基于RFPA^(3D)和微震监测的白鹤滩水电站左岸边坡稳定性分析  

Stability analysis of left bank rock slope at Baihetan hydropower station based on RFPA^(3D) software and microseismic monitoring

作　　者：杨莹 徐奴文[1] 李韬[1] 戴峰[1] 樊义林[2] 徐剑[2] 李彪[1] YANG Ying;XU Nu-wen;LI Tao;DAI Feng;FAN Yi-lin;XU Jian;LI Biao(State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan 610065, China;China Three Gorges Corporation, Beijing t 00038, China)

机构地区：[1]四川大学水力学与山区河流开发保护国家重点实验室,四川成都610065 [2]中国长江三峡集团公司,北京100038

出　　处：《岩土力学》2018年第6期2193-2202,共10页Rock and Soil Mechanics

基　　金：国家重点基础研究发展计划(973计划)(No.2015CB057903);国家自然科学基金面上项目(No.51374149);教育部新世纪优秀人才(No.NCET-13-0382)~~

摘　　要：白鹤滩水电站左岸边坡受缓倾角软弱面及NW向断层影响,施工、运行期的边坡稳定性问题尤为重要。为研究左岸边坡在开挖卸荷过程中应力场、位移场分布规律,揭示岩体内部破坏失稳机制,利用RFPA^(3D)(realistic failure process analysis)软件以拱轴线剖面为例建立准三维数值模型,再现坝基边坡岩体裂隙萌生、发育、扩展直至贯通的渐进损伤破坏过程。结合左岸边坡开挖卸荷及应力调整过程中的微震活动演化特征,圈定工程边坡潜在危险区域,探讨可能的失稳破坏模式。分析表明:基于离心加载法计算得到工程边坡开挖后安全系数为1.33;边坡表层区域受缓倾角错动带控制,变形破坏最为明显,以小范围楔形体滑移为主。该研究结果可为白鹤滩水电站坝基边坡后期施工提供依据,对于类似岩质边坡工程施工具有一定的指导作用。The stability of the left bank slope at Baihetan hydropower station is especially important in the construction and operation periods, due to the influences of the dislocation interfaces with a slightly-inclined angle and NW directional faults. In this study, the quasi-three-dimensional numerical model was established by using the realistic failure process analysis（RFPA^3D） software with the arch axis profile as an example. Then the stress distribution field and displacement field of the left bank slope were studied during excavation unloading process, and the rock failure mechanism was revealed. In addition, this study analysed the initiation, propagation, extension and interaction mechanisms of microcracks during the progressive failure process. By combining with the distribution of microseismic events during excavation unloading and stress adjustment on the left bank slope, the potentially dangerous parts of the engineering were delineated, and the possible failure modes of the slope were explored. The results showed that the safety factor of the slope after excavation was 1.33 calculated with the centrifuge loading method. It was found that the most obvious deformation and failure of the slope surface were controlled by the inclined dislocation interfaces. Meanwhile, the wedge-shaped sliding within a small scale played a dominant role in the damaged zone. This study provides references for the later construction of the left bank slope and practical guidance for constructing similar rock slopes.

关 键 词：岩石边坡 微震监测 稳定性 数值模拟 白鹤滩水电站 

分 类 号：TU457[建筑科学—岩土工程] TV741[建筑科学—土工工程]