输水管道跨越廊涿干渠方案研究

Research on scheme of water pipeline crossing over the Langzhuo main canal

对输水管道跨越南水北调配套工程——廊涿干渠的设计方案和产生影响进行分析探讨。分析对比3种常见的跨越方式,即水平定向钻施工方案、顶管方案和人工开挖跨越方案,经综合分析,采用人工开挖施工方式跨越廊涿干渠,输水管道跨越廊涿干渠交叉角度89°,跨越长度50m,管顶覆土1.22m,与廊涿干渠垂直净距0.75m。分析了跨越段涂塑钢管的管道结构设计,并验算干渠顶部荷载,确定采用D529×10涂塑钢管,内防腐环氧树脂,外防腐聚乙烯。考虑廊涿干渠检修时开挖会导致输水管道悬空,在交叉处输水管道两侧5m范围以外设置支撑,支撑采用桩柱结构,管道与支座处采用鞍型支撑。该工程实施基本不影响廊涿干渠的安全运行和日常管理。

This essay aims to discuss schemes and impact analysis of the water pipeline crossing the supporting Langzhuo main canal of the South-to-North Water Transfer Project. Three common modes are compared,i.e. horizontal directional drilling construction scheme,pipe jacking scheme and manual excavation crossing scheme. After comprehensive analysis,the manual excavation construction mode is adopted to cross the Langzhuo main canal. The water pipeline crosses the Langzhuo main canal with an angle of 89° and length of 50m. The pipe top is covered with soil of 1.22m,and the vertical clear distance from the Langzhuo main channel is 0.75m. The pipe structure design of plastic coated steel pipe in the crossing section is analyzed,and the load on the top of the main canal is checked. D529×10 plastic coated steel pipe is adopted with internal anti-corrosion epoxy resin and external anti-corrosion polyethylene. Considering that the excavation of Langzhuo main canal during maintenance will lead to the suspension of water pipeline,support shall be set outside 5m on both sides of the pipeline at the intersection.The support adopts pile column structure,and saddle support shall be adopted at the pipeline and support.This project basically does not affect the safety and daily operation of the supporting Langzhuo main canal.