Experimental and modeling investigation of the thermal conductivity of fiber-reinforced soil subjected to freeze-thaw cycles

Niu, Fujun; Liu, Jiankun; Orakoğlu, Müge Elif

doi:10.1016/j.applthermaleng.2016.07.112

Cited by 39 publications

(9 citation statements)

References 25 publications

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“…Different freezing temperatures and lengths have a greater impact on the results of F-T cycle tests (Orakoglu et al 2016), and most of the current F-T cycle tests adopt methods: freezing time is 12h, the temperature is -20℃; thawing time is 12h, the temperature is 20℃, which is too general and not targeted.…”

Section: Freeze-thaw (F-t) Cycle Testsmentioning

confidence: 99%

Freeze-thaw Performance of Phase Change Material (PCM) Incorporated Canal Foundation Expansive Soil

Chen

Huang

Wang

et al. 2021

Preprint

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Drought and water shortages severely restrict the development of agriculture in China. The complex process of freezing and thawing experienced by the canal foundation soil in cold regions will cause leakage and loss of canal water. It is a common measure to improve the foundation soil of canals in cold regions. Phase change material (PCM) store or release heat in the form of latent heat during the phase change process, which is a new type of temperature control material. In this study, PCM-modified soil was used as the research object. Volume deformation measurement, unconfined compressive strength test, differential scanning calorimetry, and scanning electron microscopy tests were carried out on modified soil samples with different PCM content after freeze-thaw (F-T) cycles. The influence of the number of F-T cycles and the content of PCM on the expansion-shrinkage deformation and mechanical properties of the modified soil was revealed. The results show that: the greater the PCM content, the smaller the volume change, but there will be an optimal mixing ratio. The stress-strain curve characteristics, the failure strain with the number of F-T cycles and the PCM content have a great relationship. The effects of F-T cycles have a greater impact on the mechanical properties of PCM-modified soil. Among them, the first cycle is the most obvious, and it stabilizes after the third cycle. PCM can inhibit the attenuation of soil strength, and the greater the amount, the better the effect. The freezing time of PCM-modified soil has been increased, the supercooling phenomenon is no longer obvious, and the thermal stability has been improved. PCM reduces the connectivity of pores, and macroscopically suppresses the expansion and shrinkage characteristics and strength attenuation of expansive soil. The studies have shown that 8% PCM-modified soil has obvious advantages in resisting the harsh weather in cold regions, which can provide a reference for actual engineering design.

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Section: Freeze-thaw (F-t) Cycle Testsmentioning

confidence: 99%

Freeze-thaw Performance of Phase Change Material (PCM) Incorporated Canal Foundation Expansive Soil

Chen

Huang

Wang

et al. 2021

Preprint

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“…With the engineering structures constructed, the pre-existing hydrothermal balance of natural foundation has been seriously disturbed. Coupled with frequent freeze-thaw cycles, the thermal imbalance of engineering structures will lead to uneven degradation of the underlying permafrost, then resulting in different degrees of engineering diseases [2][3][4][5]. Thermal conductivity is a prime influence factor of permafrost response to the external thermal disturbance and also a determining parameter of the freeze-thaw circle, which governs the unsteady heat-transfer process of soil [7,8].…”

Section: Research Significancementioning

confidence: 99%

“…Due to the temperature sensitivity of frozen soil, the mechanical properties differ greatly before and after freezing and thawing, which tends to induce various engineering diseases characterized by thaw settlement and frost heave [3]. Thermal conductivity is one of the most important parameters of frozen soil, which is also a prime influencing factor of engineering structural damage caused by thaw settlement and frost heave [4,5]. As a complex multi-phase composition, previous research indicates that the thermal conductivity of frozen soil is associated with many factors [6][7][8]: inherent mineralogical skeleton, particle size, spatial geological distribution and sampling restrictions, the research on the thermal conductivity of various soil types of permafrost regions in the QTEC is not systematic and comprehensive, which needs to be further investigated.…”

