山湖水库大坝除险加固防渗设计

Seepage prevention design for Shanhu Reservoir Main Dam Reinforcement Project

通过对山湖水库土坝除险加固防渗方案比选,设计采用了多头小直径搅拌桩防渗墙加固方案,并对该方案进行了布置与设计。经计算分析,在各种计算工况下,大坝下游坝坡最大出逸渗透坡降较加固前减小,为0.28,小于土的允许渗透坡降0.49,大坝渗透稳定满足规范要求,防渗效果明显。实施后监测结果:防渗墙后各观测点坝体渗流压力(水位)较同期的库水位均有明显下降,且波动较小,防渗墙起到了较好的效果,证明设计方案合理。

For reinforcement of earth darn of Shanhu Reservoir , the scheme of impervious wall with multi-head small diameter mixing piles were selected based on comparison of seepage prevention alternatives. An introduction was made on the arrangement and design. The results of calculation demonstrate that under various calculating operation conditions, the maximum seepage gradient of downstream dam slope is to be 0.28, less than the permissible seepage gradient of 0.49 and the value before reinforcement, so the selected schene can render significant seepage control effects with the seepage stability of main dam up to the requirements of specifications . The monitoring data after reinforcement was completed show that dam body seepage pressure（level）at various observation positions behind the impervious wall is lower than the reservoir level significantly with less fluctuation, which proves the design of impervious wall is proper with good effects.