一、概述西洱河三级水电站,是该河流四个梯级中地质条件最为复杂,也是最后兴建的一级引水式电站。引水隧洞长3200多米,设有三条施工支洞(总长约1100米)。电站位于苍山复式背斜南部倾伏端之西侧,断裂十分发育,主干断裂(F_(64))纵贯全区,破碎带宽50～100米,平行并贴近引水隧洞线(见图1),属区域性压性断裂带,其上盘派生的压扭性分支断层(F_(64)′)和拖曳褶皱(倒转),在平而上与主干断 I. Overview The Xier’er three hydropower station is the most complex geological condition in the four cascades of the river and is also the first-stage hydropower station constructed. Water diversion tunnel is more than 3200 meters long, with three construction branch holes (total length of about 1100 meters). The power station is located on the west side of the southern dip of Cangshan multiple anticline. The fault is well developed. The main fault (F_ (64)) runs through the whole area with a width of 50-100 meters and is parallel to and close to the diversion tunnel line (see Figure 1) It belongs to the regional pressure fracture zone, and the pressure-shear branch fault (F_ (64) ’) and drag fold (reverse rotation)