Cold Regions Science and Technology最新文献

{"title":"Numerical study on cooling performance of the L-shaped crushed-rock embankment in permafrost regions","authors":"Yafang Guo ,&nbsp;Wansheng Pei ,&nbsp;Mingyi Zhang ,&nbsp;Deren Liu ,&nbsp;Ruiqiang Bai ,&nbsp;Yanqiao Zhou ,&nbsp;Guanji Li","doi":"10.1016/j.coldregions.2024.104380","DOIUrl":"10.1016/j.coldregions.2024.104380","url":null,"abstract":"<div><div>In permafrost regions, crushed-rock embankments are favored for their environmental compatibility and thermal efficiency. This study introduces the innovative L-shaped crushed-rock embankment (LCRE), which features a crushed-rock layer exclusively at the base and on the sunny slope, providing a cost-effective alternative to the conventional U-shaped design. Using numerical methods, we assessed the cooling performance of the LCRE compared to other crushed-rock embankments, focusing on the impact of its geometric parameters. The findings indicate that the overall cooling performance of the LCRE is situated between that of the crushed-rock interlayer embankment and the U-shaped crushed-rock embankment, and its ability to mitigate the shady and sunny slope effect is superior to that of the U-shaped crushed-rock embankment. Additionally, our analysis reveals that increasing the horizontal width of the revetment to enhance cooling is not a cost-effective approach. The LCREs is more suitable for higher embankments than U-shaped counterparts. Despite the LCRE's advantageous thermal performance and cost benefits, its asymmetric load distribution could lead to exacerbated differential settlement, highlighting the need for further research. This study offers pivotal insights into the design and development of innovative crushed-rock embankments in permafrost regions.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"230 ","pages":"Article 104380"},"PeriodicalIF":3.8,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142756598","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":"Who skis where, when? – A method to enumerate backcountry usage","authors":"Håvard B. Toft ,&nbsp;Kristoffer Karlsen ,&nbsp;Markus Landrø ,&nbsp;Andrea Mannberg ,&nbsp;Jordy Hendrikx ,&nbsp;Audun Hetland","doi":"10.1016/j.coldregions.2024.104370","DOIUrl":"10.1016/j.coldregions.2024.104370","url":null,"abstract":"<div><div>Backcountry skiers, travelling in avalanche terrain, account for a large proportion of avalanche fatalities worldwide. Despite this, the exact count of the number of recreationists exposed to avalanches (also known as the background information), is poorly documented in most countries. Without detailed background information on temporal and spatial backcountry usage, making well-reasoned decisions from fatality statistics is impossible. This study developed a methodology to enumerate a large proportion of backcountry usage from a 2589 km² study area in Tromsø, Northern Norway. We use an extensive network of specially adapted beacon checkers – small, waterproof devices that detect and count signals from avalanche transceivers. Over two seasons, from December to May from 2021 to 2023, we recorded 56,760 individual trips. Our findings indicate that most (60.0 %) backcountry trips begin between 07:00 and 12:00, with noticeable activity in the afternoon as well. Saturdays and Sundays see the highest daily activity rates, comprising 40.1 % of total weekly traffic, while weekdays, though less busy per day, account for the remaining 59.9 %. The peak season for winter backcountry skiing is during March and April (when counts from the period December to May are considered), accounting for 56.3 % of all traffic. This monthly usage aligns with avalanche incident data, where 55.8 % of incidents occur during the same two months. Our study demonstrates the use of our methodology and advances the understanding of temporal trends from winter backcountry skiing, quantifying the movement characteristics of backcountry skiers in Tromsø, Norway.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"230 ","pages":"Article 104370"},"PeriodicalIF":3.8,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unified hardening (UH) model for saturated frozen soils","authors":"Kesong Tang,&nbsp;Yangping Yao","doi":"10.1016/j.coldregions.2024.104371","DOIUrl":"10.1016/j.coldregions.2024.104371","url":null,"abstract":"<div><div>The mechanical behavior of frozen soils is highly sensitive to temperature variations due to their complex micro-mechanisms. In regions with seasonal freeze-thaw cycles, the transition of soils between frozen and unfrozen states is significantly influencing their mechanical properties. This study synthesizes existing theories and data to categorize the effects of subzero temperatures on the properties of frozen soils. By introducing temperature and unfrozen water saturation, the phase change component of void ratio—decoupled from stress—is distinguished from actual voids, enabling the definition of the equivalent void ratio. Nonlinear relationships between temperature and other mechanical properties including elastoplastic deformation, cryogenic cohesion and ice segregation are established. Through the derivation of a loading-temperature yield equation, an elastoplastic constitutive model within a dual stress-variable framework of effective stress and temperature is established. This model captures key aspects of the behavior of frozen soils, including strength weakening due to ice segregation and temperature-induced strength changes. Applicable to conditions at or below the pore water melting point, the model's predictions align well with experimental observations.