On December 8 2011, the construction of four hydraulic tunnel, one water drainage tunnel and two communication tunnel were all completed. This is the world largest hydraulic tunnel group with the length of 120 km which is a significant project of Go West campaign. The completion marked the world difficult problem of underground construction under the condition of high stress, high depth and high-pressure water burst has been solved.
Rock burst is regarded as cancer of underground construction. Rock burst accounted for 15% of tunnel. Ertan adopted tremors monitoring system to predict happening of rock burst.
Water burst from high ground stress is a headache bothering tunnel construction. 2000-meter Jinping mountain contains rich water belts with high pressure which posed serious threats to construction. Ertan Company made water drainage holes and water storage with 21000 cube meter to solve the problem of waterburst.
General manager of Ertan Hydropower Chen Yunhua said that 2011 was the crucial year of hydropower development of Yalongjiang river. Total investment reached nearly nine billion for the construction of Jinping station 1 and Jinping station 2. The completion of tunnel laid a solid foundation for realizing targeted installed capacity of first unit of Jinping 2 and hit a new world record in approach to rock burst and high-pressure water burst. It will also contribute a lot to develop state low-carbon economy and improve hydropower technology.
