龙滩水电站碾压混凝土大坝建基面开挖轮廓设计

Design of Excavation Outline for RCC Dam Base Surface of Longtan Hydropower Station

龙滩水电站碾压混凝土大坝为目前世界上最高的碾压混凝土坝,最大坝高216.5m,其坝基的工程地质条件优越,坝基岩体较完整,力学强度高,大坝不存在沿坝基础深部的滑动失稳条件。但如何避开进水口反倾向岩质高边坡,充分利用坝址的岩体条件设计大坝建基面的开挖轮廓,达到既安全又经济的目的,一直是勘测、设计和科研等方面的重要课题,这一问题已基本得到解决。本文主要介绍龙滩水电站碾压混凝土坝整体稳定控制面确定结论及坝基可利用岩体选择依据、开挖轮廓设计、岩体质量检测标准及地质缺陷处理方法等。

The RCC dam of Longtan Hydropower Station with a height of 216. 5 m is the highest one of the same type dams in the world. Its bed rock has favorable engineering geological conditions such as having more complete bed rock with high mechanical strength, there is no instability conditions making dam sliding along the deep part of foundation. But how to make full use of the favorable bed rock conditions and avoid the unfavorable factors in layout for designing excavation of the dam base surface contour have been important issues in investigation, design, scientific research, and other aspects. This paper introduces the conclusion of determining the dam overall stability control side, selection basis that foundation rock could be used, design of surface contour excavation, rock quality standards, methods of geological defect treatment and etc.