A model for predicting the frost-heave effect of a pile embedded in the frozen soil

2018 ◽  
Vol 146 ◽  
pp. 214-222 ◽  
Author(s):  
Jian-Fei Lu ◽  
Jie Yin ◽  
Jun Shuai
Keyword(s):  
Frozen Soil ◽  
Frost Heave

Stress Analysis of Pipeline Subjected to Differential Frost Heave

2013 ◽  
Author(s):  
Yan Di ◽  
Jian Shuai ◽  
Lingzhen Kong ◽  
Xiayi Zhou
Keyword(s):  
Strain Analysis ◽  
Element Model ◽  
Frozen Soil ◽  
Computational Method ◽  
Frost Heave ◽  
Safe Operation ◽  
Stress Strain ◽  
Segregation Potential ◽  
Differential Frost Heave ◽  
Design Construction

Frost heave must be considered in cases where pipelines are laid in permafrost in order to protect the pipelines from overstress and to maintain the safe operation. In this paper, a finite element model for stress/strain analysis in a pipeline subjected to differential frost heave was presented, in which the amount of frost heave is calculated using a segregation potential model and considering creep effects of the frozen soil. In addition, a computational method for the temperature field around a pipeline was proposed so that the frozen depth and temperature variation gradient could be obtained. Using the procedure proposed in this paper, stress/strain can be calculated according to the temperature on the surface of soil and in a pipeline. The result shows the characteristics of deformation and loading of a pipeline subjected to differential frost heave. In general, the methods and results in this paper can provide a reference for the design, construction and operation of pipelines in permafrost areas.

Microstructure-Based Random Finite Element Method Simulation of Frost Heave: Theory and Implementation

2018 ◽  
Vol 2672 (52) ◽  
pp. 347-357 ◽  
Author(s):  
Shaoyang Dong ◽  
Xiong (Bill) Yu
Keyword(s):  
Finite Element ◽  
Ground Surface ◽  
Finite Element Method Simulation ◽  
Element Model ◽  
Frozen Soil ◽  
Traffic Load ◽  
Frost Heave ◽  
Holistic Model ◽  
Water Pipes ◽  
Random Finite Element

Frost heave can cause serious damage to civil infrastructure. For example, interactions of soil and water pipes under frozen conditions have been found to significantly accelerate pipe fracture. Frost heave may cause the retaining walls along highways to crack and even fail in cold climates. This paper describes a holistic model to simulate the temperature, stress, and deformation in frozen soil and implement a model to simulate frost heave and stress on water pipelines. The frozen soil behaviors are based on a microstructure-based random finite element model, which holistically describes the mechanical behaviors of soils subjected to freezing conditions. The new model is able to simulate bulk behaviors by considering the microstructure of soils. The soil is phase coded and therefore the simulation model only needs the corresponding parameters of individual phases. This significantly simplifies obtaining the necessary parameters for the model. The capability of the model in simulating the temperature distribution and volume change are first validated with laboratory scale experiments. Coupled thermal-mechanical processes are introduced to describe the soil responses subjected to sub-zero temperature on the ground surface. This subsequently changes the interaction modes between ground and water pipes and leads to increase of stresses on the water pipes. The effects of cracks along a water pipe further cause stress concentration, which jeopardizes the pipe’s performance and leads to failure. The combined effects of freezing ground and traffic load are further evaluated with the model.

Mechanics of Buried Chilled Gas Pipelines

1996 ◽  
Author(s):  
A. P. S. Selvadurai ◽  
J. Hu
Keyword(s):  
Three Dimensional ◽  
Frozen Soil ◽  
Frost Heave ◽  
Elastic Behaviour ◽  
Full Scale Test ◽  
Flexural Behaviour ◽  
Moisture Migration ◽  
Factors Influencing ◽  
Scale Test ◽  
Interaction Test

This paper examines the factors influencing the modelling of soil-pipeline interaction for a pipeline which is used to transport chilled gas. The soil-pipeline interaction is induced by the generation of discontinuous frost heave at a boundary between soils with differing frost susceptibility. The three-dimensional modelling takes into consideration the time-dependent evolution of frost heave due to moisture migration, the creep and elastic behaviour of the frozen soil and flexural behaviour of the embedded pipeline. The results of the computational model are compared with experimental results obtained from the frost heave induced soil-pipeline interaction test performed at the full scale test facilities in Caen, France.

