某水电站右坝肩边坡发育有顺坡向f1断层，破坏了 边坡岩体完整性并由此带来稳定问题。采用三维大变形有限差分法（FLAC -3D）对边坡稳定 性进行了计算研究。结果表明，边坡开挖过程中，断层上盘岩体内部出现一定的拉应力区， 并发生屈曲变形；由于边坡开挖完成后断层下部大部分出露，断层上盘岩体将发生大变形滑 移而失稳。通过强度折减法计算得到安全系数小于1.0，并可通过应变局部化带显示出 滑移失稳区位置。断层采用阻滑键加固可使其稳定，并讨论了渗流对边坡稳定性的影响。f1 断层的延伸是边坡稳定性的关键所在，因此需对其性状进行进一步探明。

Rock mass integrity of dam right abutment slope of so me hydro electric station is destroyed with Fault f1 developed, so stability pro blem is raised. The paper studies the slope stability using FLAC -3D. The result s show that tensile stress zones and buckling deformations appear in hanged wal l rockmass of fault during excavation. Hanged wall rockmass will be lost stabili ty as large deformation slipping along fault happens after excavation finished b ecause the lower part of fault will be exposed mostly. The safety factor determi ned by strength reduction method is less than 1.0, and slipping - failure zone delimited by localization band can be exhibited. The infl uence of seepage on slope is discussed. At last, the paper points out that the e xtension of Fault f1 is critical to slope stability and should be further explor ed and researched.