西水东调原水管道同安湾跨海段总体设计

General Design for Tongan Bay Cross-sea Section of Raw Water Pipeline in Westto-East Water Diversion Project

西水东调同安湾跨海段原水管道具有海底地形复杂、水文条件变化大、周边敏感因素多、两岸接线困难、工期要求紧张等诸多特点。为了安全、经济地建设跨海原水管道,对同安湾段原水管道的选址、工法、埋深、管道保护、管道防腐等关键问题进行研究。结合具体地质条件和周边环境进行多工法比选,选择适宜的管道实施方案并确定合理埋深。对于位于航道的跨海段管道区间,创新性提出膜袋混凝土管道覆盖保护层,减少浅埋海底管道意外撞击破坏与冲刷悬浮风险。通过采用增加壁厚、专用涂料以及外加电流的防腐复合措施,保障大口径钢管在海水环境的安全可靠运行。

The cross-sea raw water pipeline of Tongan Bay in the West-to-East Water Diversion Project had many characteristics,such as complex seabed topography,large changes in hydrographic condition,sensitive factors around the pipeline,difficult connection between the two sides and limited construction period requirement.In order to construct the cross-sea raw water pipeline safely and economically,the key problems such as site selection,construction method,buried depth,pipeline protection and pipeline corrosion protection of the raw water pipeline were studied.Combining with the specific geological condition and the surrounding environment,the appropriate construction method was selected and the reasonable buried depth was determined.The pipeline protective cover layer of the membrane bag concrete was innovatively proposed for the pipeline in the cross-sea section which is located in the channel,in order to reduce the risk of accidental impact damage and erosion suspension of shallow-buried submarine pipeline.The safe and reliable operation of large-diameter steel pipe in seawater environment was ensured by adopting the anti-corrosion composite measures of increasing wall thickness,special coating and applied current.