The (Landmarks, October seventh day), November 6, 1997, the Three Gorges Project damming the river.

1997, the world's largest hydroelectric project - the Three Gorges Project, after five years of construction, began damming the river.
damming the river to mark the end of one of the Three Gorges project victory, but also an important turning point in the Three Gorges Project by the investment period of transition to the earnings period. In addition, damming the river, the river will be diverted discharged by artificial diversion channel excavation the navigable way big change will take place. Thus, the Three Gorges Project damming the river for domestic and international attention. 630,000 m2 river
Three Gorges Project to be the world's most difficult closure
damming the river, on the two downstream cofferdam truncated by the construction of the main riverbed of the Yangtze River, surrounded by two cofferdams, pumping go to the river to clear the mud, and then built on the dry riverbed of the plant and the dam of the Three Gorges Project. Plan to power in 2003, the first unit will be installed here. Damming the river, actually refers to the of the upstream cofferdam Longkou closure.
Closure at Three Gorges is the most difficult of the world water conservancy projects in closure closure works. Selected in the Three Gorges closure closure design flow of 14,000 cubic meters per second to 1.94 million cubic meters, and is by far the world the largest hydropower project closure the flow - ������̩�� engineering closure discharge 1.75 times; closure discharge is the largest - - the Gezhouba closure flow rate of 2.9 times. Closure at Three Gorges water depth of 60 meters, is the world's biggest hydropower project closure water depth - the United States durrus project closure depth is 1.3 times than that of the Gezhouba water deep 40 meters closure. In deep water and flow conditions due to the Three Gorges water emergency surge underwater geological situation is very complicated, closure, to prevent the cofferdam collapsed and solve seepage problem, will be the first world-class technical problems faced since the start of the Three Gorges Project.
According to Lu Youmei, general manager of the China Yangtze River Three Gorges Project Development Corporation, the closure of the Three Gorges of the key technical problems have been overcome, and has formed a relatively complete construction. Closure, in early November, both technically and construction preparation fully grasp. the
grab of construction period closure in advance
the Generally, the hydropower project closure time should be chosen in traffic and a smaller gap between the dry season, so difficult to reduce the closure. Based on hydrological data, the Three Gorges Dam Yangtze driest traffic is generally late in late January to February, during which the traffic is generally only 3000 cubic meters per second to 6,000 cubic meters. Closure at Three Gorges Why choose a higher water level and may encounter larger floods in early November? It is understood that the reason why you want to shut-off ahead of time, because the two the cofferdam construction period is extremely urgent. Taking into account the requirements of the safe flood in the closure of the closure must grab before the arrival of the Yangtze River flood season in May 1998, filling the cofferdam to the elevation of the safety of the flood season, and built a total area of ​​72,000 square meters of anti- seepage wall, otherwise there will be disastrous consequences. Experts in the comprehensive analysis of the factors of the closure of the difficulties involved, the cofferdam of urgency, and the large traffic conditions under fully grasp closure case, to finalize the the Three Gorges closure closure is scheduled in early November.
the Three Gorges closure time select in the the Yangtze flood season shortly after November, changes in water level of the Yangtze River, this period, intercepting the actual amount of water and the water depth of how much, and now can not be completely sure. For example, in early November 1996, the Three Gorges dam site had appeared in more than 26,400 cubic meters per second flood. If this occurs, the shut-off will be more difficult. The reporter learned from the Three Gorges construction site, The related units ready to meet a variety of harsh conditions, to prepare to fight a tough battle.
