彭水水电站坝基无盖重固结灌浆试验研究

Experimental Study on Non-Cover-Weight Concretion Grouting of the Dam Base of Pengshui Hydropower Station

为缓解彭水水电站坝基固结灌浆与坝体碾压混凝土快速浇筑的矛盾,拟在坝基进行无盖重固结灌浆,并在施工前进行了裸岩固结灌浆试验。介绍了这种新型的固结灌浆试验过程及灌浆效果,对其工艺特点、存在的缺陷及适用范围进行了探讨,指出该灌浆工艺浅表层处理效果差,适用于深层基岩加固处理。而对彭水水电站坝基基岩特性进行分析后,认为需进行加固处理的部位主要为浅表层裂隙带,据此提出了裸岩固结灌浆不适合本工程坝基地质条件特点的试验结论。在此情况下,为克服裸岩固结灌浆的工艺缺陷,推荐了一种改良的无盖重固结灌浆方法:薄层混凝土表面封闭式无盖重固结灌浆法,生产性试验及施工效果均良好。

In order to ease the conflict between concretion grouting and rapid concreting of the base of Dam of Pengshui Hydropower Station, non-cover-weight concretion grouting of the dam base is adopted, and bare-rock concretion grouting test is conducted before construction of the project. The process and effect of the new concretion grouting technique are introduced, and the peculiarity, limitation and scope of application of the technique are discussed. It is pointed out that the effect of technique for shallow ground treatment is not as good as that for deep base-rock. Through analysis of the characteristics of base rock of the Pengshui Hydropower Station, it is proposed that bare-rock concretion grouting can not suit the geological condition of the project because the position of consolidation is mainly shallow ground crack. An improved non-cover-weight concretion grouting technique is recommended to overcome the shortage of the bare-rock concretion grouting, which is surface closed non-cover-weight concretion grouting at the folium concrete. The technique has good effect in testing and construction.