云南龙江水电站大坝基础处理效果分析与评价

Analysis and evaluation of dam foundation treatment effectiveness of Longjiang Hydropower Station in Yunnan Province

龙江水电站拦河坝为混凝土双曲拱坝,最大坝高110 m。坝基岩性主要为寒武系片麻岩,岩石强度较高,但由于两岸岩体局部风化厚度较大,且左岸存在较多软岩带,根据设计建议,对坝基地质缺陷部位采用深挖置换混凝土、全坝段固结灌浆、帷幕灌浆等工程措施进行了处理。处理后坝基岩石呈弱-微风化状态,岩体较完整,岩质坚硬,单孔平均波速值较高。就基础处理前后的检测数据进行了对比分析,对坝基处理效果进行了综合评价。工程竣工后已经历5个汛期和5.8级地震的考验,证明基础处理方案是合理的。其工程经验可供同类工程参考。

The dam of Longjiang Hydropower Project is a double curvature concrete arch one with the top height of 110 m. The dam base mainly consists of Cambrian gneiss of higher strength. Because the weathered thickness of both banks is large, and together with many soft rock zones on the left bank, it is to solve the geological defect parts in the dam base by engineering measures such as deep concrete replacement, whole dam consolidation grouting and curtain grouting. After the treatment, the dam base rock is slightly weathered, integrated and hard with higher single - hole average acoustic wave velocity. We compare and analyze the test data before and after treatment and make a comprehensive evaluation for the darn base treatment. The test of 5 flood seasons and 5.8 magnitude earthquake proves that the treatment scheme is reasonable.