Study on the Influence of Initial Water Content on One-Dimensional Freezing Process of the Qinghai-Tibet Silty Clay by Using Digital Image Technology

Wang, Yongtao; Wang, Boyuan; Pang, Shoude; Hua, Weihang; Ji, Zhu; Wang, Dayan

doi:10.1155/2022/9994240

Cited by 1 publication

(1 citation statement)

References 24 publications

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“…Hou et al [21] examined the impacts of freezing temperature, initial moisture content, and dry density on soil water-heat transport through indoor soil one-way freezing tests. Wang et al [22] performed one-dimensional freezing tests on Qinghai-Tibetan chalky clay soils with varying initial water contents in an open system, utilizing CCD image acquisition and CT scanning techniques. Their findings indicated that the freezing depth increased with increasing initial water content, steplike freezing structures appeared in the vertical profile, more structural polygons were observed in the horizontal profile, and ice lens segregation, solidification of unfrozen zones, and water migration during freezing were more pronounced.…”

Section: Introductionmentioning

confidence: 99%

Large-Scale Freezing and Thawing Model Experiment and Analysis of Water–Heat Coupling Processes in Agricultural Soils in Cold Regions

Hai,

Su,

Wang

et al. 2023

Water

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Heilongjiang Province, the largest commercial grain base in China, experiences significant challenges due to the environmental effects on its soil. The freezing and thawing cycle in this region leads to the transport of water and heat, as well as the exchange and transfer of energy. Consequently, this exacerbates the flooding disaster in spring and severely hampers farming activities such as plowing and sowing. To gain a better understanding of the freezing and thawing mechanisms of farmland soil in cold regions and prevent spring flooding disasters, this study focuses on Heilongjiang Province as a representative area in northeast China. The research specifically investigates the frozen and thawed soil of farmland, using a large-scale low-temperature laboratory to simulate both artificial and natural climate conditions in the cold zone. By employing the similarity principle of geotechnical model testing, the study aims to efficiently simulate the engineering prototypes and replicate the process of large-span and long-time low temperatures. The investigation primarily focuses on the evolution laws of key parameters, such as the temperature field and moisture field of farmland soil during the freeze–thaw cycle. The findings demonstrate that the cooling process of soil can be categorized into three stages: rapid cooling, slow cooling, and freezing stabilization. As the soil depth increases, the variability of the soil temperature gradually diminishes. During the melting stage, the soil’s water content exhibits a gradual increase as the temperature rises. The range of water content variation during thawing at depths of 30 cm, 40 cm, 50 cm, and 80 cm is 0.12% to 0.52%, 0.47% to 1.08%, 0.46% to 1.96%, and 0.8% to 3.23%, respectively. To analyze the hydrothermal coupling process of farmland soil during the freeze–thaw cycle, a theoretical model of hydrothermal coupling was developed based on principles of mass conservation, energy conservation, Darcy’s law of unsaturated soil water flow, and heat conduction theory. Mathematical transformations were applied after defining the relative degree of saturation and solid–liquid ratio as field functions with respect to the relative degree of saturation and temperature. The simulated temperature and moisture fields align well with the measured data, indicating that the water–heat coupling model established in this study holds significant theoretical and practical value for accurately predicting soil temperature and moisture content during the spring sowing period, as well as for efficiently and effectively utilizing frozen soil resources in cold regions.

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Section: Introductionmentioning

confidence: 99%