Ice lens formation at a silt–sand interface

1995 ◽  
Vol 32 (3) ◽  
pp. 488-495 ◽  
Author(s):  
Sharon L. Smith ◽  
Peter J. Williams
Keyword(s):  
Soil Structure ◽  
Frozen Soil ◽  
Frost Heave ◽  
Controlled Environment ◽  
Freezing And Thawing ◽  
Ground Freezing ◽  
Residual Deformations ◽  
Cumulative Residual ◽  
Lens Formation ◽  
Soil Interface

A major experiment simulating ground freezing around a buried chilled pipeline in a controlled-environment facility provided an opportunity to examine the form and orientation of ice lenses associated with a vertical interface between silt and sand. The heave of the silt decreased towards the interface and ice lenses in the silt were found to dip at an increasing angle in the same direction. Consideration of the thermal regime suggests that the direction of heat flow influences the orientation of the lenses. The interface was irregular and ice lenses at the lower part of the interface were closely aligned to it, indicating that changes in soil texture also influence ice lens orientation. Deformation of ice lenses appears to have occurred in the silt near to the interface. The arrangement of the lenses can be explained by the different thermal properties and thermodynamic behaviour of the two materials and by the mechanical "anchorage" of the sand in which there is no ice lens formation. Cycles of freezing and thawing modify soil structure and produce cumulative residual deformations which are modified by a soil interface. Key words : frost heave, ice lenses, frozen soil, vertical silt–sand interface, chilled pipeline, differential heave.

Study on the Frost Heave Characteristics of Artificial Frozen Soil Under Different Freezing Mode

2012 ◽  
Vol 204-208 ◽  
pp. 599-603
Author(s):  
Jun Hao Chen
Keyword(s):  
Structural Design ◽  
Computer Control ◽  
Frozen Soil ◽  
The Self ◽  
Frost Heave ◽  
Test Machine ◽  
Freezing Method ◽  
Artificial Freezing ◽  
Similarities And Differences ◽  
Artificial Freezing Method

At the self-developed DZL-001 computer control of frozen soil frozen-heave test machine, use artificial freezing method carry out vertical and lateral freezing two modes frost heave test of remoulded clay, each mode test includes under no replenishment and replenishment conditions. Monitor the temperature, moisture and frost heave of frozen soil at different location. Compare the similarities and differences of frost heave characteristics of two modes, master the frost heave characteristics of artificial frozen soil. The results provide a certain guidance and reference meaning to layer sidewall structural design.

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 A Coupled Thermo-Hydromechanical Model of Soil Slope in Seasonally Frozen Regions under Freeze-Thaw Action

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Yongxiang Zhan ◽  
Zheng Lu ◽  
Hailin Yao ◽  
Shaohua Xian
Keyword(s):  
Coupling Model ◽  
Frozen Soil ◽  
Frost Heave ◽  
Freezing Process ◽  
Water Migration ◽  
Soil Slope ◽  
Deep Soil ◽  
Melting Front ◽  
Freeze Thaw ◽  
Seasonally Frozen Regions

Soil slope diseases in seasonally frozen regions are mostly related to water migration and frost heave deformation of the soil. Based on the partial differential equation defined using the COMSOL Multiphysics software, a thermo-hydromechanical coupling model considering water migration, ice-water phase change, ice impedance, and frost heave is constructed, and the variations in the temperature field, migration of liquid water, accumulation of solid ice, and deformation of frost heave in frozen soil slopes are analysed. The results show that the ambient temperature has a significant effect on the temperature and moisture field of the slope in the shallow area. In addition, the degree of influence gradually weakens from the outside to the inside of the slope, and the number of freeze-thaw cycles in deep soil is less than that in shallow soil. During the freezing period, water in the unfrozen area rapidly migrates to the frozen area, and the total moisture content abruptly changes at the vicinity of the freezing front. The maximum frozen depth is the largest at the slope top and the smallest at the slope foot. During the melting period, water is enriched at the melting front with the frozen layer melting; the slope is prone to shallow instability at this stage. The melting of the frozen layer is bidirectional, so the duration of slope melting is shorter than that of the freezing process. The slope displacement is closely related to the change in temperature—a relation that is in agreement with the phenomenon of thermal expansion and contraction in unfrozen areas and reflects the phenomenon of frost heave and thaw settlement in frozen areas.

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