Located in the eastern margin of the Tibetan Plateau,the Gonghe-Yushu high-grade highway was the first of its kind in plateau permafrost regions.Most of the road sections along the high-grade highway are unstable or e...Located in the eastern margin of the Tibetan Plateau,the Gonghe-Yushu high-grade highway was the first of its kind in plateau permafrost regions.Most of the road sections along the high-grade highway are unstable or extremely unstable warm permafrost with an average annual ground temperature above −1℃,which is vulnerable to global warming and human engineering activities.This paper describes permafrost characteristics,roadbed design,and operation of the Gonghe-Yushu high-grade highway in detail.It is found that thaw settlement of warm and ice-rich permafrost is the main cause of subgrade subsidence in permafrost sections of this highway due to insufficient permafrost survey and drainage design.It is recommended that the interception and drainage system's design be optimized,and the permafrost upper limit and the variation of ground temperature be further investigated to provide essential data for the treatment of highway distress.It should be emphasized that protecting permafrost soil environment and optimized engineering design are crucial to successful high-grade highway engineering in permafrost regions.展开更多
The harsh environment in tunnels with high geothermal temperatures and humidity can adversely impact machinery,personnel,and construction.The main causes of specific problems are the unknown mechanisms of local geothe...The harsh environment in tunnels with high geothermal temperatures and humidity can adversely impact machinery,personnel,and construction.The main causes of specific problems are the unknown mechanisms of local geothermal formation,inappropriate temperature control measures,and insufficient systematic safeguards.In this study,three work sections relating to a high geothermal tunnel are:the tunnel face,middle-of-tunnel section,and outside-oftunnel section.A cooling strategy is proposed to offer technical support in achieving comprehensive cooling,overall as well as for each of the sections.First,a comprehensive geological survey explores the mechanism and exact location of the heat source.Secondly,grouting and centralized drainage measures are used to control the heat release of hot water.Enhanced ventilation,ice chillers and other applicable measures are used to control the ambient temperature.Finally,a monitoring and early warning system is established to prevent accidents.This cooling strategy has been applied in the field with good results.展开更多
基金supported by the National Natural Science Foundation of China(Nos.41801046,42161026)the Natural Science Foundation of Qinghai Province(No.2021-ZJ-716)the Transportation Science and Technology Project of Qinghai Province(No.2019-06&No.2018-02).
文摘Located in the eastern margin of the Tibetan Plateau,the Gonghe-Yushu high-grade highway was the first of its kind in plateau permafrost regions.Most of the road sections along the high-grade highway are unstable or extremely unstable warm permafrost with an average annual ground temperature above −1℃,which is vulnerable to global warming and human engineering activities.This paper describes permafrost characteristics,roadbed design,and operation of the Gonghe-Yushu high-grade highway in detail.It is found that thaw settlement of warm and ice-rich permafrost is the main cause of subgrade subsidence in permafrost sections of this highway due to insufficient permafrost survey and drainage design.It is recommended that the interception and drainage system's design be optimized,and the permafrost upper limit and the variation of ground temperature be further investigated to provide essential data for the treatment of highway distress.It should be emphasized that protecting permafrost soil environment and optimized engineering design are crucial to successful high-grade highway engineering in permafrost regions.
基金supported by the National Natural Science Foundation of China(Grant Nos.51878567 and 51878568).
文摘The harsh environment in tunnels with high geothermal temperatures and humidity can adversely impact machinery,personnel,and construction.The main causes of specific problems are the unknown mechanisms of local geothermal formation,inappropriate temperature control measures,and insufficient systematic safeguards.In this study,three work sections relating to a high geothermal tunnel are:the tunnel face,middle-of-tunnel section,and outside-oftunnel section.A cooling strategy is proposed to offer technical support in achieving comprehensive cooling,overall as well as for each of the sections.First,a comprehensive geological survey explores the mechanism and exact location of the heat source.Secondly,grouting and centralized drainage measures are used to control the heat release of hot water.Enhanced ventilation,ice chillers and other applicable measures are used to control the ambient temperature.Finally,a monitoring and early warning system is established to prevent accidents.This cooling strategy has been applied in the field with good results.
