东坑病险坝加固技术研究应用

Study on the rehabilitation technology applied on Dongkeng defective rock-fill dam

东坑水库大坝原设计为混凝土面板堆石坝,最大坝高42.0m,施工时由于堆石未采用机械碾压,空隙率高达40%,水库蓄水运行以来,大坝出现较大的位移及沉降变形且变形未趋稳定、面板严重开裂,大坝存在严重漏水等重大安全隐患。根据大坝存在的渗漏、变形和原堆石体强度较低等问题,设计采用在原堆石体上游侧增设主堆石区和新建钢筋混凝土面板的加固处理方案。该方案通过增设主堆石区,将水荷载大部分转移到原坝轴线上游新建的主堆石区上,从而降低了原堆石区承受的水荷载。东坑水库大坝除险加固后,大坝变形及渗漏水量均很小,除险加固取得了较好的效果,其设计方法和经验可供类似工程借鉴参考。

Dongkeng reservoir dam was originally designed as a concrete faced rock-fill dam which was 42.0 m high. As no mechanical compaction used, the void ratio of rock fill was as high as 40%. Since operation, problems occurred such as large displacement, going-on settlement, serious cracking of concrete slabs, severe leakage and et al. Aiming at the problems, namely the existing dam leakage, deformation, low strength of the original rockfill, the treatment scheme of adding a main rockfill zone upstream the original rockfill and new construction of impervious reinforced concrete slab was adopted, which diverted most of the water load to the newly constructed rockfill zone upstream the dam axis, resulting a decrease of water load over the original rock-fill zone. After rehabilitation, deformation and seepage amount of Dongkeng dam were small and good effect was achieved, worthy reference.