白鹤滩水电站柱状节理玄武岩固结灌浆试验成果分析与建议

白鹤滩水电站大坝建基面扩大基础范围内广泛发育柱状节理玄武岩,岩体微裂隙发育,完整性较差。爆破开挖前柱状节理基本上呈闭合状态,可灌性较差,基础处理难度大。为研究提高柱状节理玄武岩坝基岩体承载力、强度和整体性的解决方案,探索相关灌浆方案、灌浆材料、浆液配合比及施工工艺等,在柱状节理玄武岩区域进行"有盖重灌浆"和"无盖重结合0~5 m有盖重灌浆"固结灌浆试验。试验成果和物探测试成果为确定白鹤滩水电站大坝坝基固结灌浆施工方法和质量检查标准提供依据,同时也为类似地质条件工程提供参考。

Analysis and suggestion on achievement of consolidation grouting experiment of columnar jointed basalt for construction of Baihetan Hydropower Station

Within the expanded area of the foundation surface for the dam of Baihetan Hydropower Station， columnar jointed basalt is widely spreaded with developed micro-fissures and poor integrity. Before explosive excavation， the columnar joints of the rock are basically closed with lower groutability， thus the treatment of the foundation is quite difficult. In order to study the solution scheme for enhancing the bearing capacity， strength and integrity of the dam foundation of columnar jointed basalt and finding out the relevant grouting scheme， grouting materials， grout mixing ratio， construction technology， etc.， the consolidation grouting experiments of the grouting with cover-weight and without cover-weight combined with the 0~5m cover-weight grouting are made in the area of the columnar jointed basalt. The achievements from both the experiments and the geophysical prospecting lay a basis for determining the grouting construction method and the quality inspection standard， simultaneously， provide a reference for those projects with similar geological conditions as well.