Section: Introductionmentioning

confidence: 99%

Experimental Test and Prediction Model of Soil Thermal Conductivity in Permafrost Regions

et al. 2020

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Soil thermal conductivity is a dominant parameter of an unsteady heat-transfer process, which further influences the stability and sustainability of engineering applications in permafrost regions. In this work, a laboratory test for massive specimens is performed to reveal the distribution characteristics and the parameter-influencing mechanisms of soil thermal conductivity along the Qinghai–Tibet Engineering Corridor (QTEC). Based on the measurement data of 638 unfrozen and 860 frozen soil specimens, binary fitting, radial basis function (RBF) neural network and ternary fitting (for frozen soils) prediction models of soil thermal conductivity have been developed and compared. The results demonstrate that, (1) particle size and intrinsic heat-conducting capacity of the soil skeleton have a significant influence on the soil thermal conductivity, and the typical specimens in the QTEC can be classified as three clusters according to their thermal conductivity probability distribution and water-holding capacity; (2) dry density as well as water content sometimes does not have a strong positive correlation with thermal conductivity of natural soil samples, especially for multiple soil types and complex compositions; (3) both the RBF neural network method and ternary fitting method have favorable prediction accuracy and a wide application range. The maximum determination coefficient (R2) and quantitative proportion of relative error within ±10% ( P ± 10 % ) of each prediction model reaches up to 0.82, 0.88, 81.4% and 74.5%, respectively. Furthermore, because the ternary fitting method can only be used for frozen soils, the RBF neural network method is considered the optimal approach among all three prediction methods. This study can contribute to the construction and maintenance of engineering applications in permafrost regions.

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“…The degree of freeze-thaw erosion can be minimized by preventing the snow from melting and seeping into the slope, setting a heat insulation layer or crushed rock layer, controlling the slope angle, increasing the vegetation coverage, and reducing the temperature of the slope [37,38]. Landslide is a common disaster of slopes in permafrost regions.…”

Section: Geofluidsmentioning

confidence: 99%

Freeze-Thaw Stability Analysis of the High-Ice Content Soil-Rock Cutting Slope: A Case Study in Oroqen Autonomous Banner, North China

et al. 2020

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National Highway 332 (referred to as line 332) is the most convenient way for the forest areas (Oroqen Autonomous Banner, etc.) in northern China. This area is located in the high-latitude permafrost regions of the Daxing’anling Mountains. The section of line 332 from Ali River to Kubuchun Forest Farm is 116 km long, and the permafrost section is 7.45 km. Part of the section, K105+700-K105+800, is a road cutting slope with high ice content, and it is also our research object. The slope to be studied is difficult to construct and has high landslide risk, so we arranged thirty-five temperature sensors, four moisture sensors, and eighteen landmarks on the slope to grasp the dynamic changes of the slope under freeze-thaw conditions. After collecting the continuous data of temperature, moisture, settlement, and deformation of the slope, we found that the slope was undergoing freeze-thaw cycles, and the shallow slippage of the slope reached 6.811 cm in 2019. Besides, the drilled core samples were tested in the laboratory and relevant parameters were obtained. Then, the slope stability was numerically simulated in ABAQUS numerical simulation software. After two hundred freeze-thaw cycles, the slope safety factor reached 0.997, indicating that the slope was in a state of extreme equilibrium, so the potential freeze-thaw disasters must be considered during road operation, and higher requirements for the permanent protection of slopes should also be put forward. The study can provide guidance for the design and construction of road cutting slope in the permafrost regions of the Daxing’anling Mountains.

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Experimental and modeling investigation of the thermal conductivity of fiber-reinforced soil subjected to freeze-thaw cycles

Abstract: h i g h l i g h t s The thermal conductivity of soil decreased with the addition of fibers. Thermal conductivity of reinforced soil reduced when freeze-thaw cycles increased. The statistical-physical model provided good correlation with experimental data.

Cited by 39 publications

References 25 publications

Freeze-thaw Performance of Phase Change Material (PCM) Incorporated Canal Foundation Expansive Soil

Freeze-thaw Performance of Phase Change Material (PCM) Incorporated Canal Foundation Expansive Soil

Experimental Test and Prediction Model of Soil Thermal Conductivity in Permafrost Regions

Freeze-Thaw Stability Analysis of the High-Ice Content Soil-Rock Cutting Slope: A Case Study in Oroqen Autonomous Banner, North China

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