Cold Regions Science and Technology最新文献_第7页

Mapping snow gliding distances: Bridging modelled and field observations

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2024-12-16 DOI: 10.1016/j.coldregions.2024.104402

Surya Gupta , Lauren Zweifel , Axel Birkholz , Katrin Meusburger , Georg Leitinger , Christine Alewell

Snow gliding affects soil erosion patterns and depends on various factors such as slope angle, precipitation amount, and vegetation roughness. Snow gliding distance can be assessed through measurement or modeling. However, the comparison of measured with modelled data remains limited due to the scarcity of measured data. We present a long-term dataset (2010−2021) of measured snow gliding distances for two Swiss alpine Valleys (Urseren and Val Piora) using glide shoes to address this gap. We also predicted snow gliding between 2010 and 2021 using the spatial snow gliding distance model developed by Leitinger et al. (2018). Our analysis of the measured data indicates that sites with a north aspect generally exhibit shorter snow gliding distances than those facing south. Moreover, we observed an increase in snow gliding distance with steeper slope angles and a decrease with a higher roughness coefficient. Comparing measured and modelled values, the R² and Concordance Correlation Coefficient (CCC) values are 0.23 and 0.12 for the Urseren Valley and 0.24 and 0.35 for the Val Piora. Generally, the model tended to predict higher values than the measured data for both Valleys, potentially due to the large small-scale variability observed in the replicates of the measured data that cannot be caught with large-scale models. This variability highlights the dynamic nature of snow gliding distance, making it challenging to model or measure accurately. Furthermore, a covariate importance analysis revealed precipitation and slope angle as the dominant drivers of modelled snow gliding distances versus vegetation roughness (a rather local feature) for measured values.

{"title":"Mapping snow gliding distances: Bridging modelled and field observations","authors":"Surya Gupta , Lauren Zweifel , Axel Birkholz , Katrin Meusburger , Georg Leitinger , Christine Alewell","doi":"10.1016/j.coldregions.2024.104402","DOIUrl":"10.1016/j.coldregions.2024.104402","url":null,"abstract":"<div><div>Snow gliding affects soil erosion patterns and depends on various factors such as slope angle, precipitation amount, and vegetation roughness. Snow gliding distance can be assessed through measurement or modeling. However, the comparison of measured with modelled data remains limited due to the scarcity of measured data. We present a long-term dataset (2010−2021) of measured snow gliding distances for two Swiss alpine Valleys (Urseren and Val Piora) using glide shoes to address this gap. We also predicted snow gliding between 2010 and 2021 using the spatial snow gliding distance model developed by Leitinger et al. (2018). Our analysis of the measured data indicates that sites with a north aspect generally exhibit shorter snow gliding distances than those facing south. Moreover, we observed an increase in snow gliding distance with steeper slope angles and a decrease with a higher roughness coefficient. Comparing measured and modelled values, the R<sup>2</sup> and Concordance Correlation Coefficient (CCC) values are 0.23 and 0.12 for the Urseren Valley and 0.24 and 0.35 for the Val Piora. Generally, the model tended to predict higher values than the measured data for both Valleys, potentially due to the large small-scale variability observed in the replicates of the measured data that cannot be caught with large-scale models. This variability highlights the dynamic nature of snow gliding distance, making it challenging to model or measure accurately. Furthermore, a covariate importance analysis revealed precipitation and slope angle as the dominant drivers of modelled snow gliding distances versus vegetation roughness (a rather local feature) for measured values.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"231 ","pages":"Article 104402"},"PeriodicalIF":3.8,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143155349","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}

引用次数: 0

A numerical study of process complexity in permafrost dominated regions

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2024-12-14 DOI: 10.1016/j.coldregions.2024.104399

Radhakrishna Bangalore Lakshmiprasad , Fan Zhang , Ethan T. Coon , Thomas Graf

Numerical modeling of permafrost dynamics requires adequate representation of atmospheric and surface processes, a reasonable parameter estimation strategy, and site-specific model development. The three main research objectives of the study are: (i) to propose a novel methodology that determines the required level of surface process complexity of permafrost models by conducting parameter sensitivity and calibration, (ii) to design and compare three numerical models of increasing surface process complexity, and (iii) to calibrate and validate the numerical models at the Yakou catchment on the Qinghai-Tibet Plateau as an exemplary study site. The calibration was carried out by coupling the Advanced Terrestrial Simulator (numerical model) and PEST (calibration tool). Simulation results showed that (i) A simple numerical model that considers only subsurface processes can simulate active layer development with the same accuracy as other more complex models that include surface processes. (ii) Peat and mineral soil layer permeability, Van Genuchten alpha, and porosity are highly sensitive. (iii) Liquid precipitation aids in increasing the rate of permafrost degradation. (iv) Deposition of snow insulated the subsurface during the thaw initiation period. We have developed and released an integrated code that couples the numerical software ATS to the calibration software PEST. The numerical model can be further used to determine the impacts of climate change on permafrost degradation.