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"230 ","pages":"Article 104371"},"PeriodicalIF":3.8,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743710","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":"Influence mechanism of AC electric field on rime ice accretion on the insulator and its experimental verification in the natural environment","authors":"Mingchen Chi ,&nbsp;Yuyao Hu ,&nbsp;Xingliang Jiang ,&nbsp;Zongyuan Liu ,&nbsp;Yue Gao ,&nbsp;Mengyang Zhao ,&nbsp;Wentao Jia","doi":"10.1016/j.coldregions.2024.104367","DOIUrl":"10.1016/j.coldregions.2024.104367","url":null,"abstract":"<div><div>Insulator icing can easily trigger flashover trips in heavily ice-covered areas, and analyzing the formation mechanism of ice accumulation on the insulator is essential for predicting its flashover development. To accurately dissect the process of insulator icing, a coupled mathematical model of the flow field and electric field, as well as a droplet motion model were elaborated in this paper based on the principles of fluid mechanics and electromagnetic field. Subsequently, the characteristics of droplet motion deviation and its physical collision process with an insulator surface under AC electric field were investigated. The results demonstrate that the charged droplets tend to oscillate along the electric field lines in AC electric field, and the amplitude of the oscillation increases with the applied voltage increasing. Moreover, the number of droplets captured by the insulator rises with the increase of voltage, wind speed, and median volume diameter of the droplet. Combined with the simulation and natural icing experiments, it is observed that ice branches grow in the direction of electric field force, and as the voltage rises, ice branches gradually spread from the edge of the shed to its surface, increasing surface roughness. The density of ice exhibits an inverted U-shaped relationship as the electric field strength increases. Ice mass and ice length present nonlinear growth with an increase in icing time. Furthermore, compared with that without energization, the icing amount and icing length increase by more than 13 % under AC voltage of 40 kV.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"230 ","pages":"Article 104367"},"PeriodicalIF":3.8,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142757120","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 theoretical freezing model of sandstone considering the statistical arrangement of pore structure","authors":"Hui Zhang ,&nbsp;Yugui Yang ,&nbsp;Chengzheng Cai ,&nbsp;Shanshan Hou ,&nbsp;Chenxiang Li","doi":"10.1016/j.coldregions.2024.104366","DOIUrl":"10.1016/j.coldregions.2024.104366","url":null,"abstract":"<div><div>It is of great significance to understand the evolution law of unfrozen water content in frozen rocks to maintain the stability of geotechnical engineering in cold regions. Due to the different particle sizes and shapes, coupled with the diversity of cements, the internal pore structures of rocks are complex and diverse. In this study, a theoretical model for freezing point of sandstone is proposed based on the characteristics of microscopic pore structures. The characteristic of freezing point is analyzed by considering the mineral particle arrangement. A statistical theoretical model of unfrozen water in sandstone is established according to the random arrangement of mineral particles. The influence of the stacking angle of mineral particles following the normal distribution on unfrozen water content is analyzed. Finally, the NMR freezing process analysis for sandstones was carried out. The results show that the statistical theoretical model of unfrozen water fits the experimental results well. The effect of the average value of stacking angle on unfrozen water content is mainly due to the change of pore size, which leads to the change of pore water content. The standard deviation of stacking angle determines the residual water content.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"230 ","pages":"Article 104366"},"PeriodicalIF":3.8,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705941","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":"Experimental investigation of cyclic responses of frozen soil under principal stress rotation induced by wave loads","authors":"Furong Liu ,&nbsp;Wei Ma ,&nbsp;Zhiwei Zhou ,&nbsp;Zhi Wen ,&nbsp;Mingde Shen ,&nbsp;Ruiqiang Bai","doi":"10.1016/j.coldregions.2024.104368","DOIUrl":"10.1016/j.coldregions.2024.104368","url":null,"abstract":"<div><div>Under the effect of wave loads, continuous and cyclic principal stress rotation (PSR) occurs, with constant principal stress values in foundation soil units. The stability of coastal engineering structures in permafrost regions is inevitably