The Jinping-I Double Curvature Arch Dam sets new world record

The 305-meter Jinping-I Double Curvature Arch Dam on the Yalong River, designed by POWERCHINA-affiliated Chengdu Engineering Corporation Limited and constructed by Sinohydro Bureau 7 Co., Ltd., was awarded a new Guinness World Record as the highest dam in the world.

After review of the technical classifications of the world’s dams, research on dams in the participating countries of the International Commission on Large Dams (which ranks the highest dams in the world based on their classifications, flood discharging capacity, reservoir capacity, and other factors), and discussions with personnel from the Chinese National Committee on Large Dams and the International Commission on Large Dams, the Jinping-I Hydropower Station Dam has been proved to be the “highest” completed dam in the world.

Located over the Dahewan main stream of the Yalong River, at the junction of Muli and Yanyuan counties of the Yi autonomous prefecture of Liangshan, Sichuan province, the Jinping-I Hydropower Station is a controlling reservoir cascade power station of the lower reach of the main stream of the Yalong River, and a major power source in the Chinese “West-East Power Transmission Project” national strategy. The dam has a total installed capacity of 3.6 million KWH, a normal reservoir height of 1,880 meters, and total reservoir storage of 7.76 billion cubic meters. The power station is comprised of permanent buildings for water retention, discharge, and diversion for power generation. Part of the structure is the dam proper, a 305-meter concrete double curvature arch. It has now been identified as the highest completed dam in the world, four meters higher than the Eiffel Tower in Paris.

Among the major projects of the Jinping-I Hydropower Station undertaken by Sinohydro Bureau 7 Co., Ltd. are the excavation project above 1885-meter elevation on the left bank, the concrete casting project of the left bank of the dam, the foundation treatment project, the salt spray tests in A section, and road maintenance. Groundbreaking for the Power Station occurred on Nov 12, 2005, and its river closure was on Dec 4, 2006 -- two years ahead of schedule. Water preservation by closing floodgates was attained on Nov 30, 2012, and successful power generation by the two first-batch generator units occurred on Aug 30, 2013.

The project overcame world-class technical problems partly arising from size: the highest arch dam in the world, the largest high slope in the world, the left-bank geological treatment project, also the largest in the world, and the largest water head for energy dissipation in the world. In addition, the project had to deal with the most difficult mega power station construction layout in the world, and the most complex geological conditions. It also faced the most difficult on-site traffic and the most difficult control of surrounding rocks deformation stemming from large underground powerhouses under high ground stress. It has thus broken 10 world records, 10 Chinese records, and 10 industry records, and is widely acknowledged by experts at home and abroad as a project with the most technical difficulties, most dangerous working conditions, most difficult construction layout, and most difficult construction and management conditions.

As a new milestone in the history of Chinese dam construction, the Jinping-I Hydropower Station Dam has greatly accelerated Chinese hydropower construction technologies. Its completion has set new levels in the design, construction, and management of 300-meter extra high arch dams under complex geological conditions, solved the problem of stabilizing, supporting, and controlling deformation of surrounding rocks for mega underground caverns with high ground stress and low intensity. It has also advanced key technologies in large volume discharges, high water heads, collisionless flood discharging and energy dissipation in a narrow river valley, and anti-cavitation at super flow velocity.