彭水水电站上下游土石围堰防渗施工技术

Technique for anti-seepage construction of earth-rockill cofferdams of Pengshui Hydropower Station

彭水水电站上下游围堰地质条件复杂,大块石架空严重,在前期采用了高喷灌浆、塑性灌浆、双液控制性灌浆、砂浆灌注等多种灌注工艺处理,灌浆效果不明显,后采用速凝膏浆结合水泥补强灌浆工艺,基坑抽水表明防渗效果良好,为类似大架空地层防渗施工提供了一种新的处理技术。

For both the upstream and downstream earth-rockfill cofferdams for construction of Pengshui Hydropower Station, the geological condition is complicated with a stratum consisting of large rubbles hollowly-deposited seriously therein. Under this condition, the anti-seepage measures such as jet grouting, plastic grouting, double-shut grouting, mortar grouting, etc. are adopted during the fore-phase of the construction, but the grouting effect is not so significant. Consequently, a new technology combined with both the quick-setting slurry grouting and the cement grouting is applied, and then better anti-seepage effect is obtained, which is proved by the related test made after pumping of the foundation pit. This technology provides a new treatment technique for the anti-seepage measure to be used in the similar constructions under the condition of such a stratum.