soil Parameters ◽  
Frozen Soils ◽  
A Site

Abstract Various studies have been carried out for soils at normal room temperature but the studies on frozen soils are meagre. For every construction, soil investigation is the most important and the primary step for a site. For constructions at normal room temperature, there is plenty of experimentation and research data on soil is available. But lack of research data for colder regions, where the ambient temperature is below zero degrees Celsius for most of the time. It is therefore the need to study soil under the iced condition to get a better idea about the behaviour of frozen soils. There is little research on the construction and mechanical behaviour of frozen soil but no study on the very basic parameters like void ratio, bulk density, porosity, and the degree of freezing and how these parameters change as the soil temperature changes from normal room temperature to negative values. The main emphasis is on the study and experimentation of frozen soil and the formulation of different relationships between individual soil parameters at various temperatures. The methodology used is to model the soil surface (open grounds in colder regions) by taking sand as the soil after sieving. The model samples are taken into beakers with different bulk densities to replicate real site conditions in the freezer. Then by calculating factors like density, porosity, void ratio, etc at negative temperature (-5, -10, -15, -20 degree Celsius) and forming a relationship with the same parameters as that on room temperature. The experimental data obtained is used in “Eureqa software” that will utilize the input so provided and will find mathematical relations that exist in the soil parameters.

scholarly journals Effects of preferential flow on snowmelt partitioning and groundwater recharge in frozen soils

2019 ◽  
Vol 23 (12) ◽  
pp. 5017-5031 ◽  
Author(s):  
Aaron A. Mohammed ◽  
Igor Pavlovskii ◽  
Edwin E. Cey ◽  
Masaki Hayashi
Keyword(s):  
Soil Moisture ◽  
Groundwater Recharge ◽  
Preferential Flow ◽  
Frozen Soil ◽  
Time Lags ◽  
Runoff Generation ◽  
Frozen Ground ◽  
Soil Matrix ◽  
Frozen Soils ◽  
Flow Through

Abstract. Snowmelt is a major source of groundwater recharge in cold regions. Throughout many landscapes snowmelt occurs when the ground is still frozen; thus frozen soil processes play an important role in snowmelt routing, and, by extension, the timing and magnitude of recharge. This study investigated the vadose zone dynamics governing snowmelt infiltration and groundwater recharge at three grassland sites in the Canadian Prairies over the winter and spring of 2017. The region is characterized by numerous topographic depressions where the ponding of snowmelt runoff results in focused infiltration and recharge. Water balance estimates showed infiltration was the dominant sink (35 %–85 %) of snowmelt under uplands (i.e. areas outside of depressions), even when the ground was frozen, with soil moisture responses indicating flow through the frozen layer. The refreezing of infiltrated meltwater during winter melt events enhanced runoff generation in subsequent melt events. At one site, time lags of up to 3 d between snow cover depletion on uplands and ponding in depressions demonstrated the role of a shallow subsurface transmission pathway or interflow through frozen soil in routing snowmelt from uplands to depressions. At all sites, depression-focused infiltration and recharge began before complete ground thaw and a significant portion (45 %–100 %) occurred while the ground was partially frozen. Relatively rapid infiltration rates and non-sequential soil moisture and groundwater responses, observed prior to ground thaw, indicated preferential flow through frozen soils. The preferential flow dynamics are attributed to macropore networks within the grassland soils, which allow infiltrated meltwater to bypass portions of the frozen soil matrix and facilitate both the lateral transport of meltwater between topographic positions and groundwater recharge through frozen ground. Both of these flow paths may facilitate preferential mass transport to groundwater.

Properties of Frozen Soils for Cross Passage Construction in Line 1 and 2 of Wuxi Metro

2013 ◽  
Vol 353-356 ◽  
pp. 1662-1665 ◽  
Author(s):  
Xiang Dong Hu ◽  
Yan Guang Han
Keyword(s):  
Mechanical Properties ◽  
Laboratory Tests ◽  
Freezing Point ◽  
Frozen Soil ◽  
Frost Heave ◽  
Soil Test ◽  
Frozen Soils ◽  
Freezing Method ◽  
Ground Freezing ◽  
Artificial Ground Freezing

Artificial ground freezing method (AGF) was applied in cross passage constructing of line 1 and 2 of Wuxi Metro. Mechanical properties of frozen soils such as uniaxial compressive strength, modulus of elasticity, Poissons Ratio, frost heave rate and freezing point are prerequisite for design and construction of AGF. In order to obtain the parameters mentioned, laboratory tests were conducted. One was the basic geotechnical test. Another was the frozen soil test.

