工作闸门设于泄洪洞的末端，其安全运行有助于泄洪洞安全泄洪。工作闸门运行过程中有可能产生水击， 目前没有受到重视。应用特征线法数值模拟青海省某水电站泄洪洞工作闸门关闭时闸前水击的变化过程，结果表明: ① 工作闸门匀速关闭的方式可导致泄洪洞内水击波的产生，水击发生于闸门关闭后，水击压强振幅呈指数规律衰减。②工作闸门非匀速关闭方式对泄洪洞非恒定流有重要影响，闸门关闭速度先快后慢的运行方式可有效减小水击压强振幅，降 低闸门振动的可能性; 工作闸门以适当的加速度关闭时可消除水击现象，彻底避免闸门因水击引起的振动，排除了这种泄洪安全隐患。

The working gate is located at the end of the spillway tunnel． Its safe operation assists in discharging flood safely． Water hammer is developed in the closing process of working gate of spillway tunnels． At present，there is no attention to water hammer phenomenon generated in spillway tunnels． The method of characteristics is used to calculate unsteady flow pressure in spillway tunnels in the closing process of working gate． Fortunately，we have drawn some important conclusions． First，the way of working gate running at a constant speed gives rise to water hammer wave in spillway tunnel． Water hammer takes place after working gate is closed，and water hammer pressure amplitude decreases based on the exponential law． Second，the running way of working gate has influence on water hammer in spillway tunnels． If the closing speed is fast-slow，the amplitude of water hammer pressure and the possibility of working gate vibration are both reduced effectively． Therefore，water hammer can be eliminated，and working gate vibration caused by water hammer can be completely avoided only if working gate runs at appropriate and constant acceleration． Thus，the flood discharge safety hazard is ruled out．