竖井式倒虹吸管进水口水力条件的试验研究

Experiment Study on Hydraulic Condition at the Intake of Inverted Siphon with Drop Shaft

长江过江隧道采用了竖井式倒虹吸管的布置形式。利用整体模型试验预测并分析了设计方案进水口及其上游急弯箱涵布置所存在的水力学问题及其成因。试验研究表明,通过适当降低进口底板高程、优化平面线形,在急弯箱涵增设分隔墙、尾坎等综合措施可达到改善进口水流条件的目的,并提出了适用于竖井式倒虹吸管进口的消涡措施,彻底解决了管道水流掺气的问题。

The Changjiang rub-river tunnel is designed as inverted siphon with drop shaft. Based on whole model, the hydraulic problems in original design of intake and inflow elbow culvert is predicted and analyzed at intake of the tunnel. From the study, the flow condition can be greatly improved by properly lowering intake bottom, optimizing the line shape connecting the culvert and intake, and adding guide wall and ending sill in inflow elbow. The method of eliminating surface vortex is studied and presented ,and flow aeration at intake of the tunnel is avoided.Keywords:inverted-siphon with drop shaft; elbow convert; race; surface vortex; model test