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引用次数: 0

Experimental assessment of rigid surface collision effects on suspended ice particles

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2024-12-10 DOI: 10.1016/j.coldregions.2024.104394

Zonghui Liu , Xueqin Bu , Guiping Lin , Ping Huang , Yuli Chen , Dongsheng Wen

In glaciated icing conditions, when the aircraft impacts ice particles in the cloud, the ice particles may rebound, fragment or stick to the aircraft surface, further affecting the ice accretion process. However, the fragmentation mechanism particularly near the minor fragmentation zone is complex and not clear. Here, two particle diameter levels (1.24 mm and 1.56 mm) and three impact velocity levels (7 m/s, 10 m/s, 16 m/s) were set to perform ice particle impact experiment on the self-developed high-speed ice particle impact experimental setup. A Kalman filter tracking algorithm and a projective stereological method were improved and used to track and calculate the volume of the fragments, respectively. According to the statistical analysis of the experimental results, it was found that the impact character number ξ is a valid dimensionless number for measuring the degree of fragmentation. The results of the fragment volume calculation were then verified and it was found that the addition of the semi-ellipsoid shape improves the accuracy of the calculation, reducing the mean relative error by more than 9 %. Finally, a correlation between the impact character number ξ and the distribution exponent

\hat{Ψ}

was obtained. Combined with the fragmentation mode probability model and the estimate correlation for the upper cut-off position, a possible model for the fragment volume distribution near the minor fragmentation zone was constructed. Due to the existence of scale invariance and the dimensionless number in this model, it may be applicable to a higher range of ξ.

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引用次数: 0

Field monitoring study of bedrock weathering on the southern flank of the Hengduan Mountains in Southeast Tibet

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2024-12-10 DOI: 10.1016/j.coldregions.2024.104398

Liping Wang , Zhexiao Hao , Honggang Zhang , Chenlei Zheng , Weiyu Wu , Xiaoliang Yao

This study aims to reveal the patterns and influencing factors of bedrock weathering in the high-altitude cold regions on the southern flank of the Hengduan Mountains in southeastern Tibet. Based on the site characteristics, we designed and installed a simple, practical, and cost-effective remote online monitoring system. Data were collected from April 2023 to April 2024, covering the temperature of the rock surface air and at various depths within the rock, as well as the temperature, humidity, and width changes within rock fractures. The results indicate that for bedrock located on sunny slopes with relatively little rain and snow, the daily maximum temperatures on the rock surface and in shallow layers exceed the daily maximum air temperature due to solar radiation. Specifically, the daily maximum air temperature at the rock surface is approximately 5–20 °C higher than the maximum air temperature, resulting in an actual daily temperature difference of 30–40 °C on the rock surface air. Therefore, using air temperature as the boundary condition for this type of bedrock is inappropriate. For rock fractures connected to the external environment, the daily average temperature within the fracture is generally 3–8 °C higher than the daily average air temperature, and the range of temperature variation within the fracture is smaller than that of the external air temperature. However, due to differences in fracture width and depth, the humidity within fractures shows significant variation. For such slope bedrock, temperature variations in spring, summer, and autumn, rather than freeze-thaw cycles in winter, may be the primary cause of rock weathering. This study provides scientific support for engineering construction in cold regions and valuable field data to refine the theory of alpine bedrock weathering.

