Rock mechanical problems and optimization for the long and deep diversion tunnels at Jinping Ⅱ hydro

• 作 者: Shiyong Wu Ge Wang
• 机 构: Ertan Hydropower Development Co.
• 出 处: 岩石力学与岩土工程学报（英文版）
• 发表日期: 2004年期
• 关键词: Jinping Ⅱ hydropower station diversion tunnels optimized design construction met

According to site-specific environments such as high water pressures,high in-situ stresses and strong rockbursts,the design scheme of the long and deep diversion tunnels at Jinping Ⅱ hydropower station was optimized to ensure construction safety.New drainage tunnels were considered.Furthermore,lining structures and grouting pressures were modified during the excavation of tunnels.The construction scheme was updated dynamically based on the complex geological conditions.For instances,the diversion tunnels were first excavated by drilling and blasting method at the first stage of construction,and then by the combination method of tunnel boring machine (TBM) and drilling and blasting,and finally by drilling and blasting method.Through optimized scheme and updated construction scheme,the excavation of diversion tunnel #1 was successfully completed in June,2011.This paper summarizes the key issues in rock mechanics associated with the construction of the long and deep diversion tunnels at Jinping Ⅱ hydropower station.The experiences of design and construction obtained from this project could provide reference to similar projects.