Chao-Wei Wang , Yan-Hui You , Bin Yao , Bin Liu , Pei-Heng Guo , Lei Guo , Xin-Bin Wang , Qi-Hao Yu
{"title":"青藏高原冻土区现浇基脚的地温和变形监测","authors":"Chao-Wei Wang , Yan-Hui You , Bin Yao , Bin Liu , Pei-Heng Guo , Lei Guo , Xin-Bin Wang , Qi-Hao Yu","doi":"10.1016/j.accre.2024.08.002","DOIUrl":null,"url":null,"abstract":"<div><div>The long-term stability of the cast-in-place footings in permafrost regions has received much attention due to its climate sensitivity. The current research lacks long-term data validation, especially in the context of climate change. Based on the 13-year (2011–2023) temperature and deformation monitoring data from the Qinghai‒Tibet Power Transmission Line, this study investigates the characteristics of permafrost variation and its impact on the stability of tower footings under the cooling effect from thermosyphons. The results reveal that the thermosyphons effectively reduce the ground temperature around the footings. After the first freeze‒thaw cycle, the soil around the tower footings completed refreezing and maintained a frozen state. In the following 13 years, the ground temperature continued to decrease due to the cooling effect of thermosyphons. The duration notably exceeded the previously predicted 5 years. The temperature reduction at the base of the footings corresponded well with the frost jacking of the tower footings and could be divided into three distinct phases. In phase 1, the ground temperature around the footings rapidly reduced, approaching that of the natural field, while the footings experienced pronounced deformation. In phase 2, the ground temperature decreased at a faster rate, and the deformation rate of the footings slowed down. In phase 3, the frost jacking of the footings gradually retarded with the decrease in base temperature. Additionally, the ground temperature differences of over 1 °C were observed among different tower footings, which may lead to the differential deformation among the tower footings. The ground temperature differentiation is attributed to the difference in solar radiation intensity, which is shaded by the tower structure from different directions. This study provides theoretical support and empirical accumulation for the construction and maintenance of tower footings in permafrost regions.</div></div>","PeriodicalId":48628,"journal":{"name":"Advances in Climate Change Research","volume":"15 5","pages":"Pages 963-975"},"PeriodicalIF":6.4000,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Monitoring ground temperature and deformation of the cast-in-place footings in permafrost regions on the Qinghai‒Tibet Plateau\",\"authors\":\"Chao-Wei Wang , Yan-Hui You , Bin Yao , Bin Liu , Pei-Heng Guo , Lei Guo , Xin-Bin Wang , Qi-Hao Yu\",\"doi\":\"10.1016/j.accre.2024.08.002\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>The long-term stability of the cast-in-place footings in permafrost regions has received much attention due to its climate sensitivity. The current research lacks long-term data validation, especially in the context of climate change. Based on the 13-year (2011–2023) temperature and deformation monitoring data from the Qinghai‒Tibet Power Transmission Line, this study investigates the characteristics of permafrost variation and its impact on the stability of tower footings under the cooling effect from thermosyphons. The results reveal that the thermosyphons effectively reduce the ground temperature around the footings. After the first freeze‒thaw cycle, the soil around the tower footings completed refreezing and maintained a frozen state. In the following 13 years, the ground temperature continued to decrease due to the cooling effect of thermosyphons. The duration notably exceeded the previously predicted 5 years. The temperature reduction at the base of the footings corresponded well with the frost jacking of the tower footings and could be divided into three distinct phases. In phase 1, the ground temperature around the footings rapidly reduced, approaching that of the natural field, while the footings experienced pronounced deformation. In phase 2, the ground temperature decreased at a faster rate, and the deformation rate of the footings slowed down. In phase 3, the frost jacking of the footings gradually retarded with the decrease in base temperature. Additionally, the ground temperature differences of over 1 °C were observed among different tower footings, which may lead to the differential deformation among the tower footings. The ground temperature differentiation is attributed to the difference in solar radiation intensity, which is shaded by the tower structure from different directions. This study provides theoretical support and empirical accumulation for the construction and maintenance of tower footings in permafrost regions.</div></div>\",\"PeriodicalId\":48628,\"journal\":{\"name\":\"Advances in Climate Change Research\",\"volume\":\"15 5\",\"pages\":\"Pages 963-975\"},\"PeriodicalIF\":6.4000,\"publicationDate\":\"2024-10-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Advances in Climate Change Research\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S1674927824001151\",\"RegionNum\":1,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"ENVIRONMENTAL SCIENCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Advances in Climate Change Research","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1674927824001151","RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}
Monitoring ground temperature and deformation of the cast-in-place footings in permafrost regions on the Qinghai‒Tibet Plateau
The long-term stability of the cast-in-place footings in permafrost regions has received much attention due to its climate sensitivity. The current research lacks long-term data validation, especially in the context of climate change. Based on the 13-year (2011–2023) temperature and deformation monitoring data from the Qinghai‒Tibet Power Transmission Line, this study investigates the characteristics of permafrost variation and its impact on the stability of tower footings under the cooling effect from thermosyphons. The results reveal that the thermosyphons effectively reduce the ground temperature around the footings. After the first freeze‒thaw cycle, the soil around the tower footings completed refreezing and maintained a frozen state. In the following 13 years, the ground temperature continued to decrease due to the cooling effect of thermosyphons. The duration notably exceeded the previously predicted 5 years. The temperature reduction at the base of the footings corresponded well with the frost jacking of the tower footings and could be divided into three distinct phases. In phase 1, the ground temperature around the footings rapidly reduced, approaching that of the natural field, while the footings experienced pronounced deformation. In phase 2, the ground temperature decreased at a faster rate, and the deformation rate of the footings slowed down. In phase 3, the frost jacking of the footings gradually retarded with the decrease in base temperature. Additionally, the ground temperature differences of over 1 °C were observed among different tower footings, which may lead to the differential deformation among the tower footings. The ground temperature differentiation is attributed to the difference in solar radiation intensity, which is shaded by the tower structure from different directions. This study provides theoretical support and empirical accumulation for the construction and maintenance of tower footings in permafrost regions.
期刊介绍:
Advances in Climate Change Research publishes scientific research and analyses on climate change and the interactions of climate change with society. This journal encompasses basic science and economic, social, and policy research, including studies on mitigation and adaptation to climate change.
Advances in Climate Change Research attempts to promote research in climate change and provide an impetus for the application of research achievements in numerous aspects, such as socioeconomic sustainable development, responses to the adaptation and mitigation of climate change, diplomatic negotiations of climate and environment policies, and the protection and exploitation of natural resources.