Cold Regions Science and Technology最新文献

{"title":"Study on the durability and microstructure evolution of modified concrete in high altitude cold region","authors":"Ziyi Wang ,&nbsp;Fujun Niu ,&nbsp;Zhanju Lin ,&nbsp;Yuru Wang ,&nbsp;Xinlong Du ,&nbsp;Wenyan Du","doi":"10.1016/j.coldregions.2025.104670","DOIUrl":"10.1016/j.coldregions.2025.104670","url":null,"abstract":"<div><div>The cold and high-altitude regions are characterized by low air pressure, intense solar radiation, pronounced freeze-thaw cycles, and salt corrosion. For instance, the damage to concrete roads, culverts, and piers in the Tanggula area of the Qinghai-Tibet Plateau highlights the susceptibility of concrete structures in such regions to premature failure, thereby threatening the long-term safe operation of engineering projects. To enhance the service performance of concrete structures in high-altitude cold environments, this study proposes a novel approach involving the surface modification of basalt fibers using 3-glycidoxypropyltrimethoxysilane and nano-silica. The degradation characteristics of the material's mechanical properties, pore structure, and durability were systematically investigated through various characterization techniques, including apparent morphology analysis, compressive strength testing, relative dynamic elastic modulus measurement, scanning electron microscopy, and mercury intrusion porosimetry. Furthermore, the fractal dimension and KHSi-BF contribution rate were introduced to establish a damage prediction model, thereby improving the accuracy of damage assessment. The results demonstrate that KHSi-BF-N2B2 exhibits superior mechanical properties and durability compared to ordinary Portland cement (OPC) under low-pressure curing conditions. Upon incorporation of KHSi-BF, the particle size distribution of nano-silica becomes more uniform, dispersion is enhanced, and agglomeration is significantly reduced. This improves the interfacial bonding between KHSi-BF and the matrix, leading to increased compressive and tensile strengths, as well as enhanced durability. Compared with other specimens, KHSi-BF-N2B2 features fewer harmful pores and a denser microstructure. The KHSi-BF-SiO₂ cementitious system demonstrates enhanced resistance to solar radiation, freeze-thaw cycles, and salt corrosion. This research provides valuable insights and serves as an important reference for addressing the deterioration challenges faced by concrete structures in alpine and high-altitude regions.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"241 ","pages":"Article 104670"},"PeriodicalIF":3.8,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145046600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal Gradient's Impact on Segregation Frost Heave of Unsaturated Soil","authors":"Dong Zhang ,&nbsp;Xu Li ,&nbsp;Xiao-kang Li ,&nbsp;Shuang-fei Zheng ,&nbsp;Yu-dong Wu","doi":"10.1016/j.coldregions.2025.104667","DOIUrl":"10.1016/j.coldregions.2025.104667","url":null,"abstract":"<div><div>The thermal gradient is a key factor that causes and affects water migration and frost heave deformation (referred to as partial frost heave) of soil in cold regions. To investigate the influence of thermal gradient on the freezing behavior of soil in cold regions, this study used a self-developed experimental device to observe the freezing process of unsaturated soil columns with water supply under different average thermal gradients (ATGs). The deformation field of the soil freezing process was obtained using PIV technology, and the influence of thermal gradient on the migration of unsaturated soil moisture and the freezing deformation process was analyzed. The test results demonstrate the following: (1) The maximum frost heave (17.2 mm), total water uptake (270 ml), segregation crack width (11.3 mm), and peak strain (1.43) occur at the critical ATG of 1.7 °C∙cm⁻¹. (2) The thermal gradient within the frozen fringe (TGFF), but not the ATG, affects water migration, peaking at 1.1 °C·cm⁻¹ (critical ATG) and being correlated linearly with the frost heave amount (<span><math><msub><mi>H</mi><mi>v</mi></msub><mo>=</mo><mn>12.36</mn><mo>×</mo><mtext>TGFF</mtext><mo>+</mo><mn>4.12</mn></math></span>). (3) Our model <span><math><msub><mi>V</mi><mn>0</mn></msub><mo>=</mo><mn>1.85</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>10</mn></mrow></msup><mo>×</mo><mtext>TGFF</mtext></math></span> (R² = 0.97) enables the accurate prediction of the water migration rate (with a &lt; 7 % error), providing a new method for analyzing frost heave mitigation in engineering projects. A value below the critical ATG (e.g., thermal insulation at 1.7 °C·cm⁻¹) minimizes frost damage in cold-region infrastructure. These findings reveal the effect of the critical ATG on frost heave, ensuring the prevention or control of frost heave in cold region engineering projects.