白鹤滩水电站左岸边坡稳定性分析

为研究缓倾角错动带及断层对白鹤滩水电站左岸顺层岩质高边坡稳定性的影响,以勘I5线地质剖面为例建立力学模型,借助综合法试验模拟岩体内主要地质构造及相关工程措施。在此基础上,再利用RFPA3D有限元数值模拟方法,分析岩体内裂隙萌生、发育、扩展直至贯通的损伤演化过程。结果表明,混凝土置换洞阻碍裂缝沿软弱面扩展成效显著,开挖后工程边坡安全系数为1.62;离心加载法得到的边坡潜在滑移面与物理模型试验得到的裂缝扩展模式基本一致,层内错动带LS337、层间错动带C3-1、断层f101、裂缝J110等软弱结构面共同控制岩体的开裂与边坡失稳。研究成果可为本工程边坡开挖与支护以及类似工程提供参考。

Stability Analysis of Left Bank Rock Slope of Baihetan Hydropower Station

The influence of slightly-inclined angle dislocation interfaces and faults at Baihetan hydropower station was analyzed by setting up a geomechanical model of comprehensive techniques in which overloading and strength-decreasing processes concur. The initiation, propagation, extension and interaction mechanisms of microcracks during the progressive failure processes of the left bank slope were investigated by using the Realistic Failure Process Analysis code in three dimensions (RFPA3D). The comprehensive researches show that the concrete cut-off trenches could effectively decrease and prevent the faults from cracking and propagating effectively; The safety factor is equal to 1.62 under the condition of excavation; The potential sliding surface of the rock slope obtained by RFPA3D is in good agreement with the deformation and failure mode obtained by geomechanical model test; The weak structure planes such as LS337, C3-1, f101, and J110 are the controlling factors for the rock cracking and slope failure. These achievements provide significant references for later excavation and supports of the left bank slope at Baihetan hydropower station, and also offer practical instructions to other similar bedding rock slopes.