Construction of power transmission lines is becoming an important part of permafrost engineering in China.This paper reviews the construction status and problems of transmission lines in different countries,as well as...Construction of power transmission lines is becoming an important part of permafrost engineering in China.This paper reviews the construction status and problems of transmission lines in different countries,as well as corresponding solutions that would be of practical significance for sustainable engineering practices.Russia has the longest history of transmission line construction in permafrost areas,with transmission lines（mainly 220 kV and 500 kV） spanning approximately 100,000 km.However,all countries suffer from permafrost-related tower foundation stability problems caused by freezing-thawing hazards such as frost heave and thaw settlement,frost lifting,and harmful cryogenic phenomena.As point-line transmission line constructions,the lines,poles and towers should be reasonably selected and installed with a comprehensive consideration of frozen soil characteristics to effectively reduce the occurrence of freezing-thawing disasters.Reinforced concrete pile foundations are widely used in the permafrost regions,and construction in winter is also a universal practice.Moreover,facilitating engineering measures like thermosyphons are an effective way to reduce freezing-thawing hazards and to maintain the stability of tower foundations.展开更多
Atmospheric air temperature data from 92 stations in China＇s radiosonde network were used to analyze changes in the freezing level height （FLH）, glacier snow line, and ice edge from 1958-2005 （48 years） and to ex...Atmospheric air temperature data from 92 stations in China＇s radiosonde network were used to analyze changes in the freezing level height （FLH）, glacier snow line, and ice edge from 1958-2005 （48 years） and to examine the impact of these changes on the cryosphere. In general, the FLH, glacier snow line, and ice edge exhibited latitudinal zonation, declining from south to north. Trends in the FLH, glacier snow line, and ice edge showed spatial heterogeneity during the study period, with prevailing upward trends. Temporally, the FLH, glacier snow line, and ice edge trends differed on various time scales.展开更多
基金supported by the National Key Basic Research Program of China (973 Program) (No.2012CB026106)the Program for Innovative Research Group of the Natural Science Foundation of China (No.41121061)the fund of State Key Laboratory of Frozen Soil Engineer(No.SKLFSE-ZT-16)
文摘Construction of power transmission lines is becoming an important part of permafrost engineering in China.This paper reviews the construction status and problems of transmission lines in different countries,as well as corresponding solutions that would be of practical significance for sustainable engineering practices.Russia has the longest history of transmission line construction in permafrost areas,with transmission lines（mainly 220 kV and 500 kV） spanning approximately 100,000 km.However,all countries suffer from permafrost-related tower foundation stability problems caused by freezing-thawing hazards such as frost heave and thaw settlement,frost lifting,and harmful cryogenic phenomena.As point-line transmission line constructions,the lines,poles and towers should be reasonably selected and installed with a comprehensive consideration of frozen soil characteristics to effectively reduce the occurrence of freezing-thawing disasters.Reinforced concrete pile foundations are widely used in the permafrost regions,and construction in winter is also a universal practice.Moreover,facilitating engineering measures like thermosyphons are an effective way to reduce freezing-thawing hazards and to maintain the stability of tower foundations.
基金funded by the Major State Basic Research Development Program of China (973 Program) under Grant No. 2010CB951701 and No. 2010CB428606the Natural Science Foundation of China (No. 41071042 and No. 40775045)+1 种基金supported by the Innovation Project of the Chinese Academy of Sciences (KZCX2-YW-BR-22)special finance support from the China Meteorological Administration (GYHY200906017)
文摘Atmospheric air temperature data from 92 stations in China＇s radiosonde network were used to analyze changes in the freezing level height （FLH）, glacier snow line, and ice edge from 1958-2005 （48 years） and to examine the impact of these changes on the cryosphere. In general, the FLH, glacier snow line, and ice edge exhibited latitudinal zonation, declining from south to north. Trends in the FLH, glacier snow line, and ice edge showed spatial heterogeneity during the study period, with prevailing upward trends. Temporally, the FLH, glacier snow line, and ice edge trends differed on various time scales.