subjected to the persistent impact of wave loads, which poses a significant challenge to their durability. Consequently, a series of experimental studies were carried out using a frozen hollow cylinder apparatus (FHCA) to investigate the influence of crucial three-dimensional stress state parameters, including the coefficient of intermediate principal stress (<em>b</em>), mean principal stress (<em>p</em>), and principal stress rotation radius (<em>R</em>), on the deformation characteristics and dynamic property evolution of frozen soils. The results indicated that under continuous principal stress rotation, the mean principal stress <em>p</em> has a limited impact on the deformation behavior and mechanical property evolution of the frozen soil. In contrast, <em>b</em> and <em>R</em> significantly influence the mechanical properties of frozen soil. When <em>b</em> and <em>R</em> at low values, the continuous rotation of principal stress causes axial strain to develop positively, decreases the mechanical property parameter damping ratio, increases the elastic modulus, and densified the sample. However, with the increase in <em>b</em> and <em>R</em> beyond a threshold, the repeated principal stress rotation causes the axial strain to develop negatively, increases the damping ratio continuously, decreases elastic modulus, and leads to significant softening of the frozen soil with an increase in rotation cycles.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"230 ","pages":"Article 104368"},"PeriodicalIF":3.8,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705937","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":"Chemical composition and properties of Ski wax: A comprehensive analysis of fluorinated, non-fluorinated, and bio-based waxes","authors":"Lorenz Cushman,&nbsp;Justin Zsiros,&nbsp;Gus Kaeding,&nbsp;Jeffrey Bates","doi":"10.1016/j.coldregions.2024.104365","DOIUrl":"10.1016/j.coldregions.2024.104365","url":null,"abstract":"<div><div>This study analyzes the chemical composition and thermal properties of various ski wax materials, including fluorinated, non-fluorinated petroleum-based, and bio-based waxes. Advanced characterization techniques (FTIR, EDS, and DSC) were used to investigate the chemical functionality, elemental composition, and thermal behavior of these waxes. Fluorinated powder waxes were found to be composed almost entirely of fluorocarbons, while solid fluorinated waxes are primarily hydrocarbons with minimal fluorine content. Bio-based waxes exhibit unique ester and carboxylic acid functional groups. Different brands, models, and suggested temperature uses of waxes within the same physical and chemical type show similar chemical compositions. While petroleum-based compared to bio-based waxes show a significant difference in chemical structure. EDS analysis identified silicon, magnesium, and aluminum in certain waxes, possibly indicating the use of additives. DSC results showed similar thermal behavior at sub-freezing temperatures. This research lays the groundwork for understanding ski wax material science and opens up new avenues for future investigation and innovation in the ski and ski wax industry.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"230 ","pages":"Article 104365"},"PeriodicalIF":3.8,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Damage mechanism and energy evolution of frozen soil under coupled compression–shear impact loading","authors":"Zhiwu Zhu ,&nbsp;Taiyu Zhang ,&nbsp;Yanwei Wang ,&nbsp;Yue Ma ,&nbsp;Zhengqiang Cheng","doi":"10.1016/j.coldregions.2024.104361","DOIUrl":"10.1016/j.coldregions.2024.104361","url":null,"abstract":"<div><div>In cold region engineering, the impact of coupled compression–shear loading on frozen soil foundations is a critical issue that urgently needs to be addressed, as it often significantly reduces bearing capacity and can cause structural failures. Accurately characterizing the mechanical behavior of frozen soil under dynamic coupled compression–shear loading is essential for enhancing the safety and stability of cold region engineering projects. This study prepared four frozen-soil specimens with varying tilting angles to investigate failure mechanisms and energy evolution under coupled compression–shear impact loading. The impact-compression experiments were conducted on the specimens under different loading strain rates and temperature conditions using a split Hopkinson pressure bar. The results indicated that the strength of frozen soil was effectively enhanced by higher strain rates and lower temperatures, while it was reduced by increased tilting angle. The fracturing morphology of frozen soil was analyzed from both microscopic and macroscopic perspectives to reveal its failure mechanisms. To quantify the strength characteristics of the frozen soil under various loading conditions, damage variables were defined from an energy-based perspective and incorporated into the Zhu–Wang–Tang viscoelastic constitutive model. Hence, a dynamic constitutive model for frozen soil under coupled compression–shear loading was developed. The model's predictive capability was validated through comparisons with the experimental data, which revealed a high level of agreement. The results of this study provide practical insights into the failure mechanisms and construction design of frozen soil foundations under coupled compression–shear impact loading in cold region engineering.