Abstract: Uneven settlement of dam body and even cracks on dam crest are often caused by the first impoundment of core wall rockfill dam. The impoundment scheme is an important factor affecting the dam body deformation. To study the effect of impoundment on stress, deformation and cracking of high core wall rockfill dam, this paper takes Pubugou rockfill dam with high core wall as an example where cracks occurred on its dam crest during first impoundment. Combined with the actual impoundment plan, the feasibility of the preliminary impoundment plan is demonstrated. Stress, deformation and cracking of the dam body are simulated and analyzed respectively under the actual condition and the condition of preimpoundment. The results show that the wetting deformation at the bottom of upstream rockfill area can be released in advance in the pre-impoundment scheme which mitigates the influence of wetting deformation on the cracking of dam crest. Therefore, cracking on dam crest can be avoided which is beneficial to the dam safety during its first impoundment.

Key words: high core wall rockfill dam, impoundment scheme, deformation analysis, crack analysis

摘要： 蓄水引起心墙堆石坝坝体不均匀沉降甚至产生坝顶裂缝的实例屡见不鲜。蓄水方案是影响初蓄水坝体变形的重要因素，为研究其对坝体蓄水时应力变形的影响，对初蓄水坝顶产生裂缝的瀑布沟高心墙堆石坝进行了研究。结合该大坝实际蓄水方案，论证了先期蓄水方案的可行性；分别模拟并分析了实际情况下和先期蓄水情况下坝体的应力变形及裂缝情况。研究发现，先期蓄水方案能提前释放上游堆石区底部的湿化变形，缓解湿化变形对坝顶裂缝的影响，有效避免瀑布沟坝顶裂缝的产生，对心墙堆石坝初蓄水坝体安全更加有利。

关键词: 高心墙堆石坝, 蓄水方案, 变形分析, 裂缝分析