Abstract: Many unfavorable geological structures existed in the foundation of a high gravity dam, such as compression zones, weak interlayers, and fracture zones in the flexural core. Targeted treatment methods such as replacing concrete, strengthening grouting, adding cut-off walls, and optimizing the seepage prevention system of the dam foundation were adopted during construction. By analysis of deformation and seepage monitoring data during operation, it was found that the foundation deformation was stable, and there was no obvious uneven deformation or deep sliding. The uplift water level in the dam foundation was locally high, but the anti-sliding stability and foundation safety could still meet the requirements. Furthermore, the seepage stability of the foundation rock mass could meet the requirements, the dam seepage flow decreased year by year, and the effluent was clear. The operation behavior of the dam foundation was normal, which could provide reference for dam foundation treatment and seepage prevention design under similar complex geological conditions.

Key words: fracture zones in the flexural core, gravity dam, anti-sliding stability, seepage stability, deformation

摘要： 某高重力坝坝基存在挤压带、软弱夹层及挠曲核部破碎带等诸多不利地质构造，建设期采用了置换混凝土、加强灌浆、增设防渗墙等针对性处理措施。运行期变形和渗流监测结果分析表明，坝基变形稳定，不存在明显的不均匀变形和深层滑动，坝基扬压水位局部偏高，但坝基抗滑稳定安全性仍满足要求，坝基岩体渗透稳定，大坝渗流量逐年减少且出水清澈，坝基运行性态正常，可为类似复杂地质条件下坝基处理和防渗设计提供借鉴。

关键词: 挠曲核部破碎带, 重力坝, 抗滑稳定, 渗透稳定, 变形