{"title":"Field monitoring study of bedrock weathering on the southern flank of the Hengduan Mountains in Southeast Tibet","authors":"Liping Wang , Zhexiao Hao , Honggang Zhang , Chenlei Zheng , Weiyu Wu , Xiaoliang Yao","doi":"10.1016/j.coldregions.2024.104398","DOIUrl":"10.1016/j.coldregions.2024.104398","url":null,"abstract":"<div><div>This study aims to reveal the patterns and influencing factors of bedrock weathering in the high-altitude cold regions on the southern flank of the Hengduan Mountains in southeastern Tibet. Based on the site characteristics, we designed and installed a simple, practical, and cost-effective remote online monitoring system. Data were collected from April 2023 to April 2024, covering the temperature of the rock surface air and at various depths within the rock, as well as the temperature, humidity, and width changes within rock fractures. The results indicate that for bedrock located on sunny slopes with relatively little rain and snow, the daily maximum temperatures on the rock surface and in shallow layers exceed the daily maximum air temperature due to solar radiation. Specifically, the daily maximum air temperature at the rock surface is approximately 5–20 °C higher than the maximum air temperature, resulting in an actual daily temperature difference of 30–40 °C on the rock surface air. Therefore, using air temperature as the boundary condition for this type of bedrock is inappropriate. For rock fractures connected to the external environment, the daily average temperature within the fracture is generally 3–8 °C higher than the daily average air temperature, and the range of temperature variation within the fracture is smaller than that of the external air temperature. However, due to differences in fracture width and depth, the humidity within fractures shows significant variation. For such slope bedrock, temperature variations in spring, summer, and autumn, rather than freeze-thaw cycles in winter, may be the primary cause of rock weathering. This study provides scientific support for engineering construction in cold regions and valuable field data to refine the theory of alpine bedrock weathering.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"231 ","pages":"Article 104398"},"PeriodicalIF":3.8,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143154428","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}

引用次数: 0

Hydro-thermal-mechanical characteristics and sustainability of geopolymer solidified soils incorporating nano-silica in cold regions

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2024-12-09 DOI: 10.1016/j.coldregions.2024.104397

Fei Deng , Jianguo Lu , Mingyi Zhang , Wansheng Pei , Xusheng Wan , Zhongrui Yan

Geopolymer has being emerged as a promising alternative to traditional Portland cement in geotechnical engineering, particularly for subgrade applications in cold regions, owing to its eco-friendly and high-performance characteristics. However, exposing geopolymer solidified soils (GSSs) to cold environments can deteriorate the mechanical properties. Hence, it is crucial to improve the mechanical properties and freeze-thaw resistance of the GSSs. In this study, the unconfined compressive strength (UCS), hydro-thermal-deformation characteristics, and microstructure of the nano-silica geopolymer solidified soils (NSGSSs) were experimentally investigated, and the sustainability of the NSGSSs was assessed. The results showed that under the same strain condition, the stresses of the NSGSSs were larger than those of the GSSs. Besides, the UCS of the NSGSSs firstly increased and then decreased with nano-silica (NS) content, with the GSSs containing 3 wt% NS demonstrating the highest peak stress. The UCS loss rate increased with the freeze-thaw cycles (FTCs) and then stabilized, with the first FTC having the most significant impact on the UCS of the soil samples. During the FTCs, the NSGSSs exhibited a larger amplitude of soil temperature variation and residual volumetric unfrozen water content compared to the GSSs. However, the vertical deformation, frost heave and thaw settlement rates of the NSGSSs were markedly smaller than those of the GSSs. After the 9th FTC, the NSGSSs with 3 wt% NS content showed a denser structure and excellent freeze-thaw resistance. Moreover, although adding NS to GSSs increased carbon emissions and costs, the low values of the carbon emission index and economic efficiency index indicated that the substantial improvement in mechanical properties outweighed these negative aspects, particularly for the NSGSSs exposed to the FTCs. This study would provide valuable insights into the development of new eco-friendly materials and offers a novel approach for frost heave prevention and control in cold region geotechnical engineering.

