多年冻土地区铁塔现浇混凝土基础施工技术

Foundation Constructing Technique of Steel Tower Cast-in-situ Concrete in Permafrost Regions

青海—西藏±400 kV直流输电线路工程大部分铁塔基础位于青藏高原多年冻土地带,自然条件十分恶劣,建设环境极其复杂。在连续冻土上进行施工,基础施工质量是控制的关键点,它直接关系到输电线路结构的安全性和线路长久稳定运行。高海拔连续多年冻土地区输电线路施工国内外参考资料较少,国内没有成熟可供借鉴的工程实例。在工程开工准备前期,国家电网公司与青海送变电工程公司进行了一系列的研究和试验,在基础坑开挖和混凝土浇筑过程中,最大限度的减少对冻土的扰动是基础稳定的关键,也是环境保护的要求。

Most of Qinghai-Tibet ± 400kV DC transmission line project＇ s steel tower foundation locates in permafrost regions, with inferior natural condition and rather complicated constructing environment. The control of foundation constructing quality is the key factor on permafrost region;it directly concerns the structure security and stable opera- tion of transmission line. The transmission line construction on high altitude and permafrost region is lack of reference material and without mature project examples, before starting construction, the State Grid Corporation of China and related enterprises make series study and test, especially on foundation pit excavation and concrete placing, in order to maximum reduce disturbance on frozen soil, and dominate the destroy on environment in minimum level. After put- ting into operation in Qinghai-Tibet transmission line project, protection.