复杂地质条件下高压水工隧洞穿河设计研究——以巴基斯坦N-J水电站为例

Design of a High-pressure Hydraulic Tunnel that Under-crosses a River under Complex Geological Conditions in Pakistan N-J Hydropower Station

巴基斯坦N-J水电站引水洞为复杂地质条件下的高水头水工隧洞,其中一段必须从Jhelum河下穿过,该段隧洞存在内外高水头作用,设计相对复杂,可供参考的工程案例不多,系统分析总结相应的技术成果很有必要。解读该工程区域地质、隧洞围岩条件,对比不同布置方案的优劣及可行性,设计思路、参数确定,分析相应的成因、脉络等,形成的系统性技术成果,可供类似工程的设计参考。

The diversion tunnel in Pakistan N-J Hydropower Station is a high water head hydraulic tunnel under complex geological conditions.And a certain section of the tunnel has to under-cross the Jhelum River,which is of high internal and external water head actions.The design of this tunnel section is thus of great difficulties and there are few engineering cases for reference.It is thus necessary to systematically summarize the technical achievements in this project.Considering the specific regional geological conditions and the surrounding rock conditions of the tunnel,the advantages,disadvantages and feasibility of different design schemes are compared.The design ideas,parameter determination and corresponding reasons are summarized.The summarized systematic technical results can be useful reference for the design of similar projects.