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"241 ","pages":"Article 104667"},"PeriodicalIF":3.8,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145046227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variations in precipitation effects on shallow soil of seasonally frozen ground during different freeze-thaw stages","authors":"Jingyuan Wang ,&nbsp;Siqiong Luo ,&nbsp;Xiaoqing Tan ,&nbsp;Qingxue Dong ,&nbsp;Xianhong Meng ,&nbsp;Lunyu Shang ,&nbsp;Shaoying Wang ,&nbsp;Zhaoguo Li","doi":"10.1016/j.coldregions.2025.104662","DOIUrl":"10.1016/j.coldregions.2025.104662","url":null,"abstract":"<div><div>With the ongoing effects of climate warming and wetting, the impact of precipitation on freeze-thaw processes in frozen ground is gaining significance. Nevertheless, the influence of precipitation during different freeze-thaw stages on the thermal regime of shallow soil remains poorly understood on seasonally frozen ground (SFG). Here, based on the data observed at the Madoi and Maqu sites on SFG from 2014 to 2018, we analyzed the response of soil hydrothermal characteristics and freeze-thaw duration to the precipitation during different freeze-thaw stages. The relationship between soil hydrothermal characteristics and precipitation was weak on an annual scale. Interannual differences in the start and end of the freezing stage (FS) are mainly caused by variations in precipitation, which directly affect the soil liquid water content at both sites. An additional 28 mm of precipitation during the same two-month period encompassing FS postponed the start of freezing by 27 days and shortened the duration of FS by 14 days at Madoi site. Precipitation differences were minimal at Maqu site, the FS showed less variability. Furthermore, the contrasting responses between Madoi and Maqu can be attributed to differences in soil properties. The low soil ice content during the completely frozen stage (CFS) can be attributed to either low precipitation during the FS or high snowfall during CFS at Madoi site. Lower air and soil temperature after the beginning of soil freeze resulted in the higher soil ice content at Maqu site. The prolonged snow cover delayed soil thawing at the two sites. Compared to the FS, the thawing stage (TS) was more susceptible to the influence of snow cover due to the melting and infiltration of snow. Different snow melting patterns can significantly affect the soil thawing process.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"241 ","pages":"Article 104662"},"PeriodicalIF":3.8,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145019996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of water retention characteristics in frozen sandy soils using an environmentally controlled column test","authors":"Incheol Kim ,&nbsp;Ali Behdad ,&nbsp;Jongwan Eun ,&nbsp;Junhwan Lee","doi":"10.1016/j.coldregions.2025.104664","DOIUrl":"10.1016/j.coldregions.2025.104664","url":null,"abstract":"<div><div>Water retention properties in frozen soils, including the soil freezing characteristic curve (SFCC), soil water characteristic curve (SWCC), and hydraulic conductivity, are crucial for understanding water infiltration and climate change in cold regions. In this study, a novel experimental system was developed and conducted to simultaneously investigate the SFCC, SWCC, and hydraulic conductivity of sandy soils during the freezing and thawing phases. SFCC and SWCC were measured during freezing and thawing, while hydraulic conductivity was assessed under unfrozen, frozen, and thawing conditions. The results showed that supercooling effects cause a freezing point suppression of approximately 2 °C, with significant hysteresis observed in SFCC and SWCC, especially at 100 % initial saturation (<em>S</em>_<em>r,i</em>). The ice-entry value (IEV) during freezing was determined to be inversely proportional to <em>S</em>_<em>r,i</em>, with values decreasing by up to 25 % as <em>S</em>_<em>r,i</em> increased from 50 % to 100 %. Hydraulic conductivity during freezing was significantly lower than in thawing or unfrozen states, decreasing by up to 80 % at <em>S</em>_<em>r,i</em> ≥ 30 % due to pore ice formation. Differences in the IEV and air-entry value (AEV) between freezing and thawing phases were attributed to latent heat exchanges during phase transitions. This study highlights the interconnected behaviors of SFCC, SWCC, and hydraulic conductivity under freeze-thaw cycles. These findings enhance our understanding of soil behavior under freeze-thaw cycles and provide critical data for improving water infiltration models in frozen soils.