卧虎山水库放水洞工程位于大坝北端，采用砌石拱内衬钢筋混凝土管的结构型式．由于受各种因素的影响，放水洞出口水电站至今未建，使原设计放水洞有压运行变为无压运行，致使钢筋混凝土管的受力条件有了极大的改变，从而导致了竖井下游的钢筋混凝土管产生大量纵向裂缝及闸门吊杆两次断裂事故的发生．为此，对卧虎山水库放水洞病害情况进行了全面检测，在理论上分析了裂缝产生的原因，针对病害优选了效果可靠、经济可行的修复方案．运行实践表明，效果良好． The Wohushan Reservoir drainage tunnel project is located at the northern end of the dam, which adopts the structural type of reinforced concrete pipe lined with masonry arch. Due to various factors, the hydropower station at the outlet of the water diversion tunnel has not yet been built so far, and the pressure displacement operation of the original design diversion tunnel has been changed to pressureless operation. As a result, the stress conditions of the reinforced concrete pipe have been greatly changed, Of the reinforced concrete pipe to produce a large number of longitudinal cracks and gate boom occurred twice the fracture. Therefore, a comprehensive examination was carried out on the disease of diversion tunnels in the Wohushan Reservoir. The causes of the cracks were theoretically analyzed, and the rehabilitation programs with reliable results and economic feasibility were optimized for the diseases. Practice shows that the effect is good.