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23-491: The Sanmenxia Dam is a concrete gravity dam on the middle-reaches of the Yellow River near Sanmenxia Gorge on the border between Shanxi province and Henan Province , China . The dam is multi-purpose and was constructed for flood and ice control along with irrigation, hydroelectric power generation and navigation . Construction began in 1957 and was completed in 1960. It is the first major water control project on

46-467: A book that criticized the dam and the government's handling of it. The next month, the book's printer, Zhao Shun, was also arrested. Xie was later released on bail. The dam is a 106 m (348 ft) tall and 713 m (2,339 ft) long concrete gravity type. It sits at the head of a 688,400 km (265,793 sq mi) catchment area and withholds a reservoir with a 16,200,000,000 m (13,133,554 acre⋅ft) capacity. The reservoir covers

69-482: A surface area of 2,350 km (907 sq mi) and stretches 246 km (153 mi) upstream to Longmen . The dam supports a power station that can hold up to eight turbines but currently only seven are installed. Five 50 MW and 75 MW Francis turbine -generators make up the arrangement for a total installed capacity of 400 MW. Gravity dam A gravity dam is a dam constructed from concrete or stone masonry and designed to hold back water by using only

92-474: Is that their large concrete structures are susceptible to destabilising uplift pressures relative to the surrounding soil. Uplift pressures can be reduced by internal and foundation drainage systems. During construction, the exothermic curing of concrete can generate large amounts of heat. The poorly-conductive concrete then traps this heat in the dam structure for decades, expanding the plastic concrete and leaving it susceptible to cracking while cooling. It

115-406: Is the designer's task to ensure this does not occur. Gravity dams are built by first cutting away a large part of the land in one section of a river, allowing water to fill the space and be stored. Once the land has been cut away, the soil has to be tested to make sure it can support the weight of the dam and the water. It is important to make sure the soil will not erode over time, which would allow

138-456: The Wei River upstream. Chinese engineer Zhang Guangdou described the project as a "mistake" in 2004 and remarked how hydrologist Huang Wanli had been sent to hard labour for opposing the project. Other engineers oppose the dam's existence but their silence is attributed to government reprisals. In August 2010, Chinese journalist Xie Chaoping was detained for writing The Great Migration ,

161-449: The weight of the material and its resistance against the foundation. Gravity dams are designed so that each section of the dam is stable and independent of any other dam section. Gravity dams generally require stiff rock foundations of high bearing strength (slightly weathered to fresh), although in rare cases, they have been built on soil. Stability of the dam primarily arises from the range of normal force angles viably generated by

184-787: The Chinese government. In response to centuries of flooding on the Yellow River, engineers initially proposed the Sanmenxia Dam in early 1935. In 1954, the Yellow River Planning Board was established and oversaw a survey of the river with help from Soviet engineers. The Soviet engineers recommended a dam at the Sanmenxia site. Original plans for the dam called for a maximum reservoir level 360 m (1,181 ft) above sea level (ASL). This would have required

207-822: The United States. He received a master's degree from Cornell University in hydrology in 1935 and a doctor of engineering degree from University of Illinois in 1937. In 1945, Huang became an engineer in China's Ministry of Water Resources. He was the chief engineer and head of the Gansu Water Conservancy Bureau from 1947 till April 1949. He was an adviser of Northeast China Water Conservancy Administration in September 1949. He taught at Tangshan Jiaotong University starting in June 1950, and he

230-413: The Yellow River and was viewed as a major achievement of the new People's Republic of China . Subsequently, its image was printed on the country's bank notes. However, due to sediment accumulation in the reservoir, the dam later had to be re-engineered and renovated. The effects from sediment , which include flooding upstream, have placed the dam at the center of controversy and criticism-related arrests by

253-881: The biggest danger to gravity dams and that is why, every year and after every major earthquake, they must be tested for cracks, durability, and strength. Although gravity dams are expected to last anywhere from 50–150 years, they need to be maintained and regularly replaced. Huang Wanli Huang was born in Chuansha County, Jiangsu (now Pudong , Shanghai ) on 20 August 1911, the fourth of nine children of Huang Yanpei and Wang Jiusi (Chinese: 王纠思 ). In 1924, he enrolled in Wuxi Industrial School. He entered Tangshan Jiaotong University (now Southwest Jiaotong University ) in 1927 and graduated in 1932. After college, he worked as an apprentice engineer at Hangzhou-Zhejiang Railway. In 1934, Huang went to