{"title":"Hydro-thermal-mechanical characteristics and sustainability of geopolymer solidified soils incorporating nano-silica in cold regions","authors":"Fei Deng , Jianguo Lu , Mingyi Zhang , Wansheng Pei , Xusheng Wan , Zhongrui Yan","doi":"10.1016/j.coldregions.2024.104397","DOIUrl":"10.1016/j.coldregions.2024.104397","url":null,"abstract":"<div><div>Geopolymer has being emerged as a promising alternative to traditional Portland cement in geotechnical engineering, particularly for subgrade applications in cold regions, owing to its eco-friendly and high-performance characteristics. However, exposing geopolymer solidified soils (GSSs) to cold environments can deteriorate the mechanical properties. Hence, it is crucial to improve the mechanical properties and freeze-thaw resistance of the GSSs. In this study, the unconfined compressive strength (UCS), hydro-thermal-deformation characteristics, and microstructure of the nano-silica geopolymer solidified soils (NSGSSs) were experimentally investigated, and the sustainability of the NSGSSs was assessed. The results showed that under the same strain condition, the stresses of the NSGSSs were larger than those of the GSSs. Besides, the UCS of the NSGSSs firstly increased and then decreased with nano-silica (NS) content, with the GSSs containing 3 wt% NS demonstrating the highest peak stress. The UCS loss rate increased with the freeze-thaw cycles (FTCs) and then stabilized, with the first FTC having the most significant impact on the UCS of the soil samples. During the FTCs, the NSGSSs exhibited a larger amplitude of soil temperature variation and residual volumetric unfrozen water content compared to the GSSs. However, the vertical deformation, frost heave and thaw settlement rates of the NSGSSs were markedly smaller than those of the GSSs. After the 9<em>th</em> FTC, the NSGSSs with 3 wt% NS content showed a denser structure and excellent freeze-thaw resistance. Moreover, although adding NS to GSSs increased carbon emissions and costs, the low values of the carbon emission index and economic efficiency index indicated that the substantial improvement in mechanical properties outweighed these negative aspects, particularly for the NSGSSs exposed to the FTCs. This study would provide valuable insights into the development of new eco-friendly materials and offers a novel approach for frost heave prevention and control in cold region geotechnical engineering.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"231 ","pages":"Article 104397"},"PeriodicalIF":3.8,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143154442","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}

引用次数: 0

Image based ice-field characterization and load prediction in managed ice field

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2024-12-09 DOI: 10.1016/j.coldregions.2024.104381

Shamima Akter , Syed Imtiaz , Mohammed Islam , Salim Ahmed , Hasanat Zaman , Robert Gash

Accurate modelling of ice properties and ice-structure interaction forces is important for operations of ships and offshore platforms in ice-infested water. Extraction of ice features from real-time videos and images can significantly improve ice force prediction. However, accurate extraction of ice floe information is challenging due to several inherent complexities in ice images. This paper presents an ice image processing technique which can extract useful ice properties from a closely connected, unevenly illuminated floe field (with various floe sizes and shapes) with higher precision, compared to similar existing models. Several image processing features, including histogram equalization, wavelet denoising, gradient flow vector, snake algorithm, and distance transformation were applied for extracting ice features. The effectiveness of the proposed method is demonstrated through the processing of simulated and managed ice field images from ice tank, and its performance is compared with two other existing models. The new model detected the total number of floes with more than 80 % accuracy and ice concentration at 95 % and above accuracy for ice basin test images. It is also nearly 50 % faster compared to the previous model. The extracted ice features' information is then used to train and test two separate force predictors based on Support Vector Machine (SVM) and Feedforward Neural Network (FFNN). This work is a first step towards developing an image-based force prediction tool from real-life ice field.

{"title":"Image based ice-field characterization and load prediction in managed ice field","authors":"Shamima Akter , Syed Imtiaz , Mohammed Islam , Salim Ahmed , Hasanat Zaman , Robert Gash","doi":"10.1016/j.coldregions.2024.104381","DOIUrl":"10.1016/j.coldregions.2024.104381","url":null,"abstract":"<div><div>Accurate modelling of ice properties and ice-structure interaction forces is important for operations of ships and offshore platforms in ice-infested water. Extraction of ice features from real-time videos and images can significantly improve ice force prediction. However, accurate extraction of ice floe information is challenging due to several inherent complexities in ice images. This paper presents an ice image processing technique which can extract useful ice properties from a closely connected, unevenly illuminated floe field (with various floe sizes and shapes) with higher precision, compared to similar existing models. Several image processing features, including histogram equalization, wavelet denoising, gradient flow vector, snake algorithm, and distance transformation were applied for extracting ice features. The effectiveness of the proposed method is demonstrated through the processing of simulated and managed ice field images from ice tank, and its performance is compared with two other existing models. The new model detected the total number of floes with more than 80 % accuracy and ice concentration at 95 % and above accuracy for ice basin test images. It is also nearly 50 % faster compared to the previous model. The extracted ice features' information is then used to train and test two separate force predictors based on Support Vector Machine (SVM) and Feedforward Neural Network (FFNN). This work is a first step towards developing an image-based force prediction tool from real-life ice field.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"231 ","pages":"Article 104381"},"PeriodicalIF":3.8,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143155351","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}