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"241 ","pages":"Article 104664"},"PeriodicalIF":3.8,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144989393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temperature and strain rate dependence of frozen fine-grained rock infilling: Implications for permafrost slope stability","authors":"Behnoush Honarvar Sedighian,&nbsp;Timothy Newson,&nbsp;Bing Q. Li","doi":"10.1016/j.coldregions.2025.104665","DOIUrl":"10.1016/j.coldregions.2025.104665","url":null,"abstract":"<div><div>There has been a notable increase in rock slope instability and failure in permafrost regions, a trend that has coincided with, and is expected to intensify under, ongoing climate change. One of the key mechanisms driving this instability is the mechanical weakening of warming permafrost, including the degradation of frozen joint infilling materials. Despite its importance, the failure behavior of frozen joint infillings has been studied in only a limited number of experimental investigations, particularly with respect to temperature and strain rate dependence in fine-grained frozen soils. This study addresses that gap by examining the mechanical behavior of a fine-grained silica soil (Sil-Co-Sil 106) subjected to varying temperatures and strain rates to better understand the implications of permafrost degradation on slope stability. A series of uniaxial compression tests were performed at three temperatures (−20 °C, −10 °C, and − 1 °C) and three strain rates (2 %/min, 20 %/min, and 280 %/min).</div><div>Key results show that lower temperatures and higher strain rates significantly increase the uniaxial compressive strength (UCS) and lead to more abrupt post-peak stress loss. The elastic modulus also increases with decreasing temperature and higher strain rates. In contrast, the Poisson's ratio rises with slower strain rates and warmer temperatures, indicating increased susceptibility to volumetric strain. Additionally, specimens tend to yield at lower stress levels under high strain rates and elevated temperatures, pointing to reduced resistance to deformation. Crack propagation analysis revealed that higher strain rates produce larger crack angles, suggesting enhanced intergranular friction, while lower temperatures are associated with smaller crack angles, indicative of more brittle behavior. Together, these findings underscore the importance of accounting for both rheological (rate-dependent) and thermal effects in the geotechnical design of infrastructure in cold regions. As permafrost degradation accelerates, understanding the mechanical response of frozen joint infilling becomes crucial for developing resilient engineering solutions and adapting infrastructure in vulnerable, high-risk permafrost environments.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"241 ","pages":"Article 104665"},"PeriodicalIF":3.8,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145004985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular-scale insights into the freeze-thaw process of aqueous and saline solutions in hydrated‑calcium-silicate gel pores","authors":"Jiachuan Ran ,&nbsp;Yuanming Lai ,&nbsp;Mingyi Zhang ,&nbsp;Fan Yu ,&nbsp;Te Liang ,&nbsp;Wansheng Pei ,&nbsp;Hongwei Li ,&nbsp;Xulong Gao ,&nbsp;Jiwei Jia","doi":"10.1016/j.coldregions.2025.104663","DOIUrl":"10.1016/j.coldregions.2025.104663","url":null,"abstract":"<div><div>The bulk expansion and solute migration caused by ice-water phase change are the main causes for the damage and deterioration of cement-based materials in the cold region. To better understand the degradation mechanism of calcium silicate hydrate (C-S-H) at low temperatures, the freeze-thaw process of aqueous and saline solutions along the pore axis of C-S-H gel was investigated using the molecular dynamics method. The study found that during the freezing process, the spatial confinement effect of the C-S-H substrate significantly lowers the freezing point of the pore solution and reduces the growth rate of ice crystals. The differential repulsion of salt ions by ice crystals, in conjunction with the selective adsorption of ions by the C-S-H substrate, results in increased adsorption of sodium ions onto the C-S-H surface, while chloride ions are repelled into deeper pores. During thawing, the C-S-H matrix facilitates the thawing of ice crystals at higher temperatures, while inhibiting their thawing at lower temperatures. As the ice crystals thaw, chloride ions near the C-S-H surface rapidly dissolve into the solution, whereas sodium ions adsorbed on the surface are less likely to diffuse back into the solution. Temperature variations affect ion diffusion and ice crystal growth, influencing salt ion migration. These findings provide valuable scientific insights for improving the durability of cement-based materials in harsh environments.