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276-607: The dam can begin. Usually gravity dams are built out of a strong material such as concrete or stone blocks, and are built into a triangular shape to provide the most support. The most common classification of gravity dams is by the materials composing the structure: Composite dams are a combination of concrete and embankment dams . Construction materials of composite dams are the same used for concrete and embankment dams. Gravity dams can be classified by plan (shape): Gravity dams can be classified with respect to their structural height: Gravity dams are built to withstand some of

299-434: The foundation. Also, the stiff nature of a gravity dam structure endures differential foundation settlement poorly, as it can crack the dam structure. The main advantage to gravity dams over embankments is the scour -resistance of concrete, which protects against damage from minor over-topping flows. Unexpected large over-topping flows are still a problem, as they can scour dam foundations. A disadvantage of gravity dams

322-516: The left-bank cofferdam began in June 1957 and excavation was completed a year later along with the pouring of the left-bank foundation. In October 1958, construction on the right-bank cofferdam was initiated and the river was closed by November 1958. In June 1960, the reservoir was at full pool and the dam crest reached its design elevation of 353 m (1,158 ft) ASL in April 1961. The dam's generators were commissioned between 1973 and 1975. The dam

345-741: The relocation of 870,000 people and the flooding of 3,500 km (1,351 sq mi). The design was revised to a maximum level of 340 m (1,115 ft) ASL which required the relocation of 400,000 people and flooded much less area. In 1955 the Comprehensive River Basin Planning Report officially proposed the project. The report was submitted to the National People's Congress and swiftly approved that same year while preliminary construction began soon after. Under Soviet Union supervision, construction ceremoniously began on 13 April 1957. Construction on

368-612: The reservoir, particularly in the back waters. Responding to the potential crisis, a meeting was held in December 1964 with Premier Zhou Enlai . At the meeting, it was decided to reconstruct the dam's outlet works for improved discharges and silt control. The renovation was carried out immediately and in two stages. The first stage included the installation of two tunnels on the dam's left bank at an elevation of 290 m (951 ft) ASL along with converting four penstocks into flushing pipes. The flushing pipes began operating in 1966 and

391-542: The streets and beat them in public. Huang was exonerated by the Tsinghua University Communist Party Committee on February 26, 1980. On August 27, 2001, Huang died on the campus of Tsinghua University. He was buried on April 5, 2021 with his wife, Ding Yujun, at Fenghuangshan Cemetery, Area 10 Row 8 number 12, Changping District, Beijing, China. Huang was married to Ding Yujun (Chinese: 丁玉隽 ), daughter of Ding Weifen ,

414-489: The strongest earthquakes . Even though the foundation of a gravity dam is built to support the weight of the dam and all the water, it is quite flexible in that it absorbs a large amount of energy and sends it into the Earth's crust. It needs to be able to absorb the energy from an earthquake because, if the dam were to break, it would send a mass amount of water rushing downstream and destroy everything in its way. Earthquakes are

437-434: The tunnels in 1967 and 1968. In the second stage, eight bottom sluices were added to the left side of the dam which became operational between 1970 and 1971. Silt balance was achieved in 1970. Two more bottom sluices began operating in 1990 along with another in 1999 and the final in 2000. Impacts from sediment accumulation continued after renovation and also drew increasing criticism. The sediment has caused severe flooding on

460-499: The water to cut a way around or under the dam. Sometimes the soil is sufficient to achieve these goals; however, other times it requires conditioning by adding support rocks which will bolster the weight of the dam and water. There are three different tests that can be done to determine the foundation's support strength: the Westergaard, Eulerian, and Lagrangian approaches. Once the foundation is suitable to build on, construction of

483-441: Was closed, 1.8 billion metric tons of sediment had accumulated in the reservoir. Only 7% of the sediment-load was released downstream and the reservoir lost 17% of its capacity below a 335 m (1,099 ft) ASL elevation. Navigation and farmland were threatened upstream along with the relocation of an additional one million people. Despite the dam's 12 deep-sluices and alterations in the release of water, silt continued to build in

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506-404: Was the first major water project on the Yellow River and constructed with manual labor. Upon completion, it was hailed as an engineering success for the new republic and its image was printed on Chinese banknotes. Soon after completion, sediment -accumulation threatened the benefits of the dam. The Yellow River carries more sediment than any other in the world. During the 18 months after the river

529-551: Was transferred to Tsinghua University in 1953. In 1957, Huang was labeled a "Rightist" and persecuted by Mao Zedong for his criticism of the Sanmenxia Dam on the Yellow River . Then he was sent to the Poyang Lake , Jiangxi to do hard labor, and was transferred back to Tsinghua University in 1974. During Cultural Revolution, the students of Tsinghua University paraded him and other "reactionary figures" through

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