引江补汉工程是南水北调中线工程的后续工程,可行性研究阶段坝下方案输水隧洞初拟4条线路进行比选,比选线路区地形地质条件和工程地质问题复杂,具有线路长、埋深大,地层岩性复杂多样、可溶岩和软质岩分布较多,地质构造背景复杂、总体地应力水平高等地质特点,深埋长隧洞工程可能涉及的工程地质问题均有可能出现,有必要选择一条地质条件相对较优的线路。经分析研究,将线路比选考虑的地质因素分为关键地质因素、重要地质因素、一般地质因素,并建立多因子条件下的线路比选模型,经工程地质综合比选,龙安1线输水隧洞方案总体较优,地质选线成果为工程设计综合选线提供了重要依据,地质比选研究思路与方法可为同类工程提供借鉴。

The Water Diversion Project from the Three Gorges Reservoir to the Hanjiang River (WDTGH) is a follow-up project to the Middle Route Project (MRP) of the South-to-North Water Diversion (SNWD). During the feasibility study stage, four routes of water conveyance tunnel under the Danjiangkou dam were proposed for comparison based on their topographical and geological conditions and engineering geological problems. The geological conditions of the proposed routes are complex, with long routes, large burial depths, varied formation lithology, abundant dissolvable rocks and soft rocks, complex geological structure background, and high overall geostress levels. Therefore, it is necessary to select a route with relatively good geological conditions to avoid engineering geological problems that may occur in the deep-buried long tunnel project. Through analysis, the geological factors considered in the comparison and selection of the routes were classified into three levels as key geological factors, important geological factors, and general geological factors. A comparison model under the condition of multiple factors was established for comprehensive analysis and comparison on engineering geology. The study reveal that the water tunnel scheme of Long'an Line 1 has overall advantages. Thus, the results of geological route selection provide foundation for comprehensive route selection in engineering design. Additionally, the research ideas and methods of geological comparison and selection can serve as a reference for similar projects.

临平自来水厂供水工程起点位于千岛湖引水工程余杭分水点，供水对象为临平、仁和、宏畔、塘栖4个水厂，管道直径1.4~2.6 m，总长度30.9 km，远景供水规模43 万m³/d，采用全程重力流供水方式，供水用户多、线路复杂，水力过渡过程计算分析复杂、水锤防护设计难度大。首先采用华东院自主开发的供水工程水力过渡过程仿真计算软件Hysimcity进行建模及计算分析，确定供水系统水力过渡过程中压力变化情况；接着针对供水系统各个部位的水力学特点以及整个系统的水力学特性，开展整个输水系统的水锤防护设计。最终确定在临平、仁和、宏畔、塘栖水厂前设置直径1 m的超压泄压阀及各个水厂阀门一段直线关闭的联合水锤防护方案，有效解决了多用户重力流供水系统的水锤问题。

The water supply project of Linping waterworks starts from Yuhang water distribution outlet of Qiandaohu Water Diversion Project， supplying for four waterworks of Linping， Renhe， Hongpan and Tangqi. The diameter of the pipeline is 2.6~1.4 m， the total length is 30.9 km， and the prospective water supply scale is 43×10⁴ m³/d. The project adopts gravity flow water supply mode， with many water users and complex lines， so the calculation and analysis of hydraulic transient process is complex and the design of water hammer protection is difficult. In this paper， the hydraulic transient process simulation software-Hysimcity developed by Huadong Engineering Corporation Limited is used for modeling and calculation， and the pressure change of water supply system in the hydraulic transient process is obtained. According to the hydraulic characteristics of the system， the water hammer protection design of the whole water supply system is carried out. After a lot of trial calculation and analysis， when the regulating valve in front of the waterworks is closed in 120 s， the water hammer problem is effectively solved by setting the pressure relief valve with diameter of 1m in front of each waterworks.