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"230 ","pages":"Article 104361"},"PeriodicalIF":3.8,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705936","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":"Effects of increased rainfall on heat and mass transfer and deformation of sulfate saline soil: An experimental investigation","authors":"Zhixiong Zhou ,&nbsp;Fengxi Zhou ,&nbsp;Mingli Zhang ,&nbsp;Xusheng Wan ,&nbsp;Liujun Zhang","doi":"10.1016/j.coldregions.2024.104363","DOIUrl":"10.1016/j.coldregions.2024.104363","url":null,"abstract":"<div><div>To study the effect of increased rainfall on the heat and mass transfer and deformation characteristics of sulfate saline soil, a geometric similarity ratio model (1:6) of the natural site was created inside the self-developed indoor baseplate-atmospheric dual-temperature control model box. For the first time, combined with the characteristics of the surface energy change, the characteristics of water-heat-salt-mechanical coupling changes within sulfate saline soil under normal rainfall and twice the increase in rainfall were studied. The results show that the increased rainfall leads to a more significant decrease in upward shortwave radiation and downward longwave radiation, as well as a more significant increase in the surface net radiation and surface evaporation rate. Additionally, the increase in rainfall leads to an obvious cooling trend in the surface temperature. Compared with normal rainfall, an increase in rainfall leads to a significant increase in soil water content and conductivity, while soil heat flux and temperature significantly decrease. The increased rainfall caused a temperature drop of 1.6 °C at 5 cm of saline soil. Moreover, the increased rainfall leads to an increase in the heat release time of sulfate saline soil. Meanwhile, the impact of increased rainfall on the soil water content, conductivity, and temperature gradually weakens with increasing depth. The increased rainfall can exacerbate thawing settlement deformation and alleviate salt frost heave deformation. Compared with normal rainfall, twice the increase in rainfall results in a 0.9 mm increase in thawing settlement deformation and a 2.5 mm decrease in salt frost heave deformation.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"230 ","pages":"Article 104363"},"PeriodicalIF":3.8,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705935","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":"Hysteresis of unfrozen water content of tailing mud with freeze-thaw and its correlation with electrical conductivity","authors":"Wanying Xu ,&nbsp;Fangtao She ,&nbsp;Weibin Zeng ,&nbsp;Songhe Wang ,&nbsp;Jiulong Ding ,&nbsp;Xiaoliang Yao ,&nbsp;Guoping Liu ,&nbsp;Lei Li","doi":"10.1016/j.coldregions.2024.104362","DOIUrl":"10.1016/j.coldregions.2024.104362","url":null,"abstract":"<div><div>Identifying the correlation between the hysteresis of unfrozen water content and the electrical conductivity (EC) of tailing mud with freeze-thaw is essential for determining the range of frost hazards in tailings ponds by field conductivity measurement and enabling targeted treatment in coastal and seasonally frozen areas. In this study, dynamics of unfrozen water content and temperature of saturated tailing mud samples with 0.0–5.0 % NaCl were evaluated with 5TM sensor while the EC with the frequency domain reflectometry (FDR) sensor. Results show that unfrozen water hysteresis of tailing mud with freeze-thaw occurred below phase-change temperatures, with the cooling section above the warming. The area of hysteresis curve rose upon higher salinity or fewer freeze-thaw cycles. Phase-change temperatures of tailing mud, including freezing and thawing points, depressed with higher salinity but were less affected by freeze-thaw cycles, with the former coinciding with the liquidus line of NaCl solution while the latter located above. The EC curve also exhibits hysteresis with freeze-thaw and the initial salinity determines both the maximum EC value and the slope logEC/<em>T</em> below phase-change temperatures. It was concluded that the unfrozen water content, converted salt concentration and EC of frozen tailing mud show synchronous changes. A modified Michalowski model, with phase-change temperatures and residual unfrozen water content respectively simplified as proportional and exponential functions of initial salinity, was established to characterize the unfrozen water hysteresis of tailing mud with freeze-thaw cycles. A simple EC model with hysteresis was then developed by approximating the EC of frozen tailing mud as a power function of the converted salt concentration, which was applied to the tailing mud with 0.5–5.0 % NaCl in the range of −20 °C up to phase-change temperatures.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"229 ","pages":"Article 104362"},"PeriodicalIF":3.8,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661638","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}