青藏高原冻土工程地质特性与选线原则探讨

青藏500kV直流联网工程穿越青藏高原多年冻土区，冻土特有的工程问题将对工程设计、施工和安全运营产生重要影响。由于输电线路属于点线结构的工程特点，即塔基的稳定性关系到整条线路的稳定性，而塔基点位又具有一定的可调性，因此，多年冻土及厚层地下冰的分布特征对于输电线路的选线、选位较其他线性工程更具重要意义。本文主要在输电线路沿线冻土分布的基础上，重点对微地貌条件下冻土和厚层地下冰的分布发育规律进行了分析和研究。并在此基础上，结合输电线路工程特点，就线路的选线选位的原则进行了分析和确定。

PERMAFROST ENGINEERING GEOLOGICAL CHARACTERISTIC AND DISCUSSION OF ROUTE SELECTION IN QINGHAI-TIBET PLATEAU

Qinghai-Tibet 500kV DC power transmission line traverse the permafrost in Qinghai-Tibet Plateau, special engineering problems of permafrost will have the important impacts on the engineering design, construction and safe running. Because of structural trait of point and linear engineering, this means stability of tower footing have relation to the stability of all the line, but the tower footing is adjustable in degree. So the distributing character of permafrost and ground ice have more significance for the route selection and position selection than other linear engineering. In the base of distribution of permafrost along the transmission line, the article primarily study and analyze the rules of distribution and development of frozen soil and thick ground ice under the condition of tiny landform and physiognomy, and combining the engineering characteristics of transmission line, the principles of the route selection and position selection are studied and confirmed.