双曲拱坝坝基无盖重固结灌浆施工技术应用

Application of Uncovered Consolidation Grouting Technology for Double-curvature Arch Dam Foundation

针对水电工程双曲拱坝坝基无盖重固结灌浆施工特点,依托乌东德水电站大坝坝基无盖重固结灌浆施工,开展技术攻关,通过创新施工程序及方法,研究灌浆前对建基面采用裂隙封闭工艺,降低建基面浅层灌浆时外漏情况,提高建基面浅层灌浆质量;研究河床坝基局部缓倾角裂隙区域设置抗抬砂浆锚杆,保证缓倾角裂隙发育区基岩固结灌浆质量,避免灌浆施工发生岩体抬动破坏;研究表层引管补灌施工工艺,有效提高建基面表层固结灌浆效果和岩体质量等技术方法。研究成果能够为今后的大型和特大型水电站的双曲拱坝坝基无盖重固结灌浆工程施工提供有益借鉴。

Taking Wudongde hydropower station as an example,this paper studies the construction characteristics and key technology of uncovered consolidation grouting for double-curvature arch dam foundation by adopting innovative construction procedures and methods.Fissure sealing technology is applied on foundation surface ahead of grouting,in order to reduce outward leakage situations during grouting the shallow part for foundation surface,and improve the grouting quality.By setting anti-lifting grouted rock-bolt in fissure zone with gentle angles for partial riverbed dam foundation,the quality of consolidation grouting for bedrock of fissure zone with gentle angles has been ensured,and rock lifting damage during grouting has been avoided.The construction technology of supplementary grouting by surface guiding pipe has been studied to improve both the effect of surface consolidation grouting for foundation surface and the quality of rock mass.The research results can provide useful reference for future uncovered consolidation grouting for double-curvature arch dam foundation of large and super-large hydropower stations.