引用次数: 0

Safety assessment of the Qinghai–Tibet railway: Monitoring, analysis, and prediction

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2024-12-09 DOI: 10.1016/j.coldregions.2024.104395

Mengyuan Zhu , Hui Liu , Changwei Miao , Geshuang Li , Yu Zhang , Yang Zhou , Jianao Cai , Shiji Yang , Yuanxi Wang , Yichuan Wang , Wenfei Zhao

The temporal and spatial evolution regularity of the surface along the Qinghai–Tibet railway (QTR) have been examined, and intelligently sensing the potential risks is of considerable importance to its safe operation. 1166 Sentinel-1 A images from Jan. 2017 to Apr. 2023 were collected to obtain·1956 km of surface deformation along the QTR using the Small Baseline Subset Interferometric Synthetic Aperture Radar (SBAS-InSAR) technique. Satellite + UAV multi-scale 3D modeling was used with Beijing 3 (BJ-3) satellite images and key tunnel entrance drone images. Risk assessment of key geologic hazards and 3D reality verification was performed along the QTR. The QTR surface deformation was unevenly scattered in space and the maximum annual deformation rates recorded were 26 mm/year. In the permafrost region, railway deformation settled at a constant rate in the warm season and rose slowly in the cold season. Under climate warming, the warm season gradually became longer than the cold season. Adding precipitation and temperature to the analysis showed that the deformation in permafrost regions had significant aggregation characteristics. A large deformation along the railway occurred, and human activities were frequent. The reliability of the InSAR technique was verified by using Global Navigation Satellite System (GNSS) reference data along QTR. InSAR results correlated strongly with GNSS data. The Tent Mapping Sparrow Search Algorithm Long Short-Term Memory (Tent-SSA-LSTM) was proposed to forecast the forthcoming deformation along the QTR to achieve early detection and early warning. Compared with the traditional prediction model, evaluation increased by 34.1 %, 40.1 %, and 36.3 %, respectively. The findings can provide a scientific foundation for pertinent government departments in rescue and disaster prevention.

{"title":"Safety assessment of the Qinghai–Tibet railway: Monitoring, analysis, and prediction","authors":"Mengyuan Zhu , Hui Liu , Changwei Miao , Geshuang Li , Yu Zhang , Yang Zhou , Jianao Cai , Shiji Yang , Yuanxi Wang , Yichuan Wang , Wenfei Zhao","doi":"10.1016/j.coldregions.2024.104395","DOIUrl":"10.1016/j.coldregions.2024.104395","url":null,"abstract":"<div><div>The temporal and spatial evolution regularity of the surface along the Qinghai–Tibet railway (QTR) have been examined, and intelligently sensing the potential risks is of considerable importance to its safe operation. 1166 Sentinel-1 A images from Jan. 2017 to Apr. 2023 were collected to obtain·1956 km of surface deformation along the QTR using the Small Baseline Subset Interferometric Synthetic Aperture Radar (SBAS-InSAR) technique. Satellite + UAV multi-scale 3D modeling was used with Beijing 3 (BJ-3) satellite images and key tunnel entrance drone images. Risk assessment of key geologic hazards and 3D reality verification was performed along the QTR. The QTR surface deformation was unevenly scattered in space and the maximum annual deformation rates recorded were 26 mm/year. In the permafrost region, railway deformation settled at a constant rate in the warm season and rose slowly in the cold season. Under climate warming, the warm season gradually became longer than the cold season. Adding precipitation and temperature to the analysis showed that the deformation in permafrost regions had significant aggregation characteristics. A large deformation along the railway occurred, and human activities were frequent. The reliability of the InSAR technique was verified by using Global Navigation Satellite System (GNSS) reference data along QTR. InSAR results correlated strongly with GNSS data. The Tent Mapping Sparrow Search Algorithm Long Short-Term Memory (Tent-SSA-LSTM) was proposed to forecast the forthcoming deformation along the QTR to achieve early detection and early warning. Compared with the traditional prediction model, evaluation increased by 34.1 %, 40.1 %, and 36.3 %, respectively. The findings can provide a scientific foundation for pertinent government departments in rescue and disaster prevention.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"231 ","pages":"Article 104395"},"PeriodicalIF":3.8,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143154441","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}

引用次数: 0

Response characteristic parameters of six-bundle conductor lines in ultra-heavy ice zones following ice-shedding

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2024-12-08 DOI: 10.1016/j.coldregions.2024.104396