closure construction three stage
the Closure at Three Gorges construction in three stages. The first stage is the cofferdam "pre-occupied" stage 4 Dyke also advance on the main channel of the Yangtze River, the two upstream and downstream cofferdams advancing to the middle of the river, up and down the cofferdam, respectively, leaving only 460 meters and The 480-meter-wide river entrance. At the same time, in the river bottom in front of a large number of dumped stone, the riverbed deep trench site booster water depth reduced from 60 meters to over 20 meters. The upstream cofferdam Jiang first phase of construction is started from November 1996 to April 1997 completion target of construction; construction of the second phase from early September 1997 to November 3, the closure where in the door by 460 m beam as narrow as 130 meters wide, to form a closure gap; The third stage is the closure closure plan in the middle of November 6 to 8 a day, according to the meteorological and hydrological conditions, expand cross lock the final sprint of the Yangtze River. According to expert estimates, to 130 meters Longkou use 210,000 cubic meters of soil, stone blocked. In three days in a row of narrow cofferdam embankment head daily dumping 70,000 cubic meters of soil, stone, such a high intensity of construction in the history of the world's water conservancy construction is rare. According to reports, the closure closure, four in the upstream and downstream cofferdams Dyke dumped soil, stone, one of the largest stone weight 3-5 tons. Closure construction program will first lock upstream cofferdam Longkou, the downstream cofferdam trailing closure. By early October, the Three Gorges closure cofferdam river entrance has only 360 meters wide, and progress to the daily bundle narrow 4 m about advancing to the river. (History TodayOnHistory.com)
Three Gorges closure and two cofferdam construction is to take the tender to select the construction team. Was built on the Yangtze River and the Yangtze River dam Gezhouba Group Company, took on the arduous task of Closure at Three Gorges cofferdam construction. , Gezhouba Group Company tensions to mobilize large modern construction equipment, intercepting preparation has been completed to 10 million cubic meters, more than forecast need preparation 3 million cubic meters. The (history today www.lssdjt.com)
closure continually Air
Yangtze is China's golden waterway. In the construction of the Three Gorges Dam on the Yangtze, and must ensure that during the construction of the Yangtze River shipping smooth. Can ensure normal navigation, the key the Three Gorges ability closure. (L $ dj��.����T) In 1981, the Gezhouba project damming the river, about six months, with the Yangtze River unnavigable. The design of the Three Gorges Project is more fully consider shipping issues. Three Gorges Project has decided to adopt a combination of temporary ship lock navigable diversion channel program to solve navigation problems. Thus, the diversion channel and became a temporary ship lock the Three Gorges controlling the timely closure of the project. is located in the south of the Yangtze
diversion channel, a total length of 3726 meters, the bottom width of 350 meters, the channel bottom elevation of 58 meters. The river width and depth should be greater than the world famous Suez Canal and the Panama Canal. Nullah compound channel cross section, can be used to adjust the velocity distribution within the open channel. It is to guarantee the safety vent in 50 years (flow rate of 79,000 cubic meters per second) Yangtze River floods. When the Yangtze River flow is less than 20,000 cubic meters per second by vessels from the nullah. It is estimated that an average of 272 days a year by the open channel through. Builders struggling diversion channel weir water break in the May 1, 1997, a month earlier than the contract duration.
10 months 0900, the diversion channel was officially put into operation, the Three Gorges dam site, the main riverbed of the Yangtze River closed routes between ship smoothly through from this "artificial Yangtze River". In the afternoon of November 8, 2011, 3 hours 30 minutes, with the final vehicle stone dumping into the river, the Three Gorges project victory damming the river. damming the river of
the Three Gorges Project and other hydropower projects compared most difficult. It is through the main riverbed of the Yangtze River to build two cofferdams, followed by the construction of the Three Gorges Dam and powerhouse. The Three Gorges Project, with its large scale hydropower installed capacity of large, comprehensive benefits of significant known for its world-class giant engineering. Kicked off this cross lock Yangtze "Fight of the Century" from November 1996. November 8, after the hard work of the Three Gorges builders, upstream closure cofferdam only 40 meters remaining small Longkou. In 9:00 (lssjt.cn)
, Premier Li Peng on the in Longkou near site formally issued the closure order. Field deputy commander fired three flares into the sky. In an instant, the four dike head of the upstream and downstream cofferdams ready vehicles as a group of mighty lion, encroaching upon the river Pentium Longkou. Gezhouba Group, a team of a company car driver Zhu Xianqing driving a dump truck led the way, the first car to the Longkou dumped stone.
more than 400 vehicles giant loader orderly manner to take turns in four of the upstream and downstream cofferdams Dyke to dumped stone to Longkou, sparking bursts of waves, loud roaring. Longkou is gradually narrowed down to 30 m, 20 m, 10 m, 5 m ......
damming the river scene is full of grand, warm atmosphere. The reviewing stand with tapestry stitching area of ​​1080 square meters, a huge five-star red flag is particularly spectacular, of 30,000 potted grass and colorful balloons the closure ceremony site, a new dress. Dam site flags fluttering, the huge balloons hanging the congratulations closure Closure successful slogans.
At 15:00, the river closure ceremony began, the majestic strains of the national anthem echoed in the canyon. Lu Youmei, general manager of the Three Gorges Project Development Corporation, the ceremony was attended by representatives from all sectors, reported on the progress of the Three Gorges Project.
15:30 upstream cofferdam success, around two dike completely connected together. Gezhouba Group Company upstream left bank of the commander-in-chief and the right bank of the commander across the closure at a big hug. Of applause and cheers resounded through the sky. Premier Li Peng announced the closure
success, followed by three flares across the sky. At the closure scene at the moment, more than 1,000 construction troops, more than 5,000 guests and more than 40,000 local cadres and the masses of the two sides, immigrants and tourists jubilant jump for joy. Firecrackers, travel whistle, honk and stick, people cheered, vigorous symphony as an earth-shattering issue in the Three Gorges site repercussions. Colorful balloons into the sky, intercepting the scene to form a sea of ​​joy.
Jiang Zemin, Li Peng and other leaders attended the closure ceremony.