乌东德水电站左岸尾水出口边坡动态设计

Dynamic design of left tailrace slope of Wudongde Hydropower Plant

乌东德水电站左岸尾水隧洞出口边坡为典型陡倾顺向坡,最大坡高114m,顺层滑移是边坡开挖支护设计需解决的关键问题。遵循优化开挖坡比、强化锁口支护的思路开展了施工图阶段设计。由于地质条件复杂,开挖揭露岩体结构与前期勘探成果差异较大,为此开展了边坡动态加固设计。为了对边坡稳定性进行反馈分析,采用FLAC3D三维数值方法研究边坡在开挖卸荷条件下的力学响应、边坡变形破坏机制和潜在失稳模式以及不同工况下整体稳定性安全系数。计算结果及变形监测资料表明,边坡开挖与支护设计合理,满足规范要求,边坡整体稳定。该边坡设计过程可供类似工程参考。

The tailrace outlet slope on left side of Wudongde Hydropower Plant is a typical steep consequent slope with the maximum height of 114 m,and the bedding- landslide prevention is a key problem for slope excavation and support design. Slope ratio optimization and locking support reinforcement were adopted in the construction design period,however due to the complex geological conditions,the exposed rock structure greatly differed from the previous exploration results,thus dynamic reinforcement design was conducted. Feedback analysis was conducted for slope stability assessment and FLAC3 D was employed to simulate excavation response of rock mass under unloading condition and study the slope deformation instability mechanism and potential instability modes. Also slope safety factors under different cases were calculated. The simulation results and deformation monitoring indicated that the slope design of excavation and supports was rational and met the specification＇s requirements and the slope was stable in general. The slope design process provides reference for similar slope projects.