Heat transfer analysis in artificial ground freezing under high seepage: Validation and heatlines visualization

Alzoubi, Mahmoud A.; Madiseh, Ali; Hassani, Ferri; Sasmito, Agus P.

doi:10.1016/j.ijthermalsci.2019.02.005

Cited by 59 publications

(12 citation statements)

References 34 publications

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“…The temperature in the wells was measured by using the fiber optic system Silixa, based on the Raman effect. Alzoubi et al [13] have evaluated the development of a frozen wall between two freezing probes, with and without the presence of groundwater infiltration for 2D geometry, by was using ANSYS. Fan et al [14] show a case study concerning the monitoring of frozen wall formation during soil freezing using brine, then developed a three-dimensional numerical model to analyze the temperature distribution.…”

Section: Introductionmentioning

confidence: 99%

Modeling Artificial Ground Freezing for Construction of Two Tunnels of a Metro Station in Napoli (Italy)

Mauro

Normino

Cavuoto³

et al. 2020

Energies

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An artificial ground freezing (AGF) technique in the horizontal direction has been employed in Naples (Italy), in order to ensure the stability and waterproofing of soil during the excavation of two tunnels in a real underground station. The artificial freezing technique consists of letting a coolant fluid, with a temperature lower than the surrounding ground, circulate inside probes positioned along the perimeter of the gallery. In this paper, the authors propose an efficient numerical model to analyze heat transfer during the whole excavation process for which this AGF technique was used. The model takes into account the water phase change process, and has been employed to analyze phenomena occurring in three cross sections of the galleries. The aim of the work is to analyze the thermal behavior of the ground during the freezing phases, to optimize the freezing process, and to evaluate the thickness of frozen wall obtained. The steps to realize the entire excavation of the tunnels, and the evolution of the frozen wall during the working phases, have been considered. In particular, the present model has allowed us to calculate the thickness of the frozen wall equal to 2.1 m after fourteen days of nitrogen feeding.

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Section: Introductionmentioning

confidence: 99%

Modeling Artificial Ground Freezing for Construction of Two Tunnels of a Metro Station in Napoli (Italy)

Mauro

Normino

Cavuoto³

et al. 2020

Energies

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“…Until now, a lot of research studies have been performed on the stratum freezing technology [1,[6][7][8][9][10][11][12][13][14][15][16][17][18][19], but some limitations still exist. Firstly, when they are used to study the development law of the frozen wall under the seepage, most of the model tests are the single-row-pipe frozen one.…”

Section: Introductionmentioning

confidence: 99%

Experimental Study on Influencing Factors of Characteristic Index of Local Horizontal Frozen Body of Double‐Row Pipe under Seepage

Shan

Liu

et al. 2020

Advances in Materials Science and Engineering

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In order to deeply understand the influence of different factors on the characteristic indicators of the double-row-pipe partial horizontal frozen body in the sand-gravel stratum under the effect of seepage flow, several sets of sand-gravel stratum frozen model tests were carried out based on the similarity theory. The research showed that (1) under the effect of seepage flow, the backwater surface of the horizontal frozen body is in the shape of a quadratic parabolic and the development velocity of the backwater surface is inversely proportional to the square of the freezing time. The influence of seepage velocity on the downstream length and the freezing front development velocity of the backwater surface is stronger than the refrigerant temperature; (2) overlap time of the second row of frozen soil column increases with the increase of the distance between frozen pipes and seepage velocity and decreases with the decrease of the refrigerant temperature. The influence of various factors on the overlap time follows the order as the distance between freezing pipes > seepage velocity > refrigerant temperature. The average development velocity of the upstream surface decreases with the increase of the seepage velocity and the refrigerant temperature and first increases and then decreases with the increase of freezing pipe spacing. The influence of various factors on the average development velocity follows the order as seepage velocity > the distance between freezing pipes > refrigerant temperature. In addition, through the regression analysis, the quantitative relationship between the maximum arrangement spacing of the frozen pipes, the seepage velocity, and the refrigerant temperature was obtained. The research results can provide a basis for large-area partial horizontal freezing construction in Beijing sand-gravel stratum.

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“…It is well known that artificial ground freezing is a preferred construction method of mine shafts and underground urban space in water‐rich sand layers (e.g., 1–4 ). The resulting artificial frozen walls, however, are commonly of inadequate thickness and strength because of substantial groundwater seepage, which can result in water inrush and abrupt subsidence (e.g., 5,6 ). Thus, determining the freezing state and frozen section thickness during freezing is fundamental to assessing the development of artificial frozen walls.…”

Section: Introductionmentioning

confidence: 99%

Detection of the freezing state and frozen section thickness of fine sand by ultrasonic testing

Zhang

Murton

Liu

et al. 2020

Permafrost & Periglacial

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Determining the freezing state and frozen section thickness is fundamental to assessing the development of artificial frozen walls but is commonly difficult or inaccurate because of a limited number and fixed position of thermometer holes under complex field conditions. We report a novel experimental design that measures soil temperature, water content, and ultrasonic properties to monitor movement of the cryofront (0°C isotherm), water migration, and acoustic parameters during progressive upward freezing of fine sand under laboratory conditions. Ultrasonic testing during different stages of freezing revealed changes in three acoustic parameters (wave velocity, wave amplitude, and frequency spectrum). As the cryofront ascended through the sand at different water contents, wave velocity continually increased, whereas wave amplitude initially decreased and then increased. Wave velocity measurements revealed the cryofront position during freezing, but measurements of wave amplitude did not. The frequency components indicated the frequency of different evolving freezing regions during upward freezing and the freezing state of fine sand during later stages of freezing. The freezing state can be evaluated on the basis of single vs multiple peaks and the kurtosis of frequency spectrum change. An equation developed to predict the thickness of the frozen section and tested against measured values in the laboratory and field showed accuracies of 86.84–99.33%. The equation is used successfully to estimate frozen wall thickness in artificially frozen fine sand in Guangzhou, China.

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Heat transfer analysis in artificial ground freezing under high seepage: Validation and heatlines visualization

Cited by 59 publications

References 34 publications

Modeling Artificial Ground Freezing for Construction of Two Tunnels of a Metro Station in Napoli (Italy)

Modeling Artificial Ground Freezing for Construction of Two Tunnels of a Metro Station in Napoli (Italy)

Experimental Study on Influencing Factors of Characteristic Index of Local Horizontal Frozen Body of Double‐Row Pipe under Seepage

Detection of the freezing state and frozen section thickness of fine sand by ultrasonic testing

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