阿拉斯加原油管道设计原则与特殊施工要点

阿拉斯加原油管道设计有传统埋设、特殊埋设和地上敷设.传统埋设的管顶埋深变化于0.9～2.7 m之间,特殊埋设则有降(保)温系统.地上敷设有桩基架设和高管堤.在该管道的设计与施工方案制定等方面,Alyeska管道公司随项目进展采用动态设计,不断完善施工方案,严格环保要求与设计安全相互促进,利用规范解决实际问题,工程师、环境专家和项目管理者密切合作,项目组织管理形式协调有序.从五个方面,重点阐述了Alyeska管道工程对中国寒区管道工程建设的借鉴意义.

Design Modes, Changes, and Construction Processes of the Alyeska Pipeline

There were three basic construction modes during the initial period of Alaska Pipeline design: conventional burial, special burial, and above ground berm or pile bent. The top depths of the conventionally buried pipeline varied from 0. 9 to 2. 7 m in accommodation to local topography and soil conditions. In the special burial, the mechanically controlled circulation of brine coolant or pile foundations equipped with thermosyphons were designed for removing the heat from operating crude oil pipeline to keep permafrost frozen. The above ground construction mode included elevated pile foundations, and above ground berms, for reducing or preventing the heat released by oil from entering into permafrost and subsequently thawing permafrost. From the start, pipeline owners demanded an 100% burial of pipeline. At the end of the construction,the pipeline was buried only at 57% of the total length. It is concluded that the experiences leading to the success of the Alyeska Pipeline include; 1) The keys to the successful construction and operation of the pipeline are detailed surveys, research and design; 2) Dynamic design with a continuous improvement of design plans according to the progress of the surveys,design and construction;3) Democratic debates and resulted stern requirements on environmental issues facilitated the safety of pipeline; 4) Solving design and construction problems according to their practical situations based on the familiarity and clear understanding of stipulations governing the surveys, design, construction and operations of the pipeline; 5) Close cooperation among pipeline engineers, environmental research scientists, and project management personnel was critical;and 6) Non-profit organization forms of the Alyeska and Joint Alaska Pipeline Office,and their practical management styles were equally important.