Yu Teng, Bo Yan, Xinrui Zhou, Hao Yang, Yingbo Gao, Kaiwen Wu, Huachao Deng

For a transmission line passing through ultra-heavy ice zones, the ice on the conductor line may be thicker than 50 mm, and in this case small initial tension in the conductor lines leads to obvious nonlinear vibration following ice-shedding. In this paper, dynamic responses of six-bundle conductor lines in ultra-heavy ice zones are numerically simulated by means of the nonlinear geometric finite element (FE) method, which is verified by reduced-scale modeling test. The jump height, axial unbalanced force and transverse swing of conductor lines following ice-shedding are defined to reflect the characteristics of the dynamic responses. Parameter study on the dynamic responses of isolated-span and multi-span lines with different structural, icing, ice-shedding, and wind parameters following ice-shedding is carried out and a dataset is then created. Using the dataset and the extra-trees machine learning algorithm, prediction models for the dynamic response parameters are created and the software is developed. Estimation formulas for the maximum jump height and transverse swing of multi-span lines in ultra-heavy ice zones are proposed. The obtained results provide a foundation for the design of the electric insulation clearance and structure strength of the six-bundle conductor lines in ultra-heavy ice zones.

{"title":"Response characteristic parameters of six-bundle conductor lines in ultra-heavy ice zones following ice-shedding","authors":"Yu Teng, Bo Yan, Xinrui Zhou, Hao Yang, Yingbo Gao, Kaiwen Wu, Huachao Deng","doi":"10.1016/j.coldregions.2024.104396","DOIUrl":"10.1016/j.coldregions.2024.104396","url":null,"abstract":"<div><div>For a transmission line passing through ultra-heavy ice zones, the ice on the conductor line may be thicker than 50 mm, and in this case small initial tension in the conductor lines leads to obvious nonlinear vibration following ice-shedding. In this paper, dynamic responses of six-bundle conductor lines in ultra-heavy ice zones are numerically simulated by means of the nonlinear geometric finite element (FE) method, which is verified by reduced-scale modeling test. The jump height, axial unbalanced force and transverse swing of conductor lines following ice-shedding are defined to reflect the characteristics of the dynamic responses. Parameter study on the dynamic responses of isolated-span and multi-span lines with different structural, icing, ice-shedding, and wind parameters following ice-shedding is carried out and a dataset is then created. Using the dataset and the extra-trees machine learning algorithm, prediction models for the dynamic response parameters are created and the software is developed. Estimation formulas for the maximum jump height and transverse swing of multi-span lines in ultra-heavy ice zones are proposed. The obtained results provide a foundation for the design of the electric insulation clearance and structure strength of the six-bundle conductor lines in ultra-heavy ice zones.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"231 ","pages":"Article 104396"},"PeriodicalIF":3.8,"publicationDate":"2024-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143154425","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}

引用次数: 0

In-situ characterization of wave velocity in ice cover with seismic observation on guided wave

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2024-12-05 DOI: 10.1016/j.coldregions.2024.104392

Jiahui Gao , Yuxiang Zhang , Dingyi Ma , Zhinan Xie , Anliang Wang , Haonan Zhang

In-situ characterization of the acoustic velocity of sea ice is crucial for the successful application of related technologies. However, the elastic waveguide properties of ice sheets convert the acoustic energy into elastic waves of different modes. The overlap in both time and frequency domains poses significant challenges to the accuracy and feasibility of wave velocity estimation. A method for in-situ characterization of wave velocity in ice is proposed. Guided waves are generated through a unidirectional impact on the upper surface of the ice, and the resulting wavefield is collected within a close range using multi-wave, multi-component observations. By applying filters designed based on the polarization features, the wave packets of the S0 mode and SH waves are isolated. The arrival times of these waves are then used to estimate their respective propagation velocities. The propagation velocity of the S0 mode at low frequencies is approximated with that of the longitudinal wave in plate. The resulting propagation velocities of the longitudinal and shear waves are found to be consistent with previously reported results. A quantitative analysis of the uncertainty in velocity estimation is also included to identify the main causes and discuss potential solutions.

