大岗山水电站拱坝建基面开挖与基础处理设计

Excavation of dam foundation surface of Dagangshan arch dam and foundation treatment design

大岗山坝址区工程地质条件复杂,有多条断层及岩脉穿过,确定合理的坝基建基面尤为重要。在明确拱坝对坝基基本要求的前提下,阐述了确定大岗山水电站建基面的基本原则,对5处置换块及垫座给出了施工范围及处理方案。重点研究了拱坝基础固结灌浆的分区原则与施工参数。分别采用拱梁分载法和有限元法对坝体静、动应力进行了计算,计算结果表明,应力满足规范要求,从而证实了建基面开挖和固结灌浆设计的合理性。

The geological condition of Dagangshan dam site is complex with several faults and rock dikes,so the determination of rational excavation design of dam foundation surface are extremely important.Under the premise of identifying the basic requirements of dam foundation,we propose the arrangement principles of foundation surface,and present construction range and scheme for five replacement blocks and foundation cushions;and the zoning principle and construction parameters of consolidation grouting are discussed.The arch-cantilever method and FEM are used to calculate the dynamic and static stress of dam body,and the calculated stress satisfies the requirements of design code,proving the rationality of the design of foundation excavation and grouting.