Thermal and mechanical characteristics of a thermal pile in permafrost regions  

作　　者：Yun-Hu SHANG Fu-Jun NIU Kun YUAN Tian SUN Li-Bo WU 

机构地区：[1]State Key Laboratory of Frozen Soil Engineering,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China [2]Da Xing'anling Observation and Research Station of Frozen-Ground Engineering and Environment,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Jiagedaqi 165000,China [3]First Highway Consultants Co.,Ltd.,China Communications Construction Company Limited,Xi'an 710075,China [4]Jiangsu Sunpower Technology Co.,Ltd.,Nanjing 210009,China [5]School of Civil Engineering and Hydraulic Engineering,Ningxia University,Yinchuan 750021,China

出　　处：《Advances in Climate Change Research》2023年第2期255-266,共12页气候变化研究进展（英文版）

基　　金：the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(2019QZKK0905);the National Natural Science Foundation of China(42001063,41961011);the Open Fund of State Key Laboratory of Road Engineering Safety and Health in Cold and High-Altitude Regions(YGY2020KYPT-04);CCCC Scientific and Technological Research Program(2020-ZJKJPTJS04).

摘　　要：Cast-in-place pile foundations are widely used in permafrost regions to support buildings.The stability of cast-in-place pile foundations is highly sensitive to permafrost thermal regime changes.Permafrost degradation caused by climate change is increasing the disaster risk of castin-place pile foundations.However,proactive cooling methods for cast-in-place pile foundations are seldom reported.The cold energy produced by two-phase closed thermosyphons(TPCTs)can efficiently prevent the permafrost thermal regime from being disturbed by engineering activities and climate change.TPCTs were installed in a concrete pile forming a thermal pile.Then,a model experiment was conducted to explore the thermal regime,influence scope,dissipation process of cold energy,and freezing strength of the thermal pile.The results indicated that the thermal pile may significantly cool the foundation soil.Most of cold energy produced by the thermal pile dissipated during the warm period,and the cooling scope of the thermal pile can cover the area within a 40 cm(twice the pile diameter)radius around the pile.Additionally,the TPCTs can significantly improve freezing strength between the thermal pile and frozen soil.The lesson learned from this study can provide a new approach to control the thermal regime of cast-in-place pile foundation in permafrost,which was of valuable to the construction of pile foundations in cold regions.

关 键 词：Pile foundation Cold energy Two-phase closed thermosyphon Freezing strength Permafrost regions 

分 类 号：P642.14[天文地球—工程地质学]