砂卵砾石层作为混凝土面板堆石坝坝基探讨

Discussion on sand and gravel layer foundation of concrete faced rockfill dam

目前在建的水布垭混凝土面板堆石坝最大坝高233m,居世界首位。河床天然砂卵砾石层能否作为超高面板坝坝基是该工程的关键技术问题之一。超高面板坝利用砂卵砾石层作为大坝坝基国内尚无工程先例,天生桥(178m)等高面板坝对砂卵砾石层都作了挖除处理。水布垭运用综合勘察手段,查清了砂卵砾石层地质结构特征、工程地质特性,认为砂卵砾石层经过强夯加固处理后,可以部分作为大坝坝基。水布垭工程利用砂卵砾石层作为超高面板坝坝基,取得了明显的经济和工程效益;同时将为其它高面板坝在坝基利用方面提供借鉴。

Shuibuya concrete face rockfill dam is under construction, with its dam height of 233 m. Whether the natural sand gravel stratum in the river bed would serve as the foundation of the superhigh faced rockfill dam or not was one of the key technical problems of the project. In China, there was no superhigh faced rockfill dam with sand gravel stratum serving as its dam foundation. The sand gravel strata under Tianshengqiao dam with its dam height of 178 m and other high faced rockfill dams were all removed by excavation. At Shuibuya project, the geologic structural characteristics and the engineering geologic characteristics of the sand gravel stratum were found out by means of comprehensive survey and investigation. Some portions of the sand gravel stratum treated by dynamic compaction could be used as the dam foundation. Shuibuya project has made use of the sand gravel stratum as the foundation of the superhigh faced rockfill dam, resulting in remarkable economic benefit and engineering benefit.