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"241 ","pages":"Article 104663"},"PeriodicalIF":3.8,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144934001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing snow distribution in alpine PV systems: CFD-based design guidelines for power plant layout","authors":"Yael Frischholz ,&nbsp;Océane Hames ,&nbsp;Michael Lehning","doi":"10.1016/j.coldregions.2025.104654","DOIUrl":"10.1016/j.coldregions.2025.104654","url":null,"abstract":"<div><div>Solar photovoltaic installations in mountainous regions, or alpine PV, benefit from the high albedo of snow, which enhances terrain-reflected irradiance. However, snow accumulation can also cause electricity production losses and structural damage by covering or burying PV modules and supporting structures. HELIOPLANT® is an innovative design for PV power plants, featuring a cross structure with four vertical wings, each containing four PV modules arranged symmetrically around the center. Observations suggest that this design is self-regulating and passively prevents snow accumulation within the enclosed wing area. This prevents PV modules from being buried by snow, minimizing electricity loss and damage. This study evaluates the impact of the Helioplant design on local snow distribution patterns using the numerical snow transport model, snowBedFoam. The analysis considers intrinsic Helioplant parameters (azimuth, height-above-surface) and the spatial arrangement of multiple units (interspace, group size, alignment). Key findings show that grouping units together reduces the erosion capacity of the cross structure. In grouped units, the most noticeable erosion occurs in the first row facing the prevailing wind, while subsequent rows experience less erosion due to sheltering by the upwind panels. Increasing the interspace reduces this protection, leading to greater wind exposure and enhanced erosion, which is beneficial. A staggered row alignment significantly enhances snow erosion in the second row. These findings provide initial guidelines for designing Helioplant-based PV plants, with future research focusing on sloped terrains and PV yield evaluation.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"241 ","pages":"Article 104654"},"PeriodicalIF":3.8,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145019997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simultaneous study of sediment concentration and fluid velocity in an ice-covered channel","authors":"Sweta Narayan Sahu,&nbsp;Koeli Ghoshal","doi":"10.1016/j.coldregions.2025.104655","DOIUrl":"10.1016/j.coldregions.2025.104655","url":null,"abstract":"<div><div>Understanding sediment transport in turbulent flow within ice-covered channels requires simultaneous analysis of the time-averaged streamwise fluid velocity and suspended sediment concentration, as particle–turbulence interactions create a strong interdependence between the two. Higher sediment concentrations increase the fluid density, which in turn leads to flow stratification. Building on previous studies, this research presents a model that simultaneously captures velocity and concentration while incorporating the effects of stratification. To solve the model, a semi-analytical approach based on Riccati’s equation is adopted and validated against a numerical solution obtained through Runge–Kutta (R–K) method, demonstrating strong agreement across the domain. The influence of stratification on eddy viscosity is analyzed, revealing a reduction in turbulent mixing, an increase in velocity shear and a decrease in sediment concentration. Experimental datasets from previous studies are used to compare model predictions, showing good alignment with measured sediment concentration and velocity profiles. The effects of channel bed and ice cover roughness are also examined. Increased ice roughness is found to reduce sediment concentration, shift the position of maximum velocity towards the smoother surface and alter the shear stress distribution. These findings enhance the understanding of sediment transport dynamics in ice-covered environments and provide a foundation for improved predictive modeling.