锦屏一级水电站为世界最高的双曲拱坝, 为了保证坝体的安全运行, 以库区谷幅伸缩变形为研究对象, 分别分析谷幅在前期开挖阶段、初期蓄水阶段和长期蓄水阶段的伸缩变形特征以及主要影响因素。研究结果表明: 在前期开挖阶段, 谷幅处于收缩变形加速期, 变形速率在每月- 0.65 mm 左右, 变形量达到 40 mm; 初期蓄水阶段, 谷幅的收缩变形速率在每月- 0.5 mm 左右, 变形速率有减小的趋势; 长期蓄水阶段, 库区蓄水水位在1 880 m - 1 800 m- 1 880 m之间循环了 4 个周期, 从前 2 个周期可以看出库区谷幅的伸缩变形与水位的变化表现出一定的滞后特征; 随着蓄水时间的增长, 谷幅逐渐只产生微量的收缩2拉伸变形。分析谷幅变形的主要影响因素可以发现, 在前期开挖阶段谷幅变形主要由开挖后的卸荷回弹造成, 后期蓄水阶段谷幅伸缩变形主要由左岸坡体的结构变形所产生。

Jinping I Hydropower Station is a world’s highest double-curved arch dam. In order to ensure the safe operation of the dam body, the deformation of the valley area was taken as a research objective. The telescopic deformation characteristics and main influencing factors of valley amplitude in the early excavation stag e, the initial water storage stag e and the long-term water storage stage were analyzed. T he current research indicated that in the early stag e o f excavation, the g rain width was in the shrinkage deformation during the accelerated period. The deformation rate w as about - 01 65 mm/ m, while the deformation amount w as 40 mm, respectively. In t he initial stage of w at er storage, the shrinkage deformation rate of the g rain width was about - 0. 5 mm/ m, and the deformation rate had a tendency to decrease. During the long-term water storage stage, the storage area in the reservoir area had ex perienced four cycles between 1 880 m-1 800 m-1 880 m. During the first two periods of the variation characteristics, the deformation o f the v alley area show ed a certain hysteresis characteristic to the change of water level. With the increase of waterstorage time, the grain width gradually and experienced a slight shrinkage stretching phenomenon, while the overall deformation value did not greatly change. Preliminary analysis of the main influencing factors o f g rain deformation could be found that the deformat ion of the grain in t he early excavation stage was mainly caused by the unloading rebound after ex cavation. In the later stage of water storage, the valley amplitude telescopic deformation was mainly caused by the structural deformation of the left bank slope.

国家重点研发计划( 2016YFC0401908) ; 国家创新性集体基金( 41521002)