scholarly journals Detection of Pipeline Deformation Induced by Frost Heave Using OFDR Technology

2021 ◽  
Vol 9 ◽  
Author(s):  
Tao Jiang ◽  
Jing-wen Zhu ◽  
Yi Shi
Keyword(s):  
Oil And Gas ◽  
Plane Curve ◽  
Reconstruction Algorithm ◽  
Deformation Monitoring ◽  
Frozen Soil ◽  
Frost Heave ◽  
Curve Reconstruction ◽  
Seasonal Frozen Soil ◽  
Distributed Strain ◽  
Soil Area

Oil and gas pipelines are critical structures. For pipelines in the seasonal frozen soil area, frost heave of the ground will result in deformation of the pipeline. If the deformation continually increases, it will seriously threaten the pipeline safety. Therefore, it is important to monitor the deformation of the pipeline in the frozen soil area. Since optic frequency–domain reflectometer (OFDR) technology has many advantages in distributed strain measurement, this paper utilized the OFDR technology to measure the distributed strain and use the plane curve reconstruction algorithm to calculate the deformed pipeline shape. To verify the feasibility of this approach, a test was conducted to simulate the pipeline deformation induced by frost heave. Test results showed that the pipeline shape can be reconstructed well via the combination of the OFDR and curve reconstruction algorithm, providing a valuable approach for pipeline deformation monitoring.

Research on Frost Heaving of Subgrade Filling in Seasonal Frozen Soil Area

2014 ◽  
Vol 1065-1069 ◽  
pp. 783-787
Author(s):  
Jin Fang Hou ◽  
Rui Qi Zhang ◽  
Jian Yu
Keyword(s):  
Water Content ◽  
High Speed ◽  
Freezing Temperature ◽  
Frozen Soil ◽  
Coarse Grained ◽  
Freezing And Thawing ◽  
Frost Heaving ◽  
Factors Affecting ◽  
Seasonal Frozen Soil ◽  
Soil Area

Research on frost heaving of high speed railway subgrade filling in seasonal frozen soil area is developed indoor. Through freezing and thawing strength and frost heaving amount test, the research analyzes factors affecting frost heaving of subgrade filling, points out that water content, fine stuff admixing amount and plasticity of fine-grained soil have relatively large influence on frost heaving, while freezing temperature and freezing and thawing cycle index have relatively small influence. Water content is main factor to have effect on frost heaving of subgrade filling. When the water content reaches to some certain value, even coarse-grained soil can produce considerable frost heaving amount. Therefore, taking effective waterproof and drainage measures is of great importance in subgrade frost heaving prevention and treatment.

scholarly journals Mechanisms of salt rejection at the ice-liquid interface during the freezing of pore fluids in the seasonal frozen soil area

China Geology ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 449-457
Author(s):  
Huan Huang ◽  
◽  
Chang-fu Chen ◽  
Xiao-jie Mo ◽  
Ding-ding Wu ◽  
...  
Keyword(s):  
Liquid Interface ◽  
Frozen Soil ◽  
Pore Fluids ◽  
Salt Rejection ◽  
Seasonal Frozen Soil ◽  
Soil Area

scholarly journals Analysis of main points of channel freezing-thawing disease in cold region and influence of channel base soil on the disease

2021 ◽  
Vol 329 ◽  
pp. 01090
Author(s):  
Liqing Liang
Keyword(s):  
North China ◽  
Hydraulic Structure ◽  
Research Direction ◽  
Frozen Soil ◽  
Frost Heave ◽  
Cold Region ◽  
Freezing And Thawing ◽  
Cold Regions ◽  
Seasonal Frozen Soil ◽  
Base Soil

The frozen soil area in China is more than two thirds of the total territory, so the problem of frost heave is obvious. Especially in northeast, northwest, north China and other cold regions, the problem of frost heave of hydraulic structures is very common. Canal is a common hydraulic structure in agricultural water, which is affected by seasonal frozen soil and may cause problems such as lining damage, seepage and irrigation efficiency. Therefore, this paper mainly summarizes the necessity of research on channel freezingthawing damage, the research direction of channel freezing-thawing damage, and expounds the influence of seasonal frozen soil on freezing and thawing diseases in cold regions by taking the particle size of saturated soil based on channel as an example.