{"title":"In-situ characterization of wave velocity in ice cover with seismic observation on guided wave","authors":"Jiahui Gao , Yuxiang Zhang , Dingyi Ma , Zhinan Xie , Anliang Wang , Haonan Zhang","doi":"10.1016/j.coldregions.2024.104392","DOIUrl":"10.1016/j.coldregions.2024.104392","url":null,"abstract":"<div><div>In-situ characterization of the acoustic velocity of sea ice is crucial for the successful application of related technologies. However, the elastic waveguide properties of ice sheets convert the acoustic energy into elastic waves of different modes. The overlap in both time and frequency domains poses significant challenges to the accuracy and feasibility of wave velocity estimation. A method for in-situ characterization of wave velocity in ice is proposed. Guided waves are generated through a unidirectional impact on the upper surface of the ice, and the resulting wavefield is collected within a close range using multi-wave, multi-component observations. By applying filters designed based on the polarization features, the wave packets of the S0 mode and SH waves are isolated. The arrival times of these waves are then used to estimate their respective propagation velocities. The propagation velocity of the S0 mode at low frequencies is approximated with that of the longitudinal wave in plate. The resulting propagation velocities of the longitudinal and shear waves are found to be consistent with previously reported results. A quantitative analysis of the uncertainty in velocity estimation is also included to identify the main causes and discuss potential solutions.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"231 ","pages":"Article 104392"},"PeriodicalIF":3.8,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143154424","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}

引用次数: 0

Study on icing characteristics of bundled conductor of transmission line based on shadowing effect analysis

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2024-12-04 DOI: 10.1016/j.coldregions.2024.104393

Yafei Huang , Yangning Chen , Xin Yang , Zhongyi Yang , Zhan Ouyang , Xingliang Jiang , Muhammad S. Virk

Icing on transmission lines significantly threatens the safety and stability of power system. Particularly for bundled conductors, the shadowing effect of the upwind conductor on the downwind one affects airflow and droplet distribution, leading to unique icing characteristics. This paper employs numerical simulations and icing tests to investigate the icing shadowing effect of bundled conductors. Firstly, the distributions of airflow and droplets around the bundled conductor are solved by the Eulerian-Eulerian two-phase flow model. Then, by solving mass and thermodynamic balance equations, the icing mass and shape accreted on the bundled conductors under various icing conditions are obtained. Further, two novel parameters, the shadowing coefficient and the offset angle, are introduced to quantify the shadowing effect's impact on ice mass and shape. The findings indicate that the ice mass ratio on the downwind conductor to the upwind conductor is influenced by wind speed, wind angle, bundle spacing, conductor diameter, and droplet parameters. In most cases, the ratio is less than 1; however, under certain wind angles, this ratio exceeds 1. The shadowing effect also impacts the ice shape on the downwind conductor, inducing an additional offset in the ice shape. The magnitude of this offset angle is also correlated with environmental parameters. Finally, the accuracy of our numerical simulations is validated by the outcomes of natural icing tests.

{"title":"Study on icing characteristics of bundled conductor of transmission line based on shadowing effect analysis","authors":"Yafei Huang , Yangning Chen , Xin Yang , Zhongyi Yang , Zhan Ouyang , Xingliang Jiang , Muhammad S. Virk","doi":"10.1016/j.coldregions.2024.104393","DOIUrl":"10.1016/j.coldregions.2024.104393","url":null,"abstract":"<div><div>Icing on transmission lines significantly threatens the safety and stability of power system. Particularly for bundled conductors, the shadowing effect of the upwind conductor on the downwind one affects airflow and droplet distribution, leading to unique icing characteristics. This paper employs numerical simulations and icing tests to investigate the icing shadowing effect of bundled conductors. Firstly, the distributions of airflow and droplets around the bundled conductor are solved by the Eulerian-Eulerian two-phase flow model. Then, by solving mass and thermodynamic balance equations, the icing mass and shape accreted on the bundled conductors under various icing conditions are obtained. Further, two novel parameters, the shadowing coefficient and the offset angle, are introduced to quantify the shadowing effect's impact on ice mass and shape. The findings indicate that the ice mass ratio on the downwind conductor to the upwind conductor is influenced by wind speed, wind angle, bundle spacing, conductor diameter, and droplet parameters. In most cases, the ratio is less than 1; however, under certain wind angles, this ratio exceeds 1. The shadowing effect also impacts the ice shape on the downwind conductor, inducing an additional offset in the ice shape. The magnitude of this offset angle is also correlated with environmental parameters. Finally, the accuracy of our numerical simulations is validated by the outcomes of natural icing tests.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"231 ","pages":"Article 104393"},"PeriodicalIF":3.8,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143155031","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}

引用次数: 0