Abstract
The Shuangjiangkou Hydropower Station is located in the high mountain and gorge area of Aba Prefecture, Sichuan Province, and is the world's highest under-construction earth-core rockfill dam (maximum dam height 315 m), as well as one of China's most technically challenging hydropower projects. Its key structures exhibit complex geological characteristics of "seven highs and two developments" (high altitude, high cold, high seismic intensity, high in-situ stress, high and steep slopes, high flow velocity, high dam, and development of dangerous rock masses and rockbursts), facing world-class technical challenges such as seismic resistance of ultra-high earth-rock dams in complex regional structures, dam construction on deep overburden layers, treatment and intelligent early warning of ultra-high steep slopes, safety control of rockbursts and stability of cavern groups in extremely high in-situ stress areas, and modification of core wall impervious soil materials. Based on the achievements obtained during the survey, design, and construction of the Shuangjiangkou Hydropower Station, this paper systematically summarizes the major engineering geological problems encountered and their treatment measures, providing reference for similar engineering projects.
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Preamble
Major Engineering Geological Problems and Measures for Shuangjiangkou Hydropower Station on the Dadu River
ZHANG Shishu, ZHAO Xiaoping
POWERCHINA Chengdu Engineering Corporation Limited, Chengdu, 610072, China
Abstract
The Shuangjiangkou Hydropower Station is located in the high mountain and gorge region of Aba Prefecture, Sichuan Province. It features the world's highest earth-core rockfill dam currently under construction, with a maximum height of 315 m, and represents one of China's most technically challenging hydropower projects. The project is characterized by a complex geological setting with "seven highs and two developments": high altitude, severe cold, high seismic intensity, high in-situ stress, high and steep slopes, high flow velocity, and high dam height, coupled with developed dangerous rock masses and rockburst conditions. These conditions pose world-class technical challenges, including seismic design of ultra-high earth-rock dams in complex regional tectonic settings, dam construction on deep overburden layers, treatment and intelligent early warning of ultra-high steep slopes, safety control of rockbursts and stability of underground cavern groups in extremely high in-situ stress zones, and modification of impervious core wall materials.
Based on achievements obtained during the investigation, design, and construction of the Shuangjiangkou Hydropower Station, this paper systematically summarizes the major engineering geological problems encountered and their treatment measures, providing valuable references for similar projects.
Keywords: Shuangjiangkou Hydropower Station; ultra-high earth-rock dam; ultra-high steep slope; deep overburden layer; soil material modification