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"241 ","pages":"Article 104655"},"PeriodicalIF":3.8,"publicationDate":"2025-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144934002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emergency mitigation strategies for the settlement of in-service pile foundations in Permafrost Regions: Application of artificial ground freezing","authors":"Changxin Fan ,&nbsp;Zhi Wen ,&nbsp;Qiang Gao ,&nbsp;Alexander F. Zhirkov","doi":"10.1016/j.coldregions.2025.104646","DOIUrl":"10.1016/j.coldregions.2025.104646","url":null,"abstract":"<div><div>The warming and degradation of permafrost surrounding pile foundations frequently result in settlement problems. As a hidden deep foundation, there has been a lack of effective methods to address the settlement of pile foundations in permafrost regions. Conventional settlement control methods, such as thermosyphons and auxiliary piles, have been proven to be time-consuming and limited in effectively controlling settlement deformation, as demonstrated in the treatment of severe settlement damage at the K1401 dry bridge of the Qinghai-Tibet Railway. This study examines the application of artificial ground freezing as an emergency technique to mitigate settlement damage by restoring thermal stability and enhancing the ultimate bearing capacity of pile foundations. Laboratory experiments demonstrate that a 10-h freezing process reduces the average pile temperature from −0.5 °C to −3.5 °C and decreases the deformation rate from 0.0007 mm/h to 0.0002 mm/h under a 5 kN load condition. Artificial freezing for 96-h in engineering can lower the temperature of the pile side by 1.3 °C on average, leading to a 24 % increase in the ultimate bearing capacity through numerical simulation. The freezing efficiency is primarily affected by the coolant temperature, the arrangement of the freezing pipes and the ice content of the permafrost. As the ice content increases, the cooling effect of the same cooling pattern diminishes, the increment of ultimate bearing capacity decreases, with increases of 28 %, 23 %, and 17 % observed in ice-poor, ice-more, and ice-rich soils, respectively, and the time required for the ground temperature to return to its natural state also increases after artificial freezing. Based on the requirements of ultimate bearing capacity, it is recommended to freeze ice-poor and ice-more regions once every three years and ice-rich regions once every four years. To make up for the lack of freezing efficiency in the ice-rich regions, the freezing effect can be improved by further optimizing construction parameters, such as lowering the temperature of the coolant, shortening the distance between the freezing pipe and the pile side, and increasing the number of freezing pipes. This study offers a practical engineering solution and design guideline for addressing pile foundation settlement in permafrost regions.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"240 ","pages":"Article 104646"},"PeriodicalIF":3.8,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144922091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The correlation between phase transition and electrochemical characteristics of composite saline soil","authors":"Kangliang Li ,&nbsp;Zean Xiao ,&nbsp;Jingrui Liang ,&nbsp;Lihong Cui ,&nbsp;Linze Zhu ,&nbsp;Xusheng Wan ,&nbsp;Xiangtian Xu","doi":"10.1016/j.coldregions.2025.104660","DOIUrl":"10.1016/j.coldregions.2025.104660","url":null,"abstract":"<div><div>The phase transition characteristics of saline soil are closely related to its electrochemical processes. It is an effective means to investigate the phase transition mechanism by using the electrochemical characteristics of saline soil. In order to explore the electrochemical characteristics of composite saline soil in phase transition process, the electrochemical impedance spectrum of saline soils with different mass ratios of chloride and sulfate ions were tested through cooling tests. The results reveal that Nyquist plots exhibit a single reactance arc at positive temperatures, and the water/salt migration in the soil changes the electrochemical reaction process after the pore water freezing, resulting in the appearance of diffusion impedance. The impedance modulus increases linearly with the decrease in temperature before phase transition, while the formation of salt crystals and ice crystals leads to a significant increase in the impedance modulus after phase transition. The phase angle is close to zero degrees at a scanning frequency of 10⁵ Hz, indicating that the soil system exhibits resistive behavior. Moreover, the equivalent circuit model is established according to the conductive path of the composite saline soil. It was found that there is a close correlation between the value of equivalent resistance elements and the impedance modulus through comparison. In addition, the machine learning algorithms were used to predict the variation of equivalent resistance elements, which demonstrate that the XGBoost model can effectively predict the variation of resistance value, with an R² of 0.995. This research provides a theoretical reference for studying the salt expansion and frost heave mechanism of saline soil in cold regions.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"240 ","pages":"Article 104660"},"PeriodicalIF":3.8,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144917260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}