Qinghai-Tibet direct-current interconnection project is the largest transmission project constructed up to now in the paramos region of highest attitude in the world. It is also the longest project that traverses the permafrost region. The permafrost, characterized by being poor in thermal stability, rich in underground ice, very sensitive to the climate warming, and strong in water-thermal activity, causes great challenges to the tower foundation construction, which include tower foundation type selection and design, permafrost protection in the process of foundation construction and long-term foundation stability. On the basis of a study of the engineering geological conditions and principal engineering geological problems of the project, a systematic analysis is carried out on the principal engineering problems of transmission tower foundations in the permafrost region and an introduction is made to the main solutions to the problems in the process of project construction.%青藏直流联网工程是目前世界上最高海拔、高寒地区建设的最大规模的输电工程,工程挑战了沿线海拔最高、穿越多年冻土区距离最长“两个世界之最”.由于高原多年冻土具有热稳定性差、地下冰含量丰富、对气候变暖反应极敏感以及水热活动强烈等特性,冻土基础施工面临很多难题,包括冻土基础选型与设计问题、施工过程中多年冻土的保护问题和冻土基础的长期稳定问题等.在研究多年冻土区工程地质条件和主要工程地质问题的基础上,对多年冻土区杆塔基础的主要工程问题进行了系统分析,介绍了工程建设过程中针对这些问题所采取的主要对策.
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