scholarly journals Effects of preferential flow on snowmelt partitioning and groundwater recharge in frozen soils

2019 ◽  
Author(s):  
Aaron A. Mohammed ◽  
Igor Pavlovskii ◽  
Edwin E. Cey ◽  
Masaki Hayashi
Keyword(s):  
Soil Moisture ◽  
Groundwater Recharge ◽  
Preferential Flow ◽  
Frozen Soil ◽  
Time Lags ◽  
Runoff Generation ◽  
Frozen Ground ◽  
Soil Matrix ◽  
Frozen Soils ◽  
Flow Through

Abstract. Snowmelt is a major source of groundwater recharge in cold regions. Throughout many landscapes snowmelt occurs when ground is still frozen, thus frozen soil processes play an important role in snowmelt routing, and, by extension, on the timing and magnitude of recharge. This study investigated the vadose zone dynamics governing snowmelt infiltration and groundwater recharge at three grassland sites in the Canadian Prairies over the winter and spring of 2017. The region is characterised by numerous topographic depressions where ponding of snowmelt runoff results in focused infiltration and recharge. Water balance estimates showed infiltration was the dominant sink (35–85 %) of snowmelt under uplands (i.e. areas outside depressions), even when ground was frozen, with soil moisture responses indicating flow through the frozen layer. Refreezing of infiltrated meltwater during winter melt events enhanced runoff generation in subsequent melt events. At one site, time lags of up to 3 days between snowcover depletion on uplands and ponding in depressions demonstrated the role of shallow subsurface flow through frozen soil in routing snowmelt to depressions. At all sites, depression-focused infiltration and recharge began before ground thaw and a significant portion (45–100 %) occurred while the ground was partially frozen. Relatively rapid infiltration rates and non-sequential soil moisture and groundwater responses, observed prior to ground thaw, indicated preferential flow through frozen soils. The preferential flow dynamics are attributed to macropore networks within the grassland soils, which allow infiltrated meltwater to bypass portions of the frozen soil matrix and facilitate both lateral transport of meltwater between topographic positions and groundwater recharge through frozen ground. Both of these flowpaths may facilitate preferential mass transport to groundwater.

Influence of the surface water reservoir to the thermal regime of frozen ground

2020 ◽  
Vol 6 (1) ◽  
pp. 10-40
Author(s):  
Jacob B. Gorelik ◽  
Ilya V. Zemerov
Keyword(s):  
Surface Water ◽  
Climatic Factors ◽  
Water Reservoir ◽  
Temperature Shift ◽  
Educational Process ◽  
Frozen Soil ◽  
Frozen Ground ◽  
Frozen Soils ◽  
Practical Applications ◽  
Average Annual Temperature

Excessive flooding of the built-up territories in the areas of permafrost soils often occurs due to changes in natural factors (including climatic) or design deficiencies and can negatively affect frozen soils for a long time. Currently, there is no complete methodology for calculating this effect. The solution to this problem is closely related to clarifying the nature of the formation of temperature shift, which at the moment is not clear enough. The aim of the work is to create a methodology for predicting changes in soil temperature in the event of a shallow reservoir on its surface In the first part of the article, the simplest theoretical model of the phenomenon of temperature shift is proposed, on the basis of which fairly convenient analytical expressions are obtained for the average annual temperature at the bottom of the active layer, depending on climatic factors and soil properties. The model most clearly demonstrates the nature of the occurrence of the phenomenon and can be used for simple assessments, as well as in the educational process. In particular, it is demonstrated that the magnitude of the shift is caused not only by the difference in the thermophysical characteristics of thawed and frozen soil, but also by the asymmetry of climatic parameters. In the second part of the article, using the quasistationary methods, calculations of the predicted temperature of the soil when a reservoir of a given depth on its surface occurs. Unlike previously used methods, the predicted parameters of the soil are counted from its unperturbed state, which is determined by the authors previously proposed method, which allows us to evaluate the direction of the changes (towards cooling or warming). It is shown that the influence of a shallow (up to a meter deep) surface water body on the temperature of frozen soils substantially depends on the process of mixing water in the summer. For the first time, the direction of these processes has been established: with a high degree of mixing, the influence is always warming and grows with the depth of the reservoir; in the absence of mixing, the pond cools the base at shallow depths, and with an increase in depth above a certain value, an warming effect occurs, which, however, is much lower than in the presence of mixing. The practical applications of the results are considered.

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