Discussion on Moisture Migration and Law of Frost Heave of Seasonal Frozen Soil in Hetao Irrigation Area, Inner Mongolia

2012 ◽  
Vol 212-213 ◽  
pp. 260-263
Author(s):  
Ying Hao Wang ◽  
Shuo Li
Keyword(s):  
Inner Mongolia ◽  
Frozen Soil ◽  
Frost Heave ◽  
Moisture Migration ◽  
Irrigation Area ◽  
Irrigation Channel ◽  
Thaw Cycle ◽  
Channel Engineering ◽  
Seasonal Frozen Soil ◽  
Hetao Irrigation Area

Hetao irrigation area in Inner Mongolia is one of the four major irrigation areas in China, seasonal frozen soil is widely distributed in this area. Irrigation channel engineering experiences seriously freeze-thaw cycle many times in the long winter, its maintenance is the important and difficult point all long in irrigation channel engineering of Hetao irrigation area. For this, we analyze the moisture migration and law of frost heave characteristics of seasonal frozen soil in Hetao irrigation area.

Field Monitoring and Analysis of Hydraulic Soil Slope Frost Heaving Damage

2013 ◽  
Vol 353-356 ◽  
pp. 2445-2449
Author(s):  
Xiang Min Qu ◽  
Hua Zhong ◽  
Xiu Fen Wang ◽  
Bin Zhang
Keyword(s):  
Theoretical Basis ◽  
Frozen Soil ◽  
Frost Heave ◽  
Engineering Practice ◽  
Soil Slope ◽  
Frost Heaving ◽  
Seasonal Frozen Soil ◽  
Water Conservancy Project ◽  
Water Conservancy ◽  
Earth Temperature

Frost heaving damage of water conservancy project is widespread. In order to research the failure problems of hydraulic soil slope in dark seasonal frozen soil region, remote monitor and manual observation is carried out combined with field test section layout, which including air temperature, earth temperature, frozen depth, the amount of frost heaving and layered water content. It is researched that the rule of frost heave parameters variation and the damage of soil slope during freeze-thaw cycling. That offers theoretical basis and reference for construction of water conservancy project and guidance for engineering practice.

scholarly journals A Study of the Insulation Mechanism and Anti-Frost Heave Effects of Polystyrene Boards in Seasonal Frozen Soil

Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 979 ◽  
Author(s):  
Fuqiang Guo ◽  
Haibin Shi ◽  
Manjin Cheng ◽  
Wenhui Gao ◽  
Hongzhi Yang ◽  
...  
Keyword(s):  
Precast Concrete ◽  
Reduction Rate ◽  
Frozen Soil ◽  
Frost Heave ◽  
Test Field ◽  
Frost Heaving ◽  
Irrigation Area ◽  
Ground Temperatures ◽  
Seasonal Frozen Soil ◽  
Hetao Irrigation Area

The damages resulting from frost heaving are the main causes of channel destruction in seasonal frozen soil regions. Over the years, many experimental studies have been performed regarding the channel anti-frost heaving in the Hetao irrigation area. However, there have been few experimental research studies conducted regarding the insulation and anti-frost heave effects of polystyrene boards (EPS) of different thicknesses. Therefore, in order to explore the insulation mechanism and anti-frost heave effects of precast EPS laid under the conditions of different thicknesses, an anti-frost heave test field was established in the Hetao irrigation area for the examination of the ground temperatures, frozen depths, frost heave amounts, and water content change rules. This study’s results showed that, for the laid EPS with thicknesses between 2 and 12 cm, the frost-heave reduction rate ranged from 53.2% to 92.6%; total accumulated temperature warming ranged from 248.65% to 565.93%; and the frozen depth reduction rate was between 59.8% and 75.9%. It was determined that the EPS per cm additions could effectively improve the ground temperatures at a buried depth of 30 cm by 0.78 °C, and reduce the frozen depth by 10.1 cm. Then, by comprehensively considering the positive economic and insulation effects, it was determined that the most appropriate thickness of the EPS laid under the precast concrete slabs in the Hetao irrigation area of Inner Mongolia was